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Rice is highly sensitive to salt stress at flowering stage. With the objective of detection of quantitative trait loci (QTLs) in multi-environment for this stage, 180 backcross-derived lines (BC3F5) from salt tolerant donor Pokkali (AC41585) and recurrent parent IR 64 were subjected to evaluation in saline (EC = 8 dSm−1) and non-saline environments in wet season of 2014 and 2015 employing a novel phenotyping protocol. Nine multi-environmental consistent QTLs for spikelet degeneration, K+ concentration in flag leaf, stress susceptibility index for grain (SSI-Grain) and spikelet sterility (SSI-STE) on chromosomes1, 2, 3, 4 and 11 with 17–42% phenotypic variances were detected. Among several digenic epistatic interactions, one was associated with the main effect QTL (qSSI-STE-11-1) over the years. Similarly genotype × environment interaction associated with two additive QTLs, qDEG-S-2-2 and qSSI-STE-2-1 had positive effect on the resultant phenotype. Functional genes encoding calmodulin-binding protein and potassium transporter were predicted inside the consistent QTLs. Detected stable QTLs, associated markers, predicted genes and derived introgression lines with these QTLs could be utilized in future breeding programme. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the changes in the chemical composition of essential oils (EO) and the correlation between some secondary metabolites and antioxidant activity of different plant parts of Perovskia abrotanoides Kar. at the vegetative and flowering stages in Vamnan (Iran) in 2018. The EO of this plant was analyzed using the GC-Mass Spectrometry method. As the findings showed, P. abrotanoides leaf, during the flowering stage, had a greater amount of phenolic compounds, flavonoids, and anthocyanins than other parts and even the vegetative stage. At the flowering stage, the maximum antioxidant activity was obtained in the leaf (69.10%), based on the DPPH method. During the vegetative stage, the root was also in the next rank (62.10%). In this research, aerial parts of P. abrotanoides were different in terms of EO composition percentage and retention time. Likewise, 21 and 26 constitutes were identified during the vegetative and flowering stages, respectively. The major constitute was Carotol (31.105%) at the flowering stage, where IR-alpha-pinene (0.268%) had the lowest value. Overall, the results showed that P. abrotanoides can be introduced as an important source of natural antioxidant for pharmaceutical and natural food supplements due to its acceptable amount of bioactive compounds such as phenolic, flavonoids, anthocyanins, and EO. [ABSTRACT FROM AUTHOR]

Based on the daily average temperature from March 19 to April 2, 2021 at three surface meteorological stations in western Guizhou and the daily average temperature, maximum temperature and minimum temperature from March 19 to April 2, 2021 at 12 main automatic meteorological stations of red cartridge kiwifruit base, the effects of low temperature and high temperature on flowering and pollination of red cartridge kiwifruit in early spring of 2021 were analyzed. The results showed that slight cold spell in later spring in western Guizhou occurred from March 21 to 23. The lower limit of the daily average temperature required for flowering period (12 °C or below) appeared in each base of red cartridge kiwifruit during March 21 -23, which affected the red cartridge kiwifruit trees in Faer, Houchang, Miluo, Shunchang, Panlong and Jichang bases flowering and pollinating before March 20. From March 29 to April 2, the daily maximum temperature of Faer and other eleven bases was 30 °C or above, which caused the wilting and abscission of flowers and young fruits of of red cartridge kiwifruit trees in Faer, Houchang, Miluo, Shunchang, Panlong, shaomi, Jichang and Aga bases blooming and pollinating before March 24, but the flowers of red cartridge kiwifruit trees in Langdai, Longhe, Pugu and Shuangfeng bases blooming and pollinating after March 28 were not damaged. [ABSTRACT FROM AUTHOR]

Abstract Background Salt stress, a major plant environmental stress, is a critical constraint for rice productivity. Dissecting the genetic loci controlling salt tolerance in rice for improving productivity, especially at the flowering stage, remains challenging. Here, we conducted a genome-wide association study (GWAS) of salt tolerance based on exome sequencing of the Thai rice accessions. Results Photosynthetic parameters and cell membrane stability under salt stress at the flowering stage; and yield-related traits of 104 Thai rice (Oryza sativa L.) accessions belonging to the indica subspecies were evaluated. The rice accessions were subjected to exome sequencing, resulting in 112,565 single nucleotide polymorphisms (SNPs) called with a minor allele frequency of at least 5%. LD decay analysis of the panel indicates that the average LD for SNPs at 20 kb distance from each other was 0.34 (r 2), which decayed to its half value (~ 0.17) at around 80 kb. By GWAS performed using mixed linear model, two hundred loci containing 448 SNPs on exons were identified based on the salt susceptibility index of the net photosynthetic rate at day 6 after salt stress; and the number of panicles, filled grains and unfilled grains per plant. One hundred and forty six genes, which accounted for 73% of the identified loci, co-localized with the previously reported salt quantitative trait loci (QTLs). The top four regions that contained a high number of significant SNPs were found on chromosome 8, 12, 1 and 2. While many are novel, their annotation is consistent with potential involvement in plant salt tolerance and in related agronomic traits. These significant SNPs greatly help narrow down the region within these QTLs where the likely underlying candidate genes can be identified. Conclusions Insight into the contribution of potential genes controlling salt tolerance from this GWAS provides further understanding of salt tolerance mechanisms of rice at the flowering stage, which can help improve yield productivity under salinity via gene cloning and genomic selection.

High-temperature stress can cause serious abiotic damage that limits the yield and quality of rice. Heat tolerance (HT) during the flowering stage of rice is a key trait that can guarantee a high and stable yield under heat stress. HT is a complex trait that is regulated by multiple quantitative trait loci (QTLs); however, few underlying genes have been fine mapped and cloned. In this study, the F2:3 population derived from a cross between Huanghuazhan (HHZ), a heat-tolerant cultivar, and 9311, a heat-sensitive variety, was used to map HT QTLs during the flowering stage in rice. A new major QTL, qHTT8, controlling HT was identified on chromosome 8 using the bulked-segregant analysis (BSA)-seq method. The QTL qHTT8 was mapped into the 3,555,000–4,520,000 bp, which had a size of 0.965 Mb. The candidate region of qHTT8 on chromosome 8 contained 65 predicted genes, and 10 putative predicted genes were found to be associated with abiotic stress tolerance. Furthermore, qRT-PCR was performed to analyze the differential expression of these 10 genes between HHZ and 9311 under high temperature conditions. LOC_Os08g07010 and LOC_Os08g07440 were highly induced in HHZ compared with 9311 under heat stress. Orthologous genes of LOC_Os08g07010 and LOC_Os08g07440 in plants played a role in abiotic stress, suggesting that they may be the candidate genes of qHTT8. Generally, the results of this study will prove useful for future efforts to clone qHTT8 and breed heat-tolerant varieties of rice using marker-assisted selection.

