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ABSTRACTSoil salinisation has led to increasing abandonment of farmlands in the arid region of northwest China, and the cultivation of cash crops has become an important way to reuse abandoned farmlands and remediate saline soils. In this study, the effects of cotton (Cot), alfalfa (Alf), and rapeseed (Rap) cropping on the bacterial and fungal communities in saline soil were compared based on high-throughput sequencing. The results showed that soil pH and electrical conductivity (EC) of the Cot, Alf, and Rap groups decreased significantly compared with those of bare land (CK). Especially, soil pH (8.3) and EC (0.93 mS cm-1) of the Alf group decreased the most, and the contents of total nitrogen (TN) and total phosphorus (TP) increased the most, which increased by 250% and 91.4%, respectively compared with those of the CK (p < 0.05). Actinobacteriota and Proteobacteria were the dominant bacterial phyla in the three groups, Ascomycota and Basidiomycota were the dominant fungal phyla. The diversity of soil bacterial and fungal communities in the Alf group was higher than that in the Cot and Rap groups. The results of RDA and PERMANOVA analysis showed that soil pH, EC, C/N ratio, and TN were the main factors affecting soil bacterial and fungal communities in the three groups. In general, Cot, Alf, and Rap cropping all could reduce soil pH and EC and improve soil microbial community structure and diversity, but Alf cropping had the best effects in improving saline soil quality and bacterial and fungal diversity.

Root rot is a major disease that causes decline of alfalfa production, and Fusarium is a major pathogen associated with root rot. In this study, 13 Fusarium isolates were obtained from alfalfa with root rot in Gansu Province, the major alfalfa production region in China. The isolates were characterized by molecular genotyping (ITS, TEF 1-α and RPB2 fragments) and identified as six species, which included the F. acuminatum, F. incarnatum, F. oxysporum, F. proliferatum, F. redolens, and F. solani. We found that their morphology varied significantly at both the macro- and micro-levels, even for those from the same species. We developed a low cost and fast pathogenicity test and revealed that all isolates were pathogenic to alfalfa with typical root rot symptoms such as leaf yellowing and brown lesions on the root and stem. However, the virulence of the isolates differed. We also found that the conidia of all isolates germinated as early as 24 hours post inoculation (hpi), while hyphae colonized the root extensively and invaded the xylem vessel by 48 hpi. Together our results reveal that different virulent Fusarium isolates use a similar invasion strategy in alfalfa. This natural plant-fungus pathosystem is intriguing and warrants further examination, particularly with regard to efforts aimed at mitigating the impact of multiple similar vascular pathogens on infected alfalfa plants. [ABSTRACT FROM AUTHOR]

Herbivore grazing affects plant growth and community structure in grasslands. This effect could be directly through foraging and dung/urine return or indirectly through plant–soil feedbacks (PSFs). Addressing the grazing effect on the feedback of plants can explicate the causes of community changes in the grazing system. However, how grazing and PSF interact to affect plant growth remains unclear. Here, we conducted a classic PSF experiment. In the conditioning stage, two native plant species (a grass Bromus inermis and a legume Medicago sativa) were planted in the field with four simulated grazing treatments (ambient, mowing, dung/urine addition, and mowing + dung/urine addition) in a meadow grassland of northern China. In the feedback stage, B. inermis and M. sativa were planted in the soils (both unsterilized and sterilized) from each treatment in the field experiment. Plant biomass of M. sativa showed positive feedback while B. inermis showed negative feedback across all the simulated grazing treatments. Simulated grazing (mowing and dung/urine addition) increased the positive feedback of M. sativa, while decreasing the negative feedback of B. inermis. The addition of dung/urine to the soil was found to have a significantly stronger impact on plant growth feedback compared to the effect of mowing. Dung/urine addition enriches the soil with higher levels of available nitrogen and phosphorus. Our results suggested that legume plants should have positive PSFs while grass should have negative feedback, which might be amplified by grazing because of the dung/urine fertilization effect. Our study improves the understanding of PSF effects on plant growth and community change in grazed grassland. [ABSTRACT FROM AUTHOR]

Introduction: This study used Bacillus amyloliquefaciens DGL1 isolated from the arid sandy land of the Qinghai-Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of Medicago sativa under different intensities of drought stress to provide a high- quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas. Methods: The exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress. Results: Strain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes Super Oxide Dismutase (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and H2O2, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa's capacity to resist drought stress. Discussion: Strain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent. [ABSTRACT FROM AUTHOR]

Introduction: Phosphorus (P) fertilizer is critical to maintain a high yield and quality of alfalfa (Medicago sativa L.). There are several fertilizer types and soil types in China, and the application of a single type of P fertilizer may not be suitable for present-day alfalfa production. Methods: In order to select the optimal combination of alfalfa and soil type and fertilizer type for improving P utilization efficiency. We conducted a greenhouse pot experiment, calcium superphosphate (SSP), diammonium phosphate (DAP), ammonium polyphosphate (APP), potassium dihydrogen phosphate (KP), and no-fertilizer control treatments were applied to alfalfa in sandy and saline-alkali soils. The response of alfalfa root morphology and rhizosphere processes to different P fertilizers was investigated. Results and discussion: The results showed that shoot biomass of alfalfa was slightly higher in sandy soil than in saline-alkali soil. Shoot biomass of alfalfa increased by 223%-354% in sandy soil under P treatments compared with the control, and total root length increased significantly by 74% and 53% in DAP and SSP treatments, respectively. In saline-alkali soil, alfalfa shoot biomass was significantly increased by 229% and 275% in KP and DAP treatments, and total root length was increased by 109% only in DAP treatment. Net P uptake of alfalfa in DAP treatment was the highest in both soils, which were 0.73 and 0.54 mg plant-1, respectively. Alfalfa shoot P concentration was significantly positively correlated with shoot and root biomass (P < 0.05, 0.01 or 0.001) whereas negatively correlated with acid phosphatase concentration (P < 0.05). Improvement of plant growth and P uptake induced by P fertilizer application was greater in sandy soil than in saline-alkali soil. DAP and KP was the most efficient P fertilizers in both sandy soil and saline-alkali soil. [ABSTRACT FROM AUTHOR]

The establishment of the rumen microbiota plays an important role in the rumen development. However, little is known about the effects of alfalfa supplementation time on rumen microbiota establishment. Here, a total of 42 Hu lambs, sevenday-old, were chosen for the study. After a week of adjustment, six lambs were sacrificed to establish a baseline. The remaining 36 lambs were randomly split into two groups: one receiving alfalfa hay at 14 days (EAF), the other at 42 days (LAF), both groups received milk replacer and starter pellets. Introducing alfalfa at 14 days of age significantly improved total dry matter intake between 28 and 42 days (p = 0.04) and average daily gain from both 14 to 28 days (p = 0.04) and 28 to 42 days (p < 0.01), but this effect disappears from 56 to 70 days (p > 0.05). At 42 days, the abundances of Naganishia, Ascochyta, and Neosetophoma in the EAF group were significantly higher (p < 0.05) than those in the LAF group (17.8% vs. 3.97, 10.89% vs. 1.77, and 1.27% vs. 0.09%, respectively). At 56 days, the abundances of Ascochyta, Wallemia, and Aspergillus in the EAF group were significantly lower (p < 0.05) than in the LAF group (3.53% vs. 16.40, 8.78% vs. 18.89, and 2.14% vs. 4.69%). At 70 days, Aspergillus abundance in the EAF group was significantly higher (p < 0.05) than in the LAF group (2.69% vs. 0.85%). The LEfSe analysis showed that Methanobrevibacter_smithii was the archaeal biomarker at 14 days in both groups. Methanobrevibacter_sp_AbM4 was enriched at 56 days in the LAF group. Compared to the LAF group, the specific fungal biomarkers in the EAF group included Sporobolomyces and Bullera at 14 days, Naganishia, Didymella, Cleistothelebolus, and Alloleptosphaeria at 42 days, Ascochyta, Neoascochyta, and Alfaria at 70 days. Correlation analysis results showed strong patterns of association both within and between archaea and fungi, which were influenced by alfalfa supplementation time. In summary, alfalfa supplementation at 14 days of age promotes the growth performance of lambs before weaning, and alfalfa supplementation timing significantly affects rumen archaeal and fungal communities and dynamical changes. [ABSTRACT FROM AUTHOR]

