1000-grain Weight Research Articles

Phenotypic Diversity of Quinoa Landraces Cultivated in the Ecuadorian Andean Region: In Situ Conservation and Detection of Promising Accessions for Breeding Programs

Quinoa (Chenopodium quinoa Willd.) is an ancestral crop in the Ecuadorian Andean region, and its landraces have always been of great social and food importance for the native population. Currently, there is no updated information about their phenotypic diversity and conservation status nor about the changes that have occurred in the last decades. A total of 268 accessions of quinoa landraces collected at two different times (1978–1988 and 2014–2015) in three representative Ecuadorian Andean provinces (Imbabura, Cotopaxi and Chimborazo) were evaluated for forty agro-morphological (17 quantitative and 23 qualitative) traits. Most of the quantitative traits showed high variability, some of them with great importance for commercialization and germplasm selection for breeding programs (e.g., panicle width, grain width, 1000-grain weight or seed yield per plant). Ten quantitative and eleven qualitative descriptors were significantly different between both collections. Regarding the presence/absence of saponin, all the accessions collected four decades ago had saponin, while it was found in only 18% of accessions collected more recently. The phenotypic relationships in the dendrogram did not show clustered accessions by their geographical origin or by collection. A selection index allowed us to detect a few accessions recently collected in Chimborazo with high promises for future breeding programs, with high seed yields per plant values and a reduced or no saponin content. The agro-morphological information obtained may be very useful for the suitable management and conservation of this ancestral plant genetic resource, both on the farm by indigenous farming communities and ex situ by the Germplasm Bank of the Ecuadorian National Institute for Agricultural Research (INIAP).

Potential of natural plant extracts as biostimulants to alleviate salt stress-induced adverse effects on wheat

A field experiment was conducted to investigate the role of different plant extracts in alleviating salt stress-induced adverse effects on wheat plants. Two potential wheat cultivars, Galaxy-2013 and Faisalabad-2008, were sown in November 2020 in saline soil with soil electrical conductivity of 9.8 dS m-1. At the booting and anthesis stages, the wheat plants were exogenously sprayed with three different types of plant extracts, i.e., moringa leaf extract (MLE, 3%), sorghum water extract (SWE, 2%), and brassica water extract (BWE, 2.5%). The MLE spray at the booting and anthesis stages resulted in a maximal increase in 1000-grain weight (34-43%), grain yield (25-29%), biological yield (39-40%) and harvest index (23-24%) of wheat over the control. However, exogenous application of all three plant extracts in both wheat cultivars increased plant height (44-64%), spike length (99-100%), number of spikelets (40-42%), and grains per spike (32-64%), as compared to the untreated plants grown under saline conditions. Similarly, chlorophyll (Chl) a, Chl b, total chlorophyll, and carotenoid contents were higher in the MLE-treated plants than those of the plants treated with the other extracts. Overall, MLE at the rate of 3% had the most significant growth promoting effect on both wheat cultivars under saline conditions. Cultivar Faisalabad-2008 fed with different plant extracts was superior to Galaxy-2013 in terms of its performance in growth and physiological attributes under field saline stress.

Heat Stress Responsive Aux/IAA Protein, OsIAA29 Regulates Grain Filling Through OsARF17 Mediated Auxin Signaling Pathway

High temperature during grain filling considerably reduces yield and quality in rice, but its molecular mechanisms are not fully understood. We investigated the functions of a seed preferentially expressed Aux/IAA gene, OsIAA29, under high temperature-stress in grain filling using CRISPR/Cas9, RNAi, and overexpression. We observed that the osiaa29 had a higher percentage of shrunken and chalkiness seed, as well as lower 1000-grain weight than ZH11 under high temperature. Meanwhile, the expression of OsIAA29 was induced and the IAA content was remarkably reduced in the ZH11 seeds under high temperature. In addition, OsIAA29 may enhance the transcriptional activation activity of OsARF17 through competition with OsIAA21 binding to OsARF17. Finally, chromatin immunoprecipitation quantitative real-time PCR (ChIP-qPCR) results proved that OsARF17 regulated expression of several starch and protein synthesis related genes (like OsPDIL1-1, OsSS1, OsNAC20, OsSBE1, and OsC2H2). Therefore, OsIAA29 regulates seed development in high temperature through competition with OsIAA21 in the binding to OsARF17, mediating auxin signaling pathway in rice. This study provides a theoretical basis and gene resources for auxin signaling and effective molecular design breeding.

