ISHS Acta Horticulturae 403: International Symposium on Cultivar Improvement of Horticultural Crops. Part 2: Fruit Crops
RESEARCH ON COLD HARDINESS OF GERMPLASM RESOURCES OF PERSIMMON (DIOSPYROS KAKI) |
| Authors: | W. renzi, Y. yong |
| Abstract:
Temperature ecides distribution of Persimmon. It was significant for hardiness identification of Persimmon varieties to enlarge cultivation and breed new varieties, In this paper, we adopted direct methods of simulating nature condition of cold, and made a survey after calamities and did resistance way as supplement. Research found that temperature which Persimmon's dormant buds died of cold was between -17°C to - 23°C, this treating temperature was appropriate to distinguish hardiness among varieties. Observing directly reaction of growing point after treating with temperature was the most unsophisticated and effective method. The resullt of identifing 92 varieties from national germplasm resouces nursery of Persimmon was that "Denglongshi", "Hroguantoushi" and "Hyakume" were the most hardy. Avariety in deep dormant period was more hardy than that in other growth phase, and so do annual branches than secondary shoots. Diffrent thickness shoots' hardiness was not obvious diffrence. Varieties' percentage of freezing (PF) was gradually increasing with temperature'e decreasing. Resistance way was also one of the methods of determining hardiness, it didn't fit comparing among varieties of few diffence because of branches', thickness, position order, degree of substantials, ad dormant depth ect. but it can use comparing among species. Observation find that hardiness of domant buds was closely related to degree of substantials of branchs (i.e. capacity of accumulation of organic substance, big or small of pith), but didn't to many or few of down on leaf primordium, closed degree of budscale, adn position order of buds. Persimmon is a kind of subtropics fruit trees, and rather sensitive to low temperature, hence temperature restricts its distribution. Cultivative persimmon varieties often suffered from cold injury where the annual average temperature is about 10oC. Farmers hoped urgently to obtain cold resistant varieties, and also breeders expected to possess cold resistant resouces to breed cold resistant varieties. Therefore the cold resistant identification of Persimmon varities is of significance in enlarging range of cultivation and selecting cold resistant parent. | |
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