插皮接技术在棉花再生植株嫁接中的应用

Application of Bark Grafting Method on Grafting of Regeneration Cotton

首次将插皮接技术用于棉花再生植株的嫁接。详细介绍了它的操作过程和实用技巧．该法要求简单，操作方便．成活率高；成活后砧芽枝摘心留叶有利于接穗良好生长发育。在砧木适合的嫁接时期、成活率和生长速率等方面与劈接法作了比较。结果表明：插皮接对砧木和接德粗细比例无严格要求，从而延长了砧木可使用的时期。砧木生长过程中适合劈接的时间有一周左右（3～5片真叶），而在此以后的较长时间内均适合于插吱接（4～5片真叶直到开花期）；由于形成层吻合好。使用的砧木较大，有较发达的根系。在高成活率的前提下相对缩短了再生植株成活的时间。再生植株嫁接前不练苗。在嫁接后采取新的保湿和透气策略，使练苗和嫁接同期进行。有效缩短了再生植株缓苗时间。

Bark grafting method is applied in grafting of regeneration cotton for the first time. and its manipulation processes and skills are also introduced in detail. The advantages of bark grafting lie in its simpleness, easy operation, and the high survival rate of regeneration plants. Leaf remaining and tip pruning of stocks is propitious to the well growth of cions of live regeneration plant. In the experiment, Hal 7124 （Gossypium barbadense L.） with strong root system and highly resistance to disease was selected as stocks, and regeneration plant of Coker 312 was used as cions. The growth stage of stocks, survival rate and growth rate of bark grafting were compared with those of cut grafting. The results indicated that the method of cut grafting had strict demand for growth stage of stocks or the proportion of diameter between stocks andcions. As to cut grafting, the growth period of 35440 days stocks （i.e. stocks with 3-5 leaves） was the best suitable period of grafting. The survival rate of re generation cotton at this stage was higher than heretofore or after. In addition, the same size of diameter between stocks and cions was needed for cut grafting because it could make the cambiums be inte grated completely. Bark grafting had no strict selection on the growth stage of stocks or the propor tion of diameter between stocks and cions when compared with the method of cut grafting. The survival rate of grafting of regeneration cotton was about 90% using 35466 days stocks （i.e. the growth stages of stocks from four or five euphylla to florescence） in bark grafting. So under the precondition with the same highest survival rate of regeneration cotton in bark grafting, the available time of stock was prolonged one month than in cut grafting. Under the condition of the same growth stage of stock and the same grafting time, the survival rate might had significant difference between two grafting methods, whereas the growth rate ofcions had no difference. It suggestd that the growth rate ofcions was significantly positively correlated with stock growth stage （35-66 days） （r=0.94）. Since the in osculation of cambium was tighter and stocks had the flourish roots in bark grafting, it relatively re duced the surviving time of regeneration plants under the precondition of remaining the high survival rate of regeneration plants. Since new strategies of keeping humidity and ventilating were adopted in grafting, in which grafting and shoot hardening were performed simultaneously, regeneration plants need not be hardened before grafting and the time for seedling revive could be effectively reduced. In this report, essentials of grafting, management after grafting, and practical manipulation skills of regeneration plants were also discussed. It came to the conclusion that the selection of optimal grafting strategy lied on the growth stage of stock. The 35-40 days stocks （i. e. stocks with 3-5 leaves） were fit for cut grafting while 35-66 days stocks （i.e. the growth stages of stocks from four or five euphylla to florescence） were fit for bark grafting. In general, bark grafting was better than cut grafting as a whole.