INCONGRUITY IN THE PROGENY OF 'INTERSPECIFIC CROSSES OF VITIS

Debby Meredith Filler 318 words Three classes of hybrids involving Vilis riparia Michx. were evaluated for evidence of incongruity, a phenomenon reflecting passive evolutionary divergence between the genomes of the mating partners. Each class consisted of families derived from four maternal clones of V. riparia. The R x V class (Vilis riparia x V. vinifera L.) was the most divergent, and the least divergent was the intraspecific R x R class (V. riparia x V. riparia). The R x FH class (V. riparia x French Hybrid) was derived from multiple species and was highly intercrossed. Reproductive dysfunction was detected in the F 1 generation. The R x R class displayed the highest percent berry set and the largest mean number of seeds per berry, while the R x V class manifested reduced berry set and reduced mean number of seeds per berry. The intercrossed R x FH class exhibited intermediate berry set and numbers of seeds per berry. Differences in percent berry set were found to be related to percent aborted flowers, but not t