Search

Spinach (Spinacia oleracea L.) is considered a nitrogen (N) intensive plant with high nitrate (NO3-) accumulation in its leaves. The current study via a two-year field trial introduced an approach by combining N fertilization from different sources (e.g., ammonium nitrate; 33.5% N, and urea; 48% N) at different rates (180, and 360 kg N ha-1) with the foliar spraying of molybdenum (Mo) as sodium molybdate, and/or manganese (Mn) as manganese sulphate at rates of 50 and 100 mgL-1 of each or with a mixture of Mo and Mn at rates of 50 and 50 mg L-1, respectively on growth, chemical constituents, and NO3- accumulation in leaves. Our findings revealed that the highest rate of N fertilization (360 kg N ha-1) significantly increased most of the measured parameters e.g., plant length, fresh and dry weight plant-1, number of leaves plant-1, leaf area plant-1, leaf pigments (chlorophyll a, b and carotenoids), nutrients (N, P, K, Fe, Mn, Zn), total soluble carbohydrates, protein content, net assimilation rate, and NO3- accumulation, but decreased leaf area ratio and relative growth rate. Moreover, plants received urea-N fertilizer gave the highest values of all previous attributes when compared with ammonium nitrate –N fertilizers, and the lowest values of NO3- accumulation. The co-fertilization of N-Mo-Mn gave the highest values in all studied attributes and the lowest NO3- accumulation. The best treatment was recorded under the treatment of 360 kg N-urea ha-1 in parallel with the combined foliar application of Mo and Mn (50+50mg L-1). Our findings proposed that the co-fertilization of N-Mo-Mn could enhance spinach yield and its quality, while reducing NO3- accumulation in leaves, resulting agronomical, environmental and economic benefits.

The Brazilian Atlantic Forest has been affected by the deposition of Ni and Zn, among other heavy metals adsorbed on atmospheric particles, which can be incorporated into the soil. If available in the soil, they can be absorbed by plant roots. The study aimed at testing experimentally the hypotheses: 1) Ni and Zn depositions increase their bioavailable fractions in the soil; 2) pioneer tree species absorb Ni and Zn from the soil in higher level and less growth changes than non-pioneer species. The experiment was carried out with six pioneer and non-pioneer species native to the Atlantic Forest, grown for 90 days in: soil with balanced fertilization (control) and in soil enriched with Ni, Zn or Ni + Zn. At the end, the concentrations of Ni and Zn were determined in four soil fractions (F1: soluble; F2: linked to oxides/hydroxides; F3: linked to organic matter: F4: residual metals) and in leaves, stems/branches and roots. Mobility factors in soil, concentration ratios between treatments and respective controls, translocation efficiency and relative growth rate in height, leaf number and total biomass were also calculated. The results showed that Ni and Zn concentrations increased significantly in the bioavailable soil fractions (F1, F2). The absolute content of Ni and Zn in the plants directly reflected the soil level in the available forms. Pioneer tree species absorb Ni and Zn in higher level and show less changes in growth than non-pioneer tree species.

Tissue culture methods are useful in assessing the tolerance of various stresses due to the ease of controlling stress under in vitro conditions. This study aimed to investigate the response of sugarcane genotyps to drought stress using calli as a model system. For inducing sugarcane callus, the medium of Murashige and Skoog (MS) was used with different mannitol concentrations (100, 200, and 300 mM) to measure their effects on callus frequency, the day of callus initiation, embryogenic potential, relative growth rate (RGR), water and proline contents, K+ and Na+ contents, as well as the formation of shoot and roots for three sugarcane genotypes (e.g., GT 54-9, G 84-47, and pH 8013). The RAPD-PCR analysis was carried out using five oligonucleotide primers to identify the genetic variation among sugarcane genotypes. The results indicated that the degree of callus proliferation varied from 70 − 86%. The highest value of callus proliferation, PGR, shoot formation was recorded for the genotype GT 54-9 compared to the other two genotypes (G 84-47 and pH 8013). Calli treated with 100 mM mannitol showed the highest RGR, proline and waer contents for the genotype GT 54-9, while, those treated with 300 mM recorded the lowest values of these parameters for the genotype pH 8013. The genotype G 84-47 collected highest Na+ content, while the genotype pH 8013 collected highest K+ content. The results of this study recommend preference for GT 54-9 genotype, which is considered the most promising genotype, showing more tolerance to drought stress based on all studied traits.

Trade-offs exist for xerophytic shrubs between functional traits, involving in water loss and assimilate accumulation, can contribute to its survival and growth rate regulation in arid environments. However, growth analysis based on plant functional traits has been focused on the study of herbs and woody species. It is still unclear how the functional traits of xerophytic shrubs regulate their growth rate. In this study, we selectedeight xerophytic shrubs as samples to analyze the regulation process of the functional traits of shrubs on growth rate. Plants were cultivated for three years, and three harvests (every one year) were carried out. Factors explaining between-species differences in relative growth rate (RGR) varied, depending on whether different ages were considered. The results showed that RGR was positively correlated with net assimilation rate, but there was a significant negative correlation with leaf area ration (LAR), specific leaf area (SLA), and leaf biomass ratio in the age 1. However, in the age 2, RGR showed a significant positive correlation with the morphological traits (i.e., leaf area ration and specific leaf area), but not with physiological traits (i.e., net assimilation rate) and leaf biomass allocation. Our results suggested that the fluctuation of environmental factors affects the regulation path of the plant functional traits on RGR of xerophytic shrubs. However, the analysis of causality model showed that no matter in which age, net assimilation rate and leaf area ration principally drive the variation in RGR among xerophytic shrubs.

Aims: The research aimed to investigate the shade response of E. gracilis Klebs while making the irradiance a crucial factor for photosynthesis based physiological activities and its applicability for industrial level culture conditions. Study Design: Euglena was cultured at three different light intensities of 30, 90, and 210 mol m-2s-1 photoautotrophically and axenically in modified Cramer-Meyer medium at 25 ˚C as batch cultures. Methodology: The photosynthesis O2 evaluation of Euglena cultures was measured under exponential (EP), transitional (TP), and stationary phases (SP). The light compensation point (LCP), light saturation point (LSP), and dark respiration rate (DRR) were obtained. Cell volume and cell number in each culture were measured simultaneously. Cells were collected and obtained dry mass (DM) after drying aliquots at 80˚C. Specific growth rate (SGR) and relative growth rate (RGR) were calculated. Tests for homogeneity of variance were performed on all parameters and LSDs were used for the mean separation. Results: In the TP, the lowest LCP was achieved in the higher light culture. The values of both the DRR and the LSP were the same as in EP. The DRR, LCP and LSP are lower in lower PFD cultures and decreased with increasing cell titers. The cellular growth levels were lower in lower light culture and decreased as each culture grew. Cellular DM was maintained constant in the EP, where SGR almost equaled RGR. In the EP, SGR was maintained constant in each culture, SGR displayed a saturation phenomenon. In the later TP, SGR became equal to RGR and all the cultures revealed constant DM. Conclusion: Euglena photoautotrophic cultures can tolerate low light intensities. With the SGR and RGR behavior under the shade conditions, they can maintain the constant photosynthesis rate and constant dry matter level.

