Resistant Wheat Genotypes Research Articles

Evaluation of Wheat Genotypes for Growth and Yield Performance under Rainfed Conditions

This research evaluated the growth and yield potential of five wheat genotypes viz., UJ-2021, Sindh-2023, Punjab-2024, NWFP-2022 and Balochistan-2020 under rainfed environment at National Agricultural Research Centre, Islamabad during 2024. The major aim was to establish optimal and drought-tolerant genotypes in low water supply conditions. Having laid down three replications per genotype according to a randomized complete block design, the work concentrated on plant population, plant height, and number of tillers, 1000-grain weight, grain yield and biomass yield. Punjab-2024 genotype showed better performance than other genotypes in all parameters though variations were observed in plant population (210 plants/m²), plant height (112 cm), number of tillers (8. 2 per plant), 1000-grain weight (48 g), grain yield (520 g/m²), and biomass production (1. 50 kg/m²). On the other hand Balochistan-2020 had the lowest yield potential attributed to lower adaptability and productivity under rainfed environment. The current research is paramount in understanding ways of selecting better genotypes in order to increase the production of wheat under water deficit conditions. The results of Punjab-2024 indicate its enhanced yield and resource use efficiency in rainfed situation thus signifying its potential. The results are important for maintenance and improvement of high yielding and resistant wheat genotypes which would help in food security and sustainable farming. Future work should be aimed more at improving the low performing genotypes of Punjab-2024 and identify the underlying genetics for the said advantageous traits.

Transporters regulate silicon uptake to make stripe rust resistant wheat genotypes more effective

Silicon (Si) supplementation is known to aid plants in mitigating various biotic and abiotic stressors. However, the mechanisms underlying Si-mediated stress alleviation, particularly the involvement of Si transporters and genotype-specific responses, remain poorly understood. Against this backdrop, we investigated the role of Si transporters in biotic stress alleviation in specific wheat genotypes infected with stripe rust. The primary objectives were to assess the role of Si accumulation in stripe rust resistance across different wheat genotypes and to determine how Si transporters affect their resistance responses. Twenty wheat genotypes were evaluated for their ability to accumulate Si in shoots, revealing significant variations among the selected genotypes. Resistant genotypes showed higher Si concentrations than susceptible ones, leading to the selection of two contrasting genotypes, viz., WW-120 (resistant) and K-88 (susceptible), for further analysis. In these genotypes, the expression of Si transporters and various physiological and biochemical responses were studied under stripe rust infestation with and without Si supplementation. We found that Si supplementation upregulated the expression of Si transporters, with a more pronounced increase in the resistant genotype than in the susceptible one, resulting in higher Si accumulation in the former. Moreover, differential physiological and biochemical responses to rust infection and Si supplementation were observed in both genotypes, indicating genotype-dependent variations across all measured variables. Our results suggest that higher Si accumulation in resistant wheat genotypes, due to the upregulation of Si transporters, plays a crucial role in their defense against rust infection. Further elucidation of these mechanisms could be used to enhance plant resistance to biotic stressors through targeted Si management.

Identification of Rust Resistance Genes in Wheat (Triticum aestivum L.) Using Molecular Markers and Host–Pathogen Interaction Tests

