Studies on Tetraploid Cluster Bean Varieties and their Triploid and Aneuploid Progenies

Abstract

1. Tetraploidy was induced in a vegetable and a fodder type of cluster bean by treating presoaked seeds as well as apical buds with colchicine solution.2. In the tetraploids, the height was significantly increased during the later stages; the stem was thicker, and the number of branches was similar to the diploids in Pun. 3 and increased in the unbranched Sadabahar.3. Tetraploidy has brought a variety of changes in the foliar characters such as size, thickness, surface, margin, colour, etc.4. Flowering was delayed in tetraploids during monsoon season but not in summer crop. The flowers were larger and more number of them opened per inflorescence prolonging the blooming period. Pollen fertility was low and the stainable grains were variable in size.5. Fruit setting was reduced in Pun. 3, but increased significantly in Sadabahar. Pods were, however, smaller but seeds larger.6. Quadrivalents occur frequently at synapsis and anaphase separation was irregular.7. Aneuploids having 29 chromosomes were detected in the progeny of Sadabahar tetraploids which were less fertile and differed in some respects from tetraploids.8. A triploid plant was obtained in Pun. 3 which had luxuriant vegetative growth but was totally sterile. Trivalents predominated among the different meiotic configurations.