Since 2007, Ulva prolifera-induced green tide occurred every year in the offshore waters of the Yellow Sea in China, which have resulted in large economic loss and heavy damage to local marine ecosystems. In addition, ocean warming and heavy metal pollution have become two main marine environmental issues in the world. However, the interactive effects of ocean warming and zinc (Zn2+) exposure on macroalgae remain poorly studied. An experiment was conducted to determine the relative growth rate (RGR) and photosynthetic performance at different temperatures (15, 20, 25 °C) and Zn2+ concentrations (0, 0.0026, 0.026, 0.26, and 0.52 mg/L). Results showed that low temperature (15 °C) increased the RGR under the medium levels of Zn2+ (0.026 mg/L) compared with high temperature (20 and 25 °C). On the other hand, at 20 and 25 °C the inhibition of Zn2+ on the PSII quantum yield and electron transport rate of U. prolifera was promoted. Furthermore, dark respiration rate increased with increases in temperature and Zn2+ concentration, while at the high temperature, the ratio of the net photosynthetic rate and dark respiration rate were (Pn/Rd) inhibited, and the inhibition was positively related to the Zn2+ concentration at ≥0.26 mg/L. in addition, the photoprotective ability was hindered under high temperature (20 and 25 °C) and the potential photosynthetic ability was restricted under higher levels of Zn2+ concentration. We conclude that ocean warming could promote the inhibition effects of heavy metal pollutions on physiological performance of U. prolifera, and probably other marine microalgae as well, on which future studies shall be conducted

The seed reserves with 148 days after anthesis are sufficient to form 100% normal seedlings in vitro, obtaining a production gain of 101 days. Euterpe edulis (Arecaceae) is a typical palm of the Atlantic Forest with great ecological and economic value. Its seeds are characterized by hard coats, as well as recalcitrant, slow, and uneven germination, which hinder efficient seedling production. Given its risk of extinction, the objective of this study was to investigate reserve mobilization and how this impacted on the quality of maturing E. edulis seeds. Seven maturation stages separated by 20-day intervals, were assessed from 108 to 228 days after anthesis. The morphological characteristics, germination, vigor, and biochemical properties of in vitro germinated seeds, as well as the quality of the seedlings from each maturation stage were assessed. Four replications with ten seeds were evaluated at each stage. Over the experimental period, total relative growth rate of the fruits was 0.0037 mm day− 1, while moisture content decreased from 79.49 to 46.59%. The concentrations of phenols, soluble sugar, proteins, and starch decrease significantly during maturation, while there is an increase in lipids and fibers. Most variables displayed a positive correlation, except moisture, phenols, soluble sugar, proteins, and starch. E. edulis seeds possessed sufficient reserves to allow for normally developed embryos 148 days after anthesis, their 100% germination, and formation of 100% normal seedlings.

Native Middle Egypt Rabbit breed (NMER) crossbred with Gaint Flander rabbits to create a synthetic line and this study aimed to evaluate the genetic estimates of this synthetic line with comparing to the purebreds. A crossbreeding was carried out by mating bucks of Gaint Flander (G) with does of NMER (N) to get F1 (½N½G), then does and bucks of F1 were mated to get the F2 (½N½G)2, followed by two generations of inter se-mating to get a new synthetic line is called Egy-line with a genetic structure of ((½N½G)2)2. Heritability estimates for body weights were generally moderate and ranging from 0.10 to 0.24, while the estimates of heritability for growth rate were low and moderate and ranging from 0.01 to 0.23. Common litter effects of body weight were large as weaning (0.61), then declined gradually at the rabbit grew older. Also, the same trends were observed for relative growth rate (RGR). The direct additive effects were positive and highly significant for all body weights at different ages, favoring Gaint Flander and heavier comparing with NMER rabbits. Most relative growth rates during different intervals were non-significant. Gaint Flander was highly significantly and heavier in maternal additive effects in in different weeks of age comparing with NMER rabbits. Direct heterosis effect for most bodyweight was positive and highly significant, and percentages of direct heterosis increased generally with the advance of age. Maternal heterosis for growth rates from 5 to 6, 8 to 10, and 10 to weeks were positive, only. Direct recombination effects for most bodyweight were positive and highly significantly exclude weight at 5 and 6 weeks. It is concluded that a new synesthetic line (Egy-line) has proven its superiority and performance well in all different body weights and most growth rates compared to other parents and crossbreds.

Sargassum horneri is a foundational species and an important contributor to the floating seaweed stock along the northeastern coast of Asia. In this study, benthic and floating thalli of S. horneri were collected from Changdao Island (37°54′N, 120°43′E), Bohai Bay, China. We conducted an in-situ and an indoor experiment to study the acclimation potential in S. horneri to abiotic conditions at sea surface in autumn and winter. Both benthic and floating thalli were cultured in situ for two months (from October to December) at different depths: 0 m above sea level (masl) and 3 m below sea level (mbsl), and their growth rate, biochemical content, and photosynthetic performance were compared. During the first month of culture, the relative growth rate of floating thalli was 2-fold greater than that of benthic thalli at 0 masl. The photosynthetic rate of most thalli was significantly higher at 0 masl than at 3 mbsl. In the indoor experiments, floating and benthic thalli were exposed to high light intensity (400 µmol photons/(m2·s) photosynthetically active radiation (PAR)) for 21 d, and their photo-acclimation capacities were compared. Under high light intensity, the two types of thalli showed low maximum quantum yield (Fv/Fm) and light utilisation efficiency (α) but high light saturation point (Ek). Floating thalli showed higher photosynthetic rate and photoprotective ability than benthic thalli at high light intensity. The effective quantum yield of photosystem II [Y(II)] of both types of thalli recovered after a 6-day treatment with low light intensity (40 µmol photons/(m2·s)). These findings suggest that S. horneri is highly acclimated to the sea surface environment, which possibly contributes to its rapid accumulation and long free-floating periods at the sea surface.

Marine microalgae are a promising sustainable source of lipids, omega-3 fatty acids, and carbohydrates. Selected microalgae species belonging to the Bacillariophyceae, Haptophyceae, Eustigmatophyceae, and Prasinophyceae were characterised for cellular content of carbon and nitrogen, and for production yields of lipids, fatty acids, total carbohydrates, and β-glucans. Carbon and nitrogen content showed a hyperbolic decrease with increasing cell numbers for Chaetoceros calcitrans, C. muelleri, Skeletonema costatum, Tetraselmis sp., and Nannochloropsis oculata. Cultures of Pavlova lutheri and Tisochrysis lutea showed an increase in carbon content per cell, but a decrease in nitrogen content. The total lipid content of C. muelleri, C. calcitrans, N. oculata, and T. lutea increased with decreasing relative growth rate; however, the highest productivity of lipids was found in T. lutea grown at 40% of the maximum specific growth rate. The highest content of eicosapentaenoic acid was found in C. muelleri, C. calcitrans, and N. oculata, and the highest content of docosahexaenoic acid was found in T. lutea. The β-glucan fraction of the carbohydrates was highest in C. muelleri and C. calcitrans and was very low in N. oculata. Out of the species investigated, C. muelleri had the highest production yield of β-glucans, obtained when cultivated at a 40% relative growth rate.

Production of Physalis peruviana L. has gained prominence in Northeastern Brazil. However, salinity limits the crop development in the Brazilian semiarid. Thus, this research aimed to evaluate the application of Acadian® biostimulant as mitigant of the deleterious effects of salinity on growth and gas exchange of P. peruviana plants. The experiment was combining different electrical conductivity of irrigation water (0.50, 1.23, 3.00, 4.44, and 5.50 dS m−1) and biostimulant doses (0.00, 1.45, 5.00, 8.55, and 10.00 mL L−1). The main variables evaluated were plant height, stem diameter, number of leaves, root length, leaf area, specific leaf area, leaf area ratio, absolute and relative growth rate for plant height, and gas exchange. Experimental results showed that an increase in electrical conductivity of irrigation water had negatively affected the growth components and gas exchange in P. peruviana. Also, the application of seaweed-based biostimulant improves the photosynthetic capacity (43.3%), reduces transpiration rate (26.5%) and water loss by this process, further it attenuated the deleterious effects of salinity on specific leaf area, leaf area ratio, and stomatal conductance. To further elucidate the effectiveness of biostimulant application as a mitigant of salt stress, research aimed at the biochemical and enzyme activities of the plant's antioxidant system should be conducted to better understand this process.

Introduction: Ochroma pyramidale (Cav. ex Lam.) Urb. is a species with high potential for use in commercial reforestation. Knowledge of nutrient requirements in nursery increases the chances of success in the field by generating plants with adequate morphological and physiological characteristics. Objective: To identify the key nutrients for O. pyramidale growth in nursery and to characterize the associated visual symptoms of deficiency. Materials and methods: The design was completely randomized with 10 treatments: one treatment without fertilization, one treatment with complete fertilization (CF), and eight resulting from the CF treatment with suppression of N, P, K, Ca, Mg, S, B and cationic microelements (Mn, Fe, Cu and Zn). The effect of each treatment was determined by height, root collar diameter, aboveground dry biomass, root dry biomass, leaf area and relative growth rate. An analysis of variance and separation of means was performed using the Tukey's test (P < 0.05). Results and discussion: Nutrient suppression had significant effects (P < 0.05) on growth after six months in nursery. P was the most limiting element, followed by N. The other treatments showed no significant differences compared to the FC treatment. N suppression caused yellowing, and lack of P caused necrosis with subsequent death and detachment in leaves. B suppression showed no clear deficiency symptoms. Conclusion: O. pyramidale showed high nutrient uptake efficiency. Only N and P strongly limited its development, which represent the key nutrients for the species.