Exogenous application of nano-silicon, potassium sulfate, or proline enhances physiological parameters, antioxidant enzyme activities, and agronomic traits of diverse rice genotypes under water deficit conditions

Water deficit is a critical obstacle that devastatingly impacts rice production, particularly in arid regions under current climatic fluctuations. Accordingly, it is decisive to reinforce the drought tolerance of rice by employing sustainable approaches to enhance global food security. The present study aimed at exploring the effect of exogenous application using different biostimulants on physiological, morphological, and yield attributes of diverse rice genotypes under water deficit and well-watered conditions in 2-year field trial. Three diverse rice genotypes (IRAT-112, Giza-178, and IR-64) were evaluated under well-watered (14400 m3/ha in total for the entire season) and water deficit (9170 m3/ha) conditions and were exogenously sprayed by nano-silicon, potassium sulfate, or proline. The results showed that drought stress substantially decreased all studied photosynthetic pigments, growth traits, and yield attributes compared to well-watered conditions. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased compared with those under well-watered conditions. However, the foliar application of nano-silicon, potassium sulfate, and proline substantially mitigated the deleterious effects of drought stress and markedly enhanced photosynthetic pigments, antioxidant enzyme activities, growth parameters, and yield contributing traits compared to untreated stressed control. Among the assessed treatments, foliar spray with nano-silicon or proline was more effective in promoting drought tolerance. The exogenous application of proline improved chlorophyll a, chlorophyll b, and carotenoids by 21.4, 19.6 and 21.0% followed by nano-silicon treatment, which enhanced chlorophyll a, chlorophyll b, and carotenoids by 21.1, 17.6 and 9.5% compared to untreated control. Besides, the application of proline demonstrated a superior improvement in the content of proline by 52.5% compared with the untreated control. Moreover, nano-silicon exhibited the maximum enhancement of catalase and peroxidase activity compared to the other treatments. The positive impacts of applied exogenously nano-silicon or proline significantly increased panicle length, number of panicles/plant, number of grains/panicle, fertility percentage, 1000-grain weight, panicle weight, and grain yield, compared to untreated plants under water deficit conditions. In addition, the physiological and agronomic performance of evaluated rice genotypes significantly contrasted under drought conditions. The genotype Giza-178 displayed the best performance under water deficit conditions compared with the other genotypes. Consequently, the integration of applied exogenously nano-silicon or proline with tolerant rice genotype as Giza-178 is an efficient approach to ameliorating drought tolerance and achieving agricultural sustainability under water-scarce conditions in arid environments.

Genetic evaluation of hulless barley (Hordeum vulgare) genotypes for morpho-physiological traits and stripe rust resistance

Nowadays, hulless barley (Hordeum vulgare L.) is gaining importance as a raw material for food industry due to its highly nutritive value. Non-availability of high yield and disease resistant varieties has restricted its production in marginal areas over the last two decades. Therefore, an experiment was conducted during 2017–18 and 2018–19 at the Seed and Research Farm of ICAR-Indian Institute of Wheat and Barley Research, Karnal, Haryana to characterized 11 exotic hulless barley genotypes and 4 Indian barley cultivars for morpho-physiological characters and stripe rust resistance. Seedling resistant test for stripe rust was done at Regional Station (ICAR-Indian Institute of Wheat and Barley Research), Flowerdale, Shimla, Himachal Pradesh. Highly significant genotypic differences were found for morpho-physiological traits during analysis of variance. Genotype DWRNB28 showed a good combination of desirable traits, viz. early maturity (118 days), dwarf plant height (64.4 cm) and high 1000-grain weight (55.2 g). Maximum number of tillers per meter (149) was observed in DWRNB17. Genotype DWRNB25 was found resistant to maximum pathotypes (6S0, 7S0, and Q) at the seedling stage. DWRNB23 and DWRNB25 with pooled ACI=0 and ACI=0.04 respectively, were found immune to stripe rust in field conditions. These promising genotypes can be utilized as donor parents for the development of high-yielding and stripe-rust-resistant hulless barley varieties.

