Response of Assam Rice Varieties to Low Temperature Stress
Abstract
Low temperature induced injury, slow growth and prolongation of crop duration are some of the most important problems of boro rice cultivation in Assam and other eastern states of India. Any variety to be ideally fitted to the boro rice season must have cold tolerance at the vegetative stage of growth. In the present study, a set of rice varieties, randomly drawn from Assam rice collection, was evaluated for their response to low temperature stress at germination, post-germination and seedling growth stages. Several varieties, both modern and traditional, distributed across different classes and sub-classes of Assam rice germplasm, exhibited desired degree of tolerance to low temperature stress at one or the other stages of growth. Sufficient genetic diversity was observed among the varieties with Eucledian coefficient of dissimilarity ranging from 0.60 to 8.61 and average being 3.88 across the 56 genotypes. In this study, no ecotype-specific clustering was observed among the Assam rice varieties.
Keywords
Rice (Oryza sative L.), Low temperature stress, Genetic diversity, Assam rice germplasm, Boro rice
