Effect of Low Temperature on Chlorophyll and Carotenoid Content on the Seedlings of Some Selected Boro Rice Varieties

Abstract

A study was conducted to screen out the low-temperature tolerant Boro rice seedlings from November 2012 to January 2013 for facing the upcoming rice production challenge in Northwest Bangladesh. The experimental time was characterized by a prevailing low environmental temperature of below 15˚C. Five rice cultivars (V1: BR-2; V2: BR-16; V3: Pariza; V4: Minicate; V5: BRRI dhan 50) were selected for the study. The leaf proline, chlorophyll content and total carotenoid content were investigated. The V2 (BR-16) seedling synthesized the higher leaf proline (1.228 mg∙g−1) at a low temperature than those of other tested cultivars. Again, the highest amount of chlorophyll-a (3.957 mg∙g−1), chlorophyll-b (2.118 mg∙g−1), chlorophyll-a/b ratio (3.6754 mg∙g−1) and total chlorophyll (5.051 mg∙g−1) was measured in V2 (BR-16). The maximum total carotenoid (1.213 mg∙g−1) was also observed in V2. In this experiment, the V2 (BR-16) showed comparatively better potentiality to survive at low temperatures (below 15˚C) than other varieties.