Spot blotch caused by Bipolaris sorokiniana (Sacc.) Shoemaker significantly impedes global barley production by impacting grain, fodder yield, and malt quality. Host resistance presents a sustainable, cost-effective, and eco-friendly method for disease management. The extent of resistance and the number of resistant accessions are limited within barley genetic resources. Therefore, the present studies on the evaluation of the selected barley core collection consisting of 678 genotypes under the multi-environmental conditions have paramount importance. To identify stable resistance resources, the trial was conducted at Varanasi, India. This location is known as the hot spot of spot blotch. The analysis of variance (ANOVA) for determining varying levels of spot blotch resistance among the examined genotypes revealed a significant genotypic variation among the accessions against the disease based on the area under the disease progress curve (AUDPC). After correlating the disease severity with the elevated minimum temperatures and humidity levels, it was found to be higher during the first cropping season (2021–2022) with a mean AUDPC value of 852.89 ± 6.48 over the second cropping season (2022–2023) that showed a mean AUDPC of 761.10 ± 6.78. Average AUDPC scores across four test environments revealed that none of the evaluated genotypes showed a completely resistant reaction (AUDPC < 285) to spot blotch. Two genotypes (EC0667513-sel and EC0667512-sel) of six-row barley exhibited moderately resistant (MR) reaction (AUDPC < 355) under the natural field conditions; however, among these two, only EC0667513-sel was found to be MR during the validation under the artificial epiphytotic conditions. Further comparison of the performance and stability among these two MR genotypes through GGE biplot analysis indicated that EC0667512-sel was specifically adapted to certain environments, but was inconsistent overall. In contrast, EC0667513-sel indicated a good mean performance and higher stability across all environments. The GGE biplot effectively analyzed genotype-environment interactions and identified optimal evaluation sites and stable resistant genotypes for spot blotch resistance. These findings provide valuable insights for future breeding programs focused on integrating resistance traits into new barley varieties.

The understanding of the genetic diversity of germplasm of any crop is necessary for genetic improvement. Pea (Pisum sativum L.) is a very important legume crop that provides protein and several essential vitamins, carbohydrates, and minerals. The genetic diversity and population structure of pea germplasm consisted of 115 entries of Australian accessions and 4 entries of Indian varieties used as checks with varying responses and severities of rust, which were analysed using 31 polymorphic SSR (Simple Sequence Repeats) markers. The combination of the markers revealed that 78 alleles were present at 32 loci. It was also observed that each marker had three alleles with an average PIC (Polymorphic Information Content) value of 0.272. The population structure analysis showed the genetic differentiation of the entries. The model-based population structure grouped the entries into three sub-populations of SP1, SP2, and SP3 having 37, 35, and 32 entries, respectively with 15 entries as admixtures. AMOVA (Analysis of Molecular Variance) disclosed that there was 56% variation among the individuals and 20% within the population. A mean fixation index (Fst) of 0.240 among the pea entries exhibited relatively significant variation in population. This study provides basic information to select parental lines for developing rust resistant varieties to meet the ultimate goal of sustainable agriculture.