Drought is one of the most critical environmental factors constraining maize production. When it occurs at the flowering stage, serious yield losses are caused, and often, the damage is irretrievable. In this study, anthesis to silk interval (ASI), plant height (PH), and ear biomass at the silking date (EBM) of 279 inbred lines were studied under both water-stress (WS) and well-water (WW) field conditions, for three consecutive years. Averagely, ASI was extended by 25.96%, EBM was decreased by 17.54%, and the PH was reduced by 12.47% under drought stress. Genome-wide association studies were carried out using phenotypic values under WS, WW, and drought-tolerance index (WS-WW or WS/WW) and applying a mixed linear model that controls both population structure and relative kinship. In total, 71, 159, and 21 SNPs, located in 32, 59, and 12 genes, were significantly (P < 10−5) associated with ASI, EBM, and PH, respectively. Only a few overlapped candidate genes were found to be associated with the same drought-related traits under different environments, for example, ARABIDILLO 1, glycoprotein, Tic22-like, and zinc-finger family protein for ASI; 26S proteasome non-ATPase and pyridoxal phosphate transferase for EBM; 11-ß-hydroxysteroid dehydrogenase, uncharacterised, Leu-rich repeat protein kinase, and SF16 protein for PH. Furthermore, most candidate genes were revealed to be drought-responsive in an association panel. Meanwhile, the favourable alleles/key variations were identified with a haplotype analysis. These candidate genes and their key variations provide insight into the genetic basis of drought tolerance, especially for the female inflorescence, and will facilitate drought-tolerant maize breeding.

High-temperature stress can cause serious abiotic damage that limits the yield and quality of rice. Heat tolerance (HT) during the flowering stage of rice is a key trait that can guarantee a high and stable yield under heat stress. HT is a complex trait that is regulated by multiple quantitative trait loci (QTLs); however, few underlying genes have been fine mapped and cloned. In this study, the F2:3 population derived from a cross between Huanghuazhan (HHZ), a heat-tolerant cultivar, and 9311, a heat-sensitive variety, was used to map HT QTLs during the flowering stage in rice. A new major QTL, qHTT8 , controlling HT was identified on chromosome 8 using the bulked-segregant analysis (BSA)-seq method. The QTL qHTT8 was mapped into the 3,555,000–4,520,000 bp, which had a size of 0.965 Mb. The candidate region of qHTT8 on chromosome 8 contained 65 predicted genes, and 10 putative predicted genes were found to be associated with abiotic stress tolerance. Furthermore, qRT-PCR was performed to analyze the differential expression of these 10 genes between HHZ and 9311 under high temperature conditions. LOC_Os08g07010 and LOC_Os08g07440 were highly induced in HHZ compared with 9311 under heat stress. Orthologous genes of LOC_Os08g07010 and LOC_Os08g07440 in plants played a role in abiotic stress, suggesting that they may be the candidate genes of qHTT8. Generally, the results of this study will prove useful for future efforts to clone qHTT8 and breed heat-tolerant varieties of rice using marker-assisted selection. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Research & Applications in Agricultural Engineering is the property of Lukasiewicz Research Network - Industrial Institute for Agricultural Machinery 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.)

Heracleum persicum, commonly named Persian hogweed, is a principal native medicinal plant in Iran. Collecting H. persicum at the most appropriate growing stage is the key factor to achieve the high phytochemical quality to meet consumer's needs. In the present experiment, the aerial parts of this plant were harvested at up to six different developmental stages during the growing season to determine the phytochemical profiles. Our results indicated that the highest essential oil content was obtained in the mid‐mature seed stage (3.5%). The most elevated extract content was recorded in the floral budding stage (10.4%). In the vegetative stage, limonene (18.1%), in floral budding stage, caryophyllene (14.1%), anethole (14.6%), and β‐bisabolene (12.7%), in the full flowering stage, myristicin (15.0%), and hexyl butyrate (9.1%), in the early development of seeds stage, hexyl butyrate (32.1%), and octyl acetate (11.7%), in the mid‐mature seeds stage hexyl butyrate (38.8%), octyl acetate (14.5%), in the late‐mature/ripe seeds stage, hexyl butyrate (23.6%), and octyl acetate (10.5%) are recorded as the main components. The highest phenolic acids content was obtained in the floral budding stage (287.40 mg/g dried extract). The analysis of phenolic acids demonstrated cinnamic acid (8.0–225.3 mg/g extract), p‐coumaric acid (1.7–39.2 mg/g extract), p‐hydroxybenzoic acid (0.8–16.8 mg/g extract), and ferulic acid (2.4–15.8 mg/g extract) as the main phenolic acids. Cinnamic acid was found as the major phenolic compound in the vegetative stage following by floral budding, the full flowering stage, the early development of seeds, and late‐mature/ripe seeds stages. P‐coumaric acid was the most abundant phenolic compounds in the mid‐mature seeds stage. In this regard, the harvest time of H. persicum aerial parts can be selected to achieve the highest secondary metabolites of interest. The results of this study can be used as a guideline for grower to obtain the highest possible amount of desirable metabolites, beneficial in both food and pharmaceutical industries as well as their undeniable economical benefits. [ABSTRACT FROM AUTHOR]

The response of compensatory growth is an important adaptive strategy for plants to grazing. However, most previous studies on compensatory growth of plants focused on the compensation of the biomass or the number of sexual reproductive offspring and neglected the compensatory growth of vegetative reproduction (VR). This is important not only for plant compensatory growth studies, but also for theoretical and practical studies of grassland production. The clonal tussock grass Hordeum brevisubulatum was selected as the research object. Four different clipping severities (unclipping and clipping stubble at heights of 15, 10, and 5 cm) at the jointing stage and flowering stage were implemented to study the effect of simulated grazing. To explore the effect of recovery growth time on plant growth after simulated grazing, three sampling times were used at different recovery times after simulated grazing (1, 3, and 7 weeks). We found that light and moderate grazing severity significantly increased the number of vegetative reproduction modules, the promotion of simulated grazing on the number of vegetative reproduction modules was higher in the jointing stage than the flowering stage, and the increase in simulated grazing severity decreased with prolonged recovery growth time. The number of tillers significantly decreased with the increase in simulated grazing in both the jointing and flowering stages at 1 week after damage, and the decreasing effect weakened with the prolonged recovery growth time. The bud number mainly showed over-compensation, the juvenile tiller number showed complete compensation, and the tiller number showed under-compensation at 1 and 3 weeks after recovery growth. The number of tillers showed complete compensation under different grazing severities in the jointing stage, while it showed under-compensation in the flowering stage at 7 weeks after recovery growth. Our results indicated that different grazing severities in the jointing stage could promote the output of tillers with matter production capacity from vegetative reproduction modules, as well as improve the capability of compensatory growth. Therefore, in plant production, there will be a sustainable development effect on the renewal and productivity of the H. brevisubulatum population, resulting in different grazing severities in the jointing stage.

