薄壳山核桃嫩枝扦插生根技术与根系发育机理研究

Study on the softwood cutting rooting technology and root development mechanism of Carya illinoensis(Wangench.)K.Koch

【目的】完善薄壳山核桃嫩枝扦插技术体系,明确影响插穗根系发育的内源性物质。【方法】以卡多、金华、马罕3个薄壳山核桃品种为试验材料,设置激素种类、遮阳率、湿度水平和容器条件四因素四水平正交试验,研究不同因素对薄壳山核桃插穗生根率和根系效果指数的影响,并分析不同根系效果指数下,可溶性糖含量、可溶性蛋白含量、生长素(IAA)含量、脱落酸(ABA)含量、IAA/ABA、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性的变化规律。【结果】各因素对薄壳山核桃插穗生根率的影响次序为湿度水平=遮阳率>激素种类>容器条件,在IBA处理、0或60%遮阳率、60%<湿度水平≤90%下可保证薄壳山核桃插穗生根率,以IBA处理、60%遮阳率、60%<湿度水平≤80%下薄壳山核桃插穗根系发育效果较好,处于生根率筛选的优水平区间内。随着根系效果指数的增加,插穗苗干可溶性糖、可溶性蛋白含量降低,IAA含量、IAA/ABA增加、ABA含量降低,SOD、POD活性增加,其中,在根系效果指数≤0.5时,各相邻区间插穗可溶性蛋白含量和POD活性均差异显著(P<0.05);在根系效果指数≥0.3时,各相邻区间插穗IAA含量差异显著(P<0.05),且IAA/ABA提升幅度不断增大。【结论】IBA激素处理、60%遮阳率、60%<湿度水平≤80%为适宜薄壳山核桃扦插生根的优水平,插穗生根效果最优;可溶性蛋白含量、IAA含量、IAA/ABA、POD活性均与插穗根系发育密切相关。

【Objective】To improve the softwood cutting technology system for Carya illinoensis(Wangench.)K.Koch,and identify the endogenous substances affecting cutting root development.【Methods】Three Carya illinoensis(Wangench.)K.Koch varieties,Caddo,Jinhua and Mahan,were used as experimental materials to study the rooting rate and root effect index of cuttings under different hormone types,shading rates,humidity levels,and container conditions through four-factor four-level orthogonal test.The changes in soluble sugar content,soluble protein content,IAA content,ABA content,IAA/ABA,POD activity,and SOD activity with the root effect index were analyzed.【Results】The order of influence of various factors on the cuttings′rooting rate of Carya illinoensis(Wangench.)K.Koch were humidity level=shading rate>types of hormone>container conditions.Cuttings under IBA treatment,0 or 60%shading rate and 60%<humidity levels≤90%could get the optimal cutting rooting rate.While cuttings under IBA treatment,60%shading rate and 60%<humidity levels of≤80%could get the optimal cuttings′root development effect,which was within the optimal range for rooting rate screening.As the root effect index increasing,the content of soluble sugar and soluble protein in stem cuttings decreased,the IAA content and IAA/ABA increased,the ABA content decreased,SOD activity and POD activity increased.The difference in soluble protein content and POD activity between adjacent root effect index cuttings in the range of≤0.5 were significant(P<0.05).The difference in IAA content between adjacent root effect index cuttings reached significant levels within the range of≥0.3(P<0.05),and the increase in IAA/ABA continued to increase.【Conclusion】Carya illinoensis(Wangench.)K.Koch cuttings can achieve good rooting effect at IBA hormone treatment,60%shading rate and 60%<humidity level≤80%.Soluble protein,IAA content,IAA/ABA,POD activity are closely related to the root development of cuttings.