Screening of Rice Hybrids for Cold Tolerance at Seedling and Vegetative Stage under Low Temperatures

Abstract

Low temperature is one of the most important abiotic constrains in rice cultivation. Rice plant growth and development are affected by cold stress from germination to reproductive stages. Development of 48 hybrids involving twelve restorer lines and four CMS lines by using line x tester mating design. Evaluation of 69 rice genotypes including checks based on leaf score (SES, IRRI, 2013), root length, shoot length, fresh weight, dry weight, and SPAD analysis at seedling stage as well as leaf score, number of tillers, seedling growth and establishment at vegetative stage. Results indicated that the hybrids IR72081 A x JGL 11118, IR72081 A x JGL 21071, IR80559A × JGL 29662, IR80559A × KNM 110, IR80559A × SN 470, IR58025A × JGL 29662 identified as cold tolerant genotypes. This study aimed to identify cold tolerant genotypes under low temperatures at seedling and vegetative stage. Screening for cold tolerance during early growth stages potentially be an effective way of assessing cold tolerance in breeding programmes.