Phenotypic Correlation Coefficient and Path Analysis in Rice (Oryza sativa L.): An Overview

Food security as a major concern has drawn worldwide attention. The emerging issues of varying dimensions have posed new challenges to agricultural scientists to produce even more under shrinking resources to feed the rising population. Evolution of new cultivar as per need requires a continuous effort, where the selection process involves identification of suitable genotypic and phenotypic traits to breed a new cultivar. The statistical tools like correlation coefficient and path analysis are usually employed to ascertain the relationship and contribution of each trait which guides the researcher in arriving at a desired conclusion. The present article has briefly discussed the significance of using these tools and its techniques. An attempt has been made to do an overview exercise on the work reported by various workers on rice established under different methods using the above tool and technique and present it in a concise manner. Straw yield/ biomass, harvest index, total and ear bearing tillers, filled grains per panicle and panicle length are the most likely traits. However, in some cases unfilled grains have also shown positive correlation with grain yield. Head recovery, hulling percentage, kernel breadth and elongation ratio are some of the qualitative traits that can be considered. The direct association with grain yield was more prominent with harvest index, straw/ biomass yield, percent fertility and days to 50% flowering. The phenotypic traits involved and their association with economic yield, will help to formulate the breeding and agronomic strategy for higher productivity per unit area per unit time.