Character association in improved shallow rainfed lowland rices

摘要

Correlation and path-coefficients were studied on grain yield and its components in 45 rainfed lowland rice genotypes. Wide range of variation was recorded for all the traits. Highest grain yield was recorded for breeding line IR 57515-PM I-B-1-1-SKN-1-1 (5.52 t ha~(-1)), followed by IR 66882-4-4-B (5.34 t ha~(-1)). Maximum harvest index was recorded for IR-20 followed by an early rainfed popular variety Poornima. Maximum grain weight was observed for Sabita followed by Mahamaya. Highest number offertile spikelets panicle~(-1) and spikelet density were recorded for Mahsuri. Maximum panicle length was recorded for hybrid variety IR 65488 H followed by IR 43450-SKN-506-2-2-1-1. High heritability was recorded for plant height, days to 50 percent flowering and 100-grain weight. Grain yield was positively and significantly correlated with biological yield, harvest index, number of fertile spikelets panicle~(-1) and plant height at both genotypic and phenotypic levels, indicating the relative utilityof all these traits. Path-analysis indicated a greater contribution of harvest index, fertile spikelets panicle~(-1), biological yield and plant height to grain yield. The breeding lines desirable for multiple agronomic traits were IR 66882-4-4-B, Safri,Sabita, IR 57515-PMI-B-1-1-SKN-1-1, IR 57546-PMI-1B-2-2 and Safri 17.