EFFECT OF PREKINETIN AND POSTKINETIN TREATMENTS ON SALT TOLERANCE OF DIFFERENT POTATO CULTIVARS GROWING ON SALINE SOILS

Different potato cultivars were subjected to 10 −6M kinetin treatment prior to the transplantation in saline soils (pre‐kinetin treatment) and to the plants already growing on the saline soils (post‐kinetin treatment). The kinetine when applied before the exposure of plants to saline soils showed promotory effects on growth, tuberization and some biochemical parameters of potato at 0.5 % salinity. The degree of inhibition in number of tubers and yield was reduced at 1 % salinity due to pre‐kinetin treatment. The level of proline, reducing sugars and sodium was increased in different plant parts to maintain the osmoregulation. However, kinetin did not play any specific role in reducing down the increase in proline content resulted due to salinity. The level of K+ was found to be higher at low salinity in all the cultivars of potato. Higher concentrations of proteins and enhanced activity of starch synthetase at low level of salinity suggest the salutary effect of Na+ in metabolic functions of plant cells. The nitrate reductase (NR) activity was appeared to be more sensitive than starch synthetase. This could possibly be due to the localization of the enzyme and the cellular concentration of toxic substances increased under stress. Total Glyoalkaloids (TGA) content was reduced at both the salinity levels irrespective of kinetin treatments. On the contrary Na+ content was increased in all the treatments of kinetin at both levels of salinity. During this study cvs. Red Lasoda, Patrones and Atom alue approved to be more tolerant as compare to rest of the cultivars tested. This could be a combined effect of genetic setup, amendments in saline soils and pre‐kinetin treatments of plants exposed to various regimes of salinity. Furthermore it is argued that salt tolerance limit can be extended upto certain level of salinity by pre‐kinetin treatment in potato plants. Copyright © 1990, Wiley Blackwell. All rights reserved