Genome-wide identification, gene expression and haplotype analysis of the rhomboid-like gene family in wheat (Triticum aestivum L.).

The rhomboid-like (RBL) gene encodes serine protease, which plays an important role in the response to cell development and diverse stresses. However, genome-wide identification, expression profiles, and haplotype analysis of the RBL family genes have not been performed in wheat (Triticum aestivum L.). This study investigated the phylogeny and diversity of the RBL family genes in the wheat genome through various approaches, including gene structure analysis, evolutionary relationship analysis, promoter cis-acting element analysis, expression pattern analysis, and haplotype analysis. The 41 TaRBL genes were identified and divided into five subfamilies in the wheat genome. RBL family genes were expanded through segmented duplication and purification selection. The cis-element analysis revealed their involvement in various stress responses and plant development. The results of RNA-seq and quantitative real-time-PCR showed that TaRBL genes displayed higher expression levels in developing spike/grain and were differentially regulated under polyethylene glycol, NaCl, and abscisic acid treatments, indicating their roles in grain development and abiotic stress response. A kompetitive allele-specific PCR molecular marker was developed to confirm the single nucleotide polymorphism of TaRBL14a gene in 263 wheat accessions. We found that the elite haplotype TaRBL14a-Hap2 showed a significantly higher 1000-grain weight than TaRBL14a-Hap11 in at least three environments, and the TaRBL14a-Hap2 was positively selected in wheat breeding. The findings will provide a good insight into the evolutionary and functional characteristics of the TaRBL genes family in wheat and lay the foundation for future exploration of the regulatory mechanisms of TaRBL genes in plant growth and development, as well as their response to abiotic stresses.

IMPACT OF DIFFERENT NPK LEVELS AND SOWING METHODS ON MAIZE GROWTH, YIELD, AND QUALITY CHARACTERISTICS

Crop management practices are crucially important to increased yield and quality. This research study was planned to investigate the effects of different levels of NPK and sowing methods on maize. Results showed that different NPK levels and sowing methods significantly affected the growth and yield traits of maize (p<0.05). The better results for plant height (cm), leaf area index, cob length (cm), grains per cob, 1000-grain weight, grain yield (kg ha-1), protein content (%) total sugars (%) and starch (%) were recorded when crop-fertilized NPK with 150-120-120 kg ha-1. However, all these parameters were marginally different compared to NPK rate of 120-90-90 kg ha-1, except for plant height (cm). This treatment produced significantly higher grain yield and quality traits of maize compared to lower and control treatment. Minimum values for plant height (cm), leaf area index, cob length (cm), grains per cob, 1000-grain weight, grain yield kg ha-1, protein content (%), total sugars (%) and starch (%) were noted in the control treatment. In case of sowing methods, ridge sowing produced maximum plant height (cm) , leaf area index, 50% days to tasselling and yield contributing characters like cob length (cm), grains cob-1, 1000-grain weight (g) and grain yield (kg ha-1) of maize as compared to broadcasting and drilling sowing methods. But sowing methods did not significantly affected the quality characteristics of maize, particularly protein content (%), total sugars (%) and starch (%). Among different sowing methods, ridge sowing method produced the maximum grain yield kg ha-1 of maize as compared to drilling and broadcasting. Considering the results comprehensively, the NPK rate of 120-90-90 kg ha-1 under ridge method would be the best management practice for maize cultivation:

Effects of Inorganic Phosphorus and Organic Fertilizer on Growth and Yield of Common Bean (Phaseolus Vulgaris L.) under Kabul Conditions