ABSTRACTThe leaf rust (Puccinia triticina f. sp. tritici), stripe rust (Puccinia striiformis f. sp. tritici), and stem rust (Puccinia graminis f. sp. tritici) are major fungal constraints affecting wheat production worldwide. Identifying and deploying wheat varieties with diverse resistance are the best ways to manage all the rusts. Therefore, a continuous search goes on to identify diverse germplasm with effective rust resistance that expresses at different stages of plant growth (seedling and adult plant). A set of 22 rust resistant wheat genotypes and 4 checks (controls), viz., Avocet‐Yr10, Avocet ‐Yr15, Agra Local, and respective positive checks were studied for characterising rust resistance genes using host–pathogen interactions complemented by molecular markers. Among 22 elite genotypes, 05 genotypes amplified 191 bp fragment with marker PSY1E1, confirmed the presence of gene Lr19/Sr25. These genotypes also expressed resistance to most virulent leaf rust pathotypes, 77‐5 and 77‐9 in host–pathogen interaction test (HPI). Seven genotypes showed the presence of Lr34/Yr18/Sr57/Pm38/Ltn1 in homozygous state, whereas G4 showed its presence in heterozygous condition. Among 22 genotypes, 16 genotypes possessed Yr10. Five genotypes (22.7%) exhibited two gene combinations, Lr19/Sr25, and Yr10 as revealed through the detection of 191 bp fragment with marker PSY1E1 and 260 bp fragment with co‐dominantly inherited microsatellite marker Xpsp3000, respectively. All five genotypes (G2, G3, G8, G9, and G18) also expressed brown glumes controlled by the gene Rg1 tightly linked to Yr10 on the 1BS chromosome. Broad spectrum rust resistance present in these lines in good agronomic backgrounds could be used as potent genetic donors for diverse and durable rust resistance breeding programmes in wheat.

Phenotypic Assessment of Turkish Wheat Genotypes For slow Yellow Rusting Resistance (Puccinia striiformis f.sp. tritici)

Phenotypic Assessment of Turkish Wheat Genotypes For slow Yellow Rusting Resistance (Puccinia striiformis f.sp. tritici)

Evaluation of effectiveness resistance genes in wheat genotypes using marker-assisted selection for stripe rust resistance breeding”

Stripe rust, induced by Puccinia striiformis f. sp. tritici, is the most harmful and prevalent disease in temperate regions worldwide, affecting wheat production areas globally. An effective strategy for controlling the disease involves enhancing genetic resistance against stripe rust, achieved through Egyptian breeding efforts not previously conducted on wheat genotypes. The resistance level to stripe rust in thirty-eight wheat genotypes was assessed using marker-assisted selection methods. The investigation suggests that wheat breeding programs can utilize slow-rusting Yr genes, which are effective resistance genes, to develop novel genotypes with stripe rust resistance through marker-assisted breeding. Based on the four disease responses of the wheat genotypes under investigation, the results categorized the genotypes into three groups. The first group included resistant genotypes, the second group exhibited a slow-rusting character with the lowest disease symptom rates, and the last group displayed the highest disease characteristics rates throughout the three seasons, comprising fast-rusting genotypes. The rust-resistant genes identified were Yr5, Yr9, Yr10, Yr15, Yr17, Yr18, Yr26, Yr29, Yr30, and Yr36. Genes Yr26, Yr30, and Yr36 were present in all genotypes. Genotypes Misr3, Misr4, Giza168, Giza167, Giza170, Giza171, Gemmeiza9, and Gemmeiza10 carried the Yr9 gene. Only one genotype, Sids13, was found to have the Yr17 gene. Genes Yr18 and Yr29 were identified in Sids14, Giza168, Giza170, Gemmeiza9, and Gemmeiza10. However, none of the wheat genotypes showed the presence of Yr5, Yr10, or Yr15. Several backcrossing generations were conducted to introduce the Yr5 and Yr10 genes into susceptible genotypes (Misr1, Misr2, and Gemmeiza11). These genotypes are cultivated globally and are known for producing high-quality flour, making them of great importance to farmers. The study demonstrates significant potential for enhancing wheat genotypes for stripe rust resistance and increased production.

Molecular diversity and trait association analysis in different wheat genotypes for yellow rust resistance

Molecular diversity and trait association analysis in different wheat genotypes for yellow rust resistance

Identification of Wheat Septoria tritici Resistance Genes in Wheat Germplasm Using Molecular Markers.

