Shoot Fresh Weight Research Articles

Effect of the concentration and ionic form of nitrogen (N) on photosynthesis, growth and fruit production of blueberry (Vaccinium corymbosum L.)

The aim of this work was to evaluate the main effects and the interactions of nitrogen (N) concentration and ammonium (NH4+): nitrate (NO3-) proportion in the nutrient solution, on net photosynthesis, plant growth, production and quality of fruits on blueberry (Vaccinium corimbosum L.) plants. The studied factors were N concentration (0.6 and 6.0 mM) and NH4+: NO3- proportion (100 % NH4+, 50 % NH4+ - 50 % NO3- and 100 % NO3-). 243 days after the experiment establishment net photosynthesis (PN) was measured and a day after, leaf area (LA), shoots fresh weight (SFW) and roots fresh weight (RFW) were determined. Fruit yield (FY), fruit diameter (FD) and Brix degrees (oBrix) were evaluated in four harvests along fruit production period. The results showed higher values on PN, LA, SFW, FY and FD in plants that received 6.0 mM N as NH4+; nevertheless, N concentration altered the NH4+: NO3- proportion effects and at 0.6 mM N only FY and FD maintained such a pattern. It is concluded that N concentration modifies the effect of NH4+: NO3- proportion and it is proposed that the effects of both factors on photosynthesis, growth and fruit production of blueberry were mediated by their interaction with plant carbohydrates availability.

ROOT AND MORPHOLOGICAL CHARACTERISTICS OF EUCALYPTUS SEEDLINGS PRODUCED IN BIODEGRADABLE CONTAINERS

The objective of this study was to evaluate the nursery and field development of eucalyptus seedlings produced in biodegradable containers (BC), based on morphological and root characteristics, compared to the conventional method in 55-cm³ tubes. The experiment was conducted in a completely randomized experimental design, using a 3×2 factorial arrangement consisting of three types of containers (55-cm³ tubes; 76-cm³ BC; and 115-cm³ BC) and two eucalyptus clones (CO-1407 and AEC-144). The parameters evaluated in the nursery were: shoot height (SH); stem base diameter (SBD); SH-to-SBD ratio; shoot, root, and total fresh and dry weights; and total number of roots. The parameters evaluated in the field were: SH; SBD; and root distribution. Considering the evaluated characteristics, the use of 115-cm³ BC enabled the development of high-quality seedlings in all evaluation phases. BC-produced seedlings presented better quality and performance in the field. Seedlings produced in 55-cm³ tubes presented lower values for all morphological parameters evaluated in the nursery, as well as in the field up to 120 days after planting.

Effect of Organic and Inorganic Fertilizers on Growth, Yield and Quality of Radish (Raphanus sativus L.) cv. Pusa Himani

In this report, we compared the integrated effect of FYM, vermicompost, poultry manure with inorganic fertilizers incorporated with PSB for yield in radish cv. Pusa Himani in response of morphological, yield as well as quality attributes. As per data analysis T6 [NPK (75%) + vermicompost (25% of N) + PSB] significantly enhanced the highest plant height, leaf length, number of leaves per plant, fresh weight of shoot and dry weight of shoot at 20 DAS, 40 DAS and at harvest, respectively. Similarly, at harvest maximum root length, maximum root diameter, maximum average weight of root, maximum yield per hectare, minimum days to harvest and quality parameters i.e. T.S.S., ascorbic acid, chlorophyll content of leaves, net return and B-C ratio in comparison to all concentration with all integrated nutrient combination. So, we may conclude that [NPK (75%) + vermicompost (25% of N) + PSB] increase yield by stimulating source activity as well improves utilization of PGR (plant growth regulators).