A field study was conducted to quantify the effect of moisture stress on nutrient uptake and post-harvest available soil nutrient status of rice in Tamil Nadu Agricultural University, Coimbatore during Kuruvai (July-November) 2019 and Navarai (December-March) 2019-20 seasons. Nine treatments, viz., Moisture stress at panicle initiation stage for 10 days (T1), 15 days (T2), 20 days (T3) and 25 days (T4), moisture stress at flowering stage for 10 days (T5), 15 days (T6), 20 days (T7) and 25 days (T8) along with control - maintaining saturation (T9) were tested under randomized complete block design with three replications. Moisture stress was imposed by withdrawing water and not irrigating in the defined period. The result showed that significantly higher total drymatter production and N, P and K nutrient uptake (grain, straw and total) during both the seasons were observed in T9 treatment than all other moisture stress imposed treatments. The least uptake of N, P and K in grain, straw and total was recorded in T4 and was statistically at par with T3. There was reverse trend on post-harvest soil nutrient status (NPK). The study revealed that moisture stress was more sensitive during panicle initiation stage than flowering stage, which directly influenced the uptake of nutrients in rice and there was a reverse trend on post-harvest soil available nutrients (NPK). [ABSTRACT FROM AUTHOR]

Field investigation on the influence of soil moisture stress (MS) on leaf temperature of rice at 0600 hours was made in Tamil Nadu Agricultural University, Coimbatore during Kuruvai (July-November) 2019 and Navarai (December-March) 2019-20 seasons. The treatments are T1: MS for 10 days from PI, T2: MS for 15 days from PI, T3: MS for 20 days from PI, T4: MS for 25 days from PI, T5: MS for 10 days from flowering, T6: MS for 15 days from flowering, T7: MS for 20 days from flowering, T8: MS for 25 days from flowering and T9: Control (Maintaining 2cm of water throughout the crop period). The experiment was laid-out in Randomized Completely Block Design with three replications. Leaf temperature was measured using an infrared thermometer at 0600 hours. Moisture stress had a significant influence on the leaf temperature of rice in the early morning hours. In Kuruvai season, an increase in leaf temperature was to the tune of 0.13oC to 2.20oC during Panicle Initiation (PI) stage (T1, T2, T3 and T4) and 0.16oC to 2.27oC during flowering stage (T5, T6, T7 and T8) over control due to MS. Similarly, increased leaf temperature to the tune of (0.13oC to 2.97oC and 0.07oC to 2.96oC during PI stage and flowering stage, respectively) was observed due to MS treatments than MS relieved treatments and control during Navarai season. The results confirmed that the direct influence on leaf temperature of rice was due to MS irrespective of the stages and seasons. The correlation between grain yield and leaf temperature due to the MS was found to be negative. [ABSTRACT FROM AUTHOR]

The response of compensatory growth is an important adaptive strategy for plants to grazing. However, most previous studies on compensatory growth of plants focused on the compensation of the biomass or the number of sexual reproductive offspring and neglected the compensatory growth of vegetative reproduction (VR). This is important not only for plant compensatory growth studies, but also for theoretical and practical studies of grassland production. The clonal tussock grass Hordeum brevisubulatum was selected as the research object. Four different clipping severities (unclipping and clipping stubble at heights of 15, 10, and 5 cm) at the jointing stage and flowering stage were implemented to study the effect of simulated grazing. To explore the effect of recovery growth time on plant growth after simulated grazing, three sampling times were used at different recovery times after simulated grazing (1, 3, and 7 weeks). We found that light and moderate grazing severity significantly increased the number of vegetative reproduction modules, the promotion of simulated grazing on the number of vegetative reproduction modules was higher in the jointing stage than the flowering stage, and the increase in simulated grazing severity decreased with prolonged recovery growth time. The number of tillers significantly decreased with the increase in simulated grazing in both the jointing and flowering stages at 1 week after damage, and the decreasing effect weakened with the prolonged recovery growth time. The bud number mainly showed over-compensation, the juvenile tiller number showed complete compensation, and the tiller number showed under-compensation at 1 and 3 weeks after recovery growth. The number of tillers showed complete compensation under different grazing severities in the jointing stage, while it showed under-compensation in the flowering stage at 7 weeks after recovery growth. Our results indicated that different grazing severities in the jointing stage could promote the output of tillers with matter production capacity from vegetative reproduction modules, as well as improve the capability of compensatory growth. Therefore, in plant production, there will be a sustainable development effect on the renewal and productivity of the H. brevisubulatum population, resulting in different grazing severities in the jointing stage. [ABSTRACT FROM AUTHOR]

Background: This study was aimed at investigating the possible anti-inflammatory and cytotoxic effects of extracts from the flowering stage of C. argentea. This growth stage was chosen because of its high polyphenolic content and high antioxidant capacity. Methods: Anti-inflammatory potential of the aqueous, acetone and methanol extracts of C. argentea was evaluated through the inhibition of nitric oxide production (LPS-induced) on stimulated macrophages (RAW 264.7), while MTT assay was used to assess cell viability with Silymarin as standard. Cytotoxicity of the plant extracts was evaluated on murine preadipocyte cell line (3 T3-L1) using the image-based method of two DNA-binding dyes; Hoechst 33342 and propidium iodide (PI) with melphalan as standard. Results: Acetone extract exhibited moderate, dose-dependent anti-inflammatory activity with no significant toxicity to activated macrophages, however the aqueous and methanol extracts were unable to inhibit nitric oxide production at both trials. MTT assay and the toxicity assay revealed that the flowering stage extracts of C. argentea were not toxic to the RAW 264.7 macrophages and 3 T3-L1 cells at all the tested concentrations (0, 2, 50, 100 and 200 µg/mL). Conclusions: These findings corroborate the traditional use of C. argentea for painful inflammatory conditions and encourage its possible use as lead for the development of novel, non-toxic, anti-inflammatory agents. [ABSTRACT FROM AUTHOR]

