Physiological Basis of Screening Samai Varieties for Drought Tolerance under Rainfed Conditions

Abstract

A field experiment was conducted at the Regional Research Station, Paiyur main farm with the varieties viz., Paiyur 2, PM 29, KRI-11-05, MS- 110, MS- 509, MS-1211, MS-1236, MS-4700, MS-4784 and CO 4. The experiment was designed for screening the samai cultivars under rainfed conditions through the physiological and biochemical responses. Morphological characters, plant water relations, proline accumulation and soluble protein were taken in to consideration to assess the response of the various samai cultivars to rainfed condition from this experiment. Significant differences were observed for most of the morphological characters like plant height, number of leaves per plant and dry matter production per plant.   Significant differences were observed for the bio chemical attributes. Leaf proline content was high in the variety MS 1236 (0.81 mgg^-1) .The variety MS 110 recorded the maximum protein content of 10.88 mg/g. Relative water content of the leaf was high in the variety MS 1236 (71.87 %) and also recorded the maximum crop growth rate (g m²day^-1) of 0.607 and 1.074 at 0- 30 DAS and 30-60 DAS respectively. Similar trend was observed in the relative growth rate also.Significant difference was observed for grain yield among the 10 varieties tested for drought tolerance. MS -1236 recorded the maximum yield of 1.73 tonnes ha^-1 and was on par with all the varieties except MS - 509, which recorded the lowest yield of 1.48 tonnes ha^-1. The culture KRI -11-05 closely followed MS 1236 with the mean grain yield of 1.71 tonnes ha^-1.