Effect of IBA on Rooting and Growth of (Ixora chinensis L.) Terminal Cutting

The experiment was conducted at College of Horticulture, Dapoli under Dr. Balasaheb Konkan Krishi Vidyapeeth, Dapoli, in 2023. It comes under tropical location with an average well distributed rainfall 3500-4000 mm during June to October. The soil is come under lateritic textural class varied with loam, clay, sandy loam. Ixora is popular ornamental but difficult to root plant was used for the experiment. The experiment was laid out in randomized block design with eight treatments and three replications. Mature terminal cuttings of size 10-15 cm length with 4-5 leaves are dip for 5 min in the solution consisting different Indole Butryic Acid concentrations i.e. (control) 250, 500, 1000, 1500, 2000, 2500, 3000 ppm solutions. The cuttings under study recorded significant variation with respect to all the parameters, The results showed that among all treatments survival percentage (60%) maximum plant height (18.17cm), maximum number of leaves (14.08), stem girth (3.91 mm), longest root length (9.03cm), number of secondary roots (17.93), fresh and dry weight of shoot ( 3.55, 1.03g), fresh and dry weight of root (1.40, 1.18g) was recoded in T4 treatment consisting 1000 ppm IBA solution. However, for maximum number of primary roots (7.27) was observed in T3 (500 ppm) treatment.

Effects of foliar spraying with melatonin and chitosan Nano-encapsulated melatonin on tomato (Lycopersicon esculentum L. cv. Falcato) plants under salinity stress

Melatonin has been found to be crucial in the growth and development of plants under stress conditions. In this study, the effects of melatonin and nano melatonin regarding the growth and development of tomato plants, along with their photosynthetic pigment, phenol, and antioxidant activity, were investigated under saline conditions. The study was conducted using a completely randomized design with three replications, and the applied treatments were salt stress and foliar spraying of melatonin at a concentration of 0 (control), melatonin (Mel), and nano capsule-melatonin (Nano-Mel) at 500 µM. Salinity treatments included application of sodium chloride with two concentration of 0 mM NaCl (S1) and 50 mM NaCl (S2). Under saline conditions, Mel and Nano-Mel increased both shoot and root fresh and dry weights, improved relative water content (RWC), and enhanced antioxidant activity and phenolic content. Salinity elevated leaf ABA content, unaffected by Mel or Nano-Mel. Chlorophyll fluorescence and SPAD values demonstrated resilience to salinity with Mel and Nano-Mel applications. Nano-Mel notably mitigated Na + accumulation in leaves under salinity, helping maintain K + homeostasis. Proline levels rise due to salinity but decreased with Mel and Nano-Mel treatments. Electrolyte leakage (EL) increased under salinity but is significantly reduced by Mel, indicating enhanced membrane stability. The findings reveal that salinity stress significantly reduced plasma membrane intrinsic protein (PIP) expression in roots and leaves, whereas Mel and Nano-Mel treatments enhance PIP expression, particularly in roots. The study concludes that Mel and Nano-Mel effectively alleviate salinity-induced stress, promoting growth and maintaining physiological homeostasis in tomato plants.

Investigating the effect of changing the K:Ca ratio in nutrient solution on the quantitative and qualitative yield of Lilium spp. in hydroponic cultivation

Nowadays, hydroponics is an advanced method for plant production in agriculture. The optimal balance of nutrients in the nutrient solution is crucial to enhance plant performance in this method. To investigate the effect of potassium to calcium (K:Ca) ratio change in nutrient solution on quantitative and qualitative yield of lilies in hydroponic culture, a randomized complete block design with nine treatments and three replications was designed and carried out in 30% perlite and 70% sand. The treatments included different concentrations of calcium (Ca) at three levels of 0, 3, and 6 mM and different concentrations of potassium (K) at three levels of 0, 3, and 6 mM in the Hoagland nutrient solution, with K:Ca ratios of 0:0, 0:3, 0:6, 3:0, 3:3, 3:6, 6:0, 6:3, and 6:6. Results showed that the presence of different levels of potassium and calcium was found to enhance the quality of lilies by influencing nutrient uptake. The results indicated that nutrient solutions containing different ratios of K:Ca had a significant effect on reproductive height, the number of aborted buds, stem diameter at the 5% level and the number of flowers, the number of leaves, the fresh weight of shoots, the dry weight of shoots, and the longevity at the 1% level. The highest yield in terms of longevity (17 days), the number of flowers, the number of leaves, and absorption of potassium and calcium were observed in the nutrient solution with a 3:3 K:Ca ratio.