Zymoseptoria tritici (Z. tritici) is the main threat to global food security; it is a fungal disease that presents one of the most serious threats to wheat crops, causing severe yield losses worldwide, including in Kazakhstan. The pathogen leads to crop losses reaching from 15 to 50%. The objectives of this study were to (1) evaluate a wheat collection for Z. tritici resistance during the adult plant and seedling growth stages, (2) identify the sources of resistance genes that provide resistance to Z. tritici using molecular markers linked to Stb genes, and (3) identify potentially useful resistant wheat genotypes among cultivars and advanced breeding lines. This study evaluated 60 winter and spring wheat genotypes for Z. tritici resistance. According to the field reactions, 22 entries (35.7%) showed ≤10% disease severity in both years. The resistant reaction to a mix of Z. tritici isolates in the seedling stage was associated with adult plant resistance to disease in four wheat entries. The resistance of Rosinka 3 was due to the presence of Stb8; Omskaya 18 showed an immune reaction in the field and a moderately susceptible reaction in the seedling stage, possibly provided by a combination of the Stb7 and Stb2 genes. The high resistance in both the adult and seedling stages of Omskaya 29 and KR11-03 was due to the Stb4 and Stb2 genes and, possibly, due to the presence of unknown genes. A linked marker analysis revealed the presence of several Stb genes. The proportion of wheat entries with Stb genes was quite high at twenty-seven of the genotypes tested (45.0%), including four from Kazakhstan, nine from Russia, nine from the CIMMYT-ICARDA-IWWIP program, and five from the CIMMYT-SEPTMON nursery. Among the sixty entries, ten (16.7%) carried the resistance genes Stb2 and Stb8, and the gene Stb4 was found in seven cultivars (11.6%). Marker-assisted selection can be efficiently applied to develop wheat cultivars with effective Stb gene combinations that would directly assist in developing durable resistance in Kazakhstan. Resistant genotypes could also be used as improved parents in crossing programs to develop new wheat cultivars.

Molecular Mechanisms of the Stripe Rust Interaction with Resistant and Susceptible Wheat Genotypes.

Rust fungi cause significant damage to wheat production worldwide. In order to mitigate disease impact and improve food security via durable resistance, it is important to understand the molecular basis of host-pathogen interactions. Despite a long history of research and high agricultural importance, still little is known about the interactions between the stripe rust fungus and wheat host on the gene expression level. Here, we present analysis of the molecular interactions between a major wheat pathogen-Puccinia striiformis f. sp. tritici (Pst)-in resistant and susceptible host backgrounds. Using plants with durable nonrace-specific resistance along with fully susceptible ones allowed us to show how gene expression patterns shift in compatible versus incompatible interactions. The pathogen showed significantly greater number and fold changes of overexpressed genes on the resistant host than the susceptible host. Stress-related pathways including MAPK, oxidation-reduction, osmotic stress, and stress granule formation were, almost exclusively, upregulated in the resistant host background, suggesting the requirement of the resistance-countermeasure mechanism facilitated by Pst. In contrast, the susceptible host background allowed for broad overrepresentation of the nutrient uptake pathways. This is the first study focused on the stripe rust pathogen-wheat interactions, on the whole transcriptome level, from the pathogen side. It lays a foundation for the better understanding of the resistant/susceptible hosts versus pathogenic fungus interaction in a broader sense.

Screening of wild and synthetic wheat genotypes for resistance against corn leaf aphid, Rhopalosiphum maidis (Fitch)

Screening of wild and synthetic wheat genotypes for resistance against corn leaf aphid, Rhopalosiphum maidis (Fitch)

Evaluation of wheat genotypes for resistance to bacterial leaf streak caused by Xanthomonas translucens pv. undulosa in field and greenhouse trials

Bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa, is a devastating cereal disease that is becoming more common in Iran. A cost-effective and realistic strategy to cope with BLS is planting of BLS-resistant cultivars. To discover BLS-resistant genotypes, 360 hexaploid wheat genotypes were selected and inoculated with a local strain of Xanthomonas translucens pv. undulosa in the field and greenhouse in two years (2019 & 2020). In the field experiments, disease reaction of wheat plants was assessed based on both percentage of disease incidence (PDI) and the percentage of disease severity (PDS). In the greenhouse experiment, disease reaction was evaluated as the disease severity (DS). The genotypes with PDS, PDI, and DS values ≤ 20% were considered BLS-resistant or semi-resistant. Genotypes with zero or very low PDS, PDI and DS during the first and second years were considered highly resistant to the disease. Despite resistant genotypes being more prevalent than susceptible genotypes in each year, genotype responses to BLS varied over the two years, but in both years, most genotypes showed a resistance response. Forty-six genotypes (12.8%) were consistently BLS-resistant across years in the field and greenhouse trials. In 2020, field BLS intensity ratings (PDI and PDS) were positively correlated with flag leaf width and days to maturity. In contrast, PDI and PDS were negatively correlated with plant height, peduncle length, and spike length. In 2019, no significant correlations were found between PDI, PDS, and phenotypic traits. Cluster heatmaps and principal component analysis (PCA) separated resistant and susceptible genotypes. In BLS-resistant genotypes, plant height, peduncle length, and spike length were significantly longer, but flag leaf width and days to maturity were shorter. This study identified new and diverse sources of resistance to BLS that could be used in wheat breeding efforts.

