Evidence for preferential pairing in telotrisomic plants of rye

Abstract

Using C-banding it has been possible to distinguish all meiotic configurations at metaphase I in telotrisomic plants of rye. From these configurations the types of pairing among the short arms of chromosome 1R, in trisomie condition, could be directly established. The results indicate that there are actually pairing preferences and they could be responsible for the low trivalent frequencies found. The long arm of chromosome 1R, in disomic condition, seems to play an important role on pairing preferences which shows the short one. The possibility of preferences produced by chiasma formation and chiasma failures is also discussed.