PHOTOSYNTHESIS AND ANTIOXIDANT RESPONSE TO WINTER RAPESEED (BRASSICA NAPUS L.) AS AFFECTED BY BORON

Effect of boron on photosynthesis and antioxidant response to rapeseed yield was studied by the field experimentation along with plant analysis during the winter season of 2010 and 2011. The field experimentation was conducted by split plot design with three replications consisting of two factors such as i) two rapeseed cultivars (viz. Xiangzayou 1613 and 0913581613), assigned in main plots and ii) five boron levels (viz. 0, 4.5, 9.0, 13.5 and 18.0 kgha(-1)) imposed in the sub-plots. The rate of photosynthesis increased with increasing boron level upto 9.0 kgha(-1) with simultaneous increase in photosynthetically active radiation, rate of transpiration and stomatal conductance and decrease in intercellular CO2 concentration in both cultivars, while reverse trend was shown with further increase of B concentration. B @ 9.0 kgha(-1) improved the activities of antioxidant protective enzyme of SOD and POD and decreased the accumulation of MDA content in the both cultivars. Dry matter translocation increased with increasing B level upto 9.0 kgha(-1) that resulted the highest seed yield and harvest index of rapeseed in both cultivars. Thus, B @ 9 kgha(-1) is sufficient for rapeseed cultivation under the subtropical environmental condition of the Southern China. Brassica napus