Main conclusion: The present study shows that salt tolerance in the reproductive stage of rice is primarily governed by the selective Na+ and K+ transport from the root to upper plant parts. Ionic discrimination at the flag leaf, governed by differential expression of Na+- and K+-specific transporters/ion pumps, is associated with reduced spikelet sterility and reproductive stage salt tolerance. Reproductive stage salt tolerance is crucial in rice to guarantee yield under saline condition. In the present study, differential ionic selectivity and the coordinated transport (from root to flag leaf) of Na+ and K+ were investigated to assess their impact on reproductive stage salt tolerance. Four rice genotypes having differential salt sensitivity were subjected to reproductive stage salinity stress in pots. The selective Na+ and K+ transport from the root to upper plant parts was observed in tolerant genotypes. We noticed that prolonged salt exposure did not alter flag leaf greenness even up to 6 weeks; however, it had a detrimental effect on panicle development especially in the salt-susceptible genotype Sabita. But more precise chlorophyll fluorescence imaging analysis revealed salinity-induced damages in Sabita. The salt-tolerant genotype Pokkali (AC41585), a potential Na+ excluder, managed to sequester higher Na+ load in the roots with little upward transport as evident from greater expression of HKT1 and HKT2 transporters. In contrast, the moderately salt-tolerant Lunidhan was less selective in Na+ transport, but possessed a higher capacity to Na+ sequestration in leaves. Higher K+ uptake and tissue-specific redistribution mediated by HAK and AKT transporters showed robust control in selective K+ movement from the root to flag leaf and developing panicles. On the contrary, expressions of Na+-specific transporters in developing panicles were either down-regulated or unaffected in tolerant and moderately tolerant genotypes. Yet, in the panicles of the susceptible genotype Sabita, some of the Na+-specific transporter genes (SOS1, HKT1;5, HKT2;4) were upregulated. Apart from the ionic regulation strategy, cellular energy balance mediated by different plasma-membrane and tonoplastic H+-pumps were also associated with the reproductive stage salt tolerance in rice. [ABSTRACT FROM AUTHOR]

The color of bracts generally turns yellow or black from green during cereal grain development. However, the impact of these phenotypic changes on photosynthetic physiology during black bract formation remains unclear. Two oat cultivars (Avena sativa L.), ‘Triple Crown’ and ‘Qinghai 444’, with yellow and black bracts, respectively, were found to both have green bracts at the heading stage, but started to turn black at the flowering stage and become blackened at the milk stage for ‘Qinghai 444’. Their photosynthetic characteristics were analyzed and compared, and the key genes, proteins and regulatory pathways affecting photosynthetic physiology were determined in ‘Triple Crown’ and ‘Qinghai 444’ bracts. The results show that the actual PSII photochemical efficiency and PSII electron transfer rate of ‘Qinghai 444’ bracts had no significant changes at the heading and milk stages but decreased significantly (p < 0.05) at the flowering stage compared with ‘Triple Crown’. The chlorophyll content decreased, the LHCII involved in the assembly of supercomplexes in the thylakoid membrane was inhibited, and the expression of Lhcb1 and Lhcb5 was downregulated at the flowering stage. During this critical stage, the expression of Bh4 and C4H was upregulated, and the biosynthetic pathway of p-coumaric acid using tyrosine and phenylalanine as precursors was also enhanced. Moreover, the key upregulated genes (CHS, CHI and F3H) of anthocyanin biosynthesis might complement the impaired PSII activity until recovered at the milk stage. These findings provide a new insight into how photosynthesis alters during the process of oat bract color transition to black.

Abstract Background Reduction in rice yield caused by high temperature-induced spikelet sterility has been a serious concern in rice production. To date, several screening methods have been used, although their reproducibility is sometimes poor due to artifacts mainly caused by varietal differences in heading dates and panicle heights (i.e., the distance from the lamps). Methods We have developed a novel assay system for heat-induced spikelet sterility by using artificial rice paddies in phytotrons to conduct a highly reproducible assay throughout a year. Plants restricted to the main culm were treated under a series of heat conditions, and height uniformity of each plant was ensured by using height-adjustable pots. Results Results suggested that a 3-day heat treatment of 35 °C-day/29 °C-night cycles was the most suitable condition. Under the treatment, two distinct groups were identified among nine heat tolerant cultivars, with no varietal difference in panicle temperature, indicating that the system is capable of eliminating the varietal difference in panicle temperature. Conclusions It is concluded that the assay system would be a powerful tool for selecting heat tolerant varieties, as well as the analysis of genetic factors from various cultivars, eliminating potential artifacts.

Background: The leaves, roots and seeds of Lovage (Levisticum officinale Koch) being used as an herb, vegetable and spice. Objective: The aim of this study is evaluation of the changes of phytochemical compound in aerial parts of the Lovage plants at different developmental stages as well as antioxidant activity. Methods: The plants were harvested from Hezar Mountain. After drying, essential oils were extracted by steam distillation. To identify the essential components GC and GC-MS was used. Antioxidant activity of samples was examined by diphenylpicrylhydrazyl (DPPH) assay. Results: The average yield of essential oil was respectively, 2.3% and 3.1% and 1.5% respectively, in vegetative, Flowering and seed stage. The oil analysis results showed that 21 compounds were identified in the vegetative stage. β-phellandrene (10.7%) and α-Terpinyl acetate (% 38.9) and Curzerene (% 10.6) were the major compound. in the reproductive stage, 22 compounds were identified including β-phellandrene (20.3%) and α-Terpinyl acetate (% 20.4) and γ-Cadinene (12.1%). in the seed stage β-phellandrene (21.1%) and α-Terpinyl acetate (% 25.3) and Sabinene (10.2%) were the highest. Analysis of variance showed that the effect of harvesting time has significant effect on plant height, stem branch number and yield of oil. The Higher antioxidant power was observed respectively in the flowering stage (83%), vegetative stage (68%) and seed stage (60%). Conclusion: The phytochemical and antioxidant compounds in Levisticum officinale depend on the phenological stage.

Total 20 maize varieties were subjected to drought stress at flowering stage, and then the relative water content, soluble sugar content, chlorophyll content, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in their leaves, as well as their yields were determined. The drought tolerance of the physiological and biochemical indexes was scored by five-level scoring method, and the drought tolerance index was calculated by the yield index to comprehensively evaluate the drought tolerance of maize during flowering stage. The results showed that the scores of drought tolerance of the maize varieties ranged from 1. 929 3 to 5.659 5. Among them, the scores of Zhengda 619, Guidan 162 and Guidan 0810 were greater than 5.0, followed by Dika 008, Xianyu 30T60, Xianzhengda 901, Qingnong 68, South America No. 1 and Wanchuan 1306 of which the scores were in the range of 4.0 -5.0. The drought tolerance indexes were in the range of 0.410 4 - 1.096 3. Among the test maize varieties, the drought tolerance indexes of Guidan 0810, Pacific 99 and Zhengda 619 were greater than 1.0, and those of Xianyu 30T60, Dika 008 and South America No. 1 were in the range of 0. 9 -1.0. The correlation between the two kinds of evaluation results was 0. 588 7 and was extremely significant. The five-level scoring method and the drought tolerance index can be used simultaneously for the evaluation of drought tolerance of maize during flowering stage. The two aspects of evaluation results showed that Guidan 0810, Zhengda 619, Xianyu 30T60, Dika 008 and South America No. 1 were drought-tolerant varieties, among which Guidan 0810 and Zhengda 619 were extremely highly drought-tolerant varieties. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences 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.)