In Afghanistan, the main reasons for low crop yields are low soil fertility. Growing human populations has resulted in shrinking land areas and decreased soil fertility. Also, the overuse of chemical fertilizers is considered to be the main cause of soil characteristics deterioration, such as soil fertility, soil biology, and soil physical properties. On the other hand, no research has been done to find the ideal phosphorus and organic (ORGOFERT) fertilizer rate for improving common bean production in Afghanistan. Thus, it is pertinent to determine the optimum phosphorus and organic fertilizer dose for common bean cultivation in Afghanistan, where this crop is grown expensively. In 2020, a field trial took place at the agriculture faculty research farm of Kabul University during the growing season. The trial utilized a randomized complete block design (RCBD) with three replications. Each plot measured 200cm x 300cm, with plants spaced 40 cm apart in rows and 20 cm apart within rows. Different amounts of phosphorus and organic fertilizer were applied in the experiment. The results indicated that employing 50 kg of ORGOFERT and 80 kg of P2O5 fertilizers per hectare led to enhanced growth parameters such as plant height, number of branches per plant, and number of green leaves per plant, as well as improved yield attributes including the number of pods per plant, number of grains per pod, 100-grain weight, and total grain yield per hectare. The ideal amount of phosphorous and ORGOFERT fertilizer to improve the growth and production of common beans under field conditions might be the rate of 80kg P2O5 + 50 kg ORGOFERT fertilizer ha-1 under Kabul's agro-ecological conditions.

Rational Utilization of Sediment Resources Improves Rice Yield and Nitrogen Use Efficiency under Salt Stress

Soil salinization negatively affects rice growth and yield; however, how different sludge sources regulate rice growth and yield under salt stress was rarely investigated. This study evaluated the performance of two salt-tolerant rice cultivars, Chaoyou 1000 and Longliangyou 506, grown in two sediment sources, pond sediment (PS) and river sludge (RS), under salt stress (56 ds m−1 brine irrigation) with conventional soil (CS) used as the control. The results showed that the rice yield under the PS and RS treatments was enhanced by 51.0% and 43.6% as compared with CS, respectively, owing to an improvement in spikelet per panicle, 1000-grain weight, dry matter accumulation, and the chlorophyll content in both rice cultivars. Compared with CS, the total nitrogen accumulation, nitrogen grain production efficiency, nitrogen harvest index, and nitrogen partial productivity under the PS and RS treatments were increased by 18.9–28.9%, 17.0–20.6%, 7.2–16.6%, and 43.8–50.9%, respectively. Moreover, rice grown in PS and RS showed higher activities of nitrogen metabolism-related enzymes (nitrate reductase, glutamine synthetase, and glutamate synthetase) at the heading stage and higher K+ and K+/Na+ contents in the leaves. Overall, a balanced utilization of sediment resources (especially pond sediment) can effectively alleviate salt stress and improve the yield and nitrogen use efficiency in rice.

DGS1 improves rice disease resistance by elevating pathogen-associated molecular pattern-triggered immunity.

The online version contains supplementary material available at 10.1007/s42994-024-00137-9.

Manifestation of agronomically valuable traits in the progeny of a sorghum mutant carrying the genetic construct for RNA silencing of the γ-kafirin gene.

Improving the nutritional value of grain sorghum, a drought- and heat-tolerant grain crop, is an important task in the context of global warming. One of the reasons for the low nutritional value of sorghum grain is the resistance of its storage proteins (kafirins) to proteolytic digestion, which is due, among other things, to the structural organization of protein bodies, in which γ-kafirin, the most resistant to proteases, is located on the periphery, encapsulating more easily digested α-kafirins. The introduction of genetic constructs capable of inducing RNA silencing of the γ-kafirin (gKAF1) gene opens up prospects for solving this problem. Using Agrobacterium-mediated genetic transformation of immature embryos of the grain sorghum cv. Avans we have obtained a mutant with improved digestibility of endosperm proteins (up to 92 %) carrying a genetic construct for RNA silencing of the gKAF1 gene. The goal of this work was to study the stability of inheritance of the introduced genetic construct in T2-T4 generations, to identify the number of its copies, as well as to trace the manifestation of agronomically valuable traits in the offspring of the mutant. The mutant lines were grown in experimental plots in three randomized blocks. The studied lines were characterized by improved digestibility of kafirins, a modified type of endosperm, completely or partially devoid of the vitreous layer, an increased percentage of lysine (by 75 %), reduced plant height, peduncle length, 1000-grains weight, and grain yield from the panicle. In T2, a line with monogenic control of GA resistance was selected. qPCR analysis showed that in different T3 and T4 plants, the genetic construct was present in 2-4 copies. In T3, a line with a high digestibility of endosperm proteins (81 %) and a minimal decrease in agronomically valuable traits (by 5-7 %) was selected.

