Study of selected biochemical parameters related to submergence tolerance in rice (Oryza sativa L.) with special reference to land races and wild species

Abstract

A selection of twelve rice lines, mainly grown by marginal farmers in the lowland flood prone regions of West Bengal and Odisha and known for their submergence tolerant or elongating properties, were studied in context of their biochemical changes due to submergence stress. Two more rice lines, FR13A and IR42, were also included as submergence tolerant and susceptible checked varieties respectively. The parameters studied, namely, total chlorophyll, total protein, soluble and insoluble carbohydrate, amylase, invertase, pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH), are linked to submergence stress tolerance. FR13A, Khoda, Kumrogore, Kalaputia, Meghi and Bhashakalmi showed lower degradation of chlorophyll during submergence. Bhashakalmi also showed highest protein content during submergence. Both these parameters are indicators of better submergence stress tolerance of plants. In FR13A, Meghi, Khoda, Bhashakalmi, Swarna-sub1, the amount of soluble carbohydrate, during submergence, is on the lower side as they store the carbohydrate for later survival and recovery. In case of insoluble carbohydrate, in Harmanona and Panibhasha the amount is very low during submergence. In Moule, Harmanona, Panibhasha, Narayankamini very high amount of carbohydrate metabolising enzymes (amylase and invertase) can be seen during submergence which indicates their deepwater elongating nature under flood stress. Apart from FR13A, in Meghi and Khoda, a marked increase of ADH and PDC (enzymes of alcoholic fermentation pathway) can be seen during submergence which is indicative of their better performance under submergence stress. From this overall study it can be concluded that Meghi, Khoda, Kumrogore, Bhashakalmi and Kalaputia are the best performing varieties amongst the selected fourteen and this experimental work can be used for characterization of the submergence tolerant rice landraces.