Abstract Global warming has caused frequent occurrence of heat stress at the flowering stage of single-season rice in the Yangtze River region of China, which results in declines of spikelet fertility and yield in rice. Rice flowering stage is the most sensitive period to high temperatures, and therefore, the key for heat stress happening is the flowering stage coinciding with high temperature, which causes spikelet fertility decreasing in heat-sensitive varieties, and is the major factor for heat injury differences among various rice planting regions. With the development of rice breeding, temperature indexes for heat stress has been converted from daily maximum temperature of 35 °C to 38 °C with the stress duration of more than 3 d. During the flowering stage, anther dehiscence inhibition and low pollen shedding onto the stigma are two main reasons for spikelet fertility reduction under high temperatures. At panicle initiation stage, high temperatures aggravate spikelet degeneration, and destroy floral organ development. Various types of rice varieties coexist in production, and indica-japonica hybrid rice demonstrates the highest heat resistance in general, followed by indica and japonica rice varieties. In production, avoiding high temperature is the main strategy of preventing heat stress, and planting suitable cultivars and adjustment of sowing date are the most effective measures. Irrigation is an effective real-time cultivation measure to decline the canopy temperature during the rice flowering stage. We suggested that further study should be focused on exploring heat injury differences among different rice variety types, and innovating rice-planting methods according to planting system changes in rice planting regions with extreme heat stress. Meanwhile, high temperature monitor and warning systems should be improved to achieve optimal heat stress management efficiencies. [ABSTRACT FROM AUTHOR]

To evaluate the effects of methanol concentration (0, 20, 40 and 60% v/v) and application time (before and after flowering) on yield and some morphological characteristics of sesame, a field experiment was performed at the research field of Jiroft University in 2016. Treatments were arranged in a factorial based on a randomized complete block design with four replications. Based on results, Methanol concentration had significant effects on all studied characteristics, so that the highest and lowest mean value was observed at 40% methanol concentration and control, respectively. Methanol spraying time significantly influenced the stem diameter, seed number, harvest index and 1000-seed weight, so that the highest and lowest means were obtained at before and after flowering stages, respectively. The interaction of methanol concentration and methanol spraying time were significant on leaf area index, leaf number, length branches, number of lateral branches, number of capsules, seed number, plant height, shoot dry weight and seed yield. The best treatment in this study was foliar application of 40% methanol concentration at pre-flowering stage. According to the results, it can be concluded that the use of methanol could greatly improve the yield, and morphological characteristics of sesame. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences 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.)

The present study reports an unequivocal and improved protocol for efficient screening of salt tolerance at flowering stage in rice, which can aid phenotyping of population for subsequent identification of QTLs associated with salinity stress, particularly at reproductive stage. To validate the new method, the selection criteria, level and time of imposition of stress; plant growth medium were standardized using three rice genotypes. The setup was established with a piezometer placed in a perforated pot for continuous monitoring of soil EC and pH throughout the period of study. Further, fertilizer enriched soil was partially substituted by gravels for stabilization and maintaining the uniformity of soil EC in pots without hindering its buffering capacity. The protocol including modified medium (Soil:Stone, 4:1) at 8 dS m−1 salinity level was validated using seven different genotypes possessing differential salt sensitivity. Based on the important selection traits such as high stability index for plant yield, harvest index and number of grains/panicle and also high K+ concentration and low Na+- K+ ratio in flag leaf at grain filling stage were validated and employed in the evaluation of a mapping population in the modified screening medium. The method was found significantly efficient for easy maintenance of desired level of soil salinity and identification of genotypes tolerant to salinity at reproductive stage. [ABSTRACT FROM AUTHOR]

تولیدات کشاورزی شدیدأ تحت تأثیر شوری خاک و اثرات مخرب غلظت نمک در خاک­های شور می­باشند و این عامل تمدن کشاورزی قدیمی و مدرن را تحت تأثیر قرار داده است. به­منظور بررسی اثر تنش شوری آب برتعدادی از صفات مورفولوژیکی و فیزیولوژیکی مرتبط با مقاومت به شوری در دوازده رقم کلزای بهاره، آزمایشی بصورت کرت­های خرد شده با سه سطح شوری صفر، 150و 300 میلی­مولار در قالب طرح بلوک­های کامل تصادفی با سه تکرار به اجرا درآمد. در این پژوهش صفات ارتفاع بوته، طول ریشه، وزن­تر و خشک گیاه، وزن­تر و خشک ریشه، وزن صد ­دانه، عملکرد دانه در بوته، پتانسیل اسمزی، پتانسیل آب برگ، پرولین، Na+برگ، K+برگ و K+/Na+برگ ارقام اندازه­گیری شد. تجزیه واریانس حاکی از وجود اختلاف معنی­دار بین ارقام مورد مطالعه برای تمامی صفات بود. از تجزیه­خوشه­ای با روش UPGMA برای گروه ­بندی ارقام از حیث کلیه صفات و برای تمامی سطوح شوری استفاده شد. تجزیه­خوشه ­ای در شرایط تنش شوری شدید منجر به تشکیل دو خوشه گردید که ارقام Heros و Comet در اکثر صفات مورد مطالعه میانگین کمتری را به خود اختصاص دادند، لذا می­توان از آن­ها بعنوان والدین حساس در تلاقی با ارقام متحمل مانند Crakerو Amica جهت تهیه جوامع مناسب برای ترسیم نقشه ژنتیکی و مکان­یابی صفات کمی درگیر در مقاومت به شوری استفاده کرد. با شناسایی ارقام متحمل و حساس به شوری زمینه برای مطالعات مولکولی جهت درک درست سازوکار تحمل به تنش شوری در کلزا و ژن­های درگیر در این فرآیند فراهم خواهد شد.

Abstract To understand the reallocation of organic nitrogen from leaf to the flower head of rice, the role of glutamine synthetase (GS) was investigated by characterizing GS1 RNAi transgenic rice, which revealed a significant reduction in panicle number and number of seeds per panicle. We observed the expression of GS isotypes at transcriptional and protein levels in flag leaves, leaf sheaths and panicles at three different flower development stages. The mRNA expression of GS1;1 was clearly suppressed in flag leaves, especially at the flowering stage. GS1 protein was barely detectable in flag leaves until the flowering stage, while GS1 protein was compromised in the leaf sheath and panicle, with transient expression of GS2 protein at the flowering stage. The glutamine level in transgenic plants was significantly reduced in both flag leaves and panicles, but ammonium was highly accumulated. The level of other amino acids, including aspartate and asparagine, tended to be higher in RNAi transgenic plants than the wild type plants during the reproductive stage. In addition, accumulation of toxic ammonium in panicles with low glutamine level might have caused low seed-setting in the transgenic rice. These results indicated that nitrogen reallocation was critical for panicle development, and that multiple GS isotypes functioned cooperatively to complete the rice life cycle when leaf nitrogen was remobilized to the developing reproductive organs. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology 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.)