Exogenous γ-aminobutyric acid (GABA) enhances rye (Secale cereale) seedling resistance to combined freeze-thaw and cadmium stress.

Freeze-thaw is a common stress at high altitudes in northern China. There is a risk of cadmium (Cd) contamination in the region. γ-aminobutyric acid (GABA) is a natural product that regulates plant growth. Rye (Secale cereale ) was used as research material to investigate the physiological effects of exogenous GABA on rye seedlings under the single and combined stresses of freeze-thaw and cadmium. The results showed that the combined stress severely inhibited shoot length, root length, fresh weight, and dry weight, increased malondialdehyde and hydrogen peroxide contents, and significantly decreased superoxide dismutase (SOD) activity. Foliar application of 5mM GABA alleviated the negative effects of stress on seedling growth, increased soluble protein content, and reduced malondialdehyde and hydrogen peroxide contents. Exogenous GABA application also enhanced the activities of SOD and peroxidase (POD). Additionally, the presence of exogenous GABA activated the GABA metabolic process and encouraged the accumulation of phytochelatins, glutathione, and non-protein thiol. These results indicate that exogenous GABA can effectively improve the resistance of rye seedlings to freeze-thaw and Cd by regulating the antioxidant enzyme system and enhancing its own detoxification mechanism, and they provide a basis for future applications of exogenous GABA, which is beneficial for ecological protection.

The use of seedling root and shoot traits to predict the saleable yield of elite red papaya genotypes

ABSTRACT Determining the saleable fruit yield of red hermaphrodite papaya (Carica papaya L.) relies on waiting until tree maturity. Recombinant inbred lines (RIL) seedlings (F6-F7 RIL) were assessed for fresh root length, fresh shoot weight, fresh shoot width, dry root weight and dry shoot weight during three growth stages after sowing (0-30 days after sowing; DAS, 31–60 DAS and 61–90 DAS). During the 31–60 DAS period, significant intra-genotypic variation was observed for each trait across the RIL assessed. A strong genotypic correlation at growth stage II was predicted among the traits (P < 0.05; rg > 0.60), with a moderate to high broad-sense heritability (H2 b.s; > 0.30) and with genetic advances of up to 10% in the RIL compared to the parental genotypes. Growth stage II was most reliable for predicting saleable fruit yield (R 2 = 0.73) with levels of influence of traits measured across the RIL in the following order: fresh root length (40% to 70%) > dry root weight (20% to 50%) > dry shoot weight (10% to 48%) > fresh shoot width (13% to 38%) > fresh shoot weight (1% to 42%). Hence, these F7 genotypes will be used to develop new F1 hybrids with significant increases in saleable fruit yield.

Enhancing physio-biochemical characteristics in okra genotypes through seed priming with biogenic zinc oxide nanoparticles synthesized from halophytic plant extracts

