Development Of Wheat Varieties Research Articles

CORRELATION AND REGRESSION ANALYSIS FOR YIELD & RELATED ATTRIBUTES IN F2 POPULATION OF BREAD WHEAT (Triticum aestivum L.) GENOTYPES

This research was carried out to study correlation & regression analysis in bread wheat at Southern Wheat and Barley Research Institute, Tandojam in RCBD with three replications. The results showed that most of the traits were significantly different at (P≤0.01) among the genotypes. Correlation analysis showed that spikelets per spike had a positive and highly significant association with biological yield per plan (r = 0.82**). Among the F2 crosses, days to 75% heading was significantly and positively associated with the grain yield (r = 0.80**). The trait tillers per plant had a positive association of significance with grain yield per plant (r = 0.86**) and biological yield per plant (g) (r = 0.84**). Regression analysis showed that the contribution rate of plant height to the change of grain yield was 0.47%; although the contribution to the variation of grain yield per plant was 08.21%. Spike length and spikelets per spike contributed 51.99% and 57.02% to the variation of grain yield per spike. The same character, grain yield was also contributed by grains per spike and seed index with the change of 58.99% and 78.36%. Above mentioned studies have shown that seed index, tillers per plant and spike length can be used to increase the grain yield of wheat genotypes to develop wheat varieties.

Genetic variations of bread wheat varieties for bread‐making quality traits in moisture stressed areas of Wollo, Ethiopia

AbstractIn Ethiopia, wheat variety development has traditionally prioritized yield and disease resistance over bread‐making quality. To address this gap, our study evaluated 22 Ethiopian bread wheat varieties across six locations during the 2015/2016 season, utilizing a randomized complete block design with three replications. Various quality traits, including 1000‐kernel weight (TKW), hectoliter weight (HLW), Perten hardness index (HI), single kernel weight (SKW), single kernel diameter (SKD), grain protein content (PC), wet gluten (WG), Zeleny value (ZV), and starch content (SC), were analyzed. Significant effects of varieties, locations, and their interactions on these traits were observed (p < 0.01). Madawalabu, Danda'a, and Mekelle‐4 displayed superior TKW (>40 g), while Menze and Bolo exhibited higher HLW. HI values ranged from 82.8% in Sofumar to 35.5% in Mekelle‐3, indicating diverse grain hardness. Favorable milling traits were observed with SKW values exceeding 30 mg and SKD surpassing 2.5 mm. Genotype and location influenced PC (9.5%–11.0%) and WG content (21.6%–25.2%), meeting bread‐making requirements. ZV ranged from 21.9% to 31%, and SC varied from 64% to 68%, reflecting changes in starch concentration between varieties. Varietal performance varied, with Madawalabu, Menze, and Bolo showing promise. Correlation analysis revealed positive associations among HLW, SKD, SKW, TKW, PC, WG, and ZV, and a negative correlation with SC. These insights provide a foundation for targeted breeding strategies to enhance specific attributes crucial for optimal bread quality, contributing valuable information to wheat breeding programs.

Mapping of Leaf Rust Resistance Loci in Two Kenyan Wheats and Development of Linked Markers.

Leaf rust caused by the pathogen Puccinia triticina (Pt) is a destructive fungal disease of wheat that occurs in almost all wheat-growing areas across the globe. Genetic resistance has proven to be the best solution to mitigate the disease. Wheat breeders are continuously seeking new diversified and durable sources of resistance to use in developing new varieties. We developed recombinant inbred line (RIL) populations from two leaf rust-resistant genotypes (Kenya Kudu and AUS12568) introduced from Kenya to identify and characterize resistance to Pt and to develop markers linked closely to the resistance that was found. Our studies detected four QTL conferring adult plant resistance (APR) to leaf rust. Two of these loci are associated with known genes, Lr46 and Lr68, residing on chromosomes 1B and 7B, respectively. The remaining two, QLrKK_2B and QLrAus12568_5A, contributed by Kenya Kudu and AUS12568 respectively, are putatively new loci for Pt resistance. Both QLrKK_2B and QLrAus12568_5A were found to interact additively with Lr46 in significantly reducing the disease severity at adult plant growth stages in the field. We further developed a suite of six closely linked markers within the QLrAus12568_5A locus and four within the QLrKK_2B region. Among these, markers sunKASP_522 and sunKASP_524, flanking QLrAus12568_5A, and sunKASP_536, distal to QLrKK_2B, were identified as the most closely linked and reliable for marker-assisted selection. The markers were validated on a selection of 64 Australian wheat varieties and found to be polymorphic and robust, allowing for clear allelic discrimination. The identified new loci and linked molecular markers will enable rapid adoption by breeders in developing wheat varieties carrying diversified and durable resistance to leaf rust.

