Physiological studies on the effect of salinity on germination and early growth in Gossypium hirsutum L. and Gossypium arboreum L.

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Date
2011
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CCSHAU
Abstract
The present investigation was aimed on “Physiological studies on the effect of salinity on germination and early growth in Gossypium hirsutum L. and Gossypium arboreum L.” using various physiological parameters. Six cultivars of cotton (RCH-134, Bio-6488, H-1236, HHH-223, HD-123, AAH-1) were grown in screen house having four salinity levels as control, 4, 8, and 12 dSm-1. Results revealed that with progressive increase in salinity levels the seed germination, vigour index, relative water content of leaves, osmotic potential and stomatal conductance transpiration rate, as well as K+ content of leaves. Maximum reduction in seed germination was recorded in desi cotton cultivar HD-123 at highest level (12dSm-1) of salinity. A progressive increase in salinity levels on the other hand caused catalase, peroxidase activity and Na+ content of leaves enhanced. The maximum enhancement in catalase and peroxidase activity in leaf was observed in Bt. cultivars at both the sampling stages i.e at 30 and 60 DAS. Accumulation of Na+ content in leaves was maximum in desi cultivars HD-123 followed by American. Sodium content of leaves of all the cultivars of cotton increased with increasing salinity level; increase being found to highest in leaves of desi cotton cultivars. Potassium content of all cotton cultivars showed decreasing trend with increasing salinity levels. K+/Na+ ratio of leaves of all cultivars also decreased with increasing salinity level; decrease being highest in Bt. cultivars and minimum was recorded in desi cotton cultivars AAH-1. On the basis of the observations taken in the score-card it was found that Bt. cotton cultivars RCH-134 and Bio-6488 was tolerant to salinity. Both Bt. cotton cultivars (RCH-134 and Bio-6488) showed maximum no of polypeptide bands i.e 14 in SDS-PAGE, while American showed total number of thirteen polypeptide bands while desi cultivars had twelve in AAH-1 and fourteen in HD-123. Result revealed that with the progressive increase in salinity level from 4 to 12 Dsm-1 there was decrease in various physiological parameter enhanced viz; On the other hand, with the increase salinity levels increase in catalase, peroxidase enzymes and the Na+ content was recorded.
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Salinity, Germination, Gossypium hirsutum L, Gossypium arboreum L, Osmotic potential, Stomatal, catalase, Peroxidase activity, Na+ content
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