Abstract: In order to select excellent rootstock of large-fruit Castanen henryi ‘Guili 1’ and provide theoretical support for scion-stock combination interaction mechanism, C. henryi ‘Guili 1’ was grafted onto C. mollissima and C. Henryi, respectively, and their survival ratios were observed. In addtion, the C. mollissima and C. henryi seedlings were as the controls, and then the growth, Pn-PFD response curve and diurnal variation of photosynthesis of the grafted seedling were measured. The results showed that the survival ratio of the grafted seedling whose rootstock was C. henryias was much higher than that of whose rootstock was C. mollissima. Both kinds of grafted seedlings grew weaker than that of the controls. The differences of light response parameters, such as maximum net photosynthetic rate (Pmax), light saturation point (LSP), light compensation point (LCP), apparent quantum yield (AQY) and dark respiration rate (Rd) on C.henryi ‘Guili 1’ were not significantly affected by 2 different rootstocks. The range of applicable light intensity of 4 kinds of seedlings was C. mollissima＝C. mollissima/Guili 1 (C. henryi ‘Guili 1’ grafted onto C. mollissima)＞C. henryi/Guili 1 (C. henryi ‘Guili 1’ grafted onto C. henryi)＞C. henryi. The diurnal variations of net photosynthetic rate (Pn) in 4 kinds of seedlings were dual-peaked models, and the Pn of 4 kinds of seedlings all peaked at 8:40~10:00 a.m. The midday depression of photosynthesis appeared at 14:00, and the depressive range of C. henryi/Guili 1 and C.henryi were wider than that of C. mollissima and C. mollissima/Guili 1. Compared with C. mollissima and C. mollissima/Guili 1, C. henryi and C. henryi/Guili 1 were more seriously affected by environmental factors, such as scorching heat and intense light. With respect to the trends of daylong changes of photosynthetic parameters, such as Pn, stomatal conductance (Gs), transpiration rate (Tr), internal cellular CO2 concentration (Ci), stomatal limitation (Ls) and water use efficiency (WUE), C. mollissima and C. mollissima/Guili 1, C. henryi/Guili 1 and C. henryi were similar, respectively. The differences of all-day organic matter accumulation on both kinds of grafted seedling were very small. The main physiological and ecological factors affecting the daylong Pn of grafted seedlings were photosynthetically active radiation (PAR), Gs, Tr, Ci and Ls. In terms of affinity, C. henryi was more suitable for the rootstock of C. henryi ‘Guili 1’. But it was recommended that C. mollissima was used as rootstock in high altitude or strong sunshine areas.

Key words: large-fruit Castanen henryi, graft compatibility, photosynthetic characteristics, Pn-PFD response curve, diurnal variation

摘要： 为了筛选‘桂栗一号’大果锥栗优良砧木及为探讨砧穗互作机制提供理论支持，以‘桂栗一号’大果锥栗为接穗，以板栗和普通锥栗作砧木进行嫁接，观察其成活率；以板栗和普通锥栗实生苗为对照，测定其苗木生长量、光响应曲线和光合日变化等。结果表明，以普通锥栗为砧木的嫁接成活率远高于以板栗为砧木的嫁接成活率，两种砧木的‘桂栗一号’嫁接苗的长势均弱于其对照。不同砧木对‘桂栗一号’苗木的最大净光合速率（Pmax）、光饱和点（LSP）、光补偿点（LCP）、表观量子效率（AQY）和暗呼吸速率（Rd）等光响应参数的影响并不显著。4种苗木对光强的适应范围：板栗＝板栗/桂栗一（以板栗为砧木的‘桂栗一号’嫁接苗）＞锥栗/桂栗一（以锥栗为砧木的‘桂栗一号’嫁接苗）＞普通锥栗。4种苗木的Pn（净光合速率）日变化均呈“双峰曲线”，全天Pn的最高峰出现在8:40~10:00，14:00时均有光合“午休”，而普通锥栗和锥栗/桂栗一的“午休”幅度比板栗和板栗/桂栗一大。对于全天的Pn、气孔导度（Gs）、蒸腾速率（Tr）、胞间二氧化碳浓度（Ci）、气孔限制值（Ls）和水分利用效率（WUE）等光合参数变化，板栗与板栗/桂栗一、普通锥栗与锥栗/桂栗一走势分别相类似。普通锥栗和锥栗/桂栗一比板栗和板栗/桂栗一受炎热和强光等环境因素影响较为严重。以板栗或普通锥栗作砧木，在全天有机物的积累上差异小。影响嫁接苗全天Pn的主要生理生态因子为光合有效辐射（PAR）、Gs、Tr、Ci和Ls。单从亲和力上考虑，选用普通锥栗作为砧木嫁接‘桂栗一号’为佳，但在高海拔或日照强的地区建议使用板栗作为砧木。

关键词: 大果锥栗, 嫁接亲和性, 光合特性, 光响应曲线, 日变化