Evaluation of rice genotypes for seedling and reproductive stage drought tolerance

Abstract

The present investigation was undertaken to evaluate 25 drought tolerant genotypes for seedling stage and reproductive stage drought tolerance. The genotypes were evaluated under gravimetric method at three moisture levels viz., i) control at 100 % field capacity (FC) ii) water - deficit stress at 80 % Field capacity (80 % FC) and iii) water - deficit stress at 60 % Field capacity ( 60 % FC) for seedling stage drought tolerance. Observations were recorded on six morphological traits viz., seedling height, root length, shoot length, dry weight, leaf rolling and leaf drying and three physiological traits viz., chlorophyll stability index, proline content and nitrate reductase activity. The variety, APO and landraces viz., Kuliyadichan, Kattanur and Sivappuchithiraikar were identified with all desirable drought tolerant seedling traits and these genotypes also had high stress tolerance index (STI) for all the morphological traits. For reproductive stage drought tolerance, the moisture stress was imposed under field condition. Yield characters viz., number of days to maturity, panicle length, spikelet fertility and single plant yield and three physiological traits viz., chlorophyll stability index, proline content and nitrate reductase activity were recorded. Based on stress tolerance index (STI) and high mean performance, varieties viz., Anna (R) 4 and APO and landraces viz., Kattanur, Kuliyadichan and Sivappuchithiraikar were identified as drought tolerant lines for reproductive stage drought tolerance. From this study, APO, Kattanur, Kuliyadichan and Sivappuchithiraikar were identified as drought tolerant lines for seedling stage as well as reproductive stage. Therefore, these genotypes can be used as potential donors in the development of new drought tolerant varieties in rice.

Keywords

• Rice
• Drought tolerance
• seedling traits
• biochemical traits
• Stress Tolerance Index