Poor seedling germination and growth can result in large financial losses for farmers, thus, there is an urgent need for sustainable agricultural techniques to enhance seed germination and early growth. As an outcome, sustainable agriculture-which emphasizes the smart and effective utilization of resources-has gained popularity worldwide. At numerous levels, the field of nanotechnology is capable of significant benefit in achieving sustainable agricultural practices. Zinc oxide nanoparticles (ZnO NPs) have been shown to have biostimulatory properties and serve as effective solutions for addressing environmental and biotic stressors. The purpose of this study, investigating Salvadora persica halophytic leaf extract -synthesized zinc oxide nanoparticles (S-ZnONPs) as nano-priming agents to ensure okra seeds germinated under stress-free conditions. From an application perspective, we examined the effect of seed priming with varying concentrations of S-ZnO NPs (0, 20 and 40 ppm) for 18 and 24 h of soaking. Results indicated that the germination rate of hybrid variety improved with 20 ppm at 18 h, increasing by 58.22%, while mean germination time reduced by 24.62%. An enhancement trend was observed in the shoot, root length, shoot and root fresh weight, shoot and root dry weight of hybrid variety at 20ppm with 18 h priming by 34.2, 84.3, 80.2, 47.4, 50.3, and 36.2%, respectively. However, chlorophyll pigments chl a, chl b, and carotenoids was significantly raised in desi variety by 42.4, 79.31, and 142.29% with 20 ppm at 18 h priming. Hydrogen per oxide decreased up to 87.8% with 40 ppm at 24 h in hybrid variety, while, in desi variety H2O2 was reduced 88.3% with 20 ppm at 24 h. Non enzymatic antioxidant activities such as ascorbic acid, was highly increased 130.6% in hybrid at 24 h priming with 20 ppm dose. Flavonoids raised in same variety by 166.1% with 20 ppm at 18 h. Proline content was increased by 144.5% with 40ppm at 18 h. Moreover, Antioxidant enzymes, superoxide dismutase, peroxidase and catalase were significantly increased in both varieties with both levels of S-ZnO NPs and priming time. This cost-effective and environmentally safe technique to produce nanoparticles of different halophytic plants can maximize resource utilization, supporting sustainable agriculture by minimizing adverse environmental effects without compromising efficiency.

Response of Types of Cuttings and IBA Concentration from First Sprout to Highest Sprouting and Rooting in Crossandra (Crossandra infundibuliformis L.)

The present investigation was conducted under Konkan Agro-climatic conditions at College of Horticulture, Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, Dist. Ratnagiri (India) during the kharif season (2023-2024). The experiment was laid out in Factorial Randomized Block Design (FRBD) with twelve treatment combinations and three replications. Present investigation found that in types of stem cuttings treatment C1 :Softwood cuttings was found best with respect to minimum days to first sprout, days to highest sprouting , maximum number of new sprouts/cuttings, girth of sprout, length of new sprout, number of leaves, leaf area, survival(%), fresh weight of shoot, dry weight of shoot, absolute growth rate, relative growth rate, number of roots, length of longest root, fresh weight of root, dry weight of root, shoot to root ratio. In different IBA concentration treatment H4 : IBA@2000ppm was found best with respect to minimum days to first sprout, days to highest sprouting , maximum number of new sprouts/cuttings, girth of sprout, length of new sprout, number of leaves, leaf area, survival(%), fresh weight of shoot, dry weight of shoot, absolute growth rate, relative growth rate, number of roots, length of longest root, fresh weight of root, dry weight of root. In interaction effect treatment C1H4 (Softwood cuttings treated with IBA@2000 ppm) is found to be most effective among all other treatment combinations in terms of most of the parameters such as Sprouting percentage, Number of new sprouts/cuttings, Length of sprout/cuttings, Girth of new sprout, Number of leaves/cuttings, Leaf area, Survival percentage, Fresh weight of shoot, Relative Growth Rate, Fresh weight to dry weight of shoot ratio, Number of roots.

