Changes in the physiological and biochemical activities of traditional rice landraces affected by water stress during reproductive stage under field condition

A field experiment was conducted to determine the physiological performance of traditional rice landraces under water stress given at reproductive stage. Drought is one of the serious threats on rice productivity. Traditional rice landraces shows substantial adaptability to drought so Six popular rice land races, namely Rascadam, Kothamalli samba, Kaattu samba, Kallundai, Kuliyadichan and Milagu samba from Tamilnadu, India and two popular rice check varieties, namely IR64 (susceptible check), N22 (tolerant check) were used to study the physiological performance for drought tolerance. These genotypes were subjected to drought under field condition at Agricultural Research Station, Bhavanisagar, TNAU, Coimbatore. The crops were imposed with drought during reproductive stage by withholding irrigation till the soil moisture reaches below 20 per cent. The experimental design for the trial was factorial randomized block design (FRBD). Chlorophyll Index (CSI), Soluble protein, Catalase activity and Nitrate reductase activity were measured.