REDUCTION OF CHEMICAL FERTILIZER APPLICATION BY USING BIOCHAR FOR THE GROWTH AND YIELD OF RICE CV. BRRI dhan 29

A field experiment was carried out at research field, Hajee Mohammad Danesh Science and Technology University, Dinajpur to assess the reduction of chemical fertilizer application by using biochar for the growth and yield of rice cv. BRRI dhan 29. The experiment was performed with five treatments viz. T1 = Recommended doses of N, P, K and S, T2 = Biochar 10 t ha-1, T3 = Biochar 7.5 t ha-1 + half recommended doses of N, P, K and S, T4 = Biochar 5 t ha-1 + half recommended doses of N, P, K and S and T5 = Biochar 2.5 t ha-1 + half recommended doses of N, P, K and S. The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. The highest plant height (102.35 cm) and the number of tillers hill-1 (26.35) was found in the treatment T1 which was statistically similar to the treatment T3 with the values 99.93 cm and 25.89, respectively. The panicle length (25.01 cm), number of spikelets hill-1 (14.30), number of grains panicle-1 (194.50) and 1000-grain weight (25.03 g) were found maximum in the treatment T3 which was statistically similar to the treatment T1 with the values 24.89 cm, 13.87, 193.50 and 24.37 g; respectively. The highest grain yield (7.46 t ha-1) and straw yield (9.92 t ha-1) was found on T1 treatment which was statistically similar to the treatments T3 (7.42 and 9.86 t ha-1). The highest biological yield (17.28 t ha-1) was measured in the treatment T3. These results suggest that application of 7.5 t ha-1 biochar with half recommended doses of N, P, K and S may reduce 50% of N, P, K and S for rice cultivation (cv. BRRI dhan 29) as these treatments acquire statistically similar production to solely chemical fertilizer applications. However, further research is needed on biochar production, cost efficiency for biochar application and environmental aspects of biochar application.

Influence of Planting Geometry on Growth, Phenology, and Yield of White Maize in Padma-Washed Lands

This study was carried out at the Singair Upazilla of Manikganj during rabi 2015-16 to evaluate the optimum plant spacing of white maize varieties. There were three plant spacing viz. S1 (50 cm x 25 cm), S2 (60 cm x 25 cm) and S3 (70 cm x 25 cm) and two white maize varieties viz.V1 (PSC-121) and V2 (KS-510). The study was conducted using a factorial randomized complete block design (RCBD) with three replications. The variety, V1 (PSC-121) exhibited superior performance, displaying higher plant height, cob length, cob breadth, number of rows cob-1, number of grains row-1, total number of grains cob-1, 100-grain weight, grain yield plant-1, and grain yield ha-1. However, the variety, V2 (KS-510) took more days to reach key growth stages and showed lower performance in several yield attributes. Plant spacing also played a significant role, with S3 (70 cm x 25 cm) producing the maximum plant height, cob dimensions, and grain yield per plant but showed the lowest grain yield ha-1. Conversely, S1 (50 cm x 25 cm) resulted in the highest grain yield, stover yield, and biological yield, despite lower plant height and cob dimensions. The interaction between variety and plant spacing revealed interesting outcomes, such as V1S3 demonstrated the tallest plants, V2S3 exhibited higher stover yield, and V1S1 achieved the highest grain yield, biological yield, and harvest index. The study was found no significant variation in days to 1st tasseling, days to 1st silking, days to maturity, and harvest index across different plant spacing treatments. In conclusion, this research provides valuable insights into optimizing yield performance in white maize cultivation by considering both the choice of variety and appropriate planting geometry / plant spacing.

