不同基质和不同生根促进剂对紫椴嫩枝扦插生根的影响

Effects of different substrates and different rooting accelerators on softwood cutting of Tilia amurensis

【目的】解决珍贵树种紫椴嫩枝扦插生根困难的技术问题,为该树种系统地扦插繁殖技术的建立提供理论和技术支持。【方法】以2年生紫椴植株当年生半木质化枝条为材料,修剪制作的插穗,经IAA 100 mg·L^(-1)溶液浸泡基部2 h后,分别扦插于河沙、珍珠岩、V珍珠岩∶V河沙(1∶1)3种基质上,研究不同基质对紫椴嫩枝插穗生根的影响。采用完全随机区组设计,以珍珠岩为基质,研究3种生根促进剂、不同质量浓度、不同处理时间对紫椴2年生嫩枝插穗生根的影响。【结果】3种基质中,珍珠岩生根效果最好,其生根率、生根数、根鲜质量、根干质量、根系效果指数均极显著高于其他2种基质(P<0.01),分别为54.44%、3.67条/穗、190.11 mg、18.11 mg、0.637,平均根长为5.21 cm,均显著高于其他2种基质(P<0.05)。以珍珠岩为基质,观察插穗生根过程发现,紫椴嫩枝扦插20 d后,开始有少量生成愈伤组织,25 d后陆续从皮部或愈伤处萌出不定根,40 d后不定根大量增多。插穗生根类型以皮部生根为主,并兼有愈伤生根和混合生根。3种促进剂完全随机区组试验表明,用质量浓度为100 mg·L^(-1)IBA处理插穗基部8 h生根效果最好,生根率达78.89%,平均根长8.38 cm、生根数量5.83条/穗、根鲜质量435.50 mg、根干质量38.06 mg、根系效果指数达1.631,隶属函数值最大达0.963。【结论】珍珠岩适宜作为紫椴嫩枝扦插的繁殖基质,采用隶属函数法对各指标进行综合分析,100 mg·L^(-1)的IBA处理8 h,隶属函数值最大,生根效果最好。

【Objective】In order to provide theoretical and technical support for the establishment of systematic cutting propagation technology of Tilia amurensis,the technical problem of softwood cutting rooting of Tilia amurensis was studied.【Method】The softwood cuttings of two-year old Tilia amurensis were used as the experimental material to study the effects of different subtrates,which were treated with IAA of 100 mg·L^(-1)rooting accelerator for 2 h and planted in three different substrates including Yellow soil,perlite,1:1 perlite and Yellow soil.Using perlite as the cutting substrate,the effects of three rooting accelerator,concentration and time on the root formation were studied by a completely randomized block design.【Result】The perlite was the optimal substrate,and its rooting rate,rooting number,root fresh weight,root dry weight and root effect index were significantly higher than the other two substrate(P<0.01),which were 54.44%,3.67,190.11 mg,18.11 mg,0.637.The average root length was 5.21 cm,which was higher than the other two substrate(P<0.05).Using perlite as the subatrate,the rooting process of cuttings was observed.The cut wounds were healed and a small amount of callus tissue formed after 20 days,adventitious roots and callus tissue sprouted from the bark after 25 days,and a great deal of adventitious roots were generated followed 40 days.Roots were mainly induced from the bark but could also develop from callus tissues.The most effective accelerators treatment for rooting was 100 mg·L^(-1)IBA with treatment time 8 h.The rooting rate was 78.89%,the average length of roots was 8.38 cm,the number of roots was 5.83,root fresh weight was 435.50 mg,root dry weight was 38.06mg,the root effect index was 1.631,the maximum value of subordinate function was 0.963.【Conclusion】The perlite was suitable for softwood cutting rooting of Tilia amurensis,and 100 mg·L^(-1)IBA with treatment time 8 h revealed the best comprehensive effect by analysis all indexes of membership function method.