A Comprehensive study of wheat genotypes for combining ability and heritability in drought tolerance

A major challenge in wheat cultivation is the negative impact of water scarcity on growth and yield. Therefore, it is crucial to develop wheat varieties with both high productivity and resilience to drought stress to support food production and improve global food security. The study aims to identify general and specific combining abilities and to understand the genetic mechanisms responsible for key traits by employing half-diallel analysis. In the current study, a half-diallel set comprising 10 x 10 wheat genotypes was subjected to crosses in all feasible combinations, excluding reciprocals, under drought stress conditions. Significant mean squares were observed for both General Combining Ability (GCA) and Specific Combining Ability (SCA) components among the 10 parents and 45 F1 progenies across eleven traits. Assessment of variance components (s2g and s2s), narrow-sense heritability (Hn), broad-sense heritability (Hb) and the GCA/SCA ratio allowed for the determination of the relative contributions of additive and non-additive genetic components. High narrow-sense heritability was noted for traits such as days to 75 % flowering, spike length and biological yield, indicating their predominantly additive genetic control. Conversely, the remaining eight traits exhibited low narrow-sense heritability, suggesting their inheritance is primarily governed by non-additive genetic factors, thus indicating the potential benefits of heterosis breeding. Based on GCA effects, P5 demonstrated superior general combining ability across traits, except for biological yield. P1, P3, P8 and P9 exhibited better combining ability for grain yield per plant. Specific cross combinations including P7×P10, P3×P4 and P5×P6 displayed notable specific combining ability and could be leveraged to develop superior pure lines in subsequent breeding endeavors.

Breeding for water-use efficiency in wheat: progress, challenges and prospects.

Drought poses a significant challenge to wheat production globally, leading to substantial yield losses and affecting various agronomic and physiological traits. The genetic route offers potential solutions to improve water-use efficiency (WUE) in wheat and mitigate the negative impacts of drought stress. Breeding for drought tolerance involves selecting desirable plants such as efficient water usage, deep root systems, delayed senescence, and late wilting point. Biomarkers, automated and high-throughput techniques, and QTL genes are crucial in enhancing breeding strategies and developing wheat varieties with improved resilience to water scarcity. Moreover, the role of root system architecture (RSA) in water-use efficiency is vital, as roots play a key role in nutrient and water uptake. Genetic engineering techniques offer promising avenues to introduce desirable RSA traits in wheat to enhance drought tolerance. These technologies enable targeted modifications in DNA sequences, facilitating the development of drought-tolerant wheat germplasm. The article highlighted the techniques that could play a role in mitigating drought stress in wheat.

Enhancing wheat yield and nitrogen use efficiency in the Huang‐Huai‐Hai region of China: Insights from root biomass and nitrogen application responses

