Genetic diversity in barley (Hordeum vulgare L. ssp vulgare) landraces from Uttaranchal Himalaya of India

In the high altitude areas of western Himalaya, barley is a crop of marginal, low input drought stressed environments. The landraces grown in these areas are favoured for their quality, both as grain and straw. However, area under the naked barley landraces, during the last three to four decades, has declined considerably and their ex situ and in situ conservation requires attention. Morphological and RAPD descriptors of a collection of 70 landraces from the higher Himalayan ranges of Uttaranchal state were used to analyse levels of genetic diversity. A wide range of variation was recorded for various morphological characters in univariate analysis. The multivariate analysis based on six quantitative traits distinguished accessions from different geographical areas in the region but failed to separate naked from covered barleys. Clustering based on qualitative traits, however, clearly distinguished naked and covered forms. RAPD profiles efficiently differentiated naked barleys from covered forms, but could not differentiate between oriental and occidental covered forms. A set of 11 predominant landraces were subjected to detailed population genetic analysis. More diversity was observed in covered barleys than the naked forms, both for morphological and RAPD markers. The low diversity in naked barley populations was attributed to either genetic drift or to a founder effect, while the high diversity in covered barley populations was attributed to their large-scale cultivation for animal feed and brewing purposes. Allelic combinations were not randomly distributed, as a geographic trend was closely related to covered and naked barleys. Since naked barleys are poorly represented in the national collections, a systematic collection from the entire region is suggested. The genetic differences between covered and naked barleys may be relevant to breeding programmes since the variability created through hybridisation between the contrasting forms could be exploited.