Canna indica L (African arrowroot), is a beneficial, multi-use tropical perennial with a worldwide distribution, but relatively unexplored. This plant has the potential to be developed as a food crop in an intercropping system, utilizing idle land under commercial plantations such as rubber or teak. This study aimed to determine the best light-growing conditions for C. indica. A completely randomized design was used with growth light as the treatment consisting of 25%, 50%, and 100% of natural light, respectively. Leaf traits, growth characteristics, and phenotypic plasticity were used to measure C. indica’s response to different treatments. The results of this study showed that C. indica grown in low light has the best growth with increased height, leaf area, root and shoot dry weights, but decreased leaf thickness, which caused the increase in specific leaf area, leaf area ratio, and leaf weight ratio, but decreased root to shoot ratio. Based on leaf traits and biomass allocation, the phenotypic plasticity index was 0.23, a typical number for shade tolerant species. These findings were the first time to be reported for C. indica. For agroforestry practices, it can be recommended that C. indica be used as an intercropping plant under tree canopies.

Rosewood and Teak are valuable timber species, which have been heavily logged from both natural forests and plantations. Climate change has also contributed to a reduction in their numbers. We studied their light adaptability at the seedling stage to quantify the growth and physiological characteristics under 10% and 100% of full sunlight. Rosewood performed better, as indicated by the relative growth rate, chlorophyll content, and chlorophyll efficiency, under both shade and sunlight. We also simulated a sudden change in light intensity (gap opening up in the canopy) by exposing seedlings, previously under shade, to full sunlight. Rosewood seedlings responded faster (higher relative growth rate) to changing light conditions relative to Teak. We conclude that Rosewood seedlings can be planted either under shade, or in full sunlight, or in a location experiencing sudden change from shade to sunlight, while Teak seedlings should be planted under at least 10% sunlight, but not in full sunlight, as it can lead to chlorophyll and tissue damage.

To improve the nitrogen and phosphorus removal efficiency of surface flow constructed wetlands (SFCWs), biochar was added to an SFCW matrix. The effects of adding different amounts of biochar on water purification, the growth of Vallisneria natans (V. natans), and microbial mechanisms were explored through SFCW simulation experiments. The results showed that through the joint action of biochar and V. natans, the concentrations of total nitrogen, total phosphorus, and ammonia nitrogen in the effluent significantly decreased. The total biomass, relative growth rate, and chlorophyll content of V. natans were significantly reduced by adding biochar (≥20%, v/v), as the root activity and the root to leaf biomass ratio slightly increased at first and then decreased. The carbon and nitrogen contents of V. natans slightly increased with the addition of biochar (≥10%, v/v), but the phosphorus content slightly decreased. Moreover, the nitrogen content of the matrices decreased significantly over time (P

Roots can effectively consolidate and support the soil and are affected by external forces. To identify the survival strategies and soil reinforcement capability of roots against damaging forces, we investigated Hippophae rhamnoides taproots with a diameter of 1-4 mm in a coal mining subsidence area. To simulate root damage from erosion, an HG100 digital push&pull tester and self-developed experimental installation were used in situ. Relative growth rate, activity, tensile force, and strength of taproots were inhibited by damage. Significant differences occurred in these indicators depending on drawing damage type and level. Inhibition effects from persistent drawing damage on growth and tensile properties were markedly greater than those from instantaneous drawing. Inhibition effects of severe damage were markedly greater than those of mild damage. The number of living roots declined more after persistent drawing or severe injury than after instantaneous or mild damage. The taproots showed self-healing ability, and the inhibitory effect of drawing damage gradually weakened with the time of self-repair, ensuring H. rhamnoides taproots could continue to play a role in soil reinforcement. The self-healing ability of roots should be considered in vegetation restoration of erosion-prone areas to ensure that the roots' ability to resist erosion is accurately estimated. Novelty statementResearch on the soil reinforcement ability of damaged plant roots is very limited at present. This study provides a new perspective for soil reinforcement: roots can be destroyed by erosional forces while providing support for soil, the self-healing ability of plants determines whether they can provide effective support for soil in the erosive environment.

Drought and salinity are considered two major abiotic stresses that diminish cotton production worldwide. Studying common morphological and physiological responses in cotton cultivars may help plant biologists to develop and apply standard screening criteria for either of these stresses and for their combination. Therefore, this research aimed to assess the suitability of several physiological parameters as diagnostic to report on osmotic and salinity tolerance in six elite cotton genotypes. Data for relative growth rate (RGR), RGR-reduction, potassium (K+) concentrations in roots, xylem sap and shoots, stomatal conductance (gs) and net photosynthesis rate (Pn) were assessed. Based on RGR and RGR-reduction, we observed an association between osmotic tolerance and salinity tolerance of cotton genotypes. Furthermore, this study found that tolerant cotton genotypes were better able to maintain high RGR, tissue K+, and gas exchange under both hyperosmotic and saline conditions. Shoot K+ levels showed high negative correlations with both osmotic and salinity stress and emerged as a convenient and suitable parameter to assess cotton tolerance to either stress.Novelty statementCotton (Gossypium hirsutum) is a leading fiber crop that is cultivated in more than 52 countries. Much of the land where cotton is grown faces co-occurring drought and salinity abiotic stress which negatively impacts cotton yield and fiber quality. In the present study, cotton genotypes were identified with tolerance to both hyperosmolarity and salinity. Furthermore, we show that shoot potassium content is a diagnostic trait that reports on both osmotic and salinity stress and hence a convenient tool for screening cotton germplasm.

The Study was conducted to evaluate the effect of solid and liquid organic fertilizer on growth and yield of rosselle in 2016 cropping season at Institute of Agricultural Reserve Zaria, Samaru (11011’N 07038E and 686m) and Institute of Horticultural Research Farm Bagauda (12000’N 8031”Em 488m) in Northern Guinea Savannah and Sudan Savannah Ecological Zones of above sea level Nigeria. Treatments consisted of four levels of solid poultry manure (0.0, 1.0, 2.0 and 3.0) tons/ha and five levels of liquid organic manure from Grand Total Organic Fertilizer Limited (0.0, 0.5, 1.0, 1.5 and 2.9) litres/ha, which were factorially combined in a randomized complete block design (RCBD) and replicated three times. Data on growth parameter were collected on plant height (cm), plant dry weight (g), leaf Area index crop growth rate (CGR) Relative Growth Rate (RGR) and Net assimilation rate (NAR) while data on yield parameters like number of calyx per pant, 100 seed weight (g) and calyx yield per hectare kg/ha were collected. Results showed that plant height, plant dry weight(g), 100 seed weight(g) and calyx dry yield kg/ha had a significant increase with application of 2.0 litres/ha of liquid fertilizer than other rates. While application of solid poultry manure at 3.0ton/ha significantly increases plant height, net assimilation rate, leaf area index and calyx dry weight when compared with other rates. From the results obtained, the combination of 2.0 litres/ha liquid organic fertilizer and 3.0 ton/ha solid poultry manure produce the highest calyx yield at both location.

Taxonomy of Azolla was extensively studied, but still its identification based on morphological, physiological, and reproductive structure remains unclear. Hence, an attempt was made to differentiate Azolla strains based on morphological and physiological traits, keeping six known Azolla (Azolla microphylla, Azolla caroliniana, Azolla mexicana, Azolla rubra, Azolla filiculoides, and Azolla pinnata) as reference for this study. The results showed that out of 96, 21 strains were sporulated during December, 2017 to February 2018 along with two known species, i.e., A. microphylla and A. pinnata. All sporulating strains (except GSMI 1) showed morphological-resemblance with A. pinnata, whereas GSMI 1 was resembled with A. microphylla. Biplot principal coordinate analysis (PCoA) based on physiological data revealed that GSMI 1 was significantly resembled with A. microphylla. Moreover, the presence of rounded dorsal leaf lobe in A. caroliniana has made it unique in Euzolla sub-section and hence, differentiated from other four species (A. microphylla, A. mexicana, A. rubra, and A. filiculoides). WinRHIZO-based root-imaging technique showed the presence of thick root hairs in A. pinnata as compared to other Azolla strains, whereas efficiency of photosystem II (Fv /Fm, a chlorophyll fluorescence-imaging derived value) and relative growth rate were found higher in CRRI 4. In conclusion, the present study generated a presumptive classification key of 102 strains of Azolla for the first time, which indicates clearly that taxonomy in Azolla should be reviewed. Validation of these characters through molecular markers will give further insight about their classification.