Genetic Analysis and Molecular Identification of the Powdery Mildew Resistance in 116 Elite Wheat Cultivars/Lines.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease worldwide. Host resistance is the preferred method for limiting the disease epidemic, protecting the environment, and minimizing economic losses. In the present study, the reactions to powdery mildew for a collection of 600 wheat cultivars and breeding lines from different wheat-growing regions were tested using the Bgt isolate E09. Next, 116 resistant genotypes were identified and then crossed with susceptible wheat cultivars/lines to produce segregating populations for genetic analysis. Among them, 87, 19, and 10 genotypes displayed single, dual, and multiple genic inheritance, respectively. To identify the Pm gene(s) in those resistant genotypes, 16 molecular markers for 13 documented Pm genes were used to test the resistant and susceptible parents and their segregating populations. Of the 87 wheat genotypes that fitted the monogenic inheritance, 75 carried the Pm2a allele. Three, two, one, and two genotypes carried Pm21, Pm6, Pm4, and the recessive genes pm6 and pm42, respectively. Four genotypes did not carry any of the tested genes, suggesting that they might have other uncharacterized or new genes. The other 29 wheat cultivars/lines carried two or more of the tested Pm genes and/or other untested genes, including Pm2, Pm5, Pm6, and/or pm42. It was obvious that Pm2 was widely used in wheat production, whereas Pm1, Pm24, Pm33, Pm34, Pm35, Pm45, and Pm47 were not detected in any of these resistant wheat genotypes. This study clarified the genetic basis of the powdery mildew resistance of these wheat cultivars/lines to provide information for their rational utilization in different wheat-growing regions. Moreover, some wheat genotypes which may have novel Pm gene(s) were mined to enrich the diversity of resistance source.

Partial Resistance Components and Morphological Traits Aid Selection of Resistant Wheat Genotypes against Spot Blotch

Spot blotch caused by Bipolaris sorokiniana results substantial yield losses (15-80%) in an Indian subcontinent. Wheat varietal improvement through breeding followed by evaluation of elite germplasms against a particular disease is crucial method to manage diseases. Fifty diverse wheat genotypes and two susceptible checks viz., Sonalika and Nepal 297 were evaluated under artificial epiphytotic condition against spot blotch at NWRP, Bhairahawa, Nepal in 2017-18 and 2018-19. Evaluation was based on partial resistance components viz., lesion sizes, lesion types (chlorotic/ necrotic), lesion characteristics (sporulating/ non-sporulating) and area under disease progress curve (AUDPC) and morphological traits viz. lesion mimic, leaf angle, leaf tip necrosis and plant height. Statistical analysis revealed that genotypes with smaller lesion size (<1 cm), small dark brown to black lesions with or without chlorosis/ necrosis and non sporulating lesions had lower AUDPC (<225). Similarly genotypes with erect to semi erect leaf (leaf angle 1-2), medium to high leaf tip necrosis (2-4), low percentage of lesion mimic (0-22.5%) were found resistant (AUDPC<225) to moderately resistant (AUDPC value 226-315). Moreover AUDPC showed strong and positive correlation with lesion sizes (0.76), lesion types (0.84) and lesion characteristics (0.54). Twenty genotypes were found resistant (AUDPC<225), could be used as new resistance sources in breeding program. However genotypes viz., KACHU/BECARD//WBLL1*2/BRAMBLING/3/ATTILA*2/PBW65//MURGA, FRET2*2/SHAMA//TNMU/3/FRET2*2/SHAMA/4/UP2338*2/KKTS*2//YANAC/5/FRET2*2/SHAMA//PARUS/3/FRET2*2/KUKUNA, KACHU#1//PI610750/SASIA/3/KACHU/4/MUU#1//PBW343*2/KUKUNA/3/MUU/5/KACHU#1//PI610750/SASIA/3/KACHU, BORL14//KFA/2*KACHU and KFA/2*KACHU//QUELEA were found excellent based on partial resistance components and morphological traits. These genotypes could be further evaluated for yield potential in multi environment and better performing genotypes could be released as resistant varieties for spot blotch.

