Screening of Rice Genotypes for Submergence Stress Tolerance

The experiment was conducted at Department of Rice, Tamil Nadu Agricultural University, Coimbatore to study the effect of submergence on growth of various genotypes of paddy. The genotypes viz., AC1303, AC42088, AC38575, SABITA, NAVEEN, SWARNA Sub1, BLACK GORA, BAJKANI, SWARNA, PARUAT, PAU9, BRAHMANNAKHI, MAHULATA, BVD109, IET-18720, IET-18727 and IC-516009 lines were used for submergence screening. The seeds should be pre-heated at 50°C for 2-3 days for breaking the seed dormancy before sowing. The seeds were directly sown inside the tanks using wet-bed direct sowing method. Each genotype was sown in 2 rows (min.) with 3 replications with a row to row spacing of 20 cm and plant to plant spacing of 15 cm. Germinated seedlings were allowed to grown normally till 20–25 days without submergence stress. The observations like plant height (before and after submergence), Number of plants survived (before and after submergence), survival percentage and total starch content were recorded. The genotypes IET-18727, PAU9 and AC38575 had better survival percentage (80.0 to 86.7%) with higher starch content (6.3 to 6.9 mg g-1) under submerged stress conditions. The genotypes of BVD109 and SWARNA registered lesser survival percentage (26.7% and 26.3%) with starch content of 2.1 mg g-1 among the rice genotypes.