AbstractWheat yield and nitrogen use efficiency (NUE) have improved simultaneously with the genetic development of wheat varieties. However, wheat selection is carried out routinely in N‐rich field conditions, with breeding progress limited under low soil available nitrogen. Thus, we performed a 2‐year field investigation using eight milestone winter wheat varieties released between 1947 and 2017 in the Huang‐Huai‐Hai region of China with two N applications—normal (CK; 220 kg N ha−1) and reduced (RN; 110 kg N ha−1)—in Shaanxi, China, to examine changes in wheat yield, NUE, water use efficiency (WUE) and root biomass. Our findings revealed average annual yield increases of 49.615 kg ha−1 and 36.905 kg ha−1 under CK and RN, respectively. Notably, the NUE trend mirrored yield, increasing with the release year of wheat varieties, with average annual increases in NUE of 0.192 and 0.336 kg kg−1 under CK and RN, respectively. In the RN treatment, N uptake efficiency (UPE) increased with year of release, while N utilization efficiency (UTE) had no significant relationship. In the CK treatment, UTE increased with year of release, while UPE had no significant relationship. Across the 2‐year experiment, surface root biomass (0–20 cm layer) increased with year of release under CK but had no relationship under RN, while deep root biomass (20–200 cm layer) decreased with year of release under CK and increased under RN. The roots of modern wheat varieties responded better to soil nitrogen levels and produced higher yields, NUE and WUE than earlier varieties by adjusting root biomass distribution in soil.

Identification of Sr67, a new gene for stem rust resistance in KU168-2 located close to the Sr13 locus in wheat

Key messageSr67 is a new stem rust resistance gene that represents a new resource for breeding stem rust resistant wheat cultivarsRe-appearance of stem rust disease, caused by the fungal pathogen Puccinia graminis f. sp. tritici (Pgt), in different parts of Europe emphasized the need to develop wheat varieties with effective resistance to local Pgt populations and exotic threats. A Kyoto University wheat (Triticum aestivum L.) accession KU168-2 was reported to carry good resistance to leaf and stem rust. To identify the genomic region associated with the KU168-2 stem rust resistance, a genetic study was conducted using a doubled haploid (DH) population from the cross RL6071 × KU168-2. The DH population was phenotyped with three Pgt races (TTKSK, TPMKC, and QTHSF) and genotyped using the Illumina 90 K wheat SNP array. Linkage mapping showed the resistance to all three Pgt races was conferred by a single stem rust resistance (Sr) gene on chromosome arm 6AL, associated with Sr13. Presently, four Sr13 resistance alleles have been reported. Sr13 allele-specific KASP and STARP markers, and sequencing markers all showed null alleles in KU168-2. KU168-2 showed a unique combination of seedling infection types for five Pgt races (TTKSK, QTHSF, RCRSF, TMRTF, and TPMKC) compared to Sr13 alleles. The phenotypic uniqueness of the stem rust resistance gene in KU168-2 and null alleles for Sr13 allele-specific markers showed the resistance was conferred by a new gene, designated Sr67. Since Sr13 is less effective in hexaploid background, Sr67 will be a good source of stem rust resistance in bread wheat breeding programs.

Genetic analyses of grain yield and yield-attributing traits in wheat (Triticum aestivum L.) grown under terminal heat stress

Abstract (286) Terminal heat stress is a key constraint in wheat cultivation and its impact is anticipated to increase in the current context of climate change. Heat stress poses a serious threat, especially during the reproductive and grain-filling stages in wheat that can causes a significant reduction in yield. The current research was carried out to assess the nature of genetic variability and the relationship between yield and yield attributing traits of 30 different wheat genotypes grown under terminal heat stress and also to isolate the best performing genotypes based on stress tolerance indices. The highest estimates of PCV and GCV were observed for plant height (67 and 65, respectively). Most of the traits showed high heritability, among which days to germination (98.45%), plant height (96.51%), total grain per plant (99.71%) exhibited the highest. The highest genetic advance was estimated in filled spikelet per spike (97.37%). Total grain weight and hundred grain weight had strong positive correlation with yield per plant. The characters viz., plant height, chlorophyll content, no. of tiller per plant, days to 50% flowering, filled grain, hundred grain weight, flag leaf length, days to booting, total grain weight had a positive direct effect on grain yield. In this experiment, SADH-2, DSN-76, NK-5, NE-3, SA-2 had the lowest value of TOL which indicated that they had high tolerance towards heat stress. The highest value of YSI was observed in DSN-76, NE-3, BAW 1008, NK-5, SADH-22 which indicated that they had lower yield reduction and higher yield stability under heat stress. The optimum sowing date showed better performance for all the examined traits compare to heat stress condition. The identified genotypes hold promise for future breeding programs aimed at developing wheat varieties resilient to terminal heat stress.

