A study of the genetic variability of Brachiaria brizantha stapf

Abstract

Brachiaria brizantha (Hochst ex. A. Rich) Stapf. is one of the major pasture grasses in Sri Lanka because of its ability to survive long spells of dry weather. This grass had been introduced into Sri Lanka but the amount of planting material imported and the country of origin is uncertain. This study was designed to investigate the genetic variability of B. brizantha and to select high yielding and high quality clones. Two hundred and eighty three clones selected from 7000 randomly collected plants from 12 different agroclimatic regions of Sri Lanka, and 17 imported clones were included in this study. Broad sense heritability was high for plant height, total green matter yield, fresh weight of leaves and stems and total dry matter yield. The plant height in swards could be used as an indication of the yield. The correlations between yield characters and quality characters were low. Therefore, the selection for either of these characters could be made without sacrificing the other and there is a possibility of improving both the yield and quality of B. brizantha