Background: Alfalfa (Medicago sativa L.) is the most cultivated forage legume around the world. Under a variety of growing conditions, forage yield in alfalfa is stymied by biotic and abiotic stresses including heat, salt, drought, and disease. Given the sessile nature of plants, they use strategies including, but not limited to, differential gene expression to respond to environmental cues. Transcription factors control the expression of genes that contribute to or enable tolerance and survival during periods of stress. Basic-leucine zipper (bZIP) transcription factors have been demonstrated to play a critical role in regulating plant growth and development as well as mediate the responses to abiotic stress in several species, including Arabidopsis thaliana, Oryza sativa, Lotus japonicus and Medicago truncatula. However, there is little information about bZIP transcription factors in cultivated alfalfa. Result: In the present study, 237 bZIP genes were identified in alfalfa from publicly available sequencing data. Multiple sequence alignments showed the presence of intact bZIP motifs in the identified sequences. Based on previous phylogenetic analyses in A. thaliana, alfalfa bZIPs were similarly divided and fell into 10 groups. The physico-chemical properties, motif analysis and phylogenetic study of the alfalfa bZIPs revealed high specificity within groups. The differential expression of alfalfa bZIPs in a suite of tissues indicates that bZIP genes are specifically expressed at different developmental stages in alfalfa. Similarly, expression analysis in response to ABA, cold, drought and salt stresses, indicates that a subset of bZIP genes are also differentially expressed and likely play a role in abiotic stress signaling and/or tolerance. RT-qPCR analysis on selected genes further verified these differential expression patterns. Conclusions: Taken together, this work provides a framework for the future study of bZIPs in alfalfa and presents candidate bZIPs involved in stress-response signaling. [ABSTRACT FROM AUTHOR]

Background: Oxidative stress is currently one of the main threats to animal health, and flavonoids in forage have good antioxidant activity. However, the impact of fermentation on flavonoids and their antioxidant activity in forage is still unclear. This study aims to investigate the effect of lactic acid bacteria inoculation on the biological transformation of flavonoids in alfalfa silage fermentation and its relationship with antioxidant activity. Results: Compared with the raw materials, silage fermentation can increase the total flavonoid content of alfalfa. The addition of Pediococcus pentosaceus (CP115739.1) and Lactiplantibacillus plantarum (CP115741.1) can significantly increase the total flavonoid content in alfalfa silage (P < 0.05). The addition of lactic acid bacteria significantly improved the antioxidant capacity of alfalfa silage (P < 0.05). Pearson correlation analysis showed a significant correlation between total flavonoids and DPPH (R = 0.62, P < 0.05), and a highly significant correlation between total flavonoids and FRAP (R = 0.70, P < 0.01). Compared with natural silage fermentation, the addition of lactic acid bacteria leads to changes in the biological transformation process of flavonoids in alfalfa. Its unique products, 3,7,4′-trioxyflavonoids, as well as acacetin and taxifolin 7-O-rhamnoside, are significantly positively correlated with antioxidant activity. Conclusions: Silage fermentation contributes to the transformation of flavonoids, and inoculation with certain lactic acid bacteria can increase the content of flavonoids (including apigenin, luteolin, and other free flavonoids). It is worth noting that after fermentation, the antioxidant capacity of alfalfa is significantly improved, which may be attributed to the biotransformation of flavonoids related to acacetin, 3,7,4′-trihydroxyflavonoids, and taxifolin 7-O-rhamnoside. This study provides a potential pathway for obtaining value-added silage fermentation products by selecting specific lactic acid bacteria inoculants. [ABSTRACT FROM AUTHOR]

The experiment was to analyze the effects of variety and fertility period on the production performance, nutritional quality, and mineral elements of alfalfa. The experiment was conducted to determine the high-yielding and high-quality alfalfa varieties and the optimum fertility period in Chifeng area. Seven introduced varieties of alfalfa were used as study materials to compare the differences in production performance and nutritional quality among the seven varieties at the present bud stage, early flowering stage and full flowering stages. The results showed that the plant height showed an increasing trend with advancing fertility, and was significantly higher at the full flowering stage than at the bud stage and early flowering stage (P<0.05). Higher hay yields were obtained at the early flowering stage of WL168 and Golden Queen. Crude protein (CP), extract ether (EE), crude ash (Ash), and total digestible nutrients (TDN) contents showed a decreasing trend with advancing fertility. Except for the Algonquin and Hunter River varieties, CP content was significantly higher at the present bud stage and early flowering stage than at the full flowering stage (P<0.05). Whereas neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) content, and relative feeding value (RFV) increased with advancing fertility, NDF and ADF content of 54V09 was lower than those of the other varieties, and RFV of 54V09 varieties at the time of early flowering stage was significantly higher than all varieties except 55V12 (P<0.05). As the fertility period progressed, all mineral elements showed a decreasing trend. The concentrations of Ca, Mg, S, P, and K elements were significantly higher at the bud stage than full flowering stage (P<0.05). At the bud stage, 54V09 variety had the highest content of Ca, Mg, and S elements, while 55V12 variety had the highest content of P and K elements. By analyzing the mean values of each index of seven varieties in three fertility periods and using the affiliation function method for comprehensive evaluation, it was concluded that the best quality was obtained at the bud stage. The nutritional quality of different alfalfa varieties ranked in the following order: 54V09＞55V12＞WL168＞Sandri=Hunter River＞Golden Queen=Argangjin. The study indicates that in Chifeng Arukolqin area, harvesting at the bud stage can obtain high yield and high quality forage, while the 54V09 and 55V12 varieties are suitable for popularization of planting in Chifeng area. [ABSTRACT FROM AUTHOR]

Simple Summary: Western Inner Mongolia is a principal part of the arid region in northwest China, covered mainly with semifrutex and frutex plants in the native grassland. Owing to the fact that epiphytic lactic bacteria (LAB) species are sensitive to the environment, the low nutrient concentrations, low water availability, and large changes in temperature around the phyllosphere in this region may lead to LAB species with special properties. However, limited information is available on the biodiversity and ensiling parameters of LAB on the forage plants in this region. This study was conducted to investigate the genotypic and phenotypic characteristics of LAB associated with forage plants in the region, and to screen for efficient strains for well-preserved alfalfa silage. A total of 73 strains belonging to 16 species were isolated, and most of strains could grow at 5–45 °C and in 6.0% NaCl, possessed good cryotolerance and osmotolerance. Lactiplantibacillus plantarum subsp. plantarum (GI19) and sucrose was the most effective combination for alfalfa ensiling, with a higher lactic acid content and lower pH, undesirable microorganism counts, and acetic acid and NH3-N contents. This additive could be used to produce quality alfalfa silage for the region to alleviate the shortage of feed in autumn and winter. This study was conducted to investigate the genotypic and phenotypic characteristics of lactic acid bacteria (LAB) associated with forage plants in the native grassland of western Inner Mongolia and to evaluate their effects on alfalfa silage fermentation. Forage plants and their spontaneous fermentation silages were analysed using culture-based techniques for LAB isolation; the phenotypic properties and 16S rDNA and pheS or rpoA gene sequences of the isolates were evaluated; alfalfa was ensiled with four additive combinations: Lactiplantibacillus plantarum subsp. plantarum (GI19), Lact. plantarum subsp. plantarum and Pediococcus pentosaceus (GI19+GI51), GI19 and 20 g/kg fresh matter of sucrose (GI19+S), and GI19+GI51+S, for 60 d. A total of 73 strains belonging to 16 species were isolated. All isolates grew at 5–45 °C and in 3.0% NaCl, and most of them grew in 6.5% NaCl. Enterococcus faecalis and Lact. plantarum were 26.03% and 17.81% of the total isolates, respectively. All additives improved the silage quality, while GI19+S was more effective for alfalfa ensiling with a higher lactic acid content and lower pH, undesirable microorganism counts, and acetic acid and NH3-N contents than remnant additives. In conclusion, the LAB species were diverse, and most of them possessed good cryotolerance and osmotolerance; GI19+S was the optimal inoculant for alfalfa fermentation improvement. [ABSTRACT FROM AUTHOR]

SUMMARY: Rhizobial phosphatidylcholine (PC) is thought to be a critical phospholipid for the symbiotic relationship between rhizobia and legume host plants. A PC‐deficient mutant of Sinorhizobium meliloti overproduces succinoglycan, is unable to swim, and lacks the ability to form nodules on alfalfa (Medicago sativa) host roots. Suppressor mutants had been obtained which did not overproduce succinoglycan and regained the ability to swim. Previously, we showed that point mutations leading to altered ExoS proteins can reverse the succinoglycan and swimming phenotypes of a PC‐deficient mutant. Here, we report that other point mutations leading to altered ExoS, ChvI, FabA, or RpoH1 proteins also revert the succinoglycan and swimming phenotypes of PC‐deficient mutants. Notably, the suppressor mutants also restore the ability to form nodule organs on alfalfa roots. However, nodules generated by these suppressor mutants express only low levels of an early nodulin, do not induce leghemoglobin transcript accumulation, thus remain white, and are unable to fix nitrogen. Among these suppressor mutants, we detected a reduced function mutant of the 3‐hydoxydecanoyl‐acyl carrier protein dehydratase FabA that produces reduced amounts of unsaturated and increased amounts of shorter chain fatty acids. This alteration of fatty acid composition probably affects lipid packing thereby partially compensating for the previous loss of PC and contributing to the restoration of membrane homeostasis. Significance Statement: The membrane lipid phosphatidylcholine (PC) is crucial for the bacterium Sinorhizobium meliloti when generating nitrogen‐fixing nodules on the roots of their host plant. Although PC‐deficient mutants of S. meliloti cannot form any nodules on their host plant, suppressor mutants were isolated which partially recover the ability to trigger nodule formation. Among these suppressor mutants, we detected a reduced function mutant of FabA that produces reduced amounts of unsaturated and increased amounts of shorter chain fatty acids thereby probably affecting lipid packing. [ABSTRACT FROM AUTHOR]

