Meiotic behavior of the Brazilian table grape cultivar Rubi (Vitis vinifera) with a high proportion of seedless berries

Meiotic behavior, pollen fertility and germination of the Brazilian table g rape cv, Rubi (Vitis vinifera) were investigated; this cultivar produced di fferent numbers of seedless berries when cultivated at two different sites: At site A vines produced a high proportion of seedless berries while at si te B vines produced berries with a normal number of seeds. Cytological anal ysis of inflorescences collected from the two sites showed some meiotic abn ormalities, the most common being related to chromosomal segregation and te lophase micronuclei formation leading to microcyte formation in the tetrads , Cytoplasmic channels, bridges and tripolar spindles were also observed in some microsporocytes, Pollen fertility was high at both sites, approximate ly 96 % at site A and 98 % at site B, The rate of pollen germination was lo wer at site A than at site B, suggesting that the absence of seed formation is related to pollen germination rate.