SEX AND KIWIFRUIT BREEDING
Sex determination and sex expression are being studied in Actinidia. Although all known species are predominantly functionally dioecious, variation in floral development has been found in A. deliciosa. Staminate vines usually produce flowers with only rudimentary and non-functional pistils. However, some vines show variable pistil development which in some flowers is sufficient to allow fruit set. Such vines have been used as source material for breeding for hermaphroditism. Small fruit size and variable sex expression are major problems in the development of commercial hermaphrodite cultivars, but considerable progress has been made. Individual fruits of commercial size (>70g) have been produced from bisexual flowers and completely hermaphroditic vines have been selected. First results suggest that hermaphroditism may be considered as a "threshold" character with a low incidence among seedlings derived from open-pollination of partially hermaphrodite (andromonoecious) parents.
Seal, A.G. and McNeilage, M.A. (1989). SEX AND KIWIFRUIT BREEDING. Acta Hortic. 240, 35-38