Selection Index in Rainfed Upland Rice (Oryza sativa L.)

Abstract

The present investigation was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, Thiruvananthapuram during the period from May, 2014 to July, 2016. Twenty diverse rice genotypes were screened for drought tolerance.  Screening was carried out in the target environment i. e. upland virippu. Morphological characters of the genotypes were studied.  A selection index was developed for identifying the best six parents combining yield and drought tolerance. Twenty upland rice genotypes were assessed for study of genetic variability and construction of selection indices for enhancing selection efficiency. The indices were worked out on the basis of yield and eight component characters viz., panicle length, number of spikelets panicle-1, number of filled grains panicle-1, grain weight panicle-1, 1000 grain weight, straw yield plant-1, harvest index and biological yield plant-1 having high significant genotypic correlation with grain yield.  Among the twenty genotypes Vaishak ranked first with the highest index value followed by Thottacheera, Kalladiaryan, Vyttila 6, Harsha and Swarnaprabha. The varieties with least index value were Uma, Aathira and Kanchana. The highest index value showing first six parents were considered for hybridization program for the development of drought tolerant variety.