Polyphenols and phytohormones profiling of pre-harvest sprouting resistant and susceptible wheat genotypes

Pre-harvest sprouting (PHS) is one of the major threats to global food security as it significantly affects cereals’ production and quality. PHS tolerance depends on diverse factors, among which phytohormones and germination-inhibitory substances (GISs) play essential roles. However, in wheat, information related to GIS in the glume is scarce. Thus, we applied LC–MS/MS-based metabolomics analysis to explore the polyphenols and phytohormones profiles of two contrasting wheat genotypes, Lincang Hulled Wheat (LHW, PHS-resistant) and Yunmai53 (Yun53, PHS-highly susceptible). Physiological tests revealed that LHW PHS-resistance is not associated with the ability of its spikelet to prevent water absorption. The total polyphenol content of the spikes and shells of LHW was significantly higher than that of Yun53, respectively. In total, 214 phenolic compounds classified mainly into phenolic acids (42.52%), flavones (23.83%), and flavonoid carbonosides (16.36%) were identified. 180 differentially accumulated polyphenols (DAPs) were uncovered, including 168 up-regulated in LHW. 24 most up-regulated DAPs (Log2FC ≥ 8) were unveiled as potential candidate GISs. Of the identified phytohormones, abscisic acid, salicylic acid, and jasmonic acid exhibited significantly higher content in LHW compared to Yun53. Whereas, Yun53 contained significantly higher levels of ethylene and gibberellin than LHW. Our findings offer new resources for PHS control in wheat.

Wheat Septoria Disease Management and Molecular Breeding Approaches in Ethiopia: A Review

Septoria tritici blotch (STB) caused by the fungus Mycosphaerella graminicola, is one of the most important foliar diseases of wheat (T. aestivum spp., aestivum L.) worldwide. The disease is pervasive and economically significant throughout Ethiopia's wheat-growing regions. Naturally susceptible wheat cultivars of STB disease were found in the Central Highlands of Ethiopia, where incidence (98%) and severity (97%) of the disease, as well as yield loss (41%), were documented. This disease has been managed using a variety of techniques, including cultural control, chemical control, and genetic controls have been utilized to control this disease and subsequently reduce yield losses. The lack of information on the diversity of diseases worldwide and in Ethiopia now hampers the screening and selection of wheat genotypes for disease resistance. In this review, wheat septoria disease management and molecular breeding approaches in Ethiopia were assessed.

Genetic Characterization of Advance Bread Wheat Lines for Yield and Stripe Rust Resistance.

