COLD TOLERANT MECHANISM OF SOME SELECTED RICE SEEDLINGS AT LOW TEMPERATURE ENVIRONMENT

Abstract

A field experiment was carried out to investigate the physio-morphological characteristics of seedlings four rice cultivars for screening cold survival during low temperature in Northwest of Bangladesh. The test rice cultivars were V1, NERICA-10; V2, IR- 40 (GSR-IRRI- 40); V3, Lafaya and V4, Gochi, respectively. The leaf proline, chlorophyll content, relative water content (RWC), protein, starch, seedling shoot length, shoot weight and root length, root weight, total biomass, and seed germination rate were investigated. The V1 (NERICA-10) and V3 (Lafaya) seedling synthesized the higher leaf proline at low temperature than those of other tested cultivars. The highest chlorophyll-a and -b was in V1 (NERICA-10). The V3 cultivar (Lafaya) had the highest percentage of relative water content (92.93%). The V4 variety showed the highest content of protein percentage (13.35%). The highest percent starch content was found in V3 (29.82%). The V3 plants had the highest shoot weight at all times of experiment in 2012 irrespective of fresh and dried condition. This study infers that V1 (NERICA10) and V3 (Lafaya) varieties showed the better survival potentiality during cold temperature by over-synthesizing proline, chlorophyll and other physiomorphological parameters.