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.
