不同砧木品种对核桃树体生长及光合特性的影响

Effects of Different Rootstock Varieties on Growth and Photosynthetic Characteristics of Walnut

[目的]采用将同一品种嫁接到不同砧木的方法,经过调查测试和分析,揭示杂交种‘中宁奇’的砧木特性,进而阐明砧木在经济林育种和栽培中的地位和作用。[方法]以砧穗组合上宋-14/中宁奇和上宋-14/宁优为试材,测定分析不同砧穗组合的生长量和光合特性指标。[结果]嫁接亲和性调查显示:2种砧木对同一核桃品种的嫁接亲和性均较高,但差异不显著。树体生长特性调查表明:上宋-14/中宁奇树高、干径、冠幅、新梢长度、新梢粗度、新梢着生小叶数及分枝力等指标显著或极显著高于上宋-14/宁优,‘中宁奇’作砧木可显著增强核桃树体的生长势。光合特性分析结果显示:2种砧穗组合间光响应曲线特征参数存在显著差异,上宋-14/中宁奇最大净光合速率(21.93μmol·m^(-2)·s^(-1))、光饱和点(1 550μmol·m^(-2)·s^(-1))及表观量子效率(0.062 mol·mol^(-1))分别比上宋-14/宁优提高17.90%、11.51%和16.98%,而光补偿点(16.53μmol·m^(-2)·s^(-1))则显著降低35.33%。[结论]核桃杂交种‘中宁奇’与‘上宋-14’核桃品种有较强的亲和性,以‘中宁奇’作砧木可显著提高树体的生长量和光合能力,使嫁接品种对光强的利用范围变广,从而提高树体对光环境的适应性。

[ Objective ] By grafting same variety to different root stocks to reveal the rootstock characteristics of wal- nut hybrid Zhongningqi and to clarify the rootstock status and roles in the economic forest breeding and cultivation production. [Method] Taking two scionstock combinations of Shangsong-14/Zhongningqi and Shangsong-14/ Ningyou as the trial materials, the growth and photosynthesis characteristic indexes were measured and compared. Result I The result of grafting compatibility survey showed that the graft survival rate of the two rootstocks grafted the same walnut variety was higher, but no significant difference was found between them. The result of growth characteristics survey showed that the indexes of tree height, tree diameter, crown breadth, shoot length, shoot di- ameter and the amount of lateral branches of Shangsong-14/Zhongningqi were significantly or extremely significantly higher than that of Shangsong-14/Ningyou. Zhongningqi, as a root stock, could significantly enhance the growth po- tential of the walnut scion. In terms of photosynthetic characteristics, there were significant differences among pa-rameters of light response curves between the two scionstock combinations. The maximum net photosynthetic rate （21.93 μmol · m^-2 . s^-l）, light saturation point （1 550 μmol · m^-2 . s^-1） and apparent quantum yield （0.062 mol ·mol^-l） of Shangsong-14/Zhongningqi were significantly higher （ ＋ 17.90%, ＋ 11.51% and ＋ 16.98% ） compared with that of Shangsong-14/Ningyou. But the light compensation point of Shangsong-14/Zhongningql was 35.33% lower. [ Conclusion] The walnut hybrid Zhongningqi has strong grafting compatibility with walnut varie- ties. As the root stock, Zhongningqi can significantly enhance the growth potential and photosynthetic capacity of walnut tree, it can also enlarge the light range and improve the adaptability of light environment.