High-yielding Wheat Research Articles

Optimizing agronomic practices for hard winter wheat production in the Great Plains with respect to seeding rate, row spacing, and variety

AbstractWinter wheat (Triticum aestivum L.) yield in dryland areas is optimized by the improvement of genetics in combination with ideal production practices. Different combinations of seeding rate and row spacing can influence the development of wheat plants, impacting wheat yield and its components. To determine the influence of these practices, yield components, water use efficiency (WUE), biomass, and subsequent grain yield were evaluated in an experiment conducted at the High Plains Agricultural Laboratory, Sidney, NE, from 2019 until 2022, using a split‐plot randomized complete block design with four replications. Treatments consisted of four different row spacings (19, 25, 31, and 51 cm), three seeding rates (1.05, 2.1, and 3.1 million seeds ha−1), and two high performing winter wheat varieties—‘Ruth’ and ‘Robidoux’. Row spacing showed differences in wheat yield (p < 0.0001) across all years, with a significant effect of seeding rate only in 1 year and an interaction effect of the three factors in 2022 alone. Higher wheat yield was achieved with the two narrower row spacings (19 and 25 cm) compared to the wider row spacings of 38 and 51 cm. The treatment combining the 19 cm row spacing and either 2.1 or 3.1 million seed ha−1 seeding rate had the greatest yields in most years. Narrower row spacings had improved WUE in drier years as compared to wider row spacings.

Contribution of Eco-Friendly Agricultural Practices in Improving and Stabilizing Wheat Crop Yield: A Review

Wheat is considered to be a strategic crop for achieving food security. Wherefore, one of the current objectives of today’s agriculture is to ensure a consistent and sustainable yield of this particular crop while mitigating its environmental footprint. However, along with the genetic potential of varieties, agricultural practices play a key role in ensuring a high and stable yield of wheat. Under changing climatic conditions, new eco-friendly practices were adopted in the wheat farming system in recent decades. In this review, a large number of peer-reviewed articles have been screened during the last 15 years to evaluate the potential of some environmentally friendly agricultural practices such as tillage system, biological crop protection, crop rotation, intercropping systems, and the integration of resistant varieties in achieving a high and stable wheat yield. The present investigation unveiled that embracing eco-friendly agricultural methods in the wheat farming system holds the potential to engender high and sustainable wheat yields, contingent upon a normative strategy that comprehensively addresses multiple factors. These include the intrinsic attributes of the grown wheat cultivars, plant nutritional parameters, soil agrochemical characteristics, and specific climatic conditions. Further in-depth investigations under field conditions are necessary to help in the discernment of appropriate environmentally agricultural techniques that can efficaciously optimize the yield potential of the different cultivated varieties.

Drought responsiveness in six wheat genotypes: identification of stress resistance indicators.

Wheat (Triticum aestivum L.) is among the world's most important staple food crops. In the current climate change scenario, a better understanding of wheat response mechanisms to water stress could help to enhance its productivity in arid ecosystems. In this study, water relations, gas exchange, membrane integrity, agronomic traits and molecular analysis were evaluated in six wheat genotypes (D117, Syndiouk, Tunisian durum7 (Td7), Utique, Mahmoudi AG3 and BT) subjected to drought-stress. For all the studied genotypes, drought stress altered leaf area, chlorophyll content, stomatal density, photosynthetic rate and water-use efficiency, while the relative water content at turgor loss point (RWC0) remained stable. Changes in osmotic potential at turgor loss point (Ψπ0), bulk modulus of elasticity (Ɛmax) and stomatal regulation, differed greatly among the studied genotypes. For the drought-sensitive genotypes AG3 and BT, no significant changes were observed in Ψπ0, whereas the stomatal conductance (gs) and transpiration rate (E) decreased under stress conditions. These two varieties avoided turgor loss during drought treatment through an accurate stomatal control, resulting in a significant reduction in yield components. On the contrary, for Syndiouk, D117, Td7 and Utique genotypes, a solute accumulation and an increase in cell wall rigidity were the main mechanisms developed during drought stress. These mechanisms were efficient in enhancing soil water uptake, limiting leaf water loss and protecting cells membranes against leakage induced by oxidative damages. Furthermore, leaf soluble sugars accumulation was the major component of osmotic adjustment in drought-stressed wheat plants. The transcriptional analysis of genes involved in the final step of the ABA biosynthesis (AAO) and in the synthesis of an aquaporin (PIP2:1) revealed distinct responses to drought stress among the selected genotypes. In the resistant genotypes, PIP2:1 was significantly upregulated whereas in the sensitive ones, its expression showed only a slight induction. Conversely, the sensitive genotypes exhibited higher levels of AAO gene expression compared to the resistant genotypes. Our results suggest that drought tolerance in wheat is regulated by the interaction between the dynamics of leaf water status and stomatal behavior. Based on our findings, Syndiouk, D117, Utique and Td7, could be used in breeding programs for developing high-yielding and drought-tolerant wheat varieties.