This research was done to evaluate the growth and yield of potato plants raised from seed tuber pieces (STP) containing one, two, three and four eyes, for ascertaining whether seed tuber pieces containing two eyes will sustain potato growth and yield indifferently from those of larger seed tuber pieces containing more eyes. Results indicated that number of stolons and leaves per plant, leaf area, plant fresh and dry weight, relative growth rate, net assimilation rate, crop growth rate, chlorophyll a, b as well as total chlorophylls, Number of tubers and total tuber yield per plant were decreased with decreasing number of eyes in the STP. However, final emergence percentage and total carotenoids content were not significantly affected. Nevertheless, number of tubers and total tuber yield per plant did not differ significantly neither between whole seed tubers and half seed tubers containing four eyes nor half STP containing three eyes and quarter STP containing two eyes. However, all these parameters were significantly lower in response to single-eye STP compared with those containing two eyes or more. From the economic point of view, cultivation of quarter STP containing two eyes instead of half STP containing four eyes represents 50 % conservation in the seed tubers used for only 13.5 % loss in tubers yield. So, it could be concluded that the gain in net income became substantiated by cultivation of quarter STP containing at least two eyes instead of larger seed tuber pieces, even that represents half of the seed tuber.

Two field experiments were carried out at a private farm, Damietta, Egypt to study the effect of foliar application and fertigation on the biological aspects as (plant height, number of leaves and root length and plant growth biomass (i.e., fresh and dry and shoot/root ratio and relative growth rate) as well as chlorophyll contents of pepper. Four foliar potassium treatments ((K0 (control), K1; 2kg fed-1 , K2; 4kg fed-1, and K3; 6kg fed-1) ) combined with three fertigation treatments (K0 (control), K1; 66kg fed-1 K2; 132kg fed-1) were arranged in a split-plot design with three replicates. The results showed that plant height and root length increased significantly by potassium fertigation and foliar application compared to the control. In contrast, potassium fertigation and foliar application had no significant effect on leaf area and leaf area index in both seasons. Pepper fresh and dry weights decreased by increasing K fertigation compared to the control, while potassium foliar application (K-leaf) significantly increased pepper fresh and dry weights with increasing potassium compared to the control except with the treatment of 6 kg fed-1 in both seasons. Potassium fertigation and foliar application had no significant effect on chlorophyll A, B, total carbohydrates and total phenols. While vitamin C increased by increasing potassium fertigation. The treatment of 50% in the recommended dose recorded the highest vitamin C values in both seasons and the potassium foliar application with K- leaf at the rate of 4 kg k fed-1 gave the highest vitamin C values in both seasons.

Previous research has indicated that electrostatic radiation may induce biological and physiologic changes in plants and aphids. This study was conducted to determine effects of long-term exposure of electrostatic radiation on biology and feeding behavior of Sitobion avenae (F.). To imitate the natural electrostatic radiation stress, both wheat seeds and S. avenae nymphs (produced within 12 h) were exposed to an electrostatic radiation of 4 kV/cm for 20 min and 5 kV/cm intensity for 40 min, respectively. Controls received no treatment (0 kV/cm). Then, the mean relative growth rate (MRGR) and feeding behavior of the 5th-, 10th-, 15th-, 20th-, 27th-, 33rd-, and 39th-generation aphids were examined, respectively. Data showed that electrostatic radiation exposure within a certain period of time can promote weight increases of S. avenae, but long-term exposure of electrostatic radiation had an adverse effect on the weight gain of aphids. The comparison of the two treatment intensities showed that electrostatic radiation at the intensity of 4 kV/cm for 20 min had a significant influence on the probing behavior of S. avenae. This study initially evaluated the effect of electrostatic radiation on S. avenae from the aspect of nutrient feeding behavior, which further verifies the biological characteristics of electrostatic radiation.

Surveys were carried out in order to study the effects of differential incubation temperatures (37.8, 39.5, 37.5, and 37.0°C on days 1–14, 15–17 for 2 h daily, 18, and 19–20, respectively) on growth of chick embryos of the Hisex Brown cross, development of their visceral organs, and early postnatal development of chicks. Increased (39.5°C on days 15–17 for 2 h) and decreased (37.5°C and 37.0°C on days 18 and 19–20, respectively) incubating temperatures during the test period of chick embryogenesis contributed to increased body mass of embryos and their visceral organs when compared to a constant temperature (37.6°C). Significant changes in the muscular-stomach relative growth rate, represented by an increase at 37.5°C on day 18 and decreases at 39.5 and 37.0°С on days 15–17 and days 19–29, respectively, were found at the differential incubation temperatures compared with the other temperature regime in the previous period. A comparative statistical analysis of the relative growth rates of body length and mass and visceral organ mass of chick embryos at the differential incubation temperatures compared to the constant temperature did not reveal any significant differences (p > 0.05). At the differential temperatures compared to the constant temperature regime, pronounced intensive allometric increases in the chick embryo heart and liver masses and their body length and stomach mass were recorded on days 15–17 to day 18 and on days 19–20, respectively. The effects of differential incubation temperatures manifested in increasing the chick embryo’s body, heart, muscular stomach, and liver mass, early chick hatching on the 19th day, and increasing the size of body measured from gain in body weight and linear body measurements in early postnatal ontogenesis.

CRESCIMENTO E DESENVOLVIMENTO DE CULTIVARES DE FEIJÃO-CAUPI EM FUNÇÃO DA SALINIDADE DA ÁGUA DE IRRIGAÇÃO JOSÉ VALDENOR DA SILVA JÚNIOR¹; ANTÔNIO AÉCIO DE CARVALHO BEZERRA² E EVERALDO MOREIRA DA SILVA³ ¹ Programa de Pós-Graduação em Agronomia – Produção Vegetal, Centro de Ciências Agrárias, Universidade Federal do Piauí, Campus Pretrônio Portella, s/n, Bairro Ininga, CEP: 64049-550, Teresina, Piauí, Brasil, e-mail: valdenor.jr@ufpi.edu.br ² Departamento de Planejamento e Política Agrícola, Centro de Ciências Agrárias, Universidade Federal do Piauí, Campus Pretrônio Portella, s/n, Bairro Ininga, CEP: 64049-550, Teresina, Piauí, Brasil, e-mail: aecio@ufpi.edu.br ³ Programa de Pós-Graduação em Ciências Agrárias, Universidade Federal do Piauí, Campus Professora Cinobelina Elvas, Av. Monoel Gracindo, Km 01, Bairro Planalto Horizonte, CEP 64.900-000, Bom Jesus, Piauí, Brasil, e-mail:everaldo@ufpi.edu.br 1 RESUMO A salinidade do solo e da água constituem uma das principais restrições abióticas na produção de alimentos. O presente trabalho foi desenvolvido na Universidade Federal do Piauí, em Alvorada do Gurguéia, PI, com o objetivo de avaliar o efeito da salinidade da água de irrigação na morfofisiologia de cultivares de feijão-caupi. Foram estudados cinco níveis de salinidade da água de irrigação (0,01, 1,41, 2,81, 4,21 e 5,61 dS m-1); três cultivares: BRS Tumucumaque, BRS Guariba e BRS Imponente em dois períodos de cultivo. Utilizou-se o delineamento em blocos completos casualizados no esquema de parcelas subsubdivididas, com quatro repetições. Foram avaliados massa seca da parte aérea (MSPA), área foliar (AF), índice de área foliar (IAF), taxa de crescimento da cultura (TCC), taxa de crescimento relativo (TCR) e taxa de assimilação liquida (TAL). Houve efeito significativo da interação entre os fatores em todas as variáveis analisadas. MSPA, AF e IAF aos 25 DAS (dias após a semeadura), apresentaram reduções lineares aos aumentos da salinidade. BRS Tumucumaque apresentou maior tolerância aos efeitos da salinidade na fase final de crescimento, com os maiores índices de salinidade limiar para TAL, TCR e TCC. Enquanto a BRS Guariba foi mais tolerante na fase inicial de crescimento. Palavras-chave: Vigna unguiculata, estresse salino, morfologia. SILVA JÚNIOR, J. V. S.; BEZERRA, A. A. C.; SILVA, E. M. GROWTH AND DEVELOPMENT IN COWPEA CULTIVARS IN FUNCTION OF IRRIGATION WATER SALINITY 2 ABSTRACT The salinity of soil and water is one of the main abiotic restrictions in food production. This present study was developed at the Federal University of Piauí, in Alvorada do Gurguéia, PI, Brazil, with the objective to evaluate the effect of irrigation water salinity on the morphophysiology of cowpea cultivars. Five salinity levels of the irrigation water were studied (0.01, 1.41, 2.81, 4.21, and 5.61 dS m-1); three cultivars: BRS Tumucumaque, BRS Guariba and BRS Imponente in two cultivation periods. A randomized complete block design was used in the split-split plot arrangement, with four replications. Dry mass aerial part (MSPA), leaf area (AF), leaf area index (IAF), crop growth rate (TCC), relative growth rate (TCR) and liquid assimilation rate (TAL) were evaluated. There was a significant effect of the interaction between factors in all variables analyzed. MSPA, AF and IAF at 25 DAS (days after sowing), showed linear reductions to increases in salinity. BRS Tumucumaque showed greater tolerance to the salinity effects in the final growth phase, with the highest threshold salinity indexes for TAL, TCR and TCC. While the BRS Guariba was more tolerant in the initial growth phase. Keywords: Vigna unguiculata, saline stress, morphology.