INCIDENCE OF STORAGE FUNGI ACCORDING TO TOPDRESSING NITROGEN AND MAIZE VARIETIES

Maize is the main cereal grown in Brazil and is used mainly for animal feed and food consumption of its derivates. Under favorable environmental conditions, toxigenic fungi such as Fusarium, Aspergillus, and Penicillium spp. could produce mycotoxins in maize grain during plant growth or storage. This study aimed to evaluate the incidence of toxigenic fungi and its relationship with the grain weight of maize varieties grown under high and low topdressing nitrogen. The first factor consisted of 11 open-pollinated varieties, and the second factor of two topdressing nitrogen rates (60 and 180 kg ha-1). After harvesting the experimental units, the following variables were evaluated: 100-grain weight (HGW) and incidence of A. flavus, Penicillium spp., and Fusarium spp. There were differences (p<0.05) among maize varieties for all evaluated variables. There was a significant interaction between varieties and nitrogen for the percentage of seeds infected by A. flavus, Fusarium spp., and HGW. The incidence of fungi and HGW of maize depends on the variety and the topdressing nitrogen used.

Multivariate Analysis to Study Genetic Diversity for Yield and its Attributing Traits in Rice (Oryza sativa L.)

The present investigation was carried out with 72 germplasm lines and three checks of rice (Oryza sativa L.) were grown at Crop Research Station, Masodha conducted in the GPB farm, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.) during Kharif June 2022- February 2023. Data on 10 characters, including grain yield per plant focused on diversity and PCA analysis. This investigation involved the analysis of 72 rice germplasm lines alongside three checks, showcasing extensive variation in agronomic and morphological traits. The study utilized Non-hierarchical Euclidean cluster analysis to assess genetic diversity. The pseudo F-test determined the optimal grouping of 75 genotypes into six distinct clusters. Cluster distribution revealed varying genotype compositions, with Cluster V comprising the highest entries (20), followed by Clusters I, VI, and II. Intra- and inter-cluster distances illustrated significant variability among clusters, emphasizing genetic diversity. Examining agronomic traits across these clusters revealed noteworthy variations in days to 50% flowering, days to maturity, plant height, and productive tillers. Panicle length, flag leaf area, biological yield, harvest index, 1000-grain weight, and grain yield per plant also exhibited cluster-specific variations. These findings provide valuable insights for rice breeding programs, facilitating targeted enhancements of specific agronomic traits within the rice population, thus contributing to the development of more resilient and productive rice varieties.

Effects of Different Proportions of Organic Fertilizer Replacing Chemical Fertilizer on Soil Nutrients and Fertilizer Utilization in Gray Desert Soil

Organic fertilizer can improve soil management and alleviate soil nutrient loss caused by excessive fertilization. This study determines a fertilization scheme that can achieve high and stable crop yield and effective soil fertilization by exploring the effects of different organic fertilizer proportions on soil nutrient content, fertilizer utilization rate, and wheat yield. The experiment was conducted from 2018 to 2020 using the Xinchun 38 wheat variety and gray desert soil. The experiment used six treatments: no fertilizer (CK), with normal nitrogen and phosphorus fertilizer (CF). The amount of conventional chemical nitrogen fertilizer was reduced by 6%, 12%, 18%, and 24%, respectively, and supplemented with organic nitrogen fertilizer of the same proportion. The experimental treatment codes were SF6, SF12, SF18, and SF24, respectively. Plant samples from six wheat growth stages and 0–20 cm soil samples were collected to analyze the nitrogen and phosphorus content and organic matter; dry matter accumulation, crop yield, and yield components were measured at the harvest stage. Soil available nitrogen, phosphorus, potassium, and soil organic matter contents increased with the replacement ratio of organic fertilizer after three consecutive years of application. The available nutrients and organic matter in soil treated with SF18 and SF24 were significantly higher than those in CK and CF. The dry matter accumulation and nutrient accumulation of wheat increased with increasing organic fertilizer replacement rates of SF18 and SF24, respectively. Nitrogen and phosphorus fertilizer utilization rates, partial productivity, and agricultural use efficiency also increased, with the SF18 and SF24 treatments having higher organic fertilizer replacement rates than those in the other treatments. The number of ears, 1000-grain weight, and yield of wheat treated with SF18 treatment produced the best results. Therefore, continuously using organic fertilizer as a partial replacement for conventional fertilizer can increase wheat growth and soil nutrient availability, which can improve the utilization rate of fertilizer, thereby achieving stability and even a significant increase in yield.

