“…This M4 mutant plant was found to be semi-sterile. Sterility in the interchanged plants depends largely on the orientation of the multivalents (interchanged chromosomes) at first metaphase of meiosis (Rees 1961, Rana 1965, Sun and Rees 1967, Sjodin and Hagberg 1968, Ekberg 1969, Gottschalk and Baquar 1973, Simonsen 1973, Kaul 1977, Meshram et al 1981. Depending on the orientation of centromeric position, the multivalent configuration noted in the interchanged plant has been classified into disjunctional and non-disjunctional types.…”