Effects of selection in tetraploid green gram varieties

A comparative study of the effect of tetraploidy in three varieties of green gram (Phaseolus aureusRoxb.) and selection of plants with high, medium and low vigour showed that the reduced leaflet size and height at the time of flowering can be considerably improved by selection. It appeared that the diploid level can be approached or even exceeded.The reduced fruit setting can also be improved considerably but not the size of fruits and number of seeds per pod. The increased seed weight was further improved in two varieties. The increase in protein content of the tetraploid seeds was greatest in the variety with the lowest protein content at the diploid level.Though for vegetative growth selection alone would suffice to bring the tetraploids up to the diploid level, if not higher, the reduced fruit and seed setting, though responding well to selection, are unlikely to be overcome unless other breeding methods are introduced.