Response of Some Oryza Glaberrima Genotypes to Submergence Tolerance in Kaduna State, Nigeria

We evaluated Oryza glaberrima genotypes tolerance to complete submergence, and the environmental effects of its surrounding conditions at seedling stage. Six candidate genotypes (TOG6790A, TOG9266, TOG933, TOG9281, TOG9047, TOG7428) with submergence tolerant (SWARNA SUB1) and susceptible (TOG7943) checks were subjected to submergence stress 21 days after seeding for two weeks. Submergence tolerant genotypes showed reduced plant growth, with greater reductions in all morphological growth parameters. This implies a reduction in energy utilization thus conserving energy by maintaining low growth rate. However, genotypes showing rapid shoot elongation and leaf width expansion competed for energy required for the maintenance processes for survival by increasing plant photosynthesizing ability. Thus, elongation ability negatively correlated with submergence tolerance and survival percentage after de-submergence. Shoot elongation positively correlated with leaf number (r= 0.51*) and leaf width (r= 0.74*) and negatively with submergence tolerance and survival percentage after de-submergence. Environmental characterization of water conditions during complete submergence did not confer toxicity to the genotypes. Submergence tolerant Oryza glaberrima genotypes could be useful for growing in flood prone areas and can be used in conferring submergence tolerance in breeding programmes for plant advancement.