油桐芽苗砧嫁接育苗技术及解剖结构观察OACSTPCD

[Objective]Tung tree is one of the four major woody oil tree species in China.The development of tung tree industry has certain strategic significance for improving China's energy self-sufficiency.This paper aims to establish a new asexual reproduction technology system for tung tree seedlings with hypocotyle rootstocks grafting by studying the new technique of tung tree seedlings and hypocotyle grafting,so as to provide a new way for the future asexual reproduction of tung tree elite varieties.[Method]The seedlings cultivated from Vernicia montana and Vernicia fordii seeds were used as rootstocks,and the current year-old semi-woody stem segments with buds of the offsprings of Vernicia fordii'Huatong No.1'were used as scions.The effects of different rootstock species,grafting methods,grafting film types,grafting periods,seedbeds and transplanting heights on the grafting success of the seedling rootstocks were investigated for two consecutive years,and the microscopic anatomical structure of wound healing after grafting was observed.[Result]1)Under favorable conditions of other external factors,the survival rate of tung tree grafting was more than 89.0%with V.montana and V.fordii seedlings as rootstocks,and there was no significant difference in the early growth between the two,but V.montana rootstocks was more beneficial to improve the resistance of tung trees.With the V.montana seedlings as rootstocks,the survival rate of split grafting with plastic film was 184.0%higher than that of aluminum foil,and the survival rate of split grafting with plastic film was 58.7%higher than that of jointing grafting.2)The suitable length of the upper axillary buds,lower part axillary buds and petiole of scion was 1.0 cm,3.0 cm and 0.5 cm,respectively,for grafting on tung tree seedling rootstock;the suitable incision length for rootstock splitting was 1.5 cm,the height of transplanting seedbed was 15 cm,the light transmission rate of the shade net was 25%,and the grafting union should be above the ground at the time of transplantation.3)Different grafting periods had significant effects on the survival rate of tung trees by hypocotyle grafting.The survival rate of grafting in early June was 51.5%higher than that in mid-May,with significant differences(P<0.05).The seedlings grafted in early June had better growth in the later period.4)By observing the growth process of axillary buds and the anatomical structure of callus at the graft union,it was found that the wound was partially healed and the axillary buds began to expand after 10 days of grafting,and the axillary buds grew new leaves after 20 days.The wound healing degree of scion and rootstock was higher after 70 days,and it was necessary to remove the film to facilitate the growth of the grafted seedlings.[Conclusion]The technology system of grafting of tung tree seedling rootstock is successfully established in this paper.In June,the overall survival rate of tung tree hypocotyle grafting with a large number of seedlings in the field can reach more than 70.0%,which provides a practical way for asexualized seedling breeding of tung trees in the future.