Comparative metabolic analysis and antioxidant properties of purple and white wheat grains: implications for developing functional wheat varieties

Abstract Objectives Pigmented wheat has garnered increased attention due to its elevated antioxidant activity. This study aimed to compare the metabolic components and antioxidant properties of purple and white wheat grains. Materials and Methods Metabolic analysis identified a total of 405 secondary metabolites using three extraction methods: free, acid, and alkali hydrolysis. Results The results revealed that, compared with white wheat, purple wheat exhibited significantly higher levels of total polyphenols, total flavonoids, and antioxidant activity. Notably, there were substantial variations in 90, 80, and 73 secondary metabolites between white and purple wheat under the respective extraction methods. The contents of hispidulin-8-C-(2ʹʹ-O-glucosyl) glucoside, hispidulin-8-C-glucoside, diosmetin-6-C-glucoside, and scoparin decreased across all groups, while the contents of peonidin-3-O-glucoside, keracyanin, kuromanin cyanidin-3-O-glucoside, and cyanidin-3-O-(6ʹʹ-O-malonyl) glucoside increased. Conclusions These findings suggest that pathways associated with anthocyanin, flavone, and flavonol biosynthesis were influenced. Furthermore, each extraction method revealed distinct secondary metabolites. Acid and alkali hydrolysis upregulated 16 and 3 metabolites in purple wheat, and 20 and 3 metabolites in white wheat, respectively. Acid and alkaline hydrolysis also identified indole-3-carboxylic acid, vanillic acid, pyridoxine, and other metabolites with antioxidant and antihypertensive effects in both white and purple wheat. This indicates that acid and alkaline hydrolysis can dissociate a greater variety and quantity of differential metabolites. These findings offer valuable insights for breeders seeking to develop wheat varieties with enhanced functional nutritional value.

Nitrogen-Driven Genotypic Diversity of Wheat (Triticum aestivum L.) Genotypes

Imbalanced use (form, quantity, and ratio) of nitrogen fertilization can result in decreased grain yields and increased nitrogen loss, leading to adverse effects on overall environmental quality. Globally, limited empirical research has been conducted on the comprehensive effects of different levels of N that can significantly influence wheat agronomic and genotypic traits. Therefore, this study aimed to evaluate wheat genotypes for two consecutive years (2020–2021 and 2021–2022) under different N fertilization treatments: N0 (native N, without external application of N), N75 (½ of the recommended dose of N), and N150 (recommended dose of N). The study findings revealed that ‘HD 3249’ and ‘HD 3117’ were the top-performing genotypes in terms of grain yield (5.3 t ha−1; 5.0 t ha−1), straw yield (6.9 t ha−1; 6.7 t ha−1), biological yield (12.2 t ha−1; 11.8 t ha−1), and harvest index (42.9%; 42.4%). In particular, the application of N75 and N150 increased grain yields by 142.6% and 61.3%, respectively; straw yields by 72.3%; and by 110.6% over N0. Furthermore, N levels (N75 and 150) significantly increased the higher concentration of N in grain (23.1% and 33%) and straw (21.1% and 29.8%); N uptake in grain (70.2 and 104.2) and straw (64.8 and 41.5); and total N uptake (68.8% and 101.4%) than N0, respectively. Additionally, correlation analysis revealed that there were positive correlations between yields, harvest index as well as N concentration and uptake. This study identified the two elite genotypes, ‘HD 3249’ and ‘HD 3117’, with N150 splits giving a better response, which can be used as selection criteria for developing wheat varieties that are more efficient in using nitrogen, leading to high yields and N uptake.

Genome-wide identification and characterization of Puccinia striiformis-responsive lncRNAs in Triticum aestivum.

