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Genetic resources are the fundamental source of diversity to plant breeders for improvement of desired traits. However, large germplasm set is difficult to preserve and use as working collection in genetic studies, hence in the present study evaluation of genetic diversity of 604 durum germplasm originated from different geographical areas and development of core collection for representation of diverse germplasm for working collection was done. Six hundred and four durum germplasm were sown in augmented design and data were recorded for eight quantitative characters including agronomic and grain quality traits. Descriptive statistics showed large variation for all studied traits. Box plot analysis for nine different sets of germplasm showed a large variation for agronomic traits and quality traits. Principal component analysis for the first four principal components explained 71% of the cumulative variation and grouped germplasm in the main two groups. The core germplasm set was developed using corehunter package with 10% cutoff and hence 60 germplasm entries make representation in core subset based on maximum diversity and minimum redundancy. The maximum contribution to core germplasm was by each CZ (Central Zone) breeding lines and D numbers (23%) followed by exotic other lines (20%). The developed core subset was validated using multivariate analysis such as Shannon diversity index, comparison of means and homogeneity of error variances using the Levene’s test. The results described in this study will be useful for durum wheat breeders for the development of varieties with high end-use quality.

A study was conducted to understand the mode of inheritance and extent of diversity of stem rust resistance in four popular durum wheat cultivars of central India viz., HI 8498 (Malav Shakti), HI 8663 (Poshan), HI 8713 (Pusa Mangal) and HI 8737 (Pusa Anmol) using Puccinia graminis tritici (Pgt) pathotypes 15-1 (123G15) and 40-3 (127G29). These cultivars were crossed with susceptible parents i.e., Motia and Malvi Local and were also crossed among themselves in half diallel fashion. The F2 and F3 segregation data revealed that a single dominant gene each controlled resistance to the pathotype 40-3 in HI 8713 and HI 8663, while two dominant genes each governed resistance to this pathotype in HI 8737 and HI 8498. A single dominant gene each conditioned resistance to the pathotype 15-1 in all the four cultivars. The F2 segregation data of the intercrosses among the resistant parents showed that three different resistance genes controlled resistance among four cultivars against each Pgt pathotype 40-3 and 15-1. These genes seem to be different from the most commonly postulated stem rust resistance genes in Indian durum wheat germplasm viz., Sr11, Sr12, Sr7b and Sr9e which are ineffective/less effective against the test pathotypes. Hence, the genes identified in the present study can be utilized in broadening the genetic base of stem rust resistance in Indian durum wheat.