Alleviative effect of iron chlorin e6 on isoproturon phytotoxicity to wheat

Abstract Isoproturon phytotoxicity to wheat (Triticum aestivum L.) is a worry for many farmers in chemical control of weeds in wheat fields, especially in subzero weather conditions. Iron chlorin e6 (ICe6), a new plant growth regulator, has been reported to enhance crop stress resistance to alleviate damage caused by stress; however, it is not clear whether ICe6 has an alleviative effect on isoproturon phytotoxicity to wheat. We determined the alleviative effect of ICe6 on isoproturon phytotoxicity to wheat, and 0.018 g ai ha−1 was the optimal dose. Meanwhile, we also studied the photosynthetic pigment content, photosynthetic parameters, oxidative stress indicators, and antioxidant enzyme activity of wheat treated with the three different treatments. We found that the photosynthetic pigment content, antioxidant enzyme activity, and photosynthesis of wheat damaged by isoproturon were significantly lower than those of the control, and the hydrogen peroxide (H2O2) and malondialdehyde (MDA) content increased. These results indicate that isoproturon stress significantly weakened the photosynthetic and antioxidant capacity of wheat. The photosynthetic pigment content, photosynthetic parameters (excluding intercellular CO2 concentration), and antioxidant enzyme activity of isoproturon+ICe6– treated wheat were significantly higher than those of isoproturon-treated wheat. The H2O2 and MDA content was significantly lower than that of isoproturon-treated wheat. These results indicate that ICe6 treatment maintained the photosynthetic pigment content of wheat and relatively improved photosynthetic capacity, allowing photosynthesis to proceed normally. ICe6 treatment also limits the decrease in antioxidant enzyme activity, effectively clearing excess reactive oxygen species and ultimately alleviating membrane lipid peroxidation damage. In summary, ICe6 not only enhances stress resistance and increases yield in crops such as soybean [Glycine max (L.) Merr.] and canola (Brassica napus L.), but also has an alleviating effect on the isoproturon phytotoxicity to wheat, which is manifested by the improvement of photosynthetic and antioxidant abilities, ultimately leading to an increase in wheat shoot height and shoot fresh weight.

An Enhanced Interaction of Graft and Exogenous SA on Photosynthesis, Phytohormone, and Transcriptome Analysis in Tomato under Salinity Stress.

Salt stress can adversely affect global agricultural productivity, necessitating innovative strategies to mitigate its adverse effects on plant growth and yield. This study investigated the effects of exogenous salicylic acid (SA), grafting (G), and their combined application (GSA) on various parameters in tomato plants subjected to salt stress. The analysis focused on growth characteristics, photosynthesis, osmotic stress substances, antioxidant enzyme activity, plant hormones, ion content, and transcriptome profiles. Salt stress severely inhibits the growth of tomato seedlings. However, SA, G, and GSA improved the plant height by 22.5%, 26.5%, and 40.2%; the stem diameter by 11.0%, 26.0%, and 23.7%; the shoot fresh weight by 76.3%, 113.2%, and 247.4%; the root fresh weight by 150.9%, 238.6%, and 286.0%; the shoot dry weight by 53.5%, 65.1%, and 162.8%; the root dry weight by 150.0%, 150.0%, and 166.7%, and photosynthesis by 4.0%, 16.3%, and 32.7%, with GSA presenting the most pronounced positive effect. Regarding the osmotic stress substances, the proline content increased significantly by more than 259.2% in all treatments, with the highest levels in GSA. Under salt stress, the tomato seedlings accumulated high Na+ levels; the SA, G, and GSA treatments enhanced the K+ and Ca2+ absorption while reducing the Na+ and Al3+ levels, thereby alleviating the ion toxicity. The transcriptome analysis indicated that SA, G, and GSA influenced tomato growth under salt stress by regulating specific signaling pathways, including the phytohormone and MAPK pathways, which were characterized by increased endogenous SA and decreased ABA content. The combined application of grafting and exogenous SA could be a promising strategy for enhancing plant tolerance to salt stress, offering potential solutions for sustainable agriculture in saline environments.

Effect of different concentrations of soil and foliar applied zinc, boron and iron fertilizers on seedling growth, chlorophyll content and productivity of chickpea seedlings under semi-arid environment

