巴西橡胶树嫁接接合区接穗和砧木径向生长差异的研究

采用树皮嫁接后不锯砧和光镜观察的方法，研究了巴西橡胶树(Hevea brasiliensis)嫁接后8个月的接合区接穗和砧木木质部径向生长的差异现象。结果表明，接合区接穗木质部的径向生长普遍地小于砧木，这种生长差异是由接穗和砧木亲本固有生长特性的差异引起的，与嫁接亲和性无关。(1)对于同一无性系，接穗的发育阶段决定其生长能力，幼态接穗新分化的木质部显著地大于老态接穗，而两类接穗旁边的砧木之间没有明显差别。(2)砧木生长势明显地影响接穗木质部的生长，砧木生长势越强，砧木和接穗的生长就越快，两者的径向差异也越大。(3)同一砧木上各品系接穗木质部生长差异取决于接穗自身的生长特性，砧木的生长不受接穗品系的明显影响。显微观察表明橡胶树的嫁接是亲和的，接穗新分化的木质部镶嵌在砧木新分化的木质部中，维管组织如导管上下连接畅通，砧穗树皮厚度一致，愈合良好。

Studies on the difference of radial growth between scion and stock in the graft union in Hevea brasiliensis

The difference of xylem radial growth between scion and stock in the graft union in Hevea brasiliensis was studied by patch grafting (without sawing up the stock shoot above the grafting position)and microscopical observation 8 months after grafting. The results showed that the xylem radial growth of the scion was universally slower than that of the stock, and the difference was caused by the original growth characters of their parent plants of scion and stock rather than graft compatibility. (1) When scion and stock were of the same kind of clone, the scion growth ability was determined by the developmental phase, the xylem width differentiated from juvenile scion was significantly larger than that of mature scion, while there was no obvious difference between the stocks that in close proximity to the two kinds of scions. (2) The xylem growth of scion was markedly affected by the growth potential of stock. The stronger the growth potential of the stocks had, the faster the stock and scion grew, the more differences were made between the two parts. (3) When mature scions of three clones were grafted onto a single seedling, the differences of xylem growth among the scions were depended on the scions' own growth characters. The effect of scion growth on stock was insignificant. Microscopical observation indicated that the rubber tree grafting was compatible, with newly differentiated xylem of the scion inlaid in that of the stock, and vascular tissues such as vessels and the bark in the graft union connected well.