Induction of seedlessness in 'Kyoho' and 'Pione' grapes (Vitis labruscana) with application of streptomycin, GA_3, and Thidiazuron

摘要

This experiment was focused on developing a labor-saving practice for producing 'Kyoho' and 'Pione' seedless grapes (Vitis labruscana). In 'Kyoho' cultivar, seedless grapes were successfully produced by a spray of streptomycin (SM) 200 mg centre dotL~(-1) 10 days before full bloom, followed by a dipping of clusters into GA_3 25+thidiazuron (TDZ) 10 mg centre L~(-1) solution 3 days after full bloom. There were no differences in the percentage of producing seedless berries and fruit quality betweenthe treatments of one-time dipping of clusters and previous practice of dipping the clusters two-times: first into GA_3 12.5+TDZ 5 mg centre dot L~(-1) at full bloom, and second into GA_3 25+TDZ 5 mg centre dot L~(-1) 10 days after full bloom. Also, seedless grapes were successfully produced by one-time dipping treatment of SM 200+TDZ 5+GA_3 25 mg centre dot L~(-1) or SM 200+TDZ 5+GP [GA_3 25+n-propyl dihydrojasmonate (PDJ) 25 mg centre dot L~(-1)] in 'Kyoho' when vine vigor was stable. However, seedlessness decreased when vine vigor was strong. In 'Pione', seedless grape production was possible through one-time dipping treatment of SM 200+TDZ 5+GP (GA_3 25+PDJ 25 mg centre dot L~(-1)) at full bloom stage regardless of vine vigor, but the weight of berry was decreased. These results indicated that 'Kyoho' and 'Pione' seedless grapes can be safely produced by one-time dipping treatment of clusters, instead of previous practice of two-time dippings, without a loss of fruit quality. This would be conducive to labor-saving and also enhance cost effectiveness of producing seedless grapes of these two cultivars.