TaACTIN7-D regulates plant height and grain shape in bread wheat

Exploitation of new gene resources and genetic networks contributing to the control of crop yield-related traits, such as plant height, grain size, and shape, may enable us to breed modern high-yielding wheat varieties through molecular methods. In this study, via ethylmethanesulfonate mutagenesis, we identify a wheat mutant plant, mu-597, that shows semi-dwarf plant architecture and round grain shape. Through bulked segregant RNA-seq and map-based cloning, the causal gene for the semi-dwarf phenotype of mu-597 is located. We find that a single-base mutation in the coding region of TaACTIN7-D (TaACT7-D), leading to a Gly-to-Ser (G65S) amino acid mutation at the 65th residue of the deduced TaACT7-D protein, can explain the semi-dwarfism and round grain shape of mu-597. Further evidence shows that the G65S mutation in TaACT7-D hinders the polymerization of actin from monomeric (G-actin) to filamentous (F-actin) status while attenuates wheat responses to multiple phytohormones, including brassinosteroids, auxin, and gibberellin. Together, these findings not only define a new semi-dwarfing gene resource that can be potentially used to design plant height and grain shape of bread wheat but also establish a direct link between actin structure modulation and phytohormone signal transduction.

Physcion and chitosan-Oligosaccharide (COS) synergistically improve the yield by enhancing photosynthetic efficiency and resilience in wheat (Triticum aestivum L.)

As progressively increasing food safety concerns, diversified plant diseases and abiotic stresses, environmental-friendly bio-pesticides and bio-stimulants combinations may are likely to serve as a vital means of safeguarding green and sustainable food production. Accordingly, in this study, pot and field trials were performed to examine the application potential of the combination of physcion and chitosan-Oligosaccharide (COS) in wheat production. Wheat seeds were coated with physcion and COS and the effects exerted by them on morphology, physiology and yield of the wheat were investigated. As indicated by the results, the combination of physcion and COS not only did not inhibit the growth of wheat seedlings, but also synergistically increased root vigor and photosynthetic pigment content. Simultaneously, the lignin content in the roots and leaves was increased significantly. Moreover, the result confirmed that the combination of both substances reduced the MDA content, which was correlated with the up-regulation of the transcript expression level of antioxidant enzyme genes and the resulting increased enzyme activity. Furthermore, this combination synergistically increased the net photosynthetic rate (Pn) of the flag leaves and ultimately contributed to the increase in yield. Notably, the above-mentioned desirable cooperative effect was not limited by cultivars and cultivation methods. The conclusion of this study suggested that the combination of physcion and COS synergistically improved the photosynthetic rate and resilience in wheat, such that high wheat yields can be more significantly maintained, and future food security can be more effectively ensured.

Durum-21: A New High-Yielding and Good Quality Durum Wheat Variety Suitable for Pasta Production

Durum-21 (D-21) is a high-yielding, disease resistant with better-quality traits variety, developed by Wheat Research Institute Faisalabad. This variety is mainly developed for industrial purposes for pasta production. Worldwide, durum wheat is utilized for pasta production; but in Pakistan, due to a lack of research work and non-availability of quality seeds of durum wheat, bread wheat is being utilized for pasta production. D-21 is developed with the breeding code of D-21 having parentage of FKN/3/2*FR//KAD/GB/4/BB/CHA/5/AS-2002 with pedigree as PB20733-1a-2a-2a-0a-0a-19a-0a. The candidate line D-21 was developed by crossing a germplasm accession with approved bread wheat variety AS-02. The genotype was further evaluated over multiple locations in Punjab Pakistan for yield and yield-related attributes in the station, provincial, and national uniform durum yield trials executed by Wheat Research Institute (WRI), Faisalabad during 2015-20. The promising line out yielded the two commercial check varieties D-97 and Fsd-2008 by 1.42 % in the provincial yield trial and 4.2 % in the national yield trial. D-21 had desirably medium to tall plant height (96-100 cm) without anthocyanin pigment. It has erected to semi-erect growth habit at the seedling stage. Its color is green with medium waxiness on stem and yellowish-white at maturity. Its 1000-grain weight ranged from 38.9 to 39 g while the test weight remained from 69 to 78.5 g. The protein contents were 13.1 to 14.95 %; which is higher than the two checks (D-97 and Fsd-2008). Due to its better grain yield and promising nutritional and quality parameters, it was approved in the year 2021 for cultivation all over the country.

