【摘要】 对不同苗龄接穗的西瓜(葫芦砧木)嫁接苗的嫁接体愈合组织进行组织学和细胞学观察。结果表明:接穗苗龄5d、7d和10d的嫁接苗,嫁接愈合快,嫁接6d后管状分子已开始分化,8d后隔离层基本消失,维管束桥形成,近愈合面细胞内有丰富细胞器,嫁接苗的成活率达90%以上;而接穗苗龄为13d和18d的嫁接组合在嫁接8d后愈合面隔离层仍存在,愈合面两侧细胞中细胞器少,鲜见维管束桥连通,嫁接苗的成活率分别为83.3%和72%。因此认为,维管束桥的形成及愈合面细胞中丰富的细胞器,是西瓜嫁接苗成活的组织学和细胞学特征,接穗苗龄小于10d适合于进行嫁接,嫁接苗成活率高。更多还原

【Abstract】 Watermelon seedlings of different ages were grafted onto cucurbit rootstocks. The graft union formation was observed using paraffin section and a transmission electron microscope(TEM),and the survival rate was statistically analyzed. In the early days after grafting,a necrotic layer was induced between scion and rootstock. The concrescence rate of the graft combinations with 5 d,7 d and 10 d scions were higher,the necrotic layer disappeared on the 8th day after grafting,and abundant organelles occurred in the cells adjacent to the necrotic layer. Vascular bundles began to regrow after 6 days of grafting,and vascular bridges were formed after 8 days of grafting. The survival rates of these three combinations reached more than 90%. By contrast,in the graft combinations with 13 d- and 18 d-old scions,the necrotic layer could still be observed on the 8th day after grafting,and few organelles and vascular bridges were formed in the cells adjacent to the necrotic layer. The survival rates of seedlings with 13 d- and 18 d-old scions were 83.3% and 72%,respectively. Thus,the connection of vascular bridges between rootstock and scion,and abundant organelles in the cell adjacent to the necrotic layer could be considered as morphological signs of grafted seedling survival. The scion age below 10 d was appropriate for grafting.更多还原