Study On Technology Of Seedlessness And Mechanism In Fresh Grapes

Production of seedless berries in seed grapes using plant growth regulators is a simple method and theoretically independent to the genetic factors defining berry qualities. In this experiments, gibberellin (GA3) and streptomin(SM) were examined; dipping and spraying were adopted; 'Kyoho','Rizamat'and'Red Globe' cultivated in Northern of Xinjiang province were used as the plant materials. Through two years experiments ,the best suitable ways for different grapes'seedlessness had selected. For GA3dipping treatment: 'Rizamat' should be treated at the full bloom ,with the concentration of 25-100ppm, seedless rate is 95.6%.'Kyoho' was also at the full bloom period but with the concentration of 25-50ppm.'Red Globe' should be treated at about two weeks before anthesis with the concentration of 50ppm. For GA3 spraying treatment: it is not fit for 'Kyoho'. but to 'Rizamat'it made berries bigger at the beginning of anthesis with the concentration of 500-1000ppm. To 'Red Globe',it also made berries bigger at the beginning of anthesis and full bloom period .For SM treatment ,all of three varieties had the good result. the seedless rate of 'Rizamat' was 100% at the full bloom,of 'Kyoho' was 90% at about two weeks before anthesis,of 'Red Globe' was 88% at about two weeks before anthesis treated with the concentration of 200--400ppm.All treatments matured earlier than control.The pollen experiments indicated that the higher concentration of GA3,the lower pollen germinating rate of grapes when dipping from 25ppm-100ppm. That means: GA3 had the function of killing the pollen andprohibiting the pollen from germinating, and the function was relation to the part where it was putted .The function of SM with pollen wasn't obvious.The morphological study on the 'Kyoho' treated by GA3 dipping indicated that the embryo sac was often in 4-nuclear period but anthesis was earlier than control after GA3 treatment . they couldn't fertilize normally and resulted in seedless berries .Furthermore, there were many abnormal embryo sac producing seedless berries after GA3 treatment.