The effectiveness of zinc (Zn), boron (B), and iron (Fe) is reduced in semi-arid regions, which can lead to a deficiency of these nutrients and inhibit chickpea productivity. In this work, three field experiments were executed over two years where soil and foliar applications of Zn, B, and Fe were carried out, including controls (Zn0, B0, and F0), soil application at 4.125 kg/ha (Zn-1, B1, and F1) and 8.25 kg/ha (Zn-2, B2, and F2), and foliar spay at 0.3% at flowering initiating (Zn-3, B3, and F3) and one week after flowering initiation (Zn-4, B4, and F4, respectively). The results indicate that the deficiency of these nutrients inhibited chickpea growth and yield, leading to a reduction in the pigment contents. Nonetheless, soil and foliar application of Zn, B, and Fe significantly improved growth, chlorophyll contents, and yield, showing a dose-dependent effect. The best results were recorded for Zn-3, B2, and F2 treatments which significantly (P&lt;0.05) increased shoot length (20.96-85.19%), root length (42.85-93.65%), shoot fresh (23-76%) and root fresh weight (45-90.32%), compared with the control treatment. Chlorophyll parameters, including chlorophyll a and b contents, showed similar trends. Zn-3, B2, and F2 treatments significantly increased biological and grain yields, which were associated with higher values of the number of pods per plant and the number of seeds per pod. In a nutshell, we suggest that Zn foliar application at 0.3% at flowering initiation and soil application of B and Fe at 25 kg/ha are beneficial for improving the growth, pigment content, and overall productivity of chickpea.

Effect of Different Growing Media on Shoot Growth of Dragon Fruit Cuttings [Hylocereus undatus L. (Haworth) Britton &amp; Rose

The present investigation was carried out under open field conditions at Horticulture Research Farm, Babasaheb Bhimrao Ambedkar University, Lucknow,Uttar Pradesh, India, to determine the effect of different growing media on the shoot growth of dragon fruit cuttings (Hylocereus undatus L.) during the years 2022–23. The experiment was laid out in a randomized complete block design (RBD) with three replications. There were 8 treatments, viz., T1-Soil, T2-Sand, T3-Vermicompost, T4-Coco Peat, T5-Farmyard Manure, T6-Soil+Sand+Farmyard Manure, T7-Soil+ Sand+ Vermicompost and T8-Soil+Vermicompost+Coco Peat. Treatments have shown significant differences among the growth parameters in terms of number of days taken for sprouting, percent sprouting, number of sprouts per cutting, shoot diameter, length of sprout, number of spines/areoles, fresh weight of shoot, and dry weight of shoot. Among the treatment combinations, the least number of days taken for sprouting, maximum percent sprouting, maximum number of sprouts per cutting, maximum sprout and shoot length of stem cutting, maximum increase in diameter of shoot, maximum number of spines/areoles, maximum fresh weight of shoot, and maximum dry weight of shoot were found in treatment T7-Soil+ Sand+ Vermicompost, followed by T8-Soil+ Vermicompost+. Coco peat, while the minimum has been recorded in T1-Soil.

Novel nanocomposite and biochar insights to boost rice growth and alleviation of Cd toxicity

Cadmium (Cd) is an unessential and pervasive contaminant in agricultural soil, eventually affecting the food and instigating health issues. The implication of nanocomposites in agriculture attained significant attention to drive food security. Nanocomposites possess exceptional characteristics to stun the challenges of chemical fertilizers that can enhance plant yield and better nutrient bioavailability. Similarly, biochar has the ability to immobilize Cd in soil by reducing mobility and bioavailability. Rice husk biochar is produced at high temperature pyrolysis under anoxic conditions and a stable carbon-rich material is formed. To strive against this issue, rice plants were subjected to Cd (15, 20 mg kg− 1) stress and treated with alone/combined Ca + Mg (25 mg L− 1) nanocomposite and rice husk biochar. In our study, growth and yield traits showed the nurturing influence of Ca + Mg nanocomposite and biochar to improve rice defence mechanism by reducing Cd stress. Growth parameters root length 28%, shoot length 34%, root fresh weight 19%, shoot fresh weight 16%, root dry weight 9%, shoot dry weight 8%, number of tillers 32%, number of grains 20%, and spike length 17% were improved with combined application of Ca + Mg and biochar, with Cd (20 mg kg− 1), rivalled to alone biochar. Combined Ca + Mg and biochar application increased the SPAD 23%, total chlorophyll 26%, a 19%, b 18%, and carotenoids 15%, with Cd (20 mg kg− 1), rivalled to alone biochar. MDA 15%, H2O2 13%, and EL 10% were significantly regulated in shoots with combined Ca + Mg and biochar application with Cd (20 mg kg− 1) compared to alone biochar. POD 22%, SOD 17%, APX 18%, and CAT 9% were increased in shoots with combined Ca + Mg and biochar application with Cd (20 mg kg− 1) compared to alone biochar. Cd uptake in roots 13%, shoots 14%, and grains 21% were minimized under Cd (20 mg kg− 1) with combined Ca + Mg and B. pumilus application, compared to alone biochar. Subsequently, combined Ca + Mg and biochar application is a sustainable solution to boost crop production under Cd stress.