In rice growing regions where water and temperature are growth limiting factors, the use of the innovative water-saving ground cover rice production system (GCRPS) leads to a substantial increase in yields and water use efficiency. However, so far the effect of GCRPS on root growth and its possible contribution to the observed increases in yield and water use efficiency remained unclear. In order to fill in this knowledge gap, we conducted a three-year experiment comparing two production systems: traditional paddy (Paddy) and GCRPS combined with two nitrogen fertilizer regimes (0, 150 kg N ha −1 ). The parameters investigated were root dry matter, length density and surface area at maximum tillering and flowering stage as well as grain yield and water use efficiency. Our study revealed the following findings: 1) Root dry matter, root length density and surface area were significantly higher in GCRPS than in Paddy at all soil depths. 2) Across the production systems, root dry matter, root length density and surface area at soil depth of 0–40 cm at flowering stage were significant positively correlated to grain yield and total water use efficiency which suggested that improved root morphology traits, especially at flowering stage, contribute to higher grain yield and water use efficiency in GCRPS. Our results show that GCRPS has a positive effect on the development of rice roots and that the improved root development is of vital importance for higher yields. Furthermore, the improved root development in GCRPS may avoid potential lodging phenomena and increase soil organic carbon stocks, thus improving key soil functions. [ABSTRACT FROM AUTHOR]

The differing water relations between flowers and leaves on a plant reflect the lack of co-ordination between reproductive and vegetative organs during the evolution of angiosperm species. The amount of water that flowers consume has been reported to vary across species, and compared with studies of leaves, accurate measurements of flower water relations at the branch level are lacking. Further, the mechanisms by which flowers regulate their hydraulic function and structure to maintain water balance remain unclear. To explore the ecophysiological basis underpinning the differences between flowers and leaves, we measured hydraulic and morphological traits and monitored sap flow in flowers and leaves from the same branches of two Magnoliaceae species that flower before leaf emergence (Magnolia denudata Desr. and Magnolia soulangeana Soul.-Bod.). Sap flux density (Js) of flowers was 22% and 55% of that predicted for leaves in M. denudata and M. soulangeana respectively. Js of flowers commenced before predawn and ceased early in the afternoon, reflecting their night-time flowering pattern and a dramatic decrease of Js with increasing vapour pressure deficit (D) under the high light of midday. Relative to leaves, tepals were thicker and more hydrated, and had bigger but scarcer stomata, leading to lower stomatal conductance (gs) and transpiration rate (E), less negative water potential (Ψtepal) and lower hydraulic conductance. This study revealed different hydraulic patterns in the flowers and leaves of the two Magnolia species. Although flowers consumed less than half the water that leaves did, they used different strategies to maintain sufficiently high Y to sustain hydraulic safety. Magnolia flowers retained more hydrated tepals by exhibiting less water loss than leaves via lower hydraulic conductance. In contrast, Magnolia leaves maintained high transpiration rates through efficient stomatal responses to environmental changes compared with flowers. [ABSTRACT FROM AUTHOR]

Chemical composition and antioxidant activity of Opuntia microdasys flowers in different maturity stages was evaluated. Fructose, glucose, sucrose and trehalose were found; oxalic, quinic, malic, and citric acids were also detected; five hydroxycinnamoyl, two kaempferol and six isorhamnetin derivatives; 23 fatty acids were quantified in all stages, except C20:2, which was only found in post flowering stage (F3); α-, β-, γ-, and δ-tocopherols were quantified in all samples. The highest contents in soluble sugars and phenolic compounds were detected in full flowering stage (F2), while organic acids and tocopherols were predominant in vegetative stage (F1). The highest levels of saturated, monounsaturated and polyunsaturated fatty acids were found in F3, F2 and F1, respectively. F1 gave the highest antioxidant activity. Principal components analysis showed clearly individualized groups corresponding to each flowering stage, identifying the most distinctive features, which might be useful to select a flowering stage for incorporation in functional foods.

Application of microelements is one of the ways to increase quantative and qualitative characters of wheat. To evaluate the effect of zinc foliar application on yield and yield components of four wheat cultivars a factorial experiment with two factors was conducted in randomized complete blocks design with three replications in 2011-2012 year. The first factor consisted of four wheat cultivars (Falat, Bahar, Pishtaz and Tous) and the second factor composed of three levels of zinc chelate foliar applications (control, at shooting stage and at shooting + flowering stages). Zinc concentration in each application was decided to be 4 kilogram per hectare. Results showed that yield and yield components of cultivars were significantly different with each others. The highest and lowest yields were belonged to Bahar and Tous respectively. The highest yield of Bahar, as compared to the other cultivars, was due to its higher biological yield. Zinc foliar applications at shooting and shooting + flowering stages also increased biological and seed yields. Seed yield increase mainly affected by higher 1000 seed weight. In general, it seems that zinc application, due to its role in the physiology of wheat, a sensitive plant to zinc deficiency, may increase its seed yield.

Peanut production areas frequently suffer from drought, which can cause severe yield losses, increased aflatoxin, and compositional changes in seed. Midseason drought is generally the most detrimental to seed yields and in altering seed protein composition. The purpose of this study was to investigate the effect of midseason drought on arginine content in peanut genotypes with different levels of drought resistance. The experiment was conducted under field conditions for 2 years. Two water regimes (wellwatered conditions and no irrigation during 30-60 days after planting) were assigned as main plots, and five peanut genotypes were arranged in subplots. Arginine content of mature peanut seed was analyzed at harvest. Midseason drought increased arginine content in all genotypes in both years. Variation in arginine content among peanut genotypes also indicated the possibility for breeding programs to improve arginine content in peanut. [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) induced drought tolerance can be a key trait for increasing and stabilizing wheat production. These SA induced traits were studied in two Triticum aestivum L. varieties; drought tolerant, Kundan and drought sensitive, Lok1 under two different water deficit regimes: and rehydration at vegetative and flowering stages. SA alleviated the negative effects of water stress on photosynthesis more in Kundan. SA induced defense responses against drought by increasing antioxidative enzymes and osmolytes (proline and total soluble sugars). Differential proteomics revealed major role of carbon metabolism and signal transduction in enhancing drought tolerance in Kundan which was shifted towards defense, energy production and protection in Lok1. Thioredoxins played important role between SA and redox signaling in activating defense responses. SA showed substantial impact on physiology and carbon assimilation in tolerant variety for better growth under drought. Lok1 exhibited SA induced drought tolerance through enhanced defense system and energy metabolism. Plants after rehydration showed complete recovery of physiological functions under SA treatment. SA mediated constitutive defense against water stress did not compromise yield. These results suggest that exogenously applied SA under drought stress confer growth promoting and stress priming effects on wheat plants thus alleviating yield limitation. Biological significance Studies have shown morphological, physiological and biochemical aspects associated with the SA mediated drought tolerance in wheat while understanding of molecular mechanism is limited. Herein, proteomics approach has identified significantly changed proteins and their potential relevance to SA mediated drought stress responses in drought tolerant and sensitive wheat varieties. SA regulates wide range of processes such as photosynthesis, carbon assimilation, protein metabolism, amino acid and energy metabolism, redox homeostasis and signal transduction under drought. Proteome response to SA during vegetative and reproductive growth gave an insight on mechanism related water stress acclimation for growth and development to attain potential yield under drought. The knowledge gained can be potentially applied to provide fundamental basis for new strategies aiming towards improved crop drought tolerance and productivity. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at the experimental farm, Dept. of Field Crop, Coll. of Agriculture, Univ. of Baghdad ,during 2011-2012, to study the effect of potassium fertilizer levels and appilication stage on bread wheat grains quality Triticum asetivum L.(Var- Abu- Ghraib-3) and some other characteres . Factorial experiment was conducted in RCBD design with three replication involved two levels of potassium 120,180 kg.ha-1 and control treatment the second factor was three stage of application (tillering ,Booting , flowering). The results shows non significant differ between potassium leveles for all studied traits, except havest index.The potassium level 180 kg.ha-1 produced plants with highest harvest index (38.17%), in comparison to the level 120 kg.ha-1, (36.82%).The application stage at flowering time produced grains with higher protein (12.18%), when compard to the tillering and booting stages (11.32% and 12.17%) respectively. The potassium application stage at tillering was superior in protein yield and harvest index 0.935 mg.ha-1 and 40.37%, respectively. It can be conclude that potassium addition stage was more important than, it,s dosages. [ABSTRACT FROM AUTHOR]