WINTER WHEAT ASSESSMENT FOR GROWTH, GRAIN YIELD, AND QUALITY PARAMETERS UNDER DIVERSE SOIL AND CLIMATIC CONDITIONS

The presented study aims to select the early-maturing and high-yielding winter wheat genotypes via the assessment of various eco-geographical groups and to illustrate their scientific significance for the diverse environmental conditions of the Kashkadarya Region of the Republic of Uzbekistan. Twentyfour advanced wheat lines underwent selection and evaluation for comparison with six regional and promising cultivars to further improve and use for crossbreeding. Overall, eight cultivars showed promising in the desert zone of the Kashkadarya Region, 24 in the middle area, and 13 in the region’s foothills, while selecting five for the desert zone, six in the middle, and 10 in the foothills of Uzbekistan. Seventeen cultivars and advanced lines attained selection for the desert area of District Kasbi with higher protein content (14%), 21 in the middle zone of District Karshi, and 22 in the foothills of District Shahrizabz. Cultivars and advanced lines selected for the desert area of District Kasbi, in the middle zone of District Karshi, and in the foothills of District Shahrizabz numbered 14, 14, and three, respectively, where the gluten content was more than 30%. Weather conditions also affect the wheat genotype yields in the irrigated areas, and due to less rainfall in March-May of 2011, in the desert and foothills, the average yield declined by 0.2–0.23 and 0.15–0.25 t/ha in the deserts and foothills, respectively, compared with other years. The precipitation in March-May strongly correlated (r = 0.47) with the grain yield in winter bread wheat.

Improving Stem Lodging Resistance, Yield, and Water Efficiency of Wheat by Adjusting Supplemental Irrigation Frequency

Optimizing supplemental irrigation (SI) measures and enhancing stem lodging resistance can be the keys to achieving a high and stable yield and high efficiency in wheat. The experiment was established as a two-factor field trial in 2018–2020. We used four SI combinations at different stages: rain-fed (T0), SI at jointing (T1), SI at jointing + anthesis (T2), and SI at regreening + jointing + anthesis (T3) with ‘Bainong4199’ (BN4199) and ‘Zhoumai18’ (ZM18) as experimental materials. We researched the effects of different SI combinations on the stem characteristics, stem vigor, grain filling, and yield of winter wheat. The results suggest that the basal internode at the anthesis stage grew with the increase in SI amount, but the stem fracture resistance of T1 and T2 was higher than that of T0 and T3. As grain filling continued, the lodging index increased and stem vigor decreased. In comparison with T3, the average stem lodging index of T2 decreased by 21.92% for ‘BN4199’ and 36.63% for ‘ZM18’, but the WUE increased by 29.76% and 14.92%, respectively. The grain yield increased with the increase in irrigation times during the growth period; there was no significant difference between T2 and T3 in 2018–2019. In a biennial comparison, the grain yield of all treatments in 2019–2020 was significantly lower than those in 2018–2019, and the grain yield of ‘ZM 18’ was lower than that of ‘BN 4199’. Correlation analysis displayed that there were significant positive correlations between post-anthesis stem vigor and the dry matter contribution rate of post-anthesis to grains and between the grain filling rate at 21–28 days after anthesis (DAA) and stem strength at 30 DAA. In summary, selecting a high-yield lodging-resistant wheat variety with SI at jointing and anthesis was beneficial for forming strong stems and maintaining higher stem vigor at the later growth stage for grain filling, which reduced lodging risk and ensured high yield and high WUE.

Genetic mapping of the wheat leaf rust resistance gene Lr2a and its importance in Canadian wheat cultivars.