Salinity and Phoma medicaginis infection represent significant challenges for alfalfa cultivation in South Africa, Europe, Australia, and, particularly, Tunisia. These constraints have a severe impact on both yield and quality. The primary aim of this study was to establish the genetic basis of traits associated with biomass and growth of 129 Medicago sativa genotypes through genome-wide association studies (GWAS) under combined salt and P. medicaginis infection stresses. The results of the analysis of variance (ANOVA) indicated that the variation in these traits could be primarily attributed to genotype effects. Among the test genotypes, the length of the main stem, the number of ramifications, the number of chlorotic leaves, and the aerial fresh weight exhibited the most significant variation. The broad-sense heritability (H²) was relatively high for most of the assessed traits, primarily due to genetic factors. Cluster analysis, applied to morpho-physiological traits under the combined stresses, revealed three major groups of accessions. Subsequently, a GWAS analysis was conducted to validate significant associations between 54,866 SNP-filtered single-nucleotide polymorphisms (SNPs) and seven traits. The study identified 27 SNPs that were significantly associated with the following traits: number of healthy leaves (two SNPs), number of chlorotic leaves (five SNPs), number of infected necrotic leaves (three SNPs), aerial fresh weight (six SNPs), aerial dry weight (nine SNPs), number of ramifications (one SNP), and length of the main stem (one SNP). Some of these markers are related to the ionic transporters, cell membrane rigidity (related to salinity tolerance), and the NBS_LRR gene family (associated with disease resistance). These findings underscore the potential for selecting alfalfa genotypes with tolerance to the combined constraints of salinity and P. medicaginis infection. [ABSTRACT FROM AUTHOR]

Petroleum hydrocarbons are a stubborn pollutant that is difficult to degrade globally, and plant-microbial degradation is the main way to solve this type of pollutant. In this study, the physiological and ecological responses of alfalfa to petroleum hydrocarbons in different concentrations of petroleum hydrocarbon-contaminated soil with KB1 (Rhodococcus erythropolis) were analyzed and determined by laboratory potting techniques. The growth of alfalfa (CK) and alfalfa with KB1 (JZ) in different concentrations of petroleum hydrocarbons contaminated soil was compared and analyzed. The results of the CK group showed that petroleum hydrocarbons could significantly affect the activity of alfalfa antioxidant enzyme system, inhibit the development of alfalfa roots and the normal growth of plants, especially in the high-concentration group. KB1 strain had the ability to produce IAA, form biofilm, fix nitrogen, produce betaine and ACC deaminase, and the addition of KB1 could improve the growth traits of alfalfa in the soil contaminated with different concentrations of petroleum hydrocarbons, the content of soluble sugars in roots, and the stress resistance and antioxidant enzyme activities of alfalfa. In addition, the degradation kinetics of the strain showed that the degradation rate of petroleum could reach 75.2% after soaking with KB1. Furthermore, KB1 can efficiently degrade petroleum hydrocarbons in advance and significantly alleviate the damage of high concentration of petroleum hydrocarbons to plant roots. The results showed that KB1 strains and alfalfa plants could effectively enhance the degradation of petroleum hydrocarbons, which provided new ideas for improving bioremediation strategies. [ABSTRACT FROM AUTHOR]

To study the characteristics of nitrogen (N) loss on slopes, different vegetation (bare soil, alfalfa), slopes (5°, 10°, 15°), and rainfall intensities (40, 60, 80 mm/h) were set as variable factors in simulated rainfall experiments. Surface runoff accounts for 60.38–96.16% of total runoff and most N loss (57.69–88.67% of NO3−-N). Alfalfa can reduce average concentrations of N loss in runoff and reduce N loss in surface runoff by more than 48.29%, as well as subsurface runoff by 3.8%. Average N loss in subsurface runoff exceeds that of surface runoff. Rainfall intensity most affects N loss from surface runoff in bare soil conditions, and slope most affects N loss in subsurface runoff. Rainfall intensity in alfalfa treatments most influences runoff volume and N loss. The comprehensive effects of rainfall intensity, slope, and vegetation cover on the total loss of various forms of nitrogen in surface runoff can be described using a linear correlation equation, with a correlation coefficient between 0.84 and 0.91. [ABSTRACT FROM AUTHOR]

Quantifying water vapor and carbon dioxide (CO 2) exchange dynamics between the land and the atmosphere through observations and modeling is necessary in order to reproduce and project near-surface climate in coupled land–atmosphere models. The exchange of water and CO 2 occurs at the leaf surface (leaf level) and in a net manner through exchanges at all the leaf surfaces composing the vegetation canopy and at the soil surface (canopy level). These exchanges depend on the meteorological forcings imposed by the overlying atmosphere (atmospheric boundary layer level). In this paper, we investigate the effect of four canopy environmental variables (photosynthetic active radiation (PAR), water vapor pressure deficit (VPD), air temperature (T), and atmospheric CO 2 concentration (Ca)) on the local individual leaf exchange and canopy exchange of water and CO 2 at hourly timescales. Additionally, we investigate the effect of atmospheric boundary layer (ABL) processes on the local exchange. To that end, we simultaneously investigated the exchanges of water and CO 2 at leaf level and canopy level for an alfalfa field in northern Spain over 1 day in summer 2021. We used comprehensive observations ranging from stomatal conductance to ABL measurements collected during the Land Surface Interactions with the Atmosphere in the Iberian Semi-Arid Environment (LIAISE) experiment. To support the observational analysis, we used a coupled land–atmosphere model (CLASS model) that has representations at all levels considered. To relate how temporal changes of the four environmental variables modify the fluxes of water and CO 2 , we studied tendency equations of the leaf gas exchange. These mathematical expressions quantify the temporal evolution of the leaf gas exchange as a function of the temporal evolution of PAR, VPD, T , and Ca. To investigate the effects of ABL processes on the local exchange, we developed three modeling experiments that impose surface radiative perturbations by a cloud passage (which perturbed PAR, T , and VPD), entrainment of dry air from the free troposphere (which perturbed VPD), and advection of cold air (which perturbed T and VPD). The model results and observations matched the leaf gas exchange (r2 between 0.23 and 0.67) and canopy gas exchange (r2 between 0.90 and 0.95). The tendency equations of the modeled leaf gas exchange during the study day revealed that the temporal dynamics of PAR were the main contributor to the temporal dynamics of the leaf gas exchange, with atmospheric CO 2 temporal dynamics being the least important contributor. From the three modeling experiments with ABL perturbations, the surface radiative changes induced by a cloud perturbed the CO 2 exchange the most, whereas all of them perturbed the water exchange to a similar extent. Second-order effects on the dynamics of the leaf gas exchange were also identified using the tendency equations. For instance, the decrease in the net CO 2 assimilation rate during the cloud passage caused by a decrease in surface radiation was further enhanced due to the decrease in air temperature also associated with the cloud. With this research we showcase that the proposed tendency equations can disentangle the effect of environmental variables on the leaf exchange of water and CO 2 with the atmosphere, as represented in land–surface parameterization schemes. As such, this framework can become a useful tool with which to analyze these schemes in weather and climate models. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.) is an economically important commodity in the Intermountain Western United States. A major concern for alfalfa producers in this region is the alfalfa weevil (Hypera postica Gyllenhal). Insecticide resistance development coupled with regulatory changes in pesticide use has resulted in renewed interest by producers in non-chemical control methods such as cultural control. One such cultural control method is early harvest, which consists of producers timing their harvests early in the season to decrease alfalfa weevil damage. This method is thought to be effective by exposing weevil larvae to adverse conditions before significant damage occurs. Still, early harvest can be difficult to employ because recommendations are often vague. To better understand how early harvest impacts both alfalfa weevils and their natural enemies and how producers are using this method across the Intermountain Western United States, we conducted a study in alfalfa production fields in Colorado, Montana, and Wyoming over three growing seasons. We determined that the timing of the initial alfalfa harvest spanned more than 1 month across fields, and alfalfa plant stage at harvest ranged from late vegetative to early bloom. Harvest was more impactful on reducing alfalfa weevil densities the earlier it was implemented. Removing windrows in a timely manner is likely useful to further decrease alfalfa weevil densities. Harvest timing was not associated with parasitism rates of alfalfa weevil, but higher parasitism rates were associated with lower post-harvest alfalfa weevil densities. This work has increased our understanding of early harvest in an on-farm setting and to improve recommendations for producers across the Intermountain Western United States. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to investigate the effects of Lactobacillus plantarum and molasses on the nutrient composition, fermentation quality, bacterial count, aerobic stability, and microflora of alfalfa silage in sandy grasslands. The experimental treatments included control (CK), 106 CFU/g Lactobacillus plantarum (L), 5% molasses (M), and 106 CFU/g Lactobacillus plantarum + 5% molasses (LM). The nutrient composition, fermentation quality, bacterial count, aerobic stability, and microflora were determined after 14 days and 56 days of ensiling, respectively. The results showed that the addition of L, M, and LM reduced dry matter loss (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) content, and increased water-soluble carbohydrates (WSC) and ether extract (EE) content, compared to the CK group. Meanwhile, more lactic acid (LA) and accelerated fermentation were observed, causing the pH value to drop below 4.5 in the L, M, and LM groups after 56 days of ensiling. The addition of L, M, and LM promoted lactic acid bacteria (LAB), and inhibited yeast. The addition of L significantly increased the content of acetic acid (AA). In terms of microflora, the addition of L, M, and LM made Firmicutes become the dominant bacterial phylum earlier, while Lactobacillus, Weissella, and Pediococcus had a higher abundance. According to the result of Pearson's correlation, there is a very significant negative correlation between pH value and Lactobacillus (P < 0.01) and a very significant positive correlation between pH value and Lactococcus, Enterobacter, Enterococcus, and Leuconostoc (P < 0.01), whichmay be inhibited by Lactobacillus under the decreased pH value. The results of the prediction of microbial genes indicated that the addition of Mcould enhance the carbohydrate metabolism and membrane transport metabolism, which may contribute to LA production by LAB metabolism. In general, L, M and LM all improved the fermentation quality and reduced the loss of nutrients to varying degrees, but considering the fermentation quality, the overall effects of M and LM were better than L. M and LM are recommended to be used as silage additives in the process of alfalfa silage in sandy grasslands to improve the quality. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of Alfalfa polysaccharide (APS) on the growth performance and immune responses of broilers. A total of 400 1-day-old Avian broiler chicks were randomly divided into four treatment groups and administered intranasal with different levels of APS (0, 2.5, 5.0 or 10.0 mg/dose) on day 1 and day 14. Growth performance, phagocytic activity, T lymphocyte transformation, and serum antibody titers against the Newcastle disease virus (NDV) vaccine were examined. During the study period of 42 days, no significant differences were observed in food intake among treatment groups (P>0.05). The APS administered groups displayed a low FCR, especially the 2.5 mg groups (P<0.05). Broilers with 2.5 mg APS displayed a much higher phagocytic activity than the control group (P<0.05). At the same time, APS enhanced the T lymphocyte transformation in response to phytohaemagglutinin (PHA). The antibody titer to NDV was not influenced by APS on day 14, while it improved on day 28 and day 42, especially in the 2.5 mg group (P<0.05). And the above data suggest that APS could improve innate and cellular immune responses in broilers. [ABSTRACT FROM AUTHOR]