Medicinal plante Borazambol with the scientific name of Perovskia abrotanoides Karel. belongs to the family Lamiaceae. It is growing wild in the margin of mountainous roads of arid and cold climate of north Iran. It is for a long time that indigenous people by different methods in traditional medicine use its products in preventing and curing diseases. In this research, essential oils of Perovskia abrotanoides Karel, extracted and measured at the time of flowering stage and vegetative stage by different methods of distillationand then were analyzed by GC and GC/MS. The essential oil yield at vegetative stage with hydro-distillation was 2.2%, water & steam distillation (Kyzer & Long) 5.7% and steam distillation 2.5%, respectively. Major component identificated by water distillation (Clavanger) were α- terpineol (32%), n-octanol (22.5%), myrcene (7.2%), and by water and water & steam distillation (Kyzer & Long) were α- terpineol (30.3%), n-octanol (20.1%), myrcene (7.2%), and by steam distillation were α- terpineol (26.2%), n-octanol (17.4%), n-pentadecane (8.2%). The essential oil yield at flowering stage with hydro-distillation was 1.9%, water & steam distillation (Kyzer & Long) 1.5% and steam distillation 1%, respectively. Major component identificated by water distillation (Clavanger) were n-octanol (23.3%); α- terpineol (21.9%) and (Z)-β- ocimene (15.5%), and by water and steam distillation (Kyzer & Long) were α- terpineol (19.9%), n-octanol (19.9%), (Z)-β- ocimene (13.6%), and by steam distillation were n-octanol (16.6%), α- terpineol (15.3%), and (Z)-β- ocimene (13.5%).

Loquat is a high-value fruit tree with medicine and fruit homology. Loquat flowers with special fragrance, strong cold resistance and rich in various bioactive components, are valuable agricultural auxiliary products and have been widely used for making floral teas and beverages in recent years. In this study, we found the concentration of active components increased from the floral buds to initial flowers along with flower development, the bioactives of initial flowers were the richest in four flowering stages, and loquat flowers contained major volatile components such as alcohols, aldehydes and esters, which are the source of fragrance. When extract with hot water, the most efficient method was 80 °C for 30 min or boiling water within 2 h. For Baijiu (56% Vol), the best solid-to-liquid ratio was 3:100 (Dry flower: Baijiu) in 6-12 h. Baijiu achieved higher bioactive content than water extraction, the amygdalin concentration in Baijiu reached 0.3 mg/mL., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors.)

Rice is most sensitive to heat stress at the flowering stage, with different degrees of heat damage in spikelets and leaves. To investigate the heat damage in spikelets and flag leaves, two rice genotypes, N22 (heat-tolerant) and GT937 (heat-sensitive), were subjected to a heat-stress treatment (40 °C for 15 days). The results showed that more damaging was found in spikelets than in flag leaves and the heat stress significantly decreased the seed-setting rate by 12.41% in N22 and by 65.02% in GT937. However, the difference in the net photosynthetic rate of the flag leaf between heat-stressed and control was not significant. Moreover, the difference of temperatures in spikelets and flag leaves was attributed to the differences in heat dissipating. Under heat stress, the transpiration rate was significantly higher in flag leaves than in spikelets, and the temperature in flag leaves were at least 4 °C cooler than in spikelets. Although the spikelet temperatures did not differ significantly between the two genotypes under heat stress, spikelets of GT937 were more severely damaged than those of N22, which might result from the differences in the antioxidant capacities between genotypes. Results showed that little difference of superoxide dismutase, peroxidase and catalase activities of spikelets was found in N22, while significant reduction was found in GT937 under heat stress, compared with control. These results suggest that organ temperature is controlled mainly by transpirational cooling, and that heat stress is an indirect result of oxidative stress, rather than a direct result of heat damage. [ABSTRACT FROM AUTHOR]

BACKGROUND: Kiwifruit (cv. Hayward) artificial pollination is a crucial technique useful to increase fruit quality and size. However, artificial pollination efficiency depends on the timing of application and the pollination system. OBJECTIVE: The main objective is identify the best practices to be applied in the orchard to reach the best pollination by deciphering the relation between the floral stage and the pollination technique. METHODS: Many parameters were analyzed in different environments in Italy for many years, such as pollen quality (germinability, humidity, conservation at -18°C), pollination system (dry or liquid, using different machines) and flowering stage. The interaction of the pollination systems and the flowering stage were evaluated by labeling flowers according to their flowering stage and weighting the fruit later. RESULTS: The petals fall and the early petal fall stages is the best moments for dry and liquid pollination respectively. The dry blower system gave the best results. The low pollination rate observed using the pollen-lycopodium mix is due to the interfering of the lycopodium on pistils. Pollen quality was achieved keeping it at low temperature during its harvesting and must have low humidity when stored at low temperature. CONCLUSIONS: The dry pollination with pure pollen reach the best result because at the end of flowering the pistil exudate increase the pollen adhesion. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of zinc, iron and manganese fertilization on Zn, Fe and Mn concentrations in the stem and leaves and on the chlorophyll content in soybean leaves at different reproductive growth stages, two experiments were conducted in a research field of the Islamic Azad University of Kermanshah, Iran, during the 2010 and 2011 growing seasons. The experimental design consisted of a factorial experiment based on the randomized complete block method with three replicates. The treatments included three levels of Zn (0, 20 and 40 kg ha-1), Fe (0, 25 and 50 kg ha-1), and Mn (0, 20 and 40 kg ha-1), which were all applied to the soil. At 30, 60, 90 and 120 days after sowing (DAS), the SPAD readings were done on five leaves from each experimental plot for all replicates. The results indicated that the zinc application had significantly affected Zn, Fe and Mn concentrations in soybean stems at all sampling times except for the soybean stem Mn concentration at the maturity stage. In contrast, the concentration of Mn at seed filling was unaffected by iron fertilization. Also, the maximum Fe concentration in soybean stems resulting from zinc application was achieved in Zn20 treatment. The highest Zn and Mn concentrations in leaves were recorded when iron was applied in smaller amounts. Furthermore, zinc, iron and manganese applications had significant effects on the leaf chlorophyll concentration during all of the growth stages of soybean plants. In addition, increased iron and manganese fertilization raised the soybean leaf chlorophyll concentrations in all the samples. The maximum chlorophyll concentration in soybean leaves at 60 DAS was recorded in Zn20Fe50, Zn20Mn40 and Fe50Mn40 treatments (34.7, 34.0 and 35.2, respectively). [ABSTRACT FROM AUTHOR]