Leaf rust resistance gene Lr2a was located to chromosome arm 2DS in three mapping populations, which will facilitate map-based cloning and marker-assisted selection of Lr2a in wheat breeding programs. Incorporating effective leaf rust resistance (Lr) genes into high-yielding wheat cultivars has been an efficient method of disease control. One of the most widely used genes in Canada is the multi-allelic resistance gene Lr2, with alleles Lr2a, Lr2b, Lr2c, and Lr2d. The Lr2a allele confers complete resistance to a large portion of the Puccinia triticina (Pt) population in Canada. In this study, Lr2a was genetically mapped in two doubled haploid populations developed from the crosses Superb/BW278 and Superb/86ISMN 2137, and an F2 population developed from the cross Chinese Spring/RL6016. Seedlings were tested with the Lr2a avirulent Pt races 74-2 MGBJ (Superb/BW278) and 12-3 MBDS (Superb/86ISMN 2137 and Chinese Spring/RL6016) in greenhouse assays and were genotyped with 90K wheat Infinium SNP and kompetitive allele-specific PCR (KASP) markers. Lr2a was mapped to a collinear position on chromosome arm 2DS in all three populations, within a 1.00cM genetic interval between KASP markers kwm1620 and kwm1623. This corresponded to a 305kb genomic region of chromosome 2D in Chinese Spring RefSeq v2.1. The KASP marker kwh740 was predictive of Lr2a in all mapping populations. A panel of 260 wheats were tested with three Pt isolates, which revealed that Lr2a is common in Canadian wheats. The KASP markers kwh740 and kwm1584 were highly associated with resistance at the Lr2 locus, while kwm1622 was slightly less correlated. Genetic mapping of the leaf rust resistance gene Lr2a and DNA markers developed here will facilitate its use in wheat breeding programs.

An intron-located single nucleotide variation of TaGS5-3D is related to wheat grain size through accumulating intron retention transcripts.

Thirty-three stable QTL for 13 yield-related traits across ten environments were identified in the PD34/MY47 RIL population, and a candidate gene TaGS5-3D in Qmt.nwafu.3D was preliminarily identified to affect grain-related traits through accumulation of specific transcripts. Dissecting the genetic basis of yield-related traits is pivotal for improvement of wheat yield potential. In this study, a recombinant inbred line (RIL) population genotyped by SNP markers was used to detect quantitative trait loci (QTL) related to yield-related traits in ten environments. A total of 102 QTL were detected, including 33 environmentally stable QTL and 69 putative QTL. Among them, Qmt.nwafu.3D was identified as a pleiotropic QTL in the physical interval of 149.77-154.11Mb containing a potential candidate gene TaGS5-3D. An SNP (T > C) was detected in its ninth intron, and TaGS5-3D-C was validated as a superior allele associated with larger grains using a CAPS marker. Interestingly, we found that TaGS5-3D-C was closely related to significantly up-regulated expression of intron-retained transcript (TaGS5-3D-PD34.1), while TaGS5-3D-T was related to dominant expression of normal splicing transcript (TaGS5-3D-MY47.1). Our results indicated that alternative splicing associated with the SNP T/C could be involved in the regulation of grain-related traits, laying a foundation for the functional analysis of TaGS5-3D and its greater potential application in high-yield wheat breeding.

The assimilation surface of winter wheat under the effect of seed treatment with biological preparations

Purpose. To establish the peculiarities of the winter wheat assimilation apparatus development under the effect of seed treatment with biological preparations.
 Methods. Research was conducted using field, laboratory and mathematical methods in 2019–2022 in the stationary crop rotation of the Department of Crop Production of the National Academy of Sciences of Ukraine on typical podzolized chernozems in the Right Bank Forest Steppe of Ukraine. The peculiarities of the formation of the assimilation area of winter wheat under the application of biological preparations for seed treatment were studied with the use of the following preparations: Binok Zerno, Rizomax, Trichodermin, Planoriz, Urozhai Start. N32P32K32 fertilizer and complex granular fertilizer DuraSOP actibition were applied in seedbed preparation. The leaf area and glumes were calculated using the Petiole Pro program. The area of the stem was determined by the formula of the external area of the cylinder.
 Results. The flag leaf is quite important for the formation of a high yield of winter wheat, since its loss or damage significantly reduces the flow of photosynthetic assimilates into the plant. In particular, in the earing phase (BBCH 57), on average its area was 7.68 thousand m2/ha and good indicators of the formation of the area of the flag leaf were in the treatments with Binok Zerno and Harvest Start, both separately and in combination. In the next phase of development – flowering (BBCH 65) – the patterns were preserved, although the combination of Binok Zerno in a complex with fertilizer Harvest Start was better – 9.24 thousand m2/ha. A decrease in the total assimilation area was observed as a result of the gradual dying off of the leaves of the lower tiers, a reduction in the possibility of photosynthesis of the flag leaf and a decrease in the area of the ear involved in assimilation. In particular, on average according to the experiment, in the earing phase (BBCH 57), the total assimilation area of winter wheat was 51.9 thousand m2/ha; in the flowering phase (BBCH 65) 51.8 and in the phase of milk grain ripeness (BBCH 75) 29.3 thousand m2/ha. The total area of the assimilation surface in the earing phase (BBCH 57) was the largest for the combined seed treatment with the biological preparation Binok Zerno and the fertilizer Urozhai Start – 61.7 thousand m2/ha. In the future, in the phases of flowering (BBCH 65) and milk ripeness of grain (BBCH 75), the obtained patterns were preserved and the best treatment was the combined application of Binok Zerno and Harvest Start. By the end of the vegetation season, the concentration of the main photopigments in the leaves of winter wheat decreased In the phase of milk ripeness of the grain (BBCH 75), the content of chlorophyll a was 11.01 mg/g and chlorophyll b 3.93 mg/g. However, at earlier stages of wheat ontogenesis, the content of chlorophyll b in leaves increased, while chlorophyll a per gram of leaf dry matter decreased. It was established that the average content of chlorophyll a was 11.6 mg/g during the earing phase (BBCH 57), while the content of chlorophyll b was 4.09 mg/ha. In the flowering phase (BBCH 65), their content was 11,4 and 4.14 mg/ha, respectively. It was determined that the complex seed treatment with Binok Zerno + Harvest Start together with fertilizer N32P32K32 + Actibion ensured a higher content of chlorophylls – 16.3; 16.0 and 15.4 mg/g of dry matter, respectively.
 Conclusions. The application of the studied biological preparations for the seed treatment of winter wheat seeds contributes to a significant increase of the indicators of the total assimilation area of plants throughout the vegetation season, in particular its components, such as the area of flag leaves, blumes and stems, as well as the content of photosynthetic pigments. Established regularities of plant growth and development are important factors for optimizing crop cultivation technology in the conditions of the Right Bank Forest Steppe of Ukraine.