Wheat stripe rust (yellow rust) caused by Puccinia striiformis f. sp. tritici (Pst) is a serious biotic stress factor limiting wheat production worldwide. Emerging evidence demonstrates that long non-coding RNAs (lncRNAs) participate in various developmental processes in plants via post-transcription regulation. In this study, RNA sequencing (RNA-seq) was performed on a pair of near-isogenic lines-rust resistance line FLW29 and rust susceptible line PBW343-which differed only in the rust susceptibility trait. A total of 6,807 lncRNA transcripts were identified using bioinformatics analyses, among which 10 lncRNAs were found to be differentially expressed between resistance and susceptible lines. In order to find the target genes of the identified lncRNAs, their interactions with wheat microRNA (miRNAs) were predicted. A total of 199 lncRNAs showed interactions with 65 miRNAs, which further target 757 distinct mRNA transcripts. Moreover, detailed functional annotations of the target genes were used to identify the candidate genes, pathways, domains, families, and transcription factors that may be related to stripe rust resistance response in wheat plants. The NAC domain protein, disease resistance proteins RPP13 and RPM1, At1g58400, monodehydroascorbate reductase, NBS-LRR-like protein, rust resistance kinase Lr10-like, LRR receptor, serine/threonine-protein kinase, and cysteine proteinase are among the identified targets that are crucial for wheat stripe rust resistance. Semiquantitative PCR analysis of some of the differentially expressed lncRNAs revealed variations in expression profiles of two lncRNAs between the Pst-resistant and Pst-susceptible genotypes at least under one condition. Additionally, simple sequence repeats (SSRs) were also identified from wheat lncRNA sequences, which may be very useful for conducting targeted gene mapping studies of stripe rust resistance in wheat. These findings improved our understanding of the molecular mechanism responsible for the stripe rust disease that can be further utilized to develop wheat varieties with durable resistance to this disease.

A promising QTL QSns.sau-MC-3D.1 likely superior to WAPO1 for the number of spikelets per spike of wheat shows no adverse effects on yield-related traits.

A likely new locus QSns.sau-MC-3D.1 associated with SNS showing no negative effect on yield-related traits compared to WAPO1 was identified and validated in various genetic populations under multiple environments. The number of spikelets per spike (SNS) is one of the crucial factors determining wheat yield. Thus, improving our understanding of the genes that regulate SNS could help develop wheat varieties with higher yield. In this study, a recombinant inbred line (RIL) population (MC) containing 198 lines derived from a cross between msf and Chuannong 16 (CN16) was used to construct a genetic linkage map using the GenoBaits Wheat 16K Panel. The genetic map contained 5,991 polymorphic SNP markers spanning 2,813.25cM. A total of twelve QTL for SNS were detected, and two of them, i.e., QSns.sau-MC-3D.1 and QSns.sau-MC-7A, were stably expressed. QSns.sau-MC-3D.1 had high LOD values ranging from 4.99 to 11.06 and explained 9.71-16.75% of the phenotypic variation. Comparison of QSns.sau-MC-3D.1 with previously reported SNS QTL suggested that it is likely a novel one, and two kompetitive allele-specific PCR (KASP) markers were further developed. The positive effect of QSns.sau-MC-3D.1 was also validated in three biparental populations and a diverse panel containing 388 Chinese wheat accessions. Genetic analysis indicated that WHEAT ORTHOLOG OFAPO1 (WAPO1) was a candidate gene for QSns.sau-MC-7A. Pyramiding of QSns.sau-MC-3D.1 and WAP01 had a great additive effect increasing SNS by 7.10%. Correlation analysis suggested that QSns.sau-MC-3D.1 was likely independent of effective tiller number, plant height, spike length, anthesis date, and thousand kernel weight. However, the H2 haplotype of WAPO1 may affect effective tiller number and plant height. These results indicated that utilization of QSns.sau-MC-3D.1 should be given priority for wheat breeding. Geographical distribution analysis showed that the positive allele of QSns.nsau-MC-3D.1 was dominant in most wheat-producing regions of China, and it has been positively selected among modern cultivars released in China since the 1940s. Gene prediction, qRT-PCR analysis, and sequence alignment suggested that TraesCS3D03G0216800 may be the candidate gene of QSns.nsau-MC-3D.1. Taken together, these results enrich our understanding of the genetic basis of wheat SNS and will be useful for fine mapping and cloning of the gene underlying QSns.sau-MC-3D.1.