Wheat (Triticum aestivum L.) is a prominent grain crop. The goal of the current experiment was to examine the genetic potential of advanced bread wheat genotypes for yield and stripe rust resistance. Ninety-three bread wheat genotypes including three varieties (Kohat-2017, Pakistan-2013, and Morocco) were field tested in augmented design as observational nurseries at three locations (i.e., Kohat, Nowshera, and Peshawar) during the 2018-19 crop season. Various parameters related to yield and stripe rust resistance showed significant differences among genotypes for most of the characters with few exceptions. The analysis of variance revealed significant variations for all the genotypes for all the traits at all three sites with few exceptions where nonsignificant differences were noticed among genotypes. Averaged over three locations, genotypes exhibiting maximum desirable values for yield and yield components were KT-86 (325 tillers) for tillers m-2, KT-50 (2.86 g) for grain weight spike-1, KT-49 (41.6 g) for 1000-grain weight, KT-50 (74 grains) for grains spikes-1, KT-55 (4.76 g) for spike weight, and KT-36 and KT-072 (4586 kg ha-1) for grain yield. Correlation analysis revealed that grain yield had a significant positive correlation with grain spike-1 and grain weight spike-1 at Kohat, with grains spike-1, tillers m-2, and grain weight spike-1 at Nowshera, and with plant height, spike weight, 1000-grain weight, and tillers m-2 at Peshawar. Molecular marker data and host response in the field at the adult stage revealed that Yr15 and Yr10 are both still effective in providing adequate resistance to wheat against prevalent races of stripe rust. Four lines showing desirable lower average coefficient of infection (ACI) values without carrying Yr15 and Yr10 genes show the presence of unique/new resistance gene(s) in the genetic composition of these four lines. Genotype KT-072 (4586 kg ha-1 and 1.3 ACI), KT-07 (4416 kg ha-1 and 4.3 ACI), KT-10 (4346 kg ha-1 and 1.0 ACI), and KT-62 (4338 kg ha-1 and 2.7 ACI) showed maximum values for grain yield and low desirable ACI values, and these lines could be recommended for general cultivation after procedural requirements of variety release.

Non-2NS blast resistant wheat genotypes evaluated in the Brazilian Cerrado

Non-2NS blast resistant wheat genotypes evaluated in the Brazilian Cerrado

Genetic analysis of grain yield and its contributing traits in four bread wheat (Triticum aestivum L.) crosses using six parameter model

In order to create a successful and efficient breeding programme, it is highly helpful to analyse the gene action governing the expression of different traits. The objective of the present study was to use generation mean analysis to ascertain the kind and extent of gene action in bread wheat utilizing six generations (P1, P2, F1, F2, BC1 and BC2) of the four crosses, cross I (HD 2967 x PBW 752), cross II (RSP 561 x PBW 779), cross III (RSP 561 x PBW 780), and cross IV (JAUW 584 x WH 1184). These crosses included elite stripe rust resistant wheat genotypes in addition to locally adapted cultivars. The results showed that all the traits in all crosses had highly significant estimated mean effects (m), showing the quantitative inheritance of the selected traits. For grain yield and most of the selected characters, it was found that additive gene effects was shown to be less significance than dominance type gene effects. Among the different characters studied in the four crosses, the degree of dominance x dominance was large and negatively significant, whereas additive x additive gene actions were high and positively significance. In wheat breeding, it was found that selection for the improvement of grain yield and its contributing traits must be postponed until later generations because additive x dominant gene effects was of lesser significance. Keywords:  wheat; grain yield; additive; dominance; epistatic gene effects

Diversity of Pathotypes of Leaf Rust (<i>Puccinia triticina</i>) Pathogen in Wheat Crop in Nepal

Wheat (<i>Triticum aestivum</i>) is third most important crop in Nepal after rice and maize. The area of cultivation of wheat is increasing compare to last decade but its productivity could not be increased significantly due to many biotic and abiotic factors. Among them, rust disease is major biotic constraint. Leaf rust (<i>Puccinia triticina</i>) is an economically important disease which occurs on major wheat growing areas of plain and hill of the country. The leaf rust disease monitoring and samples collection were done from 32 districts across the wheat growing area. Rust infected leaves were folded such that rust pustules preserved inside without destroying spores. Excess leaf moisture was removed by keeping them in room temperature with shade drying. Proper dried samples were kept in paper envelop and diagnosed pathotypes at Indian Institute of Wheat and Barley Research (IIWBR), Indian Council of Agricultural Research (ICAR), Regional Station, Flowerdale, Shimla, India. urediospores were revived on 2% water agar and multiplied in susceptible host Agra Local. The fresh urediospores of each sample was collected from susceptible host and inoculated on 5-7 days old seedlings of the standard differential sets. The pathotypes of pathogen was diagnosed on the base on disease infection type showed in the differential sets. Pathotypes 57R39 121R63-1, 21R55, 109R31-1, 121R60-1, 93R15 and 93R39 were commonly observed in both plain and hills. Similarly, the pathotypes 125R23-1, 109R63 and 21R63 were recorded in lower belt whereas, pathotypes 5R13, 49R39, 125R28, 21R31 and 93R47 were found only at hilly regions. The pathotypes 21R55, 121R63-1, 121R63-1and 5R37 were recorded in successive years in most of the wheat growing area. Twenty one different pathotypes of <i>P. triticina</i> occur in different parts of the country. The evolving of different pathotypes diversity of pathogens may be caused by selection pressure due to same genetic materials of wheat genotypes grown in the country and conducive environment. Hence, monitoring rust pathotypes is a one of the necessary step for successful planning to manage the rust disease by developing resistant wheat genotypes.