Investigation of chromosomal genetic characteristics and identification of structural variation in the offspring of hexaploid triticale×hexaploid wheat.

Hexaploid triticale is an important genetic resource for genetic improvement of common wheat, which can broaden the genetic basis of wheat. In order to lay a foundation for the subsequent research and utilization of triticale germplasm materials, the chromosomal genetic characteristics of cross and backcross offspring of hexaploid triticale×hexaploid wheat were investigated in the process of transferring rye chromatin from hexaploid triticale to hexaploid wheat. Hybrid and backcross combinations were prepared with hexaploid triticale 16yin171 as the maternal parent and hexaploid wheat Chuanmai62 as the paternal parent. The chromosomes in root tip cells of F1, BC1F1 and BC1F2 plants were traced and identified non-denaturing florescence in situ hybridization (ND-FISH). The results indicated that the backcross setting rate of hybrid F1 was 2.61%. The transmission frequency of 2R chromosome was the highest in BC1F1 plants while the transmissibility of rye chromosome in BC1F2 plant was 6R>4R>2R, and the 5B-7B wheat translocation in BC1F2 plants showed severe segregation. A total of 24 structural variant chromosomes were observed both in BC1F1 and BC1F2 plants, including chromosome fragments, isochromosomes, translocations, and dicentric chromosomes. In addition, the seed length and 1000-grain weight of some BC1F2 plants were better than that of the hexaploid wheat parent Chuanmai 62. Therefore, multiple backcrosses should be adopted as far as possible to make the rapid recovery of group D chromosomes, ensuring the recovery of fertility in offspring, when hexaploid tritriale is used as a bridge to introduce rye genetic material into common wheat. At the same time, the potential application value of chromosomal structural variation materials should be also concerned.

Influence of Nitrogen Applications during Grain-Filling Stage on Rice (Oryza sativa L.) Yield and Grain Quality under High Temperature

High temperature frequently occurs during rice’s early grain-filling period in the south of China, negatively affecting rice yield and quality and posing a major threat to local rice production. This experiment researched the influence of 3.5 °C warming during the first 20 grain-filling days on rice yield and quality and emphatically investigated the effects of the low-broadcast nitrogen fertilizer application level (LBN), high-broadcast nitrogen fertilizer application level (HBN) and foliar nitrogen fertilizer application (FN) at heading on the rice organ temperature, leaf photosynthesis, chlorophyll fluorescence, yield and grain quality, pasting and thermal properties under high temperature in 2020 and 2022, with a widely planted japonica rice variety, “Wuyunjing31”, in order to explore the practical mitigation measures for reducing the adverse impact of high temperature on rice productivity. The results showed that high temperatures during grain filling increased the rice plant temperature, damaged the chlorophyll fluorescence system and decreased the net photosynthesis rate. This led to a decline in the seed-setting rate and grain weight, resulting in a 7.0% and 13.9% yield loss in 2020 and 2022, respectively. In addition, high temperature caused a decline in the head rice rate and an increase in chalk occurrence and pasting temperature, thereby deteriorating rice grain quality. Under high temperatures, HBN enhanced the rice yield by 3.6% and 13.0% in 2020 and 2022, respectively, while FN enhanced the rice yield by 11.5% in 2022. The increase in yield was linked to the increased seed-setting rate and 1000-grain weight. LBN did not significantly affect the rice yield under high temperatures. The positive effects of nitrogen fertilizer measures on rice yield were associated with their role in lowering plant temperature and protection against the damage to the chlorophyll fluorescence system. All three nitrogen application measures generally improved rice milling quality and appearance quality under high temperature, with HBN generally showing the greatest impact. Under high temperature, LBN and FN tended to make the texture of cooked rice softer due to the decreased consistency, retrogradation enthalpy and retrogradation percentage, and this was closely associated with the decline in amylose content. In summary, nitrogen supplementation at the heading could efficiently mitigate the adverse impact of high temperature during the early grain-filling period on rice yield and quality.

