Abstract

Thirteen genotypes of upland rice were evaluated at White Nile Research Station Farm, Kosti, of the Agricultural Research Corporation (ARC), Wad Medani Sudan for two consecutive years (2008 and 2009). The objectives of this study were to estimate the genotypic and phenotypic variability, broad sense heritability for maturity, morphological and yield associated traits. The highest genotypic coefficient of variation and genetic advance were recorded for number of tillersplant^-1 and plant height in both seasons. High heritability estimates (>85%) were recorded for plant height, number of tillersplant^-1 and 1000 grain weight in both years and high heritability estimates with low genetic advance observed for days to 50% flowering and days to maturity in both years. The high yielding genotypes were WAB891 SG14, WAB981 SG33 and Yunlu No.30 with grain yields of 3.6, 3.5 and 3.4 tha¹, respectively. Grain yield tha^-1 was significantly and negatively correlated with percent of unfilled grains/panicle. However, it was highly significantly and positively correlated with panicle length, number of tillersplant^-1, number of filled grainspanicle^-1 and 1000 grain weight in both seasons. Path coefficient analysis indicated that number of tillersplant^-1, 1000 grain weight, panicle length and number of filled grainspanicle^-1 were most directly related traits to grain yield tha^-1. Traits such as panicle length, number of tillersplant^-1, number of filled grainspanicle^-1 and 1000 grain weight could be useful as index traits for improving the total grain yield. Furthermore, our results suggest that selection for plant height, number of tillersplant^-1 and 1000 grain weight would be more effective as compared to other traits in boosting yield performance of upland rice genotypes.

Key words: Upland rice, yield component, genotypic and phenotypic variability, path coefficient analysis, broad sense heritability.