Morpho-Agronomic Evaluation of Oryza Glberrima Accessions and Interspecific O. Sativa X O. Glaberrima Derived Lines Under Drought Conditions

Two dry-season field experiments were conducted at AfricaRice research station in Benin to identify drought tolerant rice genotypes from a range of genetic resources: in 2006 using 202 backcross-inbred interspecific Oryza sativa ? Oryza glaberrima lines, replicated in 2007 (experiment 1); and in 2007 (replicated in 2008) using a population of 327 genotypes comprising O. glaberrima, O. sativa, interspecific lines and local landraces (experiment 2). Plots were fully irrigated from sowing to maturity (control) or subjected to 21-day drought (drought), respectively. Plant height, number of tillers and grain yield values were higher under control than drought for most genotypes. Contrary observations were made for leaf greenness (SPAD), leaf temperature, flowering and maturity. The 24 top-yielding lines in experiment 1 and 20 top-yielding lines in experiment 2 followed this general trend. Significant genotype ? environment interaction was observed for SPAD, number of tillers and grain yield. Grain yield, flowering and maturity were affected by drought for 98.0, 95.1 and 100% genotypes, respectively, for experiment 1, and 99.1, 99.4 and 98.2%, respectively, for experiment 2. The study identified 003-2-2, 77-2-4, 61-1-1, 94-1-5, 94-2-3, 117-2-6, 77-5-3 (interspecific lines), and TOG6383, TOG5691, RAM122, TOG5919 (O. glaberrima), as stable or high yielding genotypes under drought and potential resources for further drought studies. [PUBLICATION ABSTRACT]