Northern Japan, Hokkaido has cold weather damage in agriculture almost every four years. Cold weather damage to soybeans [Glycine max (L.) Merr] during flowering is especially severe and is caused by both low temperature and insufficient sunlight. Therefore, the damage should be analyzed from both aspects. We analyzed the effects of low temperature and shading during the flowering season on seed yield and yield components in two varieties of soybeans : cv. Hayahikari, an excellent cold weather tolerant variety, and cv. Toyomusume, a cold weather sensitive variety. The soybean plants were exposed to a low temperature of 18°C day/13°C night, shaded (50%) without low temperature treatment, or shaded at a low temperature, during the four-week flowering season. The control plants were kept under normal conditions. The results indicated that cold weather damage is mainly caused by the low temperature, which severely reduced the number of pods per plant, in Toyomusume. However, shading also reduced the number of pods per plant in both varieties. All of the yield components examined were reduced by cold weather more severely in Toyomusume than in Hayahikari. Furthermore, shading combined with low temperature treatment caused greater damage in both Hayahikari and Toyomusume than either a low temperature or shading treatment alone.

The effects of short-term exposure to a low temperature [two weeks, at 18°C/13°C (day/night) ] and long -term exposure to a low temperature [four weeks, at 18°C/13°C (day/night) ] from the beginning of flowering on pod setting were examined in one of the most cold-weather tolerant variety cv. Hayahikari and a standard sensitive variety cv. Toyomusume. The short-term exposure to a low temperature did not decrease the total number of pods even in Toyomusume. However, pod setting ability during the low temperature exposure was higher in Hayahikari than in Toyomusume. After the short-term exposure to a low temperature, pod setting showed recovery from the cold-weather damage by compensative pod setting after the low temperature treatment in both varieties. The long-term exposure to a low temperature significantly decreased the total number of pods in Toyomusume. But Hayahikari showed a greater capacity for pod setting during the low temperature. And the mechanism of tolerance was related to a superior fertilization ability during the low temperature.

In this paper, ‘Lu Feng No. 1’which is mainly cultured longan varieties in Luzhou was chosed as the research object. And we chose some experimental measurements on the basis of the local methods to promote floral bud differentiation. Before flower bud morphological differentiation, taking several regulation measures of spraying growth regulator in different proportions, girdling the primary branches and root pruning with coating the earth, we regularly measured endogenous hormones in terminal bud at flower bud differentiation period by every 1 5 d. When the differentiation finished, we calculated the rate of flower and fruit setting to discuss effects of regulation measures on change of endogenous hormones in terminal bud at flowering stage and flower formation and fruit setting. We analysed all experimental data for researching mechanism of flower formation. The result showed that all of these measures improved flower rate and fruit setting rate in different degrees remarkably. However, the control measures of ethylene regulator combination with appropriate concentrations (150 mg·L-1 and 100 mg·L-1)could improve the number of trees female flowers, female flowers rate and fruit-bearing rate of trees, among which the female flowers rate improved respectively by 32. 57% and 38. 22% than CK, the tip-blunting rate of each treatment was significantly lower than CK, and the tip-blunting rate (18. 58%)of treatment B (100 mg·L-1 ethylene regulator combination)was the minimum, which was 34. 18% lower than CK, and the growth rate of bud axis and tip-blunting rate have significant positive correlation. The different treatments improved the flowering and fruit-bearing status of longan body in different degrees, inhibited flowering reversion occurring effectively, and the effects of the treatment spraying mixed liquor consisted of 150. 00 mg·L-1 mutli-effect triazole an 100. 00 mg·L-1 ethephon and 1.0 mg·L-1 6-benzyl-aminopurine evenly in the crown most excellent. For the hormones in terminal buds, these contents and hormone balance were changed by the different measures. The results were as follows: with higher GA3 and ABA contents in the spindle differentiation stage, then GA3 content and ABA content keeping at a low level in multi-level side inflorescence rapidly-differentiation stage, lower ZT level in the entire morphological differentiation, and that was good for preventing longan flower from reversing and promoting longan bud differentiating. The change of IAA content affection was relatively complex, and its regularity was not strong. Viewing the point of hormones content proportion, smaller ratio of IAA/GA3 in the spindle differentiation stage, the bigger ratio of ZT/ABA before purple inflorescence primordia appearing-period and the lower ratio of ZT/ABA and GA3/ABA in hole morphological differentiation, which were beneficial to longan flowering. The study would provide theoretical basis for Luzhou longan high quality and high yield cultivation. [ABSTRACT FROM AUTHOR]

Mentha × piperita (L.) Huds. of the family Lamiaceae is a very important species for commercial exploitation due to the high content of essential oil. Besides the essential oils, there are also other significant secondary metabolites in peppermint, especially flavonoids and hydroxycinnamic derivatives. In this study, we evaluate the variability of essential oil constituents and of phenolic compounds in the leaves of M. × piperita during the development of inflorescence. Similar studies, dealing with the variation of the essential oils and its composition, have been performed in the past, but no attention was paid to the variation of other secondary metabolites. We examined M. × piperita cv. 'Perpeta', the domestic cultivar. The plants were cultivated in the climatic conditions of south-west Slovakia. The contents of secondary metabolites were investigated in the week periods, from the beginning of inflorescence formation to the end of flowering. The yield and the quality of essential oil have been carried out by distillation and gas chromatography mass spectrometry (GC-MS). The phenolic substances were analysed using spectrophotometric methods according to European Pharmacopoeia. The highest contents of phenolic substances have been found in leaves of plants during the flowering phenophase, the same stage when essential oil of mint also achieves the highest quality. [ABSTRACT FROM AUTHOR]