Household and plot-level survey data on adoption, outcomes, and perceptions of early sown wheat and zero tillage in Northwest India

This study collected evidence on the use of early sown wheat varieties and complementary zero tillage technologies in Northwest India. Detailed information on farmers’ knowledge, adoption decisions, personal experience, and perceptions of early sown wheat and zero tillage technologies were collected at the household level using different survey tools. Additional information on agricultural practices during the Rabi Season 2021/22 were collected at the plot level and geocoded. Overall, the dataset comprises responses from 1206 wheat farmers in 70 villages across 7 districts in Punjab and Haryana that were collected between September and October 2022. The villages were selected using stratified random sampling based on a sampling frame of 1722 communities that had been identified as predominantly wheat growing areas based on remote-sensing data from satellite images. The dataset provides rich information that may be used for assessing the diffusion and impact of recently developed wheat varieties designed for early sowing, identifying barriers to the wider adoption of these technologies, and informing policy making aimed at improving adoption and usage decisions of agricultural innovations.

Comparative transcriptomic and metabolomic analysis revealed molecular mechanism of two wheat near-isogenic lines response to nitrogen application

Nitrogen (N) is an essential nutrient element required for plant growth, and the development of wheat varieties with high nitrogen use efficiency (NUE) is an urgent need for sustainable crop production. However, the molecular mechanism of NUE between diverse wheat varieties in response to N application remains unclear. To reveal the possible molecular mechanisms underlying this complex phenomenon, we investigated the transcriptional and metabolic changes of flag leaves of two wheat near-isogenic lines (NILs) differing in NUE under two N fertilizer treatments. Comparative transcriptome analysis indicated that the expression levels of the genes responsible for carbon and nitrogen metabolism were significantly higher in high-NUE wheat. The metabolome comparison revealed that the activity of the tricarboxylic acid (TCA) cycle was enhanced in high-NUE wheat, while reduced in low-NUE wheat after the N fertilizer application. Additionally, amino acid metabolism increased in both wheat NILs but more increased in high-NUE wheat. In summary, more upregulated transcripts and metabolites were identified in high-NUE wheat, and this study provides valuable new insights for improving NUE in wheat.

Screening of leaf rust resistance genes (Lr) in the breeding lines of winter bread wheat

In the Rostov region, among cereal crops, winter wheat occupies a leading position in terms of the sown area. Breeders have developed wheat varieties, a productivity potential of which is 1.5–2 times higher than their actual yield in production. One of the most important factors that can destabilize gross grain harvests and reduce productivity are parasitic organisms, the most dangerous of which are rust pathogens (Puccinia triticina, P.striiformis, P.graminis). Brown rust (pathogen Puccinia triticina Erikss.) is one of the dangerous wheat diseases. The genetic diversity of cultivated varieties according to resistance types and genes that control it, provides reliable wheat protection against this pathogen. The purpose of the current study was to identify leaf rust resistance genes (Lr-genes) using marker selection for the winter bread wheat lines. The study was carried out in 2020–2021. The objects of research were 311 winter bread wheat lines of the FSBSI Agricultural Research Center «Donskoy». In the study of winter bread wheat lines, there were used such methods as DNA isolation using CTAB, PCR, and electrophoresis on agarose gels. Using molecular markers, there have been identified 24 samples with a functional allele of the Lr10 gene (1672, 518/21 (1), 595/21 (1) 595 (4), 625/21, 626/21, etc.), 49 samples with the dominant allele Lr26 (1105, 502/21, 526/21 (1), 526/21 (2), 529/21 (12), 557/21, etc.), 13 lines with the resistance allele of the Lr37 gene (1105, 1609, 1610, 1611, 1612, 1613, 1615, etc.). There was also found that the Lr17a gene was not detected in the studied lines.

