Karyotype Analysis and Meiotic Studies in Three Varieties of Grape (<i>Vitis vinifera</i> L.)

Abstract

Three varieties of grape viz., Alamwick, Gros colman and Selection 7 were studied with the intention of determining chromosome number as well as cytological abnormalities. The somatic chromosome number was found to be 38 in all the 3 varieties. The length of chromosomes varied in between 2.163 and 0.786 microns. Chromosomes could be classified as median and submedian. A pair of sat-chromosomes were observed in all the 3 varieties.A maximum of 1.18 chiasma frequency per bivalent was noticed in Selection 7. In all the 3 varieties 3 bivalents were associated with nucleolus. Occurrence of lagging bivalents and binucleolar condition are the only abnormalities noticed in these studies. Meiotic index was cent per cent in all the varieties. Pollen fertility varied from 91.11% to 83.47%. Slight variation was noticed in pollen diameter. Since all the 3 varieties are cytologically stable, it is recommended that all these varieties can be used in breeding programme without any hindrance for grape improvement.