Rapid Screening of Traditional Rice Cultivars against Drought Using Tolerance Indices of Seedlings

Aim: To screen the traditional cultivars of rice based on the tolerance indices of seedling characteristics. Study Design: The experimental plan used was Complete Randomized Design with 59 treatments (genotypes) and two replications. Place of Study: P.G. Laboratory, Department of Seed Science and Technology, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar district, West Bengal, India. Methodology: Seedling was raised in glass in two sets- PEG-mediated drought and normal conditions. Results: All the seedling characters showed highly significant differences among the varieties, different culture conditions as well as interaction between varieties and environment. Most of the cultivars exhibited reduction in number of primary roots per plant, root length, root fresh weight, root dry weight, shoot length, shoot fresh weight and shoot dry weight. Finally the cultivars were grouped under three categories- tolerant, semi-tolerant and susceptible based on mean tolerance index (MTI). The cultivars having ≥ 90.00, MTI Kashiya binni, Jhagri kartik and Garu Chakua were considered as tolerant. Among those three cultivars, Kashiya binni was found to be highly tolerant to drought as its MTI was ≥ 100.00 (114.96). Subsequently 22 cultivars were classified as semi-tolerant. In conclusion, the tolerance indices of seedling traits and subsequently the MTI can be used for rapid screening of rice genotypes for water stress.

Salt tolerance in wheat is associated with the maintenance of shoot biomass, stomatal conductance, and sucrose in the phloem.

Wheat (Triticum aestivum L.) is a mega-staple for millions of the world's populations and its yield potential is impacted by soil salinization. This study investigated genotypic variation in salt tolerance among six wheat genotypes, Gladius, Drysdale, GD0014, GD0120, GD0180, and GD0185. The study also characterized shoot traits, photosynthetic traits, leaf Na and K concentrations, and phloem sucrose. The plants were grown under controlled growth room conditions at 0 mM NaCl (Control) and 100 mM NaCl. The results showed that the salt tolerance index (STISFW, SFW: shoot fresh weight) varied from 0.52 for GD0120 to 0.69 for GD0180. Based on the STISFW, salt tolerance for the wheat genotypes was in the order, GD0180 > Gladius > GD0185 > Drysdale > GD0014 > GD0120. Projected shoot area (PSA) at all growth stages, 14, 20, 27, 34, and 40 DAS were strongly correlated with SFW at 45 DAS. Salt treatment significantly increased phloem sucrose level in the salt intolerant, Drysdale, while having no effect on this parameter in Gladius. Gladius showed greater maintenance of stomatal conductance than Drysdale. The relative ratio of K/Na between treatment and control was strongly correlated with the relative ratio of SFW (r = .85). The correlation between PSA at 14 DAS and SFW at 45 DAS and the correlation between the relative ratio of K/Na between treatment and control with STISFW identify these parameters to be potential traits for screening salt tolerance in wheat. Higher salt tolerance in Gladius would be associated with higher maintenance of stomatal conductance and enhanced phloem sucrose transport.