Effects of supplemental irrigation on grain yield and water and nitrogen efficiencies of winter wheat in the North China Plain.

Aiming at unbalanced coordination of irrigation and fertilization of winter wheat in the eastern North China Plain, this study investigated the effect of fertigation on wheat grain yield, grain quality, and water use efficiency (WUE) and nitrogen use efficiency (NUE) in seven irrigation and nitrogen (N) fertilization treatments. Under the field conditions, the traditional irrigation and fertilization method (total N amount of 240 kg ha-1 , application of 90 kg ha-1 at sowing irrigation at jointing and anthesis, with topdressing N of 150 kg ha-1 at jointing) was used as the control (CK). There were six fertigation treatments to compare with CK. For the fertigation treatments, the total amount of N application was set to 180 kg ha-1 and 90 kg ha-1 was applied at sowing and the remaining N fertilizer was applied through fertigation. The fertigation treatments included the combination of three fertigation frequencies (S2: at jointing and anthesis; S3: at jointing, anthesis, and filling; S4: at jointing, booting, anthesis, and filling) and two soil water replenishment depths (M1: 0-10 cm; M2: 0-20 cm). The six treatments were S4M2, S4M1, S3M2, S3M1, S2M2, and S2M1. Compared with CK, three and four irrigations (S3 and S4) maintained higher soil and plant analyzer development value and photosynthetic rate after anthesis. These treatments increased soil water extraction while reducing crop water consumption during the whole growing season, promoted the assimilation and translocation of dry matter into the grain after anthesis, and increased the 1000-grain weight. These fertigation treatments also significantly increased WUE and NUE. At the same time, the high grain protein content and grain protein yield were maintained. Compared with the CK, high wheat yield was maintained by S3M1 (drip irrigation fertilizer at the jointing, anthesis, and filling, and the depth of the moisture replenishment is 10 cm). This fertigation treatment significantly increased yield by 7.6%, WUE by 30%, NUE by 41.4%, and partial factor productivity from applied N by 25.8%; grain yield, grain protein content, and grain protein yield also performed well. Consequently, S3M1 treatment was suggested to be a good practice for reducing irrigation water and N input in the eastern North China Plain. © 2023 Society of Chemical Industry.

Farklı Çevrelerde Yetiştirilen Bazı Ekmeklik Buğday Çeşitlerinin (Triticum aestivum L.) Bazı Fizyolojik ve Verim Özelliklerinin Değerlendirilmesi