The protein content of alfalfa leaves surpasses that of stems significantly, rendering harvested alfalfa following stems-leaves separation a valuable resource for livestock feed, thus ensuring the provision of high-quality raw materials for production. This study introduces a novel process for stems-leaves separation, alongside the establishment of a suspension velocity experiment rig aimed at investigating and determining the suspension velocity of alfalfa leaves, stems, and plants across various moisture levels. The relationship among various factors including different alfalfa components, the length of lateral branches, stem lengths, Moisture Content (MC), and suspension velocity was empirically derived through experimentation. In this study, the chopping and blowing method was proposed, where the alfalfa was cut into pieces according to a certain length, and then the alfalfa was blown apart by generating airflow through a fan. To comprehensively analyze the impact of airflow velocity and cutting length on the Separation Evaluation Index, a response surface mathematical model was developed. The empirical findings indicate optimal stems and leaves separation of alfalfa when the airflow velocity reaches 4.29556 m/s, paired with a cutting length of 33.7956 mm. Conclusively, this experiment validates the efficacy of the chopping and blowing separation method for alfalfa stems and leaves segregation, thereby offering valuable insights into alfalfa stems and leaves separation practices. The outcomes of this study hold significant reference value for the broader alfalfa agricultural domain. [ABSTRACT FROM AUTHOR]

To promote the application of solar energy-heat pump combined drying technology in forage processing and enhance the drying efficiency of alfalfa, an experimental study was conducted. The research utilized a solar energy-heat pump drying system and a mesh belt dynamic drying device to investigate the drying characteristics of alfalfa. Drying characteristic curves were obtained, and the drying model and parameters were determined through model comparison. The study also analysed the impact of factors such as hot air velocity, temperature, alfalfa stacking thickness, turning angle of the spinner rack, and conveyor belt speed on the drying characteristic curves and parameters of alfalfa. A predictive model for alfalfa moisture content was developed, and the effective moisture diffusivity and activation energy were calculated. The findings revealed that alfalfa does not exhibit a constant speed drying stage, and its drying primarily occurs during the deceleration drying stage. The Logarithmic model was found to accurately describe the moisture change pattern during the dynamic drying process of alfalfa, with a model fitting coefficient R² exceeding 0.994, with an effective moisture diffusivity ranging from 2.776x10-10 m²/s to 4.7324x10-9 m²/s, and an activation energy of37.02 kJ/mol. The study suggests that increasing the hot air velocity and temperature, reducing the conveyor belt speed, and adjusting the alfalfa stacking thickness can further enhance the drying rate and reduce the drying time. [ABSTRACT FROM AUTHOR]

The present study investigates the effects of dietary alfalfa, Medicago sativa leaves, on growth performance, carcass composition, enzymatic activity, biochemical indices, intestinal histomorphometry, and disease resistance in fingerlings of common carp, Cyprinus carpio L. A feeding trial of 60 days was carried out in which common carp fingerlings were fed on experimental diets supplemented with alfalfa extract at rates of 0.0% (T0) control, 0.25% (T1), 0.50% (T2), 0.75% (T3), and 1.0% (T4). At the end of the feeding trial, specific growth rate, protein efficiency ratio, and feed conversion ratio improved significantly (P < 0.05) in groups fed on diet supplemented with alfalfa in a dose-dependent manner. The blood biochemical parameters and the activity of the digestive enzymes were significantly (P < 0.05) elevated in the alfalfa supplemented groups in a dose-dependent manner. Additionally, T4 had significantly (P < 0.05) more protein in fish carcasses than the control group. Intestinal histomorphometry and the relative percent survival following the challenge trial with Aeromonas hydrophila were also significantly (P < 0.05) enhanced by dietary alfalfa. The study concludes that alfalfa extract possesses antioxidant and immune-enhancing potential, which by improving growth and increasing the capacity to combat bacterial infections in fish proves beneficial for sustainable aquaculture. [ABSTRACT FROM AUTHOR]

The purpose of the study was to screen out alfalfa varieties suitable for planting in arid and semi-arid areas. Five alfalfa varieties were selected as experimental materials and treated with polyethylene glycol (PEG) to simulate drought stress (10%, 15%, and 20%). The germination rate, germination index, simplified vigor index, and drought resistance index of alfalfa seeds were measured, and the drought resistance of the tested alfalfa materials was evaluated by membership function. The results showed that the germination rate, germination index, simplified vigor index, and drought resistance index of alfalfa seeds decreased with the aggravation of PEG stress. Under severe (20% PEG) stress, the germination rate, germination index, and drought resistance index of Longmu 801 were the highest, and significantly higher than those of other varieties (P<0.05). The germination rate, germination index, and drought resistance index of Sitel and Sardi were significantly lower than those of other varieties (P<0.05). The ranking of drought resistance of five alfalfa materials was: Longmu 801 > Caoyuan No.3 > WL168HQ > Sitel > Sardi. The study indicates that Longmu 801 and Caoyuan No.3 have strong drought resistance and were suitable for planting in arid and semi-arid areas. [ABSTRACT FROM AUTHOR]

Cultivated grasslands are an important part of grassland ecosystems and have been proven to be major carbon sinks, then playing an important role in the global carbon balance. The effect of cultivated grassland type (Medicago sativa, Triticum aestivum, Secale cereale, and Vicia villosa grasslands) on carbon flux (including net ecosystem CO2 exchange (NEE), ecosystem respiration (ER), and gross ecosystem productivity (GEP)) downstream of the Yellow River was studied via the static chamber technique and a portable photosynthetic system. Bare land was used as a control. The results showed that the four cultivated grassland types were mainly carbon sinks, and bare land was a carbon source. The cultivated grassland types significantly affected carbon flux. The average NEE and GEP of the grassland types were in the following order from high to low: Medicago sativa, Secale cereale, Triticum aestivum, and Vicia villosa grassland. Stepwise regression analysis showed that among all measured environmental factors, soil pH, soil bulk density (BD), soil organic carbon (SOC), and soil microbial carbon (MBC) were the main factors affecting CO2 flux. The combined influence of soil BD, SOC, and pH accounted for 77.6% of the variations in NEE, while soil BD, SOC, and MBC collectively explained 79.8% of changes in ER and 72.9% of the changes in GEP. This finding indicates that Medicago sativa grassland is a cultivated grassland with a high carbon sink level. The changes in carbon flux were dominated by the effects of soil physicochemical properties. [ABSTRACT FROM AUTHOR]

