Effects of Flooding Treatments on Photosynthetic Activity of Different Greengram (Vigna radiata (L.) Wilczek) Cultivars

Abstract

The response in growth and gas exchange to a flooding condition was characterized with 8 cultivars of greengram (Vigna radiata (L.) Wilczek). Pot-grown plants were subjected to 6-d flooding and 6-d recovery treatment. The flooding treatment had serious effects on the gas exchange and electron transport of 7 cultivars except for cv. KP, while the damages were lenient in cv. KP. KP was characterized by maintaining relatively higher stomatal conductance, mesophyll conductance and photochemical efficiency of photosystem II, which was attributed to sustaining the CO₂ assimilation under flooding stress. KP was also superior in photosynthetic sustainment than other 7 cultivars under recovery treatment, which was attributable to the fact that this cultivar recovered stomatal conductance, mesophyll conductance, electron transport and the ratio of photorespiration to total carbon assimilation. These results in cv. KP lead to higher plant growth in relation to leaf area extension and dry matter.