Author : Cho Cho Aung

Summary : To screen selected rice genotypes for the tolerance to anaerobic condition during germination, two experiments (anaerobic germination (AG) and saturated (control) conditions) were carried out separately in a randomized complete block design with four replications at concrete ponds during the dry season, 2019 and in the field condition during the wet season, 2019. One hundred and thirty-eight rice genotypes and two check genotypes (Khao Hlan On- AG tolerant and IR 42- AG susceptible) were used. Based on the survival percent in both seasons under AG condition, five genotypes were identified as tolerant, twenty-four genotypes as moderately tolerant and the other genotypes as susceptible to AG condition. The selected five tolerant genotypes from phenotypic screening were confirmed by using RM 11701, RM 3475, RM 520, RM 478, RM 3753, RM 5436 and RM 8303 SSR markers. To examine the effectiveness of genotype and seed priming treatments on seedling establishment, two experiments (AG and control) conditions were carried out separately in the field condition. A split plot design with three replications was assigned with seed priming (on-farm priming, hardening, osmo-hardening (CaCl2 2.2%), hydropriming and nonpriming) as main plot factor and the newly identified five tolerant genotypes from phenotypic screening and two check genotypes (Taung Hti Pan, IR 14D 175, IR 15D 1023, IR 15D 1024, IR 15D 109, IR 42 and Khao Hlan On) as subplot factor. Based on the findings, there was no significant difference of yield affected by seed priming treatments, however, there was significant difference among genotypes under both conditions. Numerically, the higher grain yield was obtained from on-farm priming, hardening, hydropriming and osmo-hardening treatments under AG condition. Regarding the genotype, IR 15D 1023 and IR 15D 1024 gave the maximum grain yield under both conditions. In conclusion, this study highlighted that the combining of AG tolerant rice genotypes with appropriate seed priming treatments improves seedling establishment, yield and yield component characters of rice genotypes under both conditions.