Legumes have a high demand for phosphorus (P) due to energetically costly biological nitrogen fixation, but they also have effective physiological and morphological strategies for P mobilization. To evaluate the inter- and intraspecific P efficiency of small-grain legumes supplied with different P recycling fertilisers, eight accessions each of alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were cultivated in two pot experiments under greenhouse conditions until the flowering stage. To substantiate the results, some accessions were used in both experiments. Five treatments (no P, triple-superphosphate (TSP), sewage sludge ash (SSA), biowaste compost (compost), and struvite) were considered P sources. In addition to plant P uptake, the soil P pools were analysed in detail. Red clover showed higher yields and nutrient uptakes compared to alfalfa, but intraspecific effects were marginal. The addition of P resulted only partly in an increase in yield, despite the low P content in the soil. While struvite application clearly enhanced the P uptake of the plants in both experiments, SSA application had no effect compared to the control. The same treatment effect occurs with the bio-available soil P contents, which were on average 72.6 mg kg−1 after struvite and 44.3 mg kg−1 after SSA addition. Struvite as a P source was especially effective when applied to red clover. Our study aligns with previous field results and underscores the high potential of P mobilization of small-grain legumes without pronounced inter- or intraspecific differences. While struvite is suitable as a P fertiliser, the application of SSA to legumes is not recommended. [ABSTRACT FROM AUTHOR]

Summary: Dehydrins and aquaporins play crucial roles in plant growth and stress responses by acting as protector and controlling water transport across membranes, respectively. MsDHN1 (dehydrin) and MsPIP2;1 (aquaporin) were demonstrated to interact with a membrane‐anchored MYB protein, MsmMYB (as mMYB) in plasma membrane under normal condition. MsDHN1, MsPIP2;1 and MsDHN1‐MsPIP2;1 positively regulated alfalfa tolerance to water deficiency. Water deficiency caused phosphorylation of MsPIP2;1 at Ser 272, which led to release C terminus of mMYB (mMYBΔ83) from plasma membrane and translocate to nucleus, where C terminus of MsDHN1 interacted with mMYBΔ83, and promoted mMYBΔ83 transcriptional activity in response to water deficiency. Overexpression of mMYB and mMYBΔ83 down‐regulated the expression of MsCESA3, but up‐regulated MsCESA7 expression by directly binding to their promoters, and resulted in high drought tolerance in transgenic hairy roots. These results indicate that the MsDHN1‐MsPIP2;1‐MsMYB module serves as a key regulator in alfalfa against drought stress. [ABSTRACT FROM AUTHOR]

Previous researchers utilized a single-rotor, screenless hammermill to improve forage utilization by dairy cows. They also established a surrogate measurement of animal response based on a relationship between processing level index (PLI) and in-situ digestibility. After a PLI of 60% was achieved, further processing resulted in diminished returns. However, to achieve a PLI of 60%, it required two to three processing passes through the single-rotor processor. In this research, a novel two-rotor processor was developed to achieve a PLI of 60% in a single pass through the machine. The final design featured two rotors with free-swinging blunt hammers. Material was transferred tangentially from the first to the second rotor. The first rotor was operated at tip speeds ranging from 66 to 110 m·s-1, and the second rotor tip speed could be adjusted to 1.10, 1.35, or 1.65 times greater than the first. Performance was evaluated by PLI, geometric mean particle size (GMPS), and gross specific energy (GSE). The processing of whole-plant corn at 51% w.b. moisture content and 50 mm length of cut resulted in PLI values of between 60% and 69% with a reduction in GMPS to 6 mm and a GSE requirement of 4.04 to 6.71 kWh Mg-1. Processing wilted alfalfa chopped at 35 mm length of cut and 67% w.b. moisture content increased PLI from 23% (chopped only) to 72% and reduced GMPS from 24 to 8 mm. The dual-rotor processor could process whole-plant corn and wilted alfalfa forages to the desired PLI of greater than 60% in a single pass. [ABSTRACT FROM AUTHOR]

Understanding the influence of carbonates on nutrient release from minerals and their availability to plants is necessary for the management of calcareous soils. This study was conducted to investigate the effects of various levels of lime on the release of potassium (K) and iron (Fe) from the phlogopite mineral in the rhizosphere and their uptake by alfalfa. The experiment was conducted using a completely randomized design with a factorial arrangement. Alfalfa was grown in media containing a mixture of quartz sand, phlogopite, and different levels of lime (0, 20, 50, 120, and 250 g kg−1) under four types of nutrient solution (complete, Fe-free, K-free, and Fe and K free) with three replicates for six months. Alfalfa shoots and roots were harvested and their K and Fe concentrations were measured. The results showed that the biomass of both shoots and roots was significantly affected by lime. The presence of lime in the rhizosphere resulted in an increase in available Ca, thereby reducing the absorption of both K and Fe. The presence of lime was also found to change the K/Ca balance in the growth media. This appears to be the reason for the increased shoot K concentration in plants grown in the media containing less carbonates. It seems that at high concentrations in the soil solution, Ca competes greatly with Fe, reducing its availability to plants. In general, the rates of K and Fe release from phlogopite were adversely influenced by the level of carbonates in the root zone. [ABSTRACT FROM AUTHOR]

Expansins, a class of cell-wall-loosening proteins that regulate plant growth and stress resistance, have been studied in a variety of plant species. However, little is known about the Expansins present in alfalfa (Medicago sativa L.) due to the complexity of its tetraploidy. Based on the alfalfa (cultivar "XinjiangDaye") reference genome, we identified 168 Expansin members (MsEXPs). Phylogenetic analysis showed that MsEXPs consist of four subfamilies: MsEXPAs (123), MsEXPBs (25), MsEXLAs (2), and MsEXLBs (18). MsEXPAs, which account for 73.2% of MsEXPs, and are divided into twelve groups (EXPA-I–EXPA-XII). Of these, EXPA-XI members are specific to Medicago trunctula and alfalfa. Gene composition analysis revealed that the members of each individual subfamily shared a similar structure. Interestingly, about 56.3% of the cis-acting elements were predicted to be associated with abiotic stress, and the majority were MYB- and MYC-binding motifs, accounting for 33.9% and 36.0%, respectively. Our short-term treatment (≤24 h) with NaCl (200 mM) or PEG (polyethylene glycol, 15%) showed that the transcriptional levels of 12 MsEXPs in seedlings were significantly altered at the tested time point(s), indicating that MsEXPs are osmotic-responsive. These findings imply the potential functions of MsEXPs in alfalfa adaptation to high salinity and/or drought. Future studies on MsEXP expression profiles under long-term (>24 h) stress treatment would provide valuable information on their involvement in the response of alfalfa to abiotic stress. [ABSTRACT FROM AUTHOR]

Soil salinization is an abiotic stress factor that can harm plant growth. Root endophytic bacteria may be associated with the resilience of plants to saline–alkaline stress. This study investigated the diversity, composition, and function of endophytic bacterial communities in alfalfa roots under saline–alkali stress, and screened a key bacterial strain associated with saline–alkali resistance. 16 S rRNA amplicon sequencing showed that high levels of saline alkalinity significantly reduced the diversity of endophytic bacterial communities and the relative abundance of beneficial bacterial taxa, such as Rhizobiales and Pseudomonas. Long durations of saline–alkali significantly decreased the abundance of predicted functional genes related to nitrogen metabolism in the alfalfa root endophytic bacterial community. Additionally, we isolated a key strain Pseudomonas with saline-alkali tolerance which could colonise roots and considerably improve physiological characteristics and plant growth. We found that colonization with Pseudomonas can considerably enhance plant resistance to saline-alkali stress and that the composition and function of the endophytic bacterial communities in roots likely contribute to plant tolerance to saline-alkali stress. [ABSTRACT FROM AUTHOR]

