Occurrence of Reciprocal Translocation in Lathyrus boissieri Sirj (Fabaceae) from Iran

Diploid Lathyrus boissier showed the 7 bivalents in most of pollen mother cells at prophase and metaphase of meiosis. The disturbances in the meiotic stage appeared to have been caused by reciprocal translocation. Meiotic analyses of 232 pollen mother cells indicates occurrence of heterozygotic reciprocal translocation in 94 cells. When the crossing-over and chiasma formation take place in all 4 pairing segments, a ring of 4 chromosomes results, and when the chiasma was absent in one of the 4 pairing segments, a chain of 4 chromosomes results. Of the 94 transtocated MI cells examined, 24 had ring quaderivalents, 55 had open chain quaderivalents and 15 had alternate (zigzag) ring quaderivalents. From the present investigation it appears L. boissier has not acquired stability as yet and translocation has played an important role in its evolution. In this study chromosome count and meiotic behaviour of L. boissieri is presented here for the first time.