DEVELOPING RICE VARIETIES WITH ENHANCED ADAPTATION TO COLD PRONE RICE GROWING AREAS UNDER LOWLAND RAIN FED CONDITIONS OF ETHIOPIA
TADDESSE LAKEW *
Ethiopian Institute of Agricultural Research, Fogera Rice Research and Training Center, Woreta, Ethiopia.
ABEBAW DESSIE
Ethiopian Institute of Agricultural Research, Fogera Rice Research and Training Center, Woreta, Ethiopia.
ASAYE BERIE
Ethiopian Institute of Agricultural Research, Fogera Rice Research and Training Center, Woreta, Ethiopia
BETELEHEM ASRAT
Ethiopian Institute of Agricultural Research, Fogera Rice Research and Training Center, Woreta, Ethiopia.
DEJENE KEBEDE
Ethiopian Institute of Agricultural Research, Jimma Agricultural Research Centre, Jimma, Ethiopia.
HAILEMARIAM SOLOMON
Ethiopian Institute of Agricultural Research, Melkassa Agricultural Research Centre, Melkassa, Ethiopia.
*Author to whom correspondence should be addressed.
Abstract
Sixteen lowland rice genotypes were arranged in a randomized complete block design of four replications and assessed for cold tolerance, performance and yield stability. Analysis of variance revealed highly significant effects of genotype and environment for all traits studied while the interaction effect was significant for six of eleven traits. The AMMI analysis in grain yield showed that genotype, environment and their interaction were highly significant and the environment explained the highest variation, followed by the interaction. The first two multiplicative interaction principal component axes were highly significant and explained 83.8% of the interaction sum of squares. Spikelete fertility ranged from 89.9% (G1) to 97.8% (G9 and G11). Genotypes G4, G9, G11, G10, G12, G13 and G14 exhibited nearly complete panicle exesertion and high spikelet fertility indicating their tolerance to cold stress. AMMI 1 and GGE ranking biplots identified G4, G9, G11 and G12 as high yielding genotypes. While G9 was the best genotype in terms of mean yield, G4 was both high yielding and most stable genotype. Thus, genotypes that combine cold tolerance, high yield, and farmers’ preference (G4, G9 and G11) were verified and consequently, G9 and G11 were recommended for release in Fogera and similar areas.
Keywords: Rice genotype, cold tolerance, AMMI biplots, GGE biplots, grain yield.