The effects of dried tea residues on the nutritional parameters and fermentation quality, microbial community, and in vitro digestibility of alfalfa silage were investigated. In this study, dried tea residues generated from five different processing techniques (green tea, G; black tea, B; white tea, W; Pu'er raw tea, Z; Pu'er ripe tea, D) were added at two addition levels (5% and 10% fresh weight (FW)) to alfalfa and fermented for 90 days. The results showed that the tea residues increased the crude protein (CP) content (Z10: 23.85%), true protein nitrogen (TPN) content, DPPH, and ABST radical scavenging capacity, total antioxidant capacity (T-AOC), and in vitro dry matter digestibility (IVDMD) of the alfalfa silage. Moreover, the pH, ammonia-N (NH3-N) content, and acetic acid (AA) content decreased (p < 0.05). The effects of tea residues were promoted on these indicators with increasing tea residue addition. In addition, this study revealed that the influence of dried tea residues on the nutritional quality of alfalfa silage was greater than that on fermentation quality. Based on the nutrient composition, the addition of B or G to alfalfa silage can improve its silage quality, and these tea byproducts have the potential to be used as silage additives. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

DREB has been reported to be involved in plant growth and response to environmental factors. However, the function of DREB in growth and development has not been elucidated in alfalfa (Medicago sativa L.), a perennial tetraploid forage cultivated worldwide. In this study, an ortholog of MtDREB1C was characterized from alfalfa and named MsDREB1C accordingly. MsDREB1C was significantly induced by abiotic stress. The transcription factor MsDREB1C resided in the nucleus and had self-transactivation activity. The MsDREB1C overexpression (OE) alfalfa displayed growth retardation under both long-day and short-day conditions, which was supported by decreased MsGA20ox and upregulated MsGA2ox in the OE lines. Consistently, a decrease in active gibberellin (GA) was detected, suggesting a negative effect of MsDREB1C on GA accumulation in alfalfa. Interestingly, the forage quality of the OE lines was better than that of WT lines, with higher crude protein and lower lignin content, which was supported by an increase in the leaf–stem ratio (LSR) and repression of several lignin-synthesis genes (MsNST, MsPAL1, MsC4H, and Ms4CL). Therefore, this study revealed the effects of MsDREB1C overexpression on growth and forage quality via modifying GA accumulation and lignin synthesis, respectively. Our findings provide a valuable candidate for improving the critical agronomic traits of alfalfa, such as overwintering and feeding value of the forage. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.) is a superior-quality perennial legume forage crop cultivated in China. However, fertiliser applications and the environmental factors affecting alfalfa yield and quality have not been well documented. In this study, we conducted a meta-analysis using a dataset from 105 studies published between 2003 and 2023 to explore the effects of fertiliser application and environmental factors on the yield and quality of alfalfa. The results showed that compared to the non-fertiliser control levels, fertiliser application increased alfalfa yield by 24.61% and improved the quality of alfalfa by increasing crude protein by 11.63% and decreasing acid detergent fibre by 7.69% and neutral detergent fibre by 6.76%. Alfalfa yield and the crude protein effect size increased with increasing altitude but decreased with increasing latitude based on fertiliser application. The acid detergent fibre and neutral detergent fibre effect size were positively correlated with mean annual temperature and mean annual precipitation. In conclusion, applying fertiliser is a productive approach to enhance the yield and grade of alfalfa, but environmental factors have an effect. This study provides comprehensive information on fertiliser applications and environmental factors that affect alfalfa yield and quality. These results provide insight into further improving alfalfa yield and quality and contribute to the development of alfalfa. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aphis gossypii Glover is an important pest in cotton plantations. Medicago sativa L. (alfalfa) is a host plant for the aphid Aphis craccivora Koch and may prove to be an important reservoir of natural enemies to combat this pest. The objective of this study was to analyze the impact of different mowing frequencies of alfalfa traps on A. gossypii and their natural enemies, using both ground survey data and UAV remote sensing data. The alfalfa was mowed twice to facilitate the transfer of this primary natural enemy to the cotton fields. Ground surveys were carried out every five days to gather data, while temporal niche and niche overlap methods were used for further analysis. Findings collected over a period ranging from day 31 to day 91 indicated that compared to their counterparts with no alfalfa traps, the cotton fields containing these pest control measures demonstrated a reduction in the A. gossypii population of approximately 16%. A survey conducted 5 days after mowing the alfalfa on days 61 and 71 found that the cotton fields with alfalfa traps experienced a 24.14% and 26.09% reduction in A. gossypii numbers. In contrast, the cotton fields without alfalfa traps experienced a 76.92% and 55.08% increase in cotton aphid numbers during the same period. It is noteworthy that the cotton fields with alfalfa traps showed a delayed onset of cotton aphid damage of approximately 5 days compared to the fields without alfalfa traps. This discovery has significant implications for understanding the ecological control mechanism of A. gossypii within alfalfa traps. Planting alfalfa traps around fields in Xinjiang could be promoted as a method to prevent and control aphid damage. [ABSTRACT FROM AUTHOR]

Salt stress poses a significant threat to crop yields worldwide. Melatonin (MT), an endogenous hormone synthesized in plants, has emerged as a crucial player in plant responses to various abiotic stresses, including drought, salinity, heat, and cold. However, the precise molecular mechanisms underlying MT-mediated abiotic stress responses remain incompletely understood. To elucidate the key genes and pathways involved in MT-mediated alleviation of salt stress, we conducted physiological, biochemical, and transcriptomic analyses on alfalfa seedlings. Our results demonstrated that alfalfa seedlings treated with melatonin exhibited higher germination rates, longer bud lengths, and greater fresh weights compared to those subjected to salt stress alone. Furthermore, the levels of malondialdehyde (MDA) and superoxide anion (O2−) were reduced, while the activities and contents of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and glutathione (GSH) increased in response to melatonin treatment. Transcriptome analysis revealed 2181 differentially expressed genes (DEGs) in the salt-treated group, with 780 upregulated and 1401 downregulated genes. In contrast, the MT-treated group exhibited 4422 DEGs, including 1438 upregulated and 2984 downregulated genes. Functional annotation and pathway enrichment analysis indicated that DEGs were primarily involved in the biosynthesis of flavonoids, isoflavones, plant hormones, glutathione (GSH), soluble sugars, and other substances, as well as in ABC transporter and MAPK signaling pathways. Notably, the MT-treated group showed greater enrichment of DEGs in these pathways, suggesting that MT mitigates salt stress by modulating the expression of genes related to phytohormones and antioxidant capacity. Overall, our findings provide valuable insights into the molecular mechanisms underlying MT-mediated salt tolerance in alfalfa, with important implications for breeding salt-tolerant alfalfa and other crops. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Little is known about the link between the fungal community and phosphorus fractions when land use is converted from cropland to grassland in saline-alkali soil in northeastern China. Therefore, in this study, the diversity, composition, and function of fungi, as well as phosphorus fractions including Olsen-P and inorganic phosphorus (Pi), were investigated under land use conversions from maize cropland (MC) to alfalfa (Medicago sativa L.) (AG), Leymus chinensis (LG), and natural restored grasslands (RG). Results: The results showed that the Pi fractions of Ca8-P, Fe-P, Ca2-P, and Ca10-P were closely related with Olsen-P. Significantly increased Olsen-P content was found in 0–10 cm soil layer in the AG treatment, relative to LG and RG treatments (P < 0.05). The occluded P content in 0–10 cm and the Al-P content in 10–20 cm in the RG treatment were the highest. The RG treatment increased the Shannon index of fungi, as well as the abundances of phyla Mortierellomycota and phyla Glomeromycota. Higher abundance of genus Mortierella and lower abundance of genus Cladosporium were observed at RG treatment. Moreover, the RG treatment greatly reduced the abundance of plant pathogens and enhanced the abundances of mycorrhizal and ectomycorrhizal. The Olsen-P was positively correlated with the abundance of plant pathogen (P < 0.01), and the Olsen-P, Ca2-P, and Fe–P were negatively correlated with both the abundances of mycorrhizal and ectomycorrhizal (P < 0.05). Conclusion: Land use conversion from maize cropland to natural restored grassland could reduce plant pathogens and enhance useful fungi by decreasing the availability of phosphorus. [ABSTRACT FROM AUTHOR]

Developing an optimal environmentally friendly bioremediation strategy for petroleum products is of high interest. This study investigated heavy fuel oil (HFO)-contaminated soil (4 and 6 g kg−1) remediation by individual and combined bioaugmentation-assisted phytoremediation with alfalfa (Medicago sativa L.) and with cold plasma (CP)-treated M. sativa. After 14 weeks of remediation, HFO removal efficiency was in the range between 61 and 80% depending on HFO concentration and remediation technique. Natural attenuation had the lowest HFO removal rate. As demonstrated by growth rate and biomass acquisition, M. sativa showed good tolerance to HFO contamination. Cultivation of M. sativa enhanced HFO degradation and soil quality improvement. Bioaugmentation-assisted phytoremediation was up to 18% more efficient in HFO removal through alleviated HFO stress to plants, stimulated plant growth, and biomass acquisition. Cold plasma seed treatment enhanced HFO removal by M. sativa at low HFO contamination and in combination with bioaugmentation it resulted in up to 14% better HFO removal compared to remediation with CP non-treated and non-bioaugmented M. sativa. Our results show that the combination of different remediation techniques is an effective soil rehabilitation strategy to remove HFO and improve soil quality. CP plant seed treatment could be a promising option in soil clean-up and valorization. [ABSTRACT FROM AUTHOR]