Effect of Hill Temperature on Wheat Variety Development and Yield in the District of Khagrachari

The experiment which likened the execution of high-placed outcome briefly cold duration and heat-tolerant varieties under increasing temperature was carried out in two successive crop seasons (2017-18 and 2018-19) at a farmer's field in Maniksari Upzila within Khagrachari Hill District during the Rabi season (November–March). Early mature wheat types made available by BARI were sown at the ideal time and were heat, saline tolerant as a coping strategy for extreme heat stress. There were six short time wheat cultivars developed recently in heat and stress (BARI Gom 25, BARI Gom 28, BARI Gom 30, BARI Gom 32, BARI Gom 33, and Advance Line BAW 1147). BARI Gom 33 (3.86 t/ha and 3.80 t/ha) and BARI Gom 30 (3.78 t/ha and 3.56 t/ha) produced the highest crop yields over the course of a few years. BARI Gom 32 (3.00 t/ha and 3.40 t/ha), Advance line 1147 (2.96 t/ha and 3.04 t/ha), and BARI Gom 28 (2.59 t/ha and 3.10 t/ha) were found the highest yields. BARI Gom 25 (2.74 t/ha and 2.89 t/ha) had the lowest yield. The quantity of biomass yield and wheat crop output differed significantly, but the other characteristics had little bearing. BARI Gom 25 was the earliest maturing variety, and BARI Gom 33 generated the highest crop output compared to other varieties. The highest benefit cost ratio (BCR) was 1.48 displayed by BARI Gom 33 and the lowest by BARI Gom 25 which was 1.08. According to the experiment's findings, BARI Gom 33 was among the six kinds in the Khagrachari Hills' early high producing and most adaptable variety. BARI Gom 30 also may be cultivated in the Khagrachari Hills District.

Stripe rust and leaf rust resistance in CIMMYT wheat line “Mucuy” is conferred by combinations of race-specific and adult-plant resistance loci

Developing wheat varieties with durable resistance is a core objective of the International Maize and Wheat Improvement Center (CIMMYT) and many other breeding programs worldwide. The CIMMYT advanced wheat line “Mucuy” displayed high levels of resistance to stripe rust (YR) and leaf rust (LR) in field evaluations in Mexico and several other countries. To determine the genetic basis of YR and LR resistance, 138 F5 recombinant inbred lines (RILs) derived from the cross of Apav#1× Mucuy were phenotyped for YR responses from 2015 to 2020 at field sites in India, Kenya, and Mexico, and LR in Mexico. Seedling phenotyping for YR and LR responses was conducted in the greenhouse in Mexico using the same predominant races as in field trials. Using 12,681 polymorphic molecular markers from the DArT, SNP, and SSR genotyping platforms, we constructed genetic linkage maps and QTL analyses that detected seven YR and four LR resistance loci. Among these, a co-located YR/LR resistance loci was identified as Yr29/Lr46, and a seedling stripe rust resistance gene YrMu was mapped on the 2AS/2NS translocation. This fragment also conferred moderate adult plant resistance (APR) under all Mexican field environments and in one season in Kenya. Field trial phenotyping with Lr37-virulent Puccinia triticina races indicated the presence of an APR QTL accounting for 18.3–25.5% of the LR severity variation, in addition to a novel YR resistance QTL, QYr.cim-3DS, derived from Mucuy. We developed breeder-friendly KASP and indel molecular markers respectively for Yr29/Lr46 and YrMu. The current study validated the presence of known genes and identified new resistance loci, a QTL combination effect, and flanking markers to facilitate accelerated breeding for genetically complex, durable rust resistance.