Zeugodacus cucurbitae is a major pest of cucurbit plants which in India itself is responsible for causing considerable damage to vegetables. In the present study, the effect of the secondary plant metabolite chrysin was investigated on the growth, development and oviposition behaviour of melon fruit fly. Chrysin effect on Z. cucurbitae larvae was studied by incorporating it in artificial diet at 5, 25, 125, 625 and 3125 ppm concentrations with water as a control. The larval and total developmental periods were prolonged, while percentage pupation and adult emergence of first, second and third instar larvae were inhibited with chrysin treatment. The adverse effect of chrysin was considerably greater on first instar larvae where no adults emerged at the highest concentration of 3125 ppm. The larval weight, mean relative growth rate and food assimilated also declined significantly with treatment. Also, evaluation of chrysin for oviposition deterrent activity revealed reduced oviposition by females under choice as well as no-choice conditions. The findings indicated potential use of chrysin in pest management studies.

Excessive nitrogen fertilizer uses in crop field causes surface water pollution, which has a harmful effect on the ecosystem. The study was conducted to reducing the use of nitrogen fertilizers during cultivation of pulse crop and as an alternative to increase the use of biofertilizers. Rhizobium can fix atmospheric nitrogen to the soil; it can be used as an alternative to urea for the cultivation of lentil (BARI Masur-6). The Rhizobium leguminosarum was isolated from root nodules of lentil (Lens culinaris) plants and cultured in YEMA (Yeast Extract Mannitol Agar) media. The Rhizobium was screened on the ground of physiological, biochemical and environmental conditions. Different doses of urea fertilizers (20, 40, 60, 80 kg ha-1) and liquid Rhizobium were used in experimental plots. The results indicated that biofertilizer with different chemical fertilizer performed higher than application of several level of urea nitrogen fertilizer in respect of plant height, number, chlorophyll content (µg cm-1) and number of nodules plant-1 with variety BARI Masur-6. There was optimum relative growth rate (RGR) also observed. The increase in urea nitrogen levels was the reason for the decline in relative plant growth. Yield and yield contributing characters like number of pod plant-1, number of seed plant-1, 1000-grain weight (g), grain yield (t ha-1), straw yield and biological yield were significantly influenced by biofertilizer application. The assembled application of biofertilizer and chemical fertilizer produced maximum number of harvest index (%) compare to the chemical fertilizers. Significant correlation found with no of nodule, no of seed, seed weight, grain yield and straw yield. Significant correlation also found in chlorophyll content with some yield contributing characters like seed number, seed weight, grain yield and straw biomass. Further significant correlation observed between pod number and seed number, between seed weight and grain yield. Rhizobium can fulfill the alternate source of nitrogen that promoted significant growth and yield of lentil and it was much closer to the farmer’s conventional amount of urea.

A field experiment was conducted at Agronomy farm, Kerala Agricultural University during 2019-2021 to develop an eco friendly conservation method for upland rice based cropping system. Rice-okra cropping system with conservation practices were compared with conventional practice. Treatments consisted of planting methods like flat bed and raised bed with eitherinsitugreen manuring or brown manuring and with minimum soil disturbance. Various conservation practice significantly influenced the physiological parameters of rice under rice based cropping system. Highest leaf area index crop was recorded in direct seeding rice in flat bed + in situ green manuring at all stages of crop growth and it was statistically superior over other treatments. The crop growth rate, relative growth rate and net assimilation rate up to 60DAS recorded highest in direct seeding rice in flat bed +insitugreen manuring but at 90-120DAS the highest was found in direct seeding rice in raised bed + green manuring. Growing green manure crops along with ricecrop raised in flat bed or raised bed had significant influence on the growth indices of rice.

The mechanisms by which grazing animals influence aboveground net primary production (ANPP) in grasslands have long been an area of active research. The prevailing wisdom is that grazing can increase ANPP by increasing the availability of growth-limiting resources such as nitrogen and water, but recent theory suggests that the density-dependent growth of grassland vegetation can lead to grazer-stimulation of ANPP simply by removing shoot biomass and increasing relative growth rate (RGR). We compared the relative roles of resource availability and density-dependent growth in driving positive responses of ANPP to grazing in Yellowstone National Park. We measured the effects of clipping (50% simulated grazing intensity) and natural grazing on soil nitrogen availability, soil moisture, and shoot growth over 2 months in two grassland plant communities (mesic and dry) grazed primarily by bison. Clipping increased RGR by over 100% in both grassland types but had no effect on N availability or soil moisture during the same growth periods. Clipping stimulated ANPP only at mesic grassland, and the magnitude of this effect was strongly related to the initial plant biomass at the time of clipping relative to estimated peak biomass, supporting the density-dependent framework. Bison grazing had qualitatively similar effects on ANPP and RGR to clipping with no accompanying effects on N availability or soil moisture. Our results show how grazing can stimulate ANPP independent of a direct influence on resource availability simply by exploiting the dynamics of density-dependent plant growth.

This study aimed to explore the effectiveness of water hyacinth (Eichhornia crassipes) for heavy metals reduction from highly toxic glass industry effluent. Based on a 40 days laboratory-scale experiment, a total of five diluted concentrations of glass industry effluent were selected to cultivate water hyacinth. Furthermore, the kinetics and prediction models were used to analyze the metals reduction data to understand the plant behavior during the phytoextraction of heavy metals. Results suggested that water hyacinth was capable to reduce Cd (91.30%), Cu (93.55%), Fe (92.81%), Mn (93.45%), Pb (89.66%), and Zn (94.44%) metals most efficiently in 25% glass industry effluent concentration, respectively. Moreover, the growth performance of the water hyacinth plant exhibited the maximum fresh plant biomass (254.90 ± 3.75 g), chlorophyll (3.53 ± 0.11 mgg−1 fwt.), and relative growth rate (0.0026 gg−1d−1) using 25% dilution treatment respectively. Additionally, the first-order model gave the best fitting results in terms of the coefficient of determination (R2 > 0.82) and rate constant (k > 0.023 mgL−1d−1). Besides this, prediction modeling using multiple regression helped to construct mathematical equations to predict the heavy metals absorbed by water hyacinth plant tissues which were further supported by model efficiency (> 0.80) and normalized error tools (

The purpose of this research was to study the growth response of pokem ( Setaria italica ), which was inoculated by the arbuscular mycorrhizal fungi (AMF) from the tailings area. The method used in this research was a completely randomized design of factorial pattern. The factors consisted of AMF types (M)(M0: non-mycorrhizal, M1: Claroideoglomus etunicatum BGR, M2: C. lamellosum B1107S, M3: C. etunicatum L3101D), and inoculum density (I) (I: 5 g, II: 10 g per pot of planting media) with 8 replicates. The source of inoculum C. lamellosum B1107S and C. etunicatum L3101D originated from tailings in the gold mining area of Timika. The results showed that inoculation of C. etunicatum L3101D could increase the plant growth better than C. etunicatum BGR and C. lamellosum B1107S. Significant growth occurred on the parameters of the height of the plants, leaf area, dry weight and fresh weight of the plants, relative growth rate, and phosphorus absorption by the plants. The amount of nitrogen tended to decrease with AMF treatment, but it was not significant, whereas K has insiginificantly increased. The propagule density treatment increased plant growth on all parameters. The best growth occurred if the type C . etunicatum L3101D was inoculated with 10 g of propagule per planting media.