Background: Auxin/induced-3-acetic acid (Aux/IAA) is an important plant hormone that affects plant growth and resistance to abiotic stresses. Drought stress is a vital factor in reducing plant biomass yield and production quality. Alfalfa (Medicago sativa L.) is the most widely planted leguminous forage and one of the most economically valuable crops in the world. Aux/IAA is one of the early responsive gene families of auxin, playing a crucial role in response to drought stress. However, the characteristics of the Aux/IAA gene family in alfalfa and its potential function in response to drought stress are still unknown. Result: A total of 41 Aux/IAA gene members were identified in alfalfa genome. The physicochemical, peptide structure, secondary and tertiary structure analysis of proteins encoded by these genes revealed functional diversity of the MsIAA gene. A phylogenetic analysis classified the MsIAA genes into I-X classes in two subgroups. And according to the gene domain structure, these genes were classified into typical MsIAA and atypical MsIAA. Gene structure analysis showed that the MsIAA genes contained 1–4 related motifs, and except for the third chromosome without MsIAAs, they were all located on 7 chromosomes. The gene duplication analysis revealed that segmental duplication and tandem duplication greatly affected the amplification of the MsIAA genes. Analysis of the Ka/Ks ratio of duplicated MsAux/IAA genes suggested purification selection pressure was high and functional differences were limited. In addition, identification and classification of promoter cis-elements elucidated that MsIAA genes contained numerous elements associated to phytohormone response and abiotic stress response. The prediction protein–protein interaction network showed that there was a complex interaction between the MsAux/IAA genes. Gene expression profiles were tissue-specific, and MsAux/IAA had a broad response to both common abiotic stress (ABA, salt, drought and cold) and heavy metal stress (Al and Pb). Furthermore, the expression patterns analysis of 41 Aux/IAA genes by the quantitative reverse transcription polymerase chain reaction (qRT-PCR) showed that Aux/IAA genes can act as positive or negative factors to regulate the drought resistance in alfalfa. Conclusion: This study provides useful information for the alfalfa auxin signaling gene families and candidate evidence for further investigation on the role of Aux/IAA under drought stress. Future studies could further elucidate the functional mechanism of the MsIAA genes response to drought stress. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to investigate the effects of Lactobacillus plantarum (LP), cellulase (CE) and their mixture on the quality of alfalfa silage. In the experiment, LP and CE dosage were set at four levels, which were 0, 3, 5, 7 mg/kg for LP and 0, 25, 50, 75 mg/kg for CE, respectively. There were 16 treatments in total, and each treatment had three replicates. After 60 days of silage, the nutritional quality and fermentation index of alfalfa silage were measured, and the nutritional quality and fermentation index of alfalfa silage were comprehensively evaluated by membership function method. The results showed that the soluble carbohydrate (WSC) content of CE75 treatment was significantly higher than that of CE0 treatment (P<0.05). The content of acid detergent fiber (ADF) and neutral detergent fiber (NDF) in alfalfa silage decreased with the increase of CE addition at different levels of LP addition (P<0.05). Under different levels of CE, the pH value of LP5 treatment was significantly lower than that of LP0 and LP7 treatment (P<0.05). The results of membership function value showed that the highest membership function value of LP5 + CE75 treatment group was 0.729. The study indicates that adding LP and CE to alfalfa silage has positive effects on fermentation quality and nutritional components, and adding 5 mg/kg LP and 75 mg/kg CE to alfalfa silage has the best effect. [ABSTRACT FROM AUTHOR]

Background: During alfalfa harvesting and preservation, it is important to minimize losses and preserve dry matter and nutrients. Soil contamination of alfalfa forage is a common issue that occurs during the ensiling process. Soil contamination can adversely influence the quality of silage, potentially altering the fermentation process, microbial composition, and iron content. Results: In this study, different levels of soil (0, 1.5% or 7.5% contamination on a wet basis; silt loam soil) and two types of additives (LP, Lactobacillus plantarum inoculant alone; MLP, combination addition of molasses and Lactobacillus plantarum) were added to alfalfa and subjected to anaerobic fermentation for 45 days to evaluate the iron content as well as the alpha diversity and relative abundance of bacterial and fungal communities. Soil-contaminated alfalfa contained lower levels of LA (14.2–41.8 g kg−1 DM) and higher levels of AN (50.0–156.4 g kg−1 DM) compared to uncontaminated alfalfa. Soil contamination of alfalfa forage increased the abundance of Clostridia, Actinobacteria, and Alphaproteobacteria in silage. The application of LP or MLP in soil-contaminated silage increased the abundance of Lactobacillus and inhibited the growth of Enterococcus faecium, Pediococcus pentosaceus, unclassified_f_Enterobacteriaceae, and Weissella cibaria. In addition, as the level of soil contamination increased, both the total and bioaccessible iron contents in alfalfa silage increased. The dominant bacteria Lactobacillus plantarum exhibited a positive relationship with LA and bioaccessible iron contents and a negative relationship with pH, AN and BA. The dominant fungi Neocosmospora rubicola showed a positive relationship with total iron, BA, AN and pH. Conclusions: Soil contamination of alfalfa increased the abundance of Clostridia, Actinobacteria, and Alphaproteobacteria and it also increased the total and bioaccessible iron content in silage. The addition of LP and MLP improved the fermentation quality of soil-contaminated silage by increasing LA production and reducing the relative abundance of Enterococcus faecium, Pediococcus pentosaceus, unclassified_f_Enterobacteriaceae, and Weissella cibaria. [ABSTRACT FROM AUTHOR]

Annual medic (Medicago spp.) germplasm was collected from the Crimean Peninsula of Ukraine in 2008 to fill gaps in geographic coverage in the United States department of Agriculture, Agricultural Research Service, National Plant Germplasm System (NPGS) temperate-adapted forage legume collection. A total of 102 accessions across 10 Medicago species were collected. To assess genetic diversity, population structure, and to confirm taxonomic identities, the collections were phenotypically and genetically characterized. Phenotyping included the use of 24 descriptor traits while genetic characterization was accomplished using a 3K Diversity Array Technologies (DArTag) panel developed for alfalfa (Medicago sativa L.). For both field and molecular characterizations, a reference set of 92 geographically diverse and speciesrepresentative accessions were obtained from the NPGS collection. Phenotypic descriptors showed consistency among replicated plants within accessions, some variation across accessions within species, and evident distinctions between species. Because the DArTag panel was developed for cultivated alfalfa, the transferability of markers to the species being evaluated was limited, resulting in an average of ~1,500 marker loci detected per species. From these loci, 448 markers were present in 95% of the samples. Principal component and phylogenetic analysis based on a larger set of 2,396 selected markers clustered accessions by species and predicted evolutionary relationships among species. Additionally, the markers aided in the taxonomic identity of a few accessions that were likely mislabeled. The genotyping results also showed that sampling individual plants for these mostly self-pollinating species is sufficient due to high reproducibility between single (n=3) and pooled (n=7) biological replicate leaf samples. The phenotyping and the 2,396 Single Nucleotide Polymorphism (SNP) marker set were useful in estimating population structure in the Crimean and reference accessions, highlighting novel and unique genetic diversity captured in the Crimean accessions. This research not only demonstrated the utility of the DArTag marker panel in evaluating the Crimean germplasm but also highlighted its broader application in assessing genetic resources within the Medicago genus. Furthermore, we anticipate that our findings will underscore the importance of leveraging genetic resources and advanced genotyping tools for sustainable crop improvement and biodiversity conservation in annual medic species. [ABSTRACT FROM AUTHOR]

Non-thermal plasma (NTP) has proven to be a green method in the agricultural field for the stimulation of germination, growth, and production of nutraceutical compounds in some cases. However, the process is far from being fully understood and depends on the targeted plant species and the NTP used. In this work, we focus on the production of alfalfa sprouts from NTP-treated seeds under different voltage conditions. A flexible electrode configuration was used to produce the NTP, which can also be placed on packages for in-package treatments. The surface of the seeds was analyzed, indicating that the microstructure was strongly affected by NTP treatment. Biometric measurements evidenced the possibility of stimulating the sprout growth in some conditions by up to 50% compared to the sprouts obtained from untreated seeds. Biochemical traits for the sprouts obtained in different processing conditions were also studied, such as the concentrations of chlorophyll pigments, flavonoids and polyphenols, and antioxidant activity. Most NTP treatments led to inhibitory effects, proving the strong dependence between NTP treatment and targeted plant species. [ABSTRACT FROM AUTHOR]

