Intraspecific genetic variation among Sehima nervosum genotypes in relation to agro-climatic diversity

Abstract

Abstract Context. The genus Sehima is an important component of grasslands worldwide and is the dominant grass of Sehima–Dichanthium grasslands of India. It is an excellent fodder and a good source of lignocellulosic material and several industrially important biomolecules. Aims. We aimed to characterise and conserve locally adapted diverse germplasm of S. nervosum, collected from different agro-climatic zones, for effective utilisation. Methods. Morphological and nutritive traits were measured and statistically analysed for diversity in a germplasm collection of S. nervosum genotypes from diverse agro-climatic conditions of India, and a representative core subset was created. Key results. Morphological traits and nutritive parameters such as crude protein content and digestibility showed wide variability among accessions. Principal component analysis established that plant height, number of tillers per tussock and number of nodes per tiller accounted for half of the variation present. Tiller internode length, stem diameter, and leaf blade length and width also contributed >5 unit points each to the cumulative proportion of variance accounted for. Conclusions. The set of germplasm, possessing substantial variability, is a valuable genetic resource for developing new cultivars. Genotypes identified with high protein content could be used as forage, and those with high cellulose and hemicelluloses as a biofuel resource. Implications. Genotypes can be separately identified for forage and biofuel, and the core subset can effectively be used for evaluation and selection of genotypes in target environments. Additionally, the core subset can be used to establish and rejuvenate sustainable pastures by allowing natural selection.