咖啡双根嫁接苗生长及光合特性比较研究

以大粒种咖啡‘1号’（Caffea liberica No. 1）和中粒种咖啡‘热研1号’（Caffea canephora Reyan No. 1）的种子苗形成不同双根靠接苗组合,以‘热研1号’高产无性系为接穗,包括中粒种双根嫁接苗（T1）,大粒种中粒种双根嫁接苗（T2）,大粒种双根嫁接苗（T3）,以常规种间嫁接苗（CK,植株地下部为一条大粒种1号根系,地上部与双根苗一致）为对照,比较不同嫁接处理植株生物量、根系形态及光合特性,并分析高径比及苗木质量指数。结果表明：T1和T2处理较CK植株根尖数分别提高407.14%和780.28%、净光合速率分别提高25.11%和57.49%、总生物量分别提高168.26%和209.35%。同时,苗木质量指数分别提高195.79%和244.17%,苗木长势较粗壮,T1和T2处理通过提高植株根系吸收及光合能力提升苗木质量。而T3较CK植株高径比提高25.28%,较CK增加一条大粒种根系,并未显著提高T3处理植株生物量,且苗木长势较细高,后期易形成“高脚苗”,大田定植效果差。因此,中粒种双根苗和大粒种中粒种双根苗生长优势明显,以大粒种中粒种双根苗长势最佳。

Growth and Photosynthetic Characteristics of Coffee Double Roots Grafting Seedling

In order to improve the quality of coffee seedling, the seed seedlings of Caffea liberica No. 1 and Caffea canephora Reyan No. 1 were used as the grafting materials, and high-yielding clone C. canephora Reyan No. 1 was used as the scion. Biomass, root morphology characteristics, photosynthetic characteristics, height diameter ratio and seedling quality index among C. canephora Reyan No. 1 double roots grafting seedling (T1), C. liberica No. 1/ C. canephora Reyan No. 1 double roots grafting seedling (T2), C. liberica No. 1 double roots grafting seedling (T3) and conventional interspecific grafting seedling (CK, C. liberica No. 1 single root grafting seedling) were observed. Compared with CK, root tip number, p_n, total biomass and seedling quality index of T1 and T2 were increased by 407.14% and 780.28%, 25.11% and 57.49%, 168.26% and 209.35%, 195.79% and 244.17%, respectively. The seedling quality of T1 and T2 was improved by raising plant root absorption and photosynthetic ability. The height diameter ratio of T3 was increased by 25.28%, and there was no significant difference in total biomass between CK and T3. Compared with the seedling of CK, the week seedling of T3 grew thinner and taller, and then grew into coffee tall-footed seedlings more easily. In summary, the advantage was evident in the plant growth of T1 and T2, particularly in T2 treatment.