Evaluation of wheat Genotypes for heat stress and disease resistance in multiple environments of Bangladesh

Twenty-seven advanced lines including three exiting varieties (BARI Gom 21, BARI Gom 32 and BARI Gom 33) were evaluated in alpha lattice design with two replications at Bangladesh Wheat and Maize Research Institute, Dinajpur and regional stations at Joydebpur, Jashore and Rajshahi under irrigated timely sown (ITS) and irrigated late sawn (ILS) conditions. The objective of the study was to find out the heat-tolerant wheat lines for future breeding programme to develop heat-tolerant wheat varieties. The genotypes were evaluated for phenological variation such as heading and maturity, yield and yield components, disease reaction, sterility, visual grain quality, etc. The results showed that the highest grain yield (5951 kg ha-1) was recorded with genotype BAW 1415 at Dinajpur under ITS condition and the lowest grain yield (1923 kg ha-1) was observed in BAW 1416 at Rajshahi under ILS condition. Considering the overall performances, genotypes BAW 1402, BAW 1403, BAW 1406, BAW 1407, BAW 1408, BAW 1411, BAW 1422 and BAW 1425 performed better. Considering disease infestation, genotypes BAW 1374, BAW 1393, BAW 1394, BAW 1397, BAW 1399 and BAW 1401 showed a good level of resistance to both leaf rust (LR) and wheat blast (WB). These genotypes could be selected for future breeding programmes to develop heat-tolerant and diseases resistance varieties. Bangladesh J. Agri. 2022, 47(2): 1-16

Characterization of wheat (Triticum aestivum) genotypes for multiple fungal resistance using functional markers

Wheat (Triticum aestivum L.) encounters 15–20% yield loss due to fungal diseases. A study was carried out to analyse the allelic variations in functional genes associated with multiple fungal disease resistance, viz. rusts, smuts and powdery mildew in 58 contrasting wheat genotypes. The experiments were conducted at Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana during 2020–21. A set of 29 simple sequence repeat (SSR) markers was selected for screening, out of which 24 markers showed amplifications (82.7%) and 23 showed polymorphism (95.83%) with a total of 46 alleles. Alleles per locus varied from 1 to 3 with a mean of 1.96 alleles per locus. At a similarity coefficient of 0.66, dendrogram grouped all the genotypes into 2 major clusters. Two and three dimensional plots also confirmed the distribution. Results showed that genotypes PBW 725 and WH 1268 were found to be most diverse at a similarity coefficient of 77%. SSR polymorphism rates were analysed using polymorphism information content, expected heterozygosity, marker index, discriminating power and resolving power values, where first two ranged from 0.03–0.65, and later three ranged from 0.03–1.94, 0.03–0.66 and 0.03–2.00, respectively. Based on these results, 8 proficient markers, viz. Barc232, Swm271, Xbarc124, Xbarc32, Xwmc44, Xgwm296, Gpw5029 and Xwmc557 are suggested for Indian wheat fungal disease resistance profiling. Among these, first two markers (Barc232 and Swm271) were detected in most (57) of the genotypes which are associated with ut6 and Lr75 genes, providing resistance to loose smut and leaf rust, respectively. This study can further help in gene pyramiding for producing multiple disease resistant genotypes.