This study aimed to evaluate the performance of some bread wheat varieties in different environments, and to reveal the relationships between some physiological parameters and yield and yield components. Three bread wheat varieties, (Namely, Basribey 95, Alibey, and Kaşifbey 95), were used as plant materials. Field experiments were conducted during the 2009-2010 and 2010-2011 growing seasons in Aydın and Menemen locations. The experimental layout was a RCBD with three replications at each location and year. In the study, canopy temperature depression (CTD), chlorophyll content (CC), stomatal conductance (SC), grain yield (GY), plant height (PH), spike number per square meter (S/m2), thousand kernel weight (TKW), test weight (TW), grain number per spike (G/S), single spike yield (SSY), number of days to heading (DHE), were examined. CTD in ZGS 65 had a decisive role in gaining high grain yield. Also, CC in ZGS 65 and ZGS 71 might be defined as an important physiological traits. On the other hand, the contribution of the SC parameter determined in ZGS 55, ZGS 65 and ZGS 71 to the yield depends on the environment. Those parameters could be selection criteria for high-yield wheat breeding due to positive and significant correlations with grain yield. And also SC and CC parameters might be used in yield estimation on wheat.

Performance and Stability Analysis of Selected Durum Wheat Genotypes Differing in Their Kernel Characteristics.

Breeding of high-yielding and stable durum wheat varieties with improved kernel characteristics is needed for dry regions around the globe. The aim of this study was to investigate the performance and stability of eight durum wheat genotypes varying in their kernel characteristics across 15 contrasting environments. The tested material included three recombinant inbred lines (NUR-072, NUR-106 and NUR-238) derived from a cross between Norsi, a Jordanian landrace with special kernel characteristics and UC1113 Yr36+Gpc-B1, an elite line from USA. Field trials were carried out for three constitutive growing seasons under rainfed conditions, except for three environments where supplementary irrigation was provided. After the harvest, grain yield (GY), total yield (TW), and harvest index (HI) were recorded. Additionally, several kernel-related traits, including thousand kernel weight (TKW), kernel area (KA), kernel width (KW), kernel length (KL), kernel circularity (KC), and kernel length-width ratio (KL:KW) were evaluated. Analysis of variance for all tested traits revealed high significant variations (p ≤ 0.01) between the genotype (except for TW) and the genotype × environment (G × E) interaction. Genotype effect contributed to substantial percentage of variation (>75%) for KA, KL, KC and KL:KW, whereas KW showed a lower percentage similar to GY. Regarding the G × E effect, explained variation was highest for the TW (67.79%), and lowest for KL (6.47%). For GY, Norsi produced significantly the lowest mean value (249.99 g.m-2) while, Bolenga produced the highest mean value (377.85 g.m-2) although no significant differences were observed with the remaining genotypes. On the other hand, Norsi, NUR-072 and NUR-106 showed best performance for TKW and kernel-related traits with NUR-106 producing the highest mean value for KL (9.07 mm). The GGE biplot and AMMI analysis of GY identified Bolenga, Um Qais and NUR-106 as good performers across several environments, while Norsi exhibited the poorest performance. For TKW, Norsi was the best performer across different environments followed by NUR-106, which showed excellent performance under irrigated and saline conditions. For stability analysis, NUR-106 emerged as the most stable genotype in this study for GY and several kernel-related traits, particularly for KL and KC. In conclusion, the results of this study offer valuable insights for durum wheat breeders seeking to develop high-yielding and stable varieties with special kernel characteristics suitable for cultivation in dry areas.

Improved chloroplast Pi allocation helps sustain electron transfer to enhance photosynthetic low-phosphorus tolerance of wheat

Phosphorus (P) deficit limits high wheat (Triticum aestivum L.) yields. Breeding low-P-tolerant cultivars is vital for sustainable agriculture and food security, but the low-P adaptation mechanisms are largely not understood. Two wheat cultivars, ND2419 (low-P-tolerant) and ZM366 (low-P-sensitive) were used in this study. They were grown under hydroponic conditions with low-P (0.015 mM) or normal-P (1 mM). Low-P suppressed biomass accumulation and net photosynthetic rate (A) in both cultivars, whereas ND2419 was relatively less suppressed. Intercellular CO2 concentration did not decrease with the decline of stomatal conductance. Additionally, maximum electron transfer rate (Jmax) decreased sooner than maximum carboxylation rate (Vcmax). Results indicate that impeded electron transfer is directly responsible for decreased A. Under low-P, ND2419 exhibited greater PSII functionality (potential activity (Fv/Fo), maximum quantum efficiency (Fv/Fm), photochemical quenching (qL) and non-photochemical quenching (NPQ) required for electron transfer than ZM366, resulting more ATP for Rubisco activation. Furthermore, ND2419 maintained higher chloroplast Pi concentrations by enhancing chloroplast Pi allocation, compared with ZM366. Overall, the low-P-tolerant cultivar sustained electron transfer under low-P by enhancing chloroplast Pi allocation, allowing more ATP synthesis for Rubisco activation, ultimately presenting stronger photosynthesis capacities. The improved chloroplasts Pi allocation may provide new insights into improve low-P tolerance.

