Phenotypic and molecular evaluation of Arachis hypogaea L. against foliar fungal diseases

Groundnut improvement tasks are generally engrossed to breed foliar fungal disease-resistant varieties. Early and late leaf spot diseases of groundnuts cause significant loss in yield and quality of groundnut seeds. Simple Sequence Repeat (SSR) markers represent high polymorphic amplification, while Inter-simple sequence (ISSR) is being used widely for diversity assessment due to their large size and reproducible results. The current investigation was carried out with 96 groundnut genotypes for morpho-physiological characterization, disease indexing for early and late leaf spot diseases under field conditions and by employing SSR and ISSR markers for diversity assessment. In correlation analysis, kernel weight was found positively and highly significantly correlated with harvest index and pod weight (r ​= ​0.906) at 1% level of significance. While, pod weight is negatively correlated with early leaf spot at 30 days (r ​= ​-0.401) and at 45 days (r ​= ​-0.410), late leaf spot at 70 days (r ​= ​-0.342) and at 85 days (r ​= ​-0.309) at 1% significant level. With the use of SSR markers, a total 16 alleles were recognized with a mean of 3.20 alleles per locus. The gene multiplicity differed from 0.6074 to 0.6491 for the markers Seq5D05 and PM137 respectively with an average of 0.6289. A total 18 alleles were produced by ISSR markers with an average of 3.6 alleles per locus. In our study, the gene diversity varied from 0.5877 to 0.6625 for the markers ISSR3 and ISSR21 respectively with an average of 0.6164. Diverse group of groundnut germplasm has been identified on the basis of SSR and ISSR markers along with morphological characterization.