Unlocking Triticum aestivum L. resilience: Exogenous proline's remarkable role in mitigating lead stress, and delving into the secrets of TaGSK1 gene expression

The application of proline as foliar spraying has emerged as a promising solution to combat lead-induced crop stress. This study highlights the effectiveness of external proline in enhancing wheat crop health under lead stress. We reveal how lead stress negatively impacts key factors like biomass, chlorophyll levels, and crop yield, particularly in 100-grain weight. Gas exchange parameters, including stomatal conductance, CO2 levels, photosynthesis, water-use efficiency, and transpiration, also suffer under lead stress. Significantly, exposure to lead stress triggers the activation of antioxidant enzymes and elevates levels of proline, calcium, and protein. Nonetheless, the application of foliar proline proves highly effective in alleviating these detrimental effects by reducing reactive oxygen species and enhancing proline and protein levels in wheat. Additionally, our findings demonstrate a significant upregulation of TaGSK1 gene expression at different proline concentrations. Compared to controls, TaGSK1 expression increases by 1.7-fold under 50 mM proline stress and an impressive 4.7-fold under 200 mM proline stress in wheat. This finding holds promise in alleviating the adverse effects of lead stress and strengthening crop resilience for a more secure and sustainable future in wheat cultivation amid various stressors.

Co-application of biochar and salt tolerant PGPR to improve soil quality and wheat production in a naturally saline soil

Soil salinity is a global problem that drastically reduces crop productivity. Therefore, there is a need to make saline soils productive. Plant growth promoting rhizobacteria (PGPR) and biochar have been shown to increase crop productivity and soil fertility when applied separately. However, their co-application in this regard has not been studied extensively. In this study, a biochar was co-applied with Bacillus thuringiensis or Bacillus tropicus, characterized as P-solubilizing and salt-tolerant PGPR, to wheat grown in a naturally saline soil (EC 8.12 dS m−1). Co-application of biochar with PGPR increased the number of tillers & spikes, straw yield, and 100-grain weight by 16–28.57%, 26.9–36.6%, 18–21.8%, and 34–37.9% respectively. This led to a 37% and 34% increase in grain yield in the case of co-application with B. thuringiensis and B. tropicus respectively. The higher growth and yield were thanks to better plant nutrition and mitigated salinity stress under co-application. Briefly, the co-application increased phosphorus content in grain, straw, and roots by up to 9–43%, 45–69%, and 5–21.5% respectively, which was higher than that in individual applications of biochar or any PGPR. In addition, co-application increased microbial biomass by 61–77% and soil available phosphorus by 37–53% across two PGPR. Evidently, the co-application contributed to increased P nutrition in two ways. Firstly, the biochar itself served as a source of available P. Secondly, the PGPR solubilized it more abundantly when biochar was there. As far the salinity stress, biochar, its co-application with B. thuringiensis, and with B. tropicus increased soil K+/Na+ by 36%, 72% and 44% respectively leading to 40%, 63%, and 55% higher K+/Na+ in grain, straw, and roots respectively. Overall, our results indicate that biochar and PGPR worked in tandem to substantially improve soil quality and wheat production compared to their sole applications. We conclude that co-application of salt tolerant PGPR and biochar is a more sustainable and better technology to produce wheat in a naturally saline soil compared to their sole applications.