Variability for Photosynthesis in Brassica and Allied Genera

Different physiological parameters viz: carbon exchange rate, stomatal diffusive resistance, chlorophyll content, transpiration and days to flowering of crop Brassicas and their wild allies were examined. Coeno species such as Brassica oxyrrhina, Brassica amplexicaulis, Diptotaxis vimenea, Diptotaxis catholica, Erucas-trum laevigatum, Sinapis arvensis, Trachystoma ballii, Enarthrocarpus lyratus and Moricandia arvensis, have been identified as high photosynthesizing species with the range of photosynthesis varying from 21.9 to 28.9 µ mol m⁻²s⁻¹. Whereas, Brassica tourniforti local, B. tourniforti exotic, Diptotaxis muralis and Erueastrum cardaminoides were grouped as species having low rate of photosynthesis (range 9.06 to 14.30 µ mol m⁻²s⁻¹). Photosynthesis in crop Brassicas viz: Brassica oleracea, B. campestris, B. carinata and B. juncea was significantly lower than wild species. This information will help in introgressing genes of high photosynthesis from wild species to crop Brassica through suitable genetic approach to improve their productivity.