PHOTOSYNTHESIS AND DRY-MATTER PRODUCTION IN T-MONOCOCCUM AND TRITICUM-AESTIVUM WHEAT IN RESPONSE TO EAR REMOVAL

The photosynthesis, shoot formation, leaf area development and dry matter production were examined in control and de-eared plants of T. monococcum, var. G 1372 and T. aestivum var. Sonalika. The removal of ears decreased the diurnal maintenance of photosynthesis and consequently, the dry matter production in Sonalika but not in G 1372. There was a considerable growth of alternative sinks such as shoots and roots when ear sinks were removed. This alternative sink capacity of de-eared plants seemed to have compensated for limited sink demand of ears in G 1372 but could not entirely compensate for the more efficient grain sink in Sonalika. The diploid wheat produced more dry matter than the hexaploid wheat in the pre-ear emergence period and less in the pose-ear emergence period. In the pre-ear emergence period, the difference in dry matter appeared to be mostly because of the difference in duration to ear emergence. During the post-ear emergence period, the lower dr; matter in G 1372 seemed to be owing to a rapid decrease in photosynthesis rare after anthesis because of the lower sink capacity of its grains.