Responses of Growth, Enzyme Activity, and Flower Bud Differentiation of Pepper Seedlings to Nitrogen Concentration at Different Growth Stages

The concentration of nitrogen fertilizer is matched with the nutrient requirements in different growth stages of plants, which coordinates their vegetative and reproductive growth. In this study, the influences of nitrogen concentration before and after initiation of flower bud differentiation (first and second stage, respectively) on pepper seedling quality were studied. The chlorophyll a content, sucrose synthase activity, and sucrose phosphate synthase activity of pepper seedlings grown under moderate nitrogen (15 mmol L−1) in the first stage combined with high nitrogen (25.61 mmol L−1) in the second stage were 15.7%, 39.3%, and 34.6% higher than those of the same nitrogen concentration (15 mmol L−1) in the first and second stages treatment, respectively. The regression model also showed that the values of flower bud diameter, shoot fresh weight, root fresh weight, and glutamine synthetase activity of pepper were high under the condition of moderate nitrogen in the first stage and higher nitrogen in the second stage. In addition, the results of comprehensive evaluation showed that moderate nitrogen (15 mmol L−1) in the first stage and high nitrogen (25.61 mmol L−1) in the second stage treatment ranked first, which improved carbon and nitrogen metabolism, increased biomass accumulation, and promoted the flower bud differentiation and flowering of pepper seedlings.

Plant Beneficial Desert Actinomycete, Modestobacter caceresii KNN 45-2bT, Promote Growth of Tomato (Lycopersicum esculentum Mill.) under Drought Condition

Drought stress is currently the most serious challenge to global food security and agricultural productivity. Desert actinobacteria have gained attention as potential candidates for enhancing plant growth in water stress environments. In this regard, a desert actinomycete, namely Modestobacter caceresii strain KNN 45-2bT, was selected to investigate its plant growth promoting abilities and drought tolerance. Next, this desert strain was inoculated to tomato (Lycopersicum esculentum Mill.) under drought, and the results included increases in root length, shoot and root fresh weight, shoot and root dry weight, total fresh weight and dry weight, fruit weight, proline accumulation, total soluble sugar content and trolox content. Stress treatments on the bacterized tomato plants also resulted in the reduction of hydrogen peroxide accumulation. Putative proteins coding sequences conferring plant growth promoting (PGP) traits (IAA production, phosphate solubilization, siderophore production, nitrogen fixation) and drought response (biosynthesis of proline metabolism, oxidative and osmotic stress response) were also detected from their genomic analyses. In conclusion, these results provide credence to the idea that the inoculation of tomato plants with plant beneficial desert actinomycete is an effective method of combating the negative effects of drought stress.

Cadmium (Cd) detoxification and activation of plant defense enzymes activation in Wheat (Triticum aestivum) through the use of endophytic Bacillus thuringiensis and Salix alba root powder

Cadmium (Cd) is a toxic heavy metal and a threat to the ecosystem therefore the current investigation was designed to use endophytic bacteria from the Salix alba roots and to investigate its plant growth promoting and Cd detoxification ability with and without Salix alba root powder. In a complete randomized design (CRD), the cadmium sulfate was applied at the rate of 20mg/kg and 40mg/kg soil. The Bacillus thuringiensis (Accession # MW979616) was identified from Salix alba roots. The combination of Bacillus thuringiensis inoculated seeds +0.5gm root powder showed significant increase in wheat shoot dry weight, root fresh weight, catalase, and ascorbate peroxidases by 457%, 223%, 105% and 74%, respectively. The application of Bacillus thuringiensis with Salix alba root powder boosted the plant growth and defense at higher concentrations of Cd. In another treatment with Bacillus thuringiensis inoculated seeds + CdSO4 40mg/kg + 0.5gm root powder significantly increased the shoot fresh weight, root fresh weight, root dry weight, proline, sugar, superoxide dismutase, and peroxidase by 456%, 650%, 115%, 91%, 80%, 350%, and 250%, respectively with 80% reduction in plant Cd accumulation and increased bacterial population. Bacillus thuringiensis and Salix alba root powder can be useful for plant growth, Cd toxicity mitigation, accelerating bacterial activity in Cd-contaminated soil and uplifting the plant defense under heavy metal stress.