The effectiveness of forms of mineral fertilisers and productivity of winter wheat on grey-meadow soils of Kyrgyzstan

Fertilisation of winter wheat is necessary to provide the crop with nutrients for optimal growth, development, and formation of the crop. However, the effectiveness of fertilisers may depend on their shape, soil conditions, and climate. The purpose of the study is to examine the effectiveness of using various forms of mineral fertilisers on the formation of productivity of winter wheat on grey-meadow soils of Kyrgyzstan. In 2019-2021, field experiment was conducted in the Educational-experimental Farm of the Kyrgyz National Agrarian University, named after K.I. Skryabin to achieve this goal. As a result of the study, it was identified that the formation of high yields of winter wheat is closely related to the use of nitrogen-containing fertilisers in crop rotation, which contributes to the accumulation of nitrate nitrogen in the soil. The substantial effect of ammonium nitrate and granulated superphosphate on the nitrogen regime of the soil was also noted. The concentration of carbon-ammonium-soluble phosphates is determined by the actions of ammonium sulphate, ammonium nitrate, and all forms of phosphorus fertilisers, but no special changes in the phosphate regime of the soil under the influence of forms of phosphorus fertilisers were identified. However, when using complex fertilisers, a slight accumulation of mobile phosphorus in the soil was noted. The introduction of ammonium nitrate ensures the yield of winter wheat grain at the level of 56 centner/ha, ammonium sulphate – 53.1 centner/ha. granulated superphosphate provided the highest level of winter wheat yield – 55.5 centner/ha and the highest increase in yield against the background of nitrogen-potassium nutrition – 8.7 centner/ha. Therefore, for winter wheat, after rowed precursors, it is preferable to apply ammonium nitrate from nitrogen forms of fertilisers. As an alternative to it – ammonium sulphate or urea, from phosphorus forms of fertilisers – granular superphosphate. The practical importance of the results of the study allows for developing more effective methods of using fertilisers and increasing the productivity of grain crops on grey-meadow soils of Kyrgyzstan and in other regions with similar soil and climatic conditions

Heterogeneous population distribution enhances resistance to wheat lodging by optimizing the light environment

Lodging is still the key factor that limits continuous increases in wheat yields today, because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation. The mechanical properties of the culm are mainly determined by lignin, which is affected by the light environment. However, little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm lodging. Therefore, in this study, we used the wheat cultivar “Xinong 979” to establish a low-density homogeneous distribution treatment (LD), high-density homogeneous distribution treatment (HD), and high-density heterogeneous distribution treatment (HD-h) to study the regulatory effects and mechanism responsible for differences in the lodging resistance of wheat culms under different population distributions. Compared with LD, HD significantly reduced the light transmittance in the middle and basal layers of the canopy, the net photosynthetic rate in the middle and lower leaves of plants, the accumulation of lignin in the culm, and the breaking resistance of the culm, and thus the lodging index values increased significantly, with lodging rates of 67.5% in 2020–2021 and 59.3% in 2021–2022. Under HD-h, the light transmittance and other indicators in the middle and basal canopy layers were significantly higher than those under HD, and the lodging index decreased to the point that no lodging occurred. Compared with LD, the activities of phenylalanine ammonia-Lyase (PAL), 4-coumarate: coenzyme A ligase (4CL), catechol-O-methyltransferase (COMT), and cinnamyl-alcohol dehydrogenase (CAD) in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation, and the relative expression levels of TaPAL, Ta4CL, TaCOMT, and TaCAD were significantly downregulated. However, the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compared with HD. A partial least squares path modeling analysis found significant positive effects between the canopy light environment, the photosynthetic capacity of the middle and lower leaves of plants, lignin synthesis and accumulation, and lodging resistance in the culms. Thus, under conventional high-density planting, the risk of wheat lodging was significantly higher. Accordingly, the canopy light environment can be optimized by changing the heterogeneity of the population distribution to improve the photosynthetic capacity of the middle and lower leaves of plants, promote lignin accumulation in the culm, and enhance lodging resistance in wheat. These findings provide a basis for understanding the mechanism responsible for the lower mechanical strength of the culm under high-yield wheat cultivation, and a theoretical basis and for developing technical measures to enhance lodging resistance.