Leaf area loss is a frequent problem in crops, and it can be caused by biotic or abiotic factors. Reduced leaf area can produce alterations in plants, affecting their metabolism, growth, and yield. The leaf area in lettuce plants (Lactuca sativa L.) is often affected by herbivores such as slugs. The effects of partial defoliation on the growth of lettuce plants were evaluated under greenhouse conditions in Tunja, Colombia. Some plants had half of their leaves removed, while others were left intact as a control. The variables normally used in the basic analysis of plant growth were evaluated. There was nonsignificant difference between the two treatments; however, lettuce plants showed a remarkable ability to reduce the negative effect caused by partial defoliation, and they managed to maintain a balance in the root to shoot ratio, leaf area ratio, specific leaf area, leaf weight ratio, DM partitioning, and harvestable DM. Partial defoliation decreased the absolute growth rate by 17.8% and the relative growth rate by 13.8%. Additionally, the chlorophyll content index and the number of leaves increased by 16.0% and 15.4%, respectively, in plants subjected to partial defoliation compared with the control plants. These results indicate the regeneration capacity of the plants after partial defoliation.

○ The potential amelioration of Al (Al) toxicity by elevated dissolved inorganic carbon (DIC = CO 2 + HCO 3 - ) in the root medium was investigated in both NH 4 + - and NO 3 - -fed Lycopersicon esculentum (tomato) plants. ○ Hydroponically grown L. esculentum seedlings were intermittently supplied with 50 μM AlCl 3 and the nutrient solutions aerated with either 360 or 5000 ppm CO 2 . Relative growth rate (RGR), nitrogen uptake, root respiration and root incorporation of DI 14 C and subsequent partitioning were measured. ○ Al reduced the RGR of plants grown with 360 ppm root-zone CO 2 . At elevated root-zone CO 2 , Al had no significant effect on the RGR of NO 3 - -fed plants whereas the RGR of the NH 4 + -fed plants was increased by 21 %. Al decreased the respiratory quotient (Rq) by 15% at 360 ppm CO 2 , but had no influence at 2000 ppm CO 2 . Exudation of organic 14 C, especially of [ 14 C]-organic acids derived from root incorporation of DI 14 C, was increased by Al. ○ It is concluded that elevated DIC partially ameliorated Al toxicity by providing anaplerotic carbon for organic acid synthesis.

Planting high-quality seedlings with desirable growth attributes are associated with successful survival and growth performance following outplanting. Considering that most tree species from the Dipterocarpaceae family are on the IUCN Red List of Threatened Species, proper conservation of such species is necessary. Very little is known with no clear consensus regarding whether increasing the seedling production period enhances outplanting survival and growth potential of tropical dipterocarp species planted under enrichment planting in Malaysia. In this study, one potential Bornean tropical indigenous species, Shorea macrophylla (de Vriese) P.S. Ashton, was produced in the Universiti Malaysia Sarawak nursery and outplanted at Sampadi Forest Reserve, Sarawak. Different nursery production periods (3, 6, 9, and 24 months) were tested for the species at the time of planting as well as for the subsequent growth performance after 12, 24, and 42 months of outplanting. The findings revealed that older (9- and 24-month-old) S. macrophylla seedlings were morphologically larger from younger (3- and 6-month-old) seedlings. Nonetheless, the overall pooled mean survival rates declined from 61.7 to 44.6% after 12, 24, and 42 months of outplanting. For the 42-month period, the survival rate for the 9-month-old seedlings was significantly higher than that for the 3-, 6-, and 24-month-old seedlings. Notwithstanding, the relative growth rate of the stem diameter was higher for the 3- and 9-month-old seedlings than for the 6- and 24-month-old seedlings after 42 months of outplanting. Thus, maintaining plant material from the seedlings produced at 3, 6, and 9 months of age would be beneficial for the initiation of transplantation in restoration programmes in Sarawak. The 24-month-old seedlings will also be useful, especially during irregular flowering and unpredictable fruiting intervals. A further experimental study on other environmental factors that could influence the outplanting performance of the seedlings in the tropical forest restoration area of Sarawak, Malaysia, is necessary.

Purpose: to study morphometric parameters of absolute values of linear and weight body sizes, specific growth rate and relative (allometric) growth of chicken embryos of the «Lohmann Brown» egg cross at different stages of embryogenesis.Materials and methods. The absolute values of linear and weight body sizes of chicken embryos were estimated using morphometric methods. The formula of I. I. Schmalhausen and S. Brody was calculated the specific growth rate of length and body weight of chicken embryos by the formula simple allometry — relative (allometric) growth of body length from body mass.Results. This is manifested in the increase in the specific growth rate of body length of the embryo at 5 days of the late-fetal stage, 8th, 10th, 12th day of the early-fetal stage and specific growth rate of body mass for 6 days of the late-fetal stage of the late-fetal stage, 10-th and 12-th day of the early-fetal stage. At all stages of embryo development, there is a negative allometry of the relative growth rate of the embryo body length, except for 14 days of the mid-fetal stage, where negative isometry was observed (b=-1,000). Higher values of the power coefficient reflecting the slower growth of the embryo in length relative to their body weight, observed in late-fetal stage at 5-6 days (b=0,913-0,995), in early-fetal stage — 10-e (b=0,960) and 12 days (b=0,928), in mid-fetal stage — 13-th (b=0,821) and 15 days (b=0,981) and late-fetal stage — 20 days (b=0,836).Conclusion. New knowledge derived from this study can be applied not only in research, but in the poultry industry to assess the impact of preincubation processing of eggs on the development of embryos and embryonic mortality at different stages of embryogenesis, the definition of normal and abnormal development of embryos, as well as to assess the impact of other factors, artificial incubation on embryo development, hatchability of eggs and safety of poultry.

The G protein α-subunit, GPA1, is an integral component of several signaling pathways in plants, including response to abiotic stress. However, the molecular mechanism behind these processes remains largely unknown in the cucumber plant (Cucumis sativus L.). In order to further understand the role of CsGPA1 in cucumber under drought stress, changes in plant growth, physiological parameters, and gene expression of CsAQPs were all measured under water stress induced by polyethylene glycol (PEG) using wild type (WT) and CsGPA1-interference (RNAi) cucumber seedlings. Our results demonstrated that the RNAi plants had lower drought tolerance, displaying seriously withered leaves, lower relative growth rate, lower root-shoot ratio, and lower root activity under drought stress compared to WT plants. Physiological studies indicated that the suppression of CsGPA1 weakened drought stress tolerance due to higher water loss rate in the leaves, higher levels of hydrogen peroxide (H2O2), increased malondialdehyde (MDA) content, lower free proline content, lower soluble sugar content, lower soluble protein content, and decreased antioxidant enzyme activities. qRT-PCR analysis demonstrated that the interference of CsGPA1 up-regulated the expression of most AQP genes (except for CsPIP2;3 in leaves) and down-regulated the expression of CsPIP1;2, CsPIP1;4, CsPIP2;1, and CsPIP2;4 in roots under drought stress when compared to WT plants. Our results demonstrated that CsGPA1 could function as a positive regulator in drought stress response by decreasing the accumulation of reactive oxygen species (ROS), improving permeable potentials, and reducing water loss in cucumber plants.