Factors affecting the processes of androgenesis during wheat anthers cultivation (review)

The current study was carried out in order to analyze the literature devoted to the researches of a number of factors affecting the processes of androgenesis in vitro in wheat anther culture. Triticum aestivum L. is one of the most stable food crops in the world. An important step for wheat breeders is to improve the productivity potential with appropriate grain quality and resistance to unfavorable environmental factors. In order to improve and speed up the breeding process, a targeted selection of the initial material is required with the involvement of donors according to the main limiting traits and properties. In this regard, the use of modern breeding methods and biotechnological techniques, which make it possible to quickly obtain a new initial material with desirable economically valuable traits becomes an urgent issue. The use of haploidy methods, namely, the development of plants with a single set of chromosomes from an immature wheat anther culture (androgenesis), has great prospects for such work. According to the researchers, the efficiency of the method in vitro depends on many factors, such as influence of a genotype, growing conditions, a selection period, pre-treatment, a nutrient medium formula and cultivation conditions. According to some critical reviews, a genotype dependence, low efficiency, and albinism can pose serious limitations to the application of the anther culture method. However, other research groups have made significant efforts to reduce the impact of these negative factors. Due to continuous improvements, the well-established method of anther culture cultivation in vitro can be an effective way to develop wheat varieties and lines with the desired traits and properties.

Characterization of Pyrenophora tritici-repentis (tan spot of wheat) races in Kazakhstan

Tan spot, caused by Pyrenophora tritici-repentis, is an economically important foliar disease of wheat in Kazakhstan. Population structure of the pathogen changes every year due to climate change. This study aimed to characterize the race structure of P. tritici-repentis isolates recovered from wheat in south and north Kazakhstan, and identify tan spot resistance in host genotypes based on disease phenotypes and molecular screening. Virulence profiles were determined within 40 isolates of the pathogen from wheat crops during the 2020 growing season. Seven races, (1, 3, 4, 5, 6, 7 and 8) were identified. A collection of 80 wheat accessions, including promising lines and cultivars from Kazakhstan and Russia, were evaluated for their reactions to races 1 and 5 of the pathogen, and to Ptr ToxA and Ptr ToxB, using greenhouse assessments and molecular markers diagnostic for the Tsn1 and Tsc2 genes. From a practical viewpoint, 18 wheat genotypes were insensitive to the two races and the two Ptr toxins. This resistant germplasm can be used in breeding programmes aiming to develop wheat varieties resistant to P. tritici-repentis.

Genetic Divergence in Micronutrient Rich wheat– A Tool to Identify Diverse Parents

Aim: To Study genetic divergence in the micronutrient rich lines to identify diverse parents for hybridization.
 Study Design: Randomized Complete Block Design
 Place and Duration of Study: Division of Plant Breeding and Genetics, She-e-Kashmir University of Agricultural Sciences and Technology of Jammu during rabi 2019-20.
 Methodology: Nature and magnitude of variability in forty-nine zinc/iron rich genotypes along with three commercial varieties with stripe rust resistance could be grouped into five clusters using D2–Statistics.
 Results: Fifty-two lines were placed in five cluster with most of the micronutrient rich lines lying in cluster I except for HP-44 , HP 49 , HP 14 and HP 13 placed in cluster II, III, IV and V respectively indicating them to be divergent than the rest. Further HD 3086, RSP 561 and JAUW-683 were in the cluster I indicating them to be less diverse with respect to traits under study. The traits that contributed mast towards divergence were grain yield per plant(25) percent followed by number of tillers per plant (20.7) percent and 1000 grain weight (14) percent zinc and iron add little contribution of 8 and 7 percent respectively to the total divergence hence could not classified the genotypes into different cluster based on inter cluster distance Cluster III and Cluster V had the greatest inter-cluster distance, followed by Cluster III and Cluster IV, Cluster II and Cluster V, and Cluster II and Cluster IV.
 Conclusion: Developing wheat varieties with enhanced content of iron and zinc is one of the most sought objectives in a present world to alleviate micronutrient malnutrition. Modern wheat varieties exhibit little diversity in zinc and iron levels in the grain, but large-scale screening has found significant amounts of zinc and iron in wild relatives and progenitors of cultivated wheat.