Evaluation of Submergence Tolerance in Landrace Rice Cultivars by Various Growth and Yield Parameters

Abstract

Flash flood causes a serious damage to rice crops in northern and eastern parts of Bangladesh almost every year. This study was designed to identify useful agronomic parameters for evaluation of submergence tolerance and to evaluate genotypes by multiple agronomic parameters for submergence tolerance at different growth stages. Twenty-one aman rice genotypes were tested against three submergence treatments viz. (i) no submergence or control, (ii) submerge at 10 days after transplanting (DAT), and (iii) submerge at 30 DAT. The experiment was laid out in a split plot design with three replications. The plants were completely submerged in the tanks for 14 days. Dry matter production, growth, yield, and yield components of rice were significantly reduced due to interaction effect of genotypes × submergence. Submergence at the early stage of growth (10 DAT) was more detrimental to plant growth than what happened at later stages (30 DAT). Wide genotypic differences in relative submergence tolerance based on grain and tiller numbers were identified. Grains and tiller numbers contributed most of the variation to seed yield among parameters investigated. When genotypes were ranked for submergence tolerance based on the means of multiple parameters, dramatic changes of submergence tolerance at early and later stages were observed in four genotypes; BRRI dhan33, Lalchikon, Achin and Sadamota were identified with a favorable combination of submergence tolerance. Cluster group ranking of genotypes based on multiple agronomic characters can be applied in submergence tolerance breeding to evaluate submergence tolerance and may have great advantage over conventional methods.