AGRONOMIC DIVERSITY AMONG RICE (ORYZA SATIVA L.) LINES IN A GERMPLASM COLLECTION FROM KENYA

Abstract

Landraces are precious genetic resources, because they contain huge genetic variability which can beused to complement and broaden the gene pool of advanced genotypes. Knowledge of the genetic diversity and population structure of germplasm collections is an important foundation for crop improvement. The aim of this study  was  to morphologically characterize the Kenyan rice germplasm collection for identification of important agronomic traits for improved yield.    Field experiments were carried out in order to study the diversity in morpho-physiological characteristics of rice genetic material collected from different Kenyan rice growing regions. A total of 50 lines were used in this study. The experiment was carried out at the JKUAT rice experimental field. Each line was sown in single plots  that were 2m long at spacing of 20cm with rows 0.4m apart. The time to heading and to maturity significantly differed between the varieties tested (p<0.05) ranging from 75  -  140 days and the time to maturity from 120 -  185 days. Most of the lines were resistant to lodging and to shattering. Significant variability was observed for "panicle length" (p< 0.01) that ranged from 16 to 30 cm. Over 50  % of the lines tested showed well-exserted panicle. The glumes were less than grain in all lines evaluated. Over 90 % of the lines did have apiculus color. Differences among lines were also observed for "leaf blade anthocyanin coloration", where over 90%  showed no blade anthocyanin coloration. There was significant difference for the "awning" characteristic (p<0.05) with over 50 % being awnless. Results from the study indicate that genetic variability exists within the Kenyan rice germplasm which form  a good source of materials that could be screened for useful traits and exploited in the rice breeding programs.