Winter low temperature disturbance in the southern subtropics has important effects on the weed community structure, but the role of uniquely low temperatures in biological invasions is unclear. Here, we examined the competitive effects of an invasive plant, Bidens pilosa L., and its native congener, Bidens biternata (Lour.) Merr. et Sherff, during high and low temperature seasons to determine whether low temperatures promote the competitiveness of B. pilosa in the southern subtropics of China. The growth and physiological responses of the two Bidens species to low (10/5 °C) and optimum (30/25 °C) temperatures were examined to determine how the invasive B. pilosa responds to low temperature stress. Our results showed that the competitive balance index values of B. pilosa in low temperature seasons were significantly higher than those in high temperature seasons, which implied that low temperatures may be more beneficial to the competitiveness of B. pilosa than high temperatures in the southern subtropics. The smaller decline in the relative growth rate and the photosynthetic ability of B. pilosa compared with B. biternata under low temperature stress indicated that the former was less negatively affected by low temperature than the latter. A higher DPPH· (1.1-diphenyl-2-picrylhy-drazyl) scavenging rate and greater heat-stable protein content in B. pilosa under low temperatures might help the invasive plant to maintain more effective physiological functions and thus a higher growth rate. Overall, the uniquely low temperature in the southern subtropics of China is expected to promote the invasiveness of the exotic B. pilosa.

Tolerance to waterlogging and recovery ability was compared among the three subspecies of subterranean clover (Trifolium subterraneum L.) to identify tolerance mechanisms, in order to guide future subclover breeding activities. Three cultivars each of ssp. yanninicum, subterraneum and brachycalycinum were grown in a controlled environment glasshouse with T. michelianum as a waterlogging-tolerant control. After 28 days of growth two treatments were imposed for 35 days: free-draining (control) and waterlogged. A 21-day recovery period followed. After 35 days, waterlogging reduced shoot dry weight (DW) to 58–27% and root DW to 35–21% of respective controls in each subspecies. Shoot relative growth rate (RGR) of yanninicum was least affected (78–104% of control), compared to subterraneum (51–100%) and brachycalycinum (45–69%). The subterraneum cv. Denmark had a similar response to subspecies yanninicum. Shoot RGR of T. michelianum was 138% of its control. After recovery, all traits (except tap root length) recovered to control values. Up to 21 days, the main traits associated with waterlogging tolerance (shoot and root growth) were high petiole length, less petiole anthocyanin pigmentation and high leaf chlorophyll content, but by 35 days these were a high proportion of leaf biomass, high stomatal conductance and enhanced root porosity. Average root diameter and nodulation rates were unrelated to waterlogging tolerance. Subspecies yanninicum had superior waterlogging tolerance. Priority traits for easily-assessed indicators of waterlogging tolerance are less reduction of leaf size and high stomatal conductance.

Silicon (Si) has an important role in mitigating diverse biotic and abiotic stresses in plants, mainly via the silicification of plant tissues. Environmental changes such as atmospheric CO2 concentrations may affect grass Si concentrations which, in turn, can alter herbivore performance. We recently demonstrated that pre-industrial atmospheric CO2 increased Si accumulation in Brachypodium distachyon grass, yet the patterns of Si deposition in leaves and whether this affects insect herbivore performance remains unknown. Moreover, it is unclear whether CO2 -driven changes in Si accumulation are linked to changes in gas exchange (e.g. transpiration rates). We therefore investigated how pre-industrial (reduced; rCO2 , 200 ppm), ambient (aCO2 , 410 ppm) and elevated (eCO2 , 640 ppm) CO2 concentrations, in combination with Si-treatment (Si+ or Si-), affected Si accumulation in B. distachyon and its subsequent effect on the performance of the global insect pest, Helicoverpa armigera. rCO2 increased Si concentrations by 29% and 36% compared to aCO2 and eCO2 respectively. These changes were not related to observed changes in gas exchange under different CO2 regimes, however. The increased Si accumulation under rCO2 decreased herbivore relative growth rate (RGR) by 120% relative to eCO2, whereas rCO2 caused herbivore RGR to decrease by 26% compared to eCO2 . Si supplementation also increased the density of macrohairs, silica and prickle cells, which was associated with reduced herbivore performance. There was a negative correlation among macrohair density, silica cell density, prickle cell density and herbivore RGR under rCO2 suggesting that these changes in leaf surface morphology were linked to reduced performance under this CO2 regime. To our knowledge, this is the first study to demonstrate that increased Si accumulation under pre-industrial CO2 reduces insect herbivore performance. Contrastingly, we found reduced Si accumulation under higher CO2 , which suggests that some grasses may become more susceptible to insect herbivores under projected climate change scenarios.

Food consumption and utilization parameters of Plutella xylostella (L.) were studied on the leaves of eight cabbage cultivars under laboratory conditions (27 ± 2 °C, 70 ± 5 % RH, 16 L: 8D photoperiod). The present study evaluated the effect of different biochemical factors of cabbage cultivars on the food consumption and utilization parameters of P. xylostella. All the food consumption and utilization parameters differed significantly among the cabbage cultivars. The highest values of relative consumption rate (RCR) and relative growth rate (RGR) were observed on the cabbage cultivars ‘NS 183’, ‘DEB 806’, ‘Green Express’ and ‘Mohor’. The highest values of the efficiency of conversion of ingested (3.94 %) and digested (4.95 %) food was observed on the cabbage cultivar ‘DEB 806’. In contrast, the 4th instar P. xylostella larvae fed on the cabbage cultivar ‘Lucky Ball’ exhibited the lowest values of RCR (1.31 mg food consumed/mg body weight/ day), RGR (0.33 mg weight gain/mg body weight/ day), ECI (2.47 %) and ECD (2.95 %). The food consumption and utilization parameters of P. xylostella were positively correlated with the protein: carbohydrate (P:C) ratio of cabbage cultivars. The food consumption and utilization parameters of P. xylostella showed a non-significant correlation with the total glucosinolate content and total phenolic content of cabbage cultivars. The present study will help to identify effective resistant or tolerant cabbage cultivars for the development of Integrated Pest Management strategies against P. xylostella.

The module GA-GID1-DELLA (Gibberellin-Gibberellin Receptor-DELLA proteins) provides a point for the integration of signals potentially relevant in determining nutrient utilisation and acquisition efficiencies. In this study, we explored the role of components of this module during the acclimation of barley plants (Hordeum vulgare L.) to different phosphorus (P) supplies by using two related genotypes, harbouring either the WT or the Sln1d alleles of the DELLA-coding gene Sln1. Dwarf Sln1d plants exhibited reduced shoot P utilisation efficiency (PUtE) and better performance at low levels of P supply. The superior PUtE displayed by WT plants disappeared when corrected by internal P concentration, indicating that multiple analyses are necessary to fully understand the meaning of PUtE estimates. Over a wide range of external supplies of P, Sln1d plants displayed enhanced P concentration, which was associated with low relative growth rate, high biomass partitioning to roots and high P-uptake-rate, thus suggesting that the effect of the Sln1d allele on P dynamics is not simply a consequence of slow growth habit. An enhanced P concentration was also found in a mutant with defective GAs-synthesis. Our results suggest that components of the GA-GID1-DELLAs module contribute to set the acclimation response of barley plants to low P supply through both P-dynamics dependent and P-dynamics independent mechanisms.

Oilseed crops grown in different types of soil experience nutrient deficiency, especially sulphur, zinc and boron, which affect crop productivity. To tackle it, nutrient management practices must be streamlined to avoid improper fertilizations and deterioration of soil health. With this background, experimental trials were conducted to study the effect of sulphur, zinc and boron application on the growth, yield components and yield of hybrid sunflower at AyanAthur village, Ariyalur district (TN) during the summer seasons of 2016 and 2017. The experiments were laid out in Randomized Block Design (RBD) with three replications. The growth components of sunflower (plant height, leaf area index, dry matter production, leaf area duration (LAD) and growth analysis parameters such as crop growth rate (CGR), relative growth rate(RGR), net assimilation rate(NAR) and chlorophyll content, yield components and seed yield were significantly (level of significance P>0.05) influenced by foliar application of 0.5% Zn on bud initiation stage and seed formation stage and B @ 0.3% on bud initiation stage and ray floret formation stage along with S(sulphur) @ 40 kg ha-1 and RDF(recommended dose of fertilizers) as a soil application. Growth and yield parameters responded very little with the RDF alone. From both experimental results, we found that foliar application of Zn @ 0.5%and B @ 0.3% along with S @ 40 kg ha-1 and RDF recorded the highest percentage of dry matter production (44.4%), number of filled seeds (30.1%) and yield (32.4%) of hybrid sunflower.