In the production of economic forests, there are common issues such as excessive application of water and fertilizer, redundant plant growth, and low economic benefits. Reasonable water and fertilizer management can not only help address these problems but also improve the absorption and use efficiency of water and fertilizer resources by plants, promoting the green and efficient development of the fruit and forestry industry. In order to explore a suitable water and nitrogen management mode for Lycium barbarum, field experiments were conducted in this study from 2021 to 2022. Specifically, four irrigation modes (according to the proportion ratio of soil moisture content to field moisture capacity θf, 45–55% θf (W1, severe water deficiency), 55–65% θf (W2, moderate water deficiency), 65–75% θf (W3, mild water deficiency), and 75–85% θf (W4, sufficient irrigation)) and four nitrogen application levels (0 kg·ha−1 (N0, no nitrogen application), 150 kg·ha−1 (N1, low nitrogen application level), 300 kg·ha−1 (N2, medium nitrogen application level), and 450 kg·ha−1 (N3, high nitrogen application level)) were set up to analyze the influences of water and nitrogen control on the plant height, stem diameter, chlorophyll content, photosynthetic characteristics and yield, and economic benefits of Lycium barbarum in the Lycium barbarum + Alfalfa system. The study results show that the plant height and stem diameter increment of Lycium barbarum increase with the irrigation amount, increasing first and then decreasing with the increase in the nitrogen application level. Meanwhile, the chlorophyll contents in Lycium barbarum continuously increase throughout their growth periods, with Lycium barbarum treated with W4N2 during all growth periods presenting the highest contents of chlorophyll. In a Lycium barbarum + Alfalfa system, the daily variation curve of the Lycium barbarum net photosynthetic rate presents a unimodal pattern, with maximum values of the daily average net photosynthetic rate and daily carboxylation rate appearing among W4N2-treated plants (19.56 μmol·m−2·s−1 and 157.06 mmol·m−2·s−1). Meanwhile, the transpiration rates of Lycium barbarum plants continuously decrease with the increased degree of water deficiency and decreased nitrogen application level. W1N2-treated plants exhibit the highest leaf daily average water use efficiency (3.31 μmol·s−1), presenting an increase of 0.50–10.47% in efficiency compared with plants under other treatments. The coupling of water and nitrogen has significantly improved the yields and economic benefits of Lycium barbarum plants, with W4N2-treated and W3N2-treated plants presenting the highest dried fruit yield (2623.07 kg·ha−1) and net income (50,700 CNY·ha−1), respectively. Furthermore, compared with other treatment methods, these two treatment methods (W4N2 and W3N2) exhibit increases of 4.04–84.08% and 3.89–123.35% in dried fruit yield and net income indexes, respectively. Regression analysis shows that, in a Lycium barbarum + Alfalfa system, both high yields and economic benefits of Lycium barbarum plants can be achieved using an irrigation amount of 4367.33–4415.07 m3·ha−1 and a nitrogen application level of 339.80–367.35 kg·ha−1. This study can provide a reference for improving the productivity of Lycium barbarum plants and achieving a rational supply of water and nitrogen in Lyciun barbarum + Alfalfa systems in the Yellow River Irrigation Area of Gansu, China, and other similar ecological areas. [ABSTRACT FROM AUTHOR]

Floral bud growth influences seed yield and quality; however, the molecular mechanism underlying the development of floral buds in alfalfa (Medicago sativa) is still unclear. Here, we comprehensively analyzed the transcriptome and targeted metabolome across the early, mid, and late bud developmental stages (D1, D2, and D3) in alfalfa. The metabolomic results revealed that gibberellin (GA), auxin (IAA), cytokinin (CK), and jasmonic acid (JA) might play an essential role in the developmental stages of floral bud in alfalfa. Moreover, we identified some key genes associated with GA, IAA, CK, and JA biosynthesis, including CPS, KS, GA20ox, GA3ox, GA2ox, YUCCA6, amid, ALDH, IPT, CYP735A, LOX, AOC, OPR, MFP2, and JMT. Additionally, many candidate genes were detected in the GA, IAA, CK, and JA signaling pathways, including GID1, DELLA, TF, AUX1, AUX/IAA, ARF, GH3, SAUR, AHP, B-ARR, A-ARR, JAR1, JAZ, and MYC2. Furthermore, some TFs related to flower growth were screened in three groups, such as AP2/ERF-ERF, MYB, MADS-M-type, bHLH, NAC, WRKY, HSF, and LFY. The findings of this study revealed the potential mechanism of floral bud differentiation and development in alfalfa and established a theoretical foundation for improving the seed yield of alfalfa. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.) is an important forage legume and soil salinization seriously affects its growth and yield. In a previous study, we identified a salt-tolerant variety 'Gongnong NO.1' and a salt-sensitive variety 'Sibeide'. To unravel the molecular mechanism involved in salt stress, we conducted transcriptomic analysis on these two cultivars grown under 0 and 250 mM NaCl treatments for 0, 12, and 24 h. Totals of 336, and 548 differentially expressed genes (DEGs) in response to NaCl were, respectively, identified in the 'Gongnong NO.1' and 'Sibeide' varieties. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway enrichment analysis showed that the DEGs were classified in carbohydrate metabolism, energy production, transcription factor, and stress-associated pathway. Expression of MsHPCA1, encoding a putative H2O2 receptor, was responsive to both NaCl and H2O2 treatment. MsHPCA1 was localized in cell membrane and overexpression of MsHPCA1 in alfalfa increased salt tolerance and H2O2 content. This study will provide new gene resources for the improvement in salt tolerance in alfalfa and legume crops, which has important theoretical significance and potential application value. [ABSTRACT FROM AUTHOR]

Subsurface drainage and organic fertilizer application are two important measures for improving saline–alkali soils, while the effects of different drainage spacings combined with organic fertilizer application amounts on alfalfa growth and coastal saline soil properties have seldom been evaluated. This study designed subsurface drainage pipes at four spacing distances, including 0 m (CK, without subsurface drainage), 6 m (S1), 12 m (S2), and 18 m (S3), and three organic fertilizer application amounts, including 3000 kg/ha (N1), 4500 kg/ha (N2), and 6000 kg/ha (N3), to observe the effects of different combinations of subsurface pipe spacings and organic fertilization amounts on alfalfa yield, quality, soil salinity, and nutrients. The results showed that the yield of alfalfa increased with higher fertilization amounts and smaller spacing between drainage pipes. The highest yield occurred in the S1N3 treatment, and the three batches reached 1268.5 kg/ha, 3168.0 kg/ha, and 2613.3 kg/ha, respectively, significantly (p < 0.05) higher than CK for all three batches. The increase in organic fertilizer amount resulted in an increase of 0.5–9.3% in the crude protein content, a decrease of 1.8–3.4% in the neutral detergent fiber content, and a decrease of 1.3–5.5% in the acid detergent fiber content for alfalfa plants. Under CK, the contents of quality indicators in alfalfa were the highest. For the drainage treatments, the quality indicator contents were overall at a higher level under S3. Subsurface drainage had a reduction effect on the salinity of all the 0–80 cm soils. For the surface soil, it was detected that smaller spacing was beneficial for reducing soil salt content, while higher fertilization amounts increased the salt content. S1 reduced the soil salt content by 36.3–46.1% compared to CK; however, N3 increased the salt content by 7.0–16.2% compared to the other two fertilization treatments. In addition, smaller spacing between the subsurface drainage pipes generally reduced the soil's available nitrogen, and total nitrogen increased the C/N ratio but had no significant effect on the organic matter. It was concluded that the spacing between subsurface drainage pipes and the application amounts of organic fertilizer have remarkable impacts on alfalfa yield and quality, mainly by changing the soil salinity and nutrient status. [ABSTRACT FROM AUTHOR]

The epiphytic microbiota source on plants plays a crucial role in the production of high-quality silage. To gain a better understanding of its contribution, the microbiota of alfalfa (M1C0), corn (M0C1) and the resulting mixture (M1C1) was applied in alfalfa-corn mixed silage production system. M1C0 decreased ammonia-N levels in terms of total nitrogen (57.59-118.23 g/kg TN) and pH (3.59-4.40) values (p < 0.01), which increased lactic acid (33.73-61.89 g/kg DM) content (p < 0.01). Consequently, this resulted in higher residual water-soluble carbohydrate (29.13-41.76 g/kg DM) and crude protein (152.54-167.91 g/kg DM) contents, as well as lower NDF (427.27 g/kg DM) and ADF (269.53 g/kg DM) contents in the silage compared to M1C1- and M0C1-treated samples. Moreover, M1C0 silage showed significantly higher bacterial alpha diversity indices (p < 0.05), including the number of observed species and Chao1 and Shannon diversity indices, at the later stages of ensiling. Lactobacillus, Kosakonia and Enterobacter were the dominant bacterial species in silages, with a relative abundance of >80%. However, the abundance of Lactobacillus amylovorus in M0C1- and M1C1-treated silage increased (p < 0.01) in the late stages of ensiling. These findings confirmed that the epiphytic microbiota source exerts competitive effects during anaerobic storage of alfalfa-corn mixed silage. [ABSTRACT FROM AUTHOR]