Influence of fertilizer levels and wild oat (Avena ludoviciana) management on growth, yield and economics of wheat (Triticum aestivum) cultivation

The present study was carried out at the Chaudhary Charan Singh Haryana Agricultural University, Hisar during the winter (rabi) season of 2015–16 and 2016–17, to investigate influence of fertilizer levels and different treatments of wild oat (Avena ludoviciana Durieu.) management on growth and yield of wheat (Triticum aestivum L.). There were 24 treatments and 3 replications with fertilizer (Levels-03) and wild oat (management -08) treatments as main and subplot treatments in split-plot design. Results of the 2 year study showed, higher grain yield (44.7 q/ha), straw yield (66.7 q/ha) and benefit: cost ratio (1.80) in recommended dose of fertilizer (RDF) when compared 120% RDF (40.22 q/ha, 61.24 q/ha and 1.58 respectively). Weed-free (55.3 q/ha, 79.1 q/ha and 2.03) and pinoxaden @ 50 g/ha (54.8 q/ha, 78.6 q/ha and 2.18) being at par with each other resulted in higher grain and straw yields, whereas weedy check exhibited the least values. Clodinafop @ 60 g/ha recorded significantly higher grain, straw yield and benefit: cost (B:C) ratio than with sulfosulfuron @ 25 g/ha though it was significantly lower than the pinoxaden @ 50g/ha. Pendimethalin @ 1.5 kg/ha and metribuzin @ 175 g/ha ensued statistically similar grain, straw yield and B : C ratio, followed by weedy check. The results also indicated that, fertilizers given in larger dosages only served to increase the weed population rather than wheat output. In the higher dosage of fertilizer, weeds becomes resistant to normal dosage of herbicides. Recommended dose of fertilizer along with suitable herbicide application or manual weeding could result in higher yield of wheat.

GENETIC ANALYSIS AND EXPRESSION PROFILING OF TAHSP90A TRANSCRIPTS CONFER HEAT TOLERANCE IN WHEAT

Heat stress has emerged as a chief problem impeding wheat crop productivity. In several crops, specific HSP90A genes have intensively managed induced fluctuations in temperature. A wheat plant with TaHSP90A transcripts had the potential to cope with temperature stress. It enables plants to survive in transient extremes of temperature and under heat stress. The presented study design enhanced temperature tolerance plasticity with high yield in wheat through a line × tester mating design containing lines (12) and testers (4) having a differential expression of TaHSP90A transcripts (TraesCS2A02G033700.1, TraesCS5B02G258900.3, and TraesCS5D02G268000.2), then hybridized to get the F1 (48) wheat hybrids. For heat treatment, temperature raising was only in the daytime, through the tunnel at anthesis (for two weeks). Data recording for several morphological and physiological parameters went along with the relative expression of TaHSP90A transcripts for hybrid evaluation. After one hour of heat treatment, the relative expression of TaHSP90A transcripts’ determination in the flag leaf followed. The manifestation of TaHSP90A transcripts’ upregulation was two folds in several hybrids after heat treatment. Best lines, testers, and selected crosses having TaHSP90A transcripts with high yield and heat tolerance compared with parents can further benefit breeding programs aiming toward tolerance against heat stress in changing climate scenarios.

'MH-21,' A NOVEL HIGH-YIELDING AND RUSTS RESISTANT BREAD WHEAT VARIETY FOR IRRIGATED AREAS OF PUNJAB, PAKISTAN

Developing high-yielding wheat varieties tolerant to abiotic and biotic stresses is a challenge wheat breeder currently face. Wheat Research Institute (WRI), Ayub Agricultural Research Institute (AARI), Faisalabad, Pakistan, has released 65 wheat varieties, including MH-21, for several zones since its establishment in 1906. MH-21, with the varietal code V-12304, gave 11.2% and 10.28% more grain yield than the check variety (Faisalabad-08), respectively, in preliminary (2011–2012) and regular yield trials (2012–2013). Then, testing it in outstation yield trials proceeded over 21 locations in Punjab province (2013–2014) and 18 locations all over Pakistan (2014–2015, 2017–2018, and 2019– 2020) for yield and disease constancy, simultaneous with agronomic field trials and quality lab testing during 2014–2018 and 2014–2016, respectively. It exhibited an amber seed color, semi-erect growth habit at booting, erect flag leaf attitude, hairiness auricle, awned yellowish ear, and elevated shoulder and beak shape of glumes traits. DNA fingerprinting of MH-21 ensued to compare its genetic background with previously registered 21 wheat varieties. Given the promising stable performance in multi-locations over the years for better grain yield, nutritional quality, and resistance against rusts, the Punjab Seed Council approved V12304 in 2021 with the name „MH-21‟ for general cultivation in irrigated areas of Punjab, Pakistan.