Italian ryegrass (Lolium multiflorum) is a widely cultivated forage with high nutritional value and good palatability. Salinity, however, is a negative factor to lessen output and quality in Italian ryegrass. The aim of this study was to elucidate the salt tolerance mechanism of two Italian ryegrass cultivars, 'Abundant' and 'Angus'. Under hydroponic conditions, two cultivars of Italian ryegrass with different salt tolerance were exposed to 0 and 300 mM NaCl solution for 1 week, respectively. The results showed that salt stress decreased relative growth rate and relative water content, especially in salt-sensitive 'Angus'. The salt-tolerant 'Abundant' cultivar alleviated reactive oxygen species (ROS) induced burst and cell damage. However, 'Angus' exhibited a greater activity of superoxide dismutase (SOD) and peroxidase (POD) than 'Abundant'. Additionally, 'Abundant' exhibited higher photosynthetic efficiency than 'Angus' under salt stress condition. Salt treatment significantly increased the Na/K, Na/Mg, and Na/Ca ratios in the leaves and roots of both cultivars, with a pronounced effect in salt-sensitive 'Angus'. The metabolite analysis of leaf polar extracts revealed 41 salt responsive metabolites in both cultivars, mainly consisting of amino acids, organic acids, fatty acids, and sugars. Following exposure to salt conditions, salt-sensitive 'Angus' had a higher level of metabolites and more uniquely upregulated metabolites were detected. Based on these findings, we conclude that the 'Abundant' cultivar emerged as a favorite in saline-alkali soil, while the 'Angus' cultivar is suitable for planting in normal soil. It appears that the high salt tolerance of 'Abundant' is partly to prevent the plant from ionic homeostasis disruption.

The effects of temperature on the photosynthesis and growth of a subtropical red alga, Phycocalidia tanegashimensis (= Pyropia tanegashimensis, Bangiaceae, Bangiales) from Tanegashima Island, Japan, were determined to better understand the ecology of the macroscopic gametophyte. Net photosynthesis–irradiance (P–E) curves, determined at 12, 20, and 28°C, revealed that the maximum net photosynthetic rates occurred at 28°C. A gross photosynthesis–temperature (P–T) curve, determined at temperatures between 8 and 36°C, supported this result and indicated that optimal temperature ( $$ {T}_{opt}^{GP} $$ ) for maximum gross photosynthetic rates was 27.3°C (25.9–28.8 95% highest density credible intervals, HDCI). However, after 4 days of incubation at constant temperature, the effective quantum yields (ΔF/Fm') of photosystem II, determined between 4 and 40°C under 50 μmol photons m−2 s−1 (12L:12D), were greatest at 22.1°C (20.9–23.4 HDCI) and declined quickly below 20°C and 32°C. The relative growth rate (RGR) was highest at 25.8°C (22.5–28.1 HDCI) at the conclusion of a 6-day culture (4 to 36°C) under 50 μmol photons m−2 s−1 (12L:12D). Compared to other temperate species of Bangiaceae, P. tanegashimensis appears to be well adapted to relatively high temperatures. The macroscopic gametophyte stage of Bangiaceae is regarded to be adapted to cold temperatures to overwinter; nevertheless, the significance of our study is that a year-round occurrence of P. tanegashimensis is enabled by its high optimal temperatures for photosynthesis and growth.

The present study aimed to determine the effect of L-arginine (L-Arg) supplementation in drinking water on the productive performance, biochemical traits, antioxidant status, carcass traits and economic efficiency of growing rabbit during summer conditions from July to September, 2020. Sixty male Baladi Red growing rabbits (35 days), were individually weighed and randomly divided into four equal treatment groups with five replicates (3 rabbits each). Rabbits were fed same pelleted ration ad-libitum. Each experimental group was supplied with drinking water from a separate container. The first group served as control (unsupplied), while the second, third and fourth groups supplemented with L-Arg in drinking water by levels 1, 2 and 3 g / L, respectively, during the experimental period (35 – 90 days of age). The results indicated that the group supplemented with 2 g L-Arg/L in drinking water had significantly improved body weight, body weight gain, performance index, relative growth rate percentage and feed conversion ratio at the end of the experimental period (90 day of age). The relative weights of pre-slaughter weight and total edible parts were significantly increased for the groups supplied with 1 and 2 g of L-Arg/L compared with other experimental groups. Triglyceride and high density lipoprotein concentrations for the group supplied with 2g L-Arg/L in drinking water recorded the significantly lowest values compared with the other groups and statistically equals with control group. Results of IgG, IgM, TAC and MDA for the group supplied with 2 g L-Arg/L were significantly improved compared with other experimental groups. In conclusion, supplementation growing rabbit males by 2 g L-Arg/ L in drinking water could improve productive performance, immunity and economic efficiency under summer conditions.

Kalmegh Andrographis paniculata is an erect annual herb consider as “king of bitter. The experiment was laid out in randomized block design with three replications. The various phytohormones were applied as foliar at 30 days after transplanting. The treatments comprised of T1 (NAA 50 mg/l), T2 (NAA 100 mg/l), T3 (NAA 200 mg/l), T4 (GA3 50 mg/l), T5 (GA3 100 mg/l), T6 (GA3 200 mg/l), T7 (paclobutrazol 50 mg/l), T8 (paclobutrazol 100 mg/l), T9 (paclobutrazol 200 mg/l) andT10 (control). Results were significantly increase plant height with GA3 100 mg/l treatment while minimum plant height was recorded in paclobutrazol 100 mg/l application during the different growth stages as compared to control. The various morphological growth parameter i.e. number of leaves, number of primary branches were significantly higher in GA3 100 mg/l treatment as compared to control during the growth period of Kalmegh. The results concern to physiological parameters indicated that the leaf area, relative growth rate and net assimilation rate increase significantly in the GA3 100 mg/l during the different growth stages.

Seed vigor is the key performance parameter of good quality seed. A panel was prepared by shortlisting genotypes from all the phenotypic groups representing seedling growth parameters from a total of 278 germplasm lines. A wide variation was observed for the traits in the population. The panel was classified into four genetic structure groups. Fixation indices indicated the existence of linkage disequilibrium in the population. A moderate to high level of diversity parameters was assessed using 143 SSR markers. Principal component, coordinate, neighbor-joining tree and cluster analyses showed subpopulations with a fair degree of correspondence with the growth parameters. Marker–trait association analysis detected eight novel QTLs, namely qAGR4.1, qAGR6.1, qAGR6.2 and qAGR8.1 for absolute growth rate (AGR); qRSG6.1, qRSG7.1 and qRSG8.1 for relative shoot growth (RSG); and qRGR11.1 for relative growth rate (RGR), as analyzed by GLM and MLM. The reported QTL for germination rate (GR), qGR4-1, was validated in this population. Additionally, QTLs present on chromosome 6 controlling RSG and AGR at 221 cM and RSG and AGR on chromosome 8 at 27 cM were detected as genetic hotspots for the parameters. The QTLs identified in the study will be useful for improvement of the seed vigor trait in rice.

Underwater light reduction is presumably becoming more frequent and intensified due to eutrophication and algal blooms, which may significantly affect submerged macrophytes’ growth. However, a comprehensive understanding of how light reduction influences growth-related traits and responses is currently lacking. Here, we compiled data from 333 records of 62 published works that used controlled experiments to explore the responses of functional traits associated with growth to light reduction. Our results indicated that light reduction significantly decreased the relative growth rate (RGR), ramet number (RM), shoot biomass (SB), root biomass (RB), soluble carbohydrates (SC), and leaf number (LN) by 38.2%, 60.0%, 59.2%, 55.4%, 30.0%, and 56.1%, respectively, but elevated the chlorophyll content (Chl) by 25.8%. Meanwhile, the responses of RGR to light reduction increased significantly with the responses of RM, SB, RB, and root-to-shoot ratio (R/S). Considering the relationships among the growth-related traits, we further found that the responses of RGR to light reduction were mainly driven by the RM rather than leaf photosynthetic capability, indicating the importance of tiller ability under low light stress. We also identified a tipping point of the response of RGR to light reduction, which might be incorporated into hydrophyte dynamic models to improve precision. Our results highlight the importance of growth-related traits, andthese traits may need to be incorporated into models to improve the prediction of distribution and area for submerged species or to provide guidance for the restoration and sustainable development of aquatic ecosystems.