叶面喷施多效唑对杉木无性系幼株生长的效应分析

Effect Analysis of Foliar Spraying with Paclobutrazol on Growth of Young Cunninghamia lanceolata Clones

【目的】杉木(Cunninghamia lanceolata)是我国南方的重要用材树种,探究叶面喷施多效唑对不同杉木无性系幼株的施用效果及其剂量效应,旨在为杉木母株早期生长调控提供参考。【方法】以杉木优良无性系(T-c04、T-c08、T-cF1)幼株为材料,分析测定有效成分浓度分别为0.12、0.24、0.48 g/L的多效唑处理对无性系株高、地径、根茎萌条数、偏冠情况、针叶相对叶绿素含量(SPAD)、针叶厚度和生物量的影响。【结果】叶面喷施多效唑对无性系T-c04株高抑制程度最为显著(P<0.05),其株高增长量仅为对照(以喷施蒸馏水为对照,CK)的24.59%~36.06%,而无性系T-c08、T-cF1株高增长量则分别为对照的42.68%~52.68%、39.97%~46.88%。施用多效唑对杉木无性系幼株地径增长和根茎萌条的发生均有一定的促进作用。在地径增长方面,以多效唑0.48 g/L处理施用效果最好且对T-cF1的效果尤为明显(比对照提高41.0%);在根茎萌条数量方面,多效唑对无性系T-c04施用效果最为显著(P<0.05),且以多效唑0.24 g/L处理效果最佳。此外,多效唑会促使杉木幼株产生偏冠现象,多效唑0.12 g/L处理和多效唑0.24 g/L处理均使无性系T-c04、T-cF1幼株发生严重偏冠。多效唑对不同杉木无性系幼株的针叶相对叶绿素含量、针叶厚度的作用效果不一。多效唑对杉木地上部分生长和总生物量积累起抑制作用,但可有效提高各无性系植株的壮苗指数。【结论】叶面喷施多效唑对杉木不同无性系幼株施用效果不一,且存在一定的剂量效应。总体而言,喷施多效唑对株高和总生物量起抑制作用,对地径增长、根茎萌条数、偏冠发生、壮苗指数提高等方面起促进作用。

【Objective】Cunninghamia lanceolata is an important timber species in southern China,and the application effect and dose effect of foliar spraying paclobutrazol on different clones of C.lanceolata were explored,aiming to provide reference for early growth regulation of C.lanceolata mother plants.【Method】The young plants from excellent clones of C.lanceolata(T-c04,T-c08 and T-cF1)were used as materials.The effects of paclobutrazol treament with active component concentrations of 0.12,0.24 and 0.48 g/L on clonal plant height,ground diameter,number of rhizome germination,partial crown,relative chlorophyll content(SPAD)of needles,needle thickness and biomass were determined.【Result】Foliar spraying paclobutrazol had the most significant inhibitory effect on plant height of T-c04 clone(P<0.05),and the increase in plant height was only 24.59%~36.06%of the control(Spraying distilled water as control,CK).However,the increase in plant height of T-c08 and T-cF1 clones was 42.68%~52.68%and 39.97%~46.88%of the control.The application of paclobutrazol had a certain effect on the growth of young clonal plants and the occurrence of rhizome germination.In terms of diameter growth,the application of 0.48 g/L paclobutrazol had the best effect,and the effect on T-cF1 was especially obvious(41.0%higher than the control).In terms of the number of rhizome germination,the application effect of paclobutrazol on T-c04 clones was the most significant(P<0.05),and the treatment with paclobutrazol 0.24 g/L had the best.In addition,paclobutrazol induced partial crown phenomenon of young C.lanceolata.Both paclobutrazol 0.12 and 0.24 g/L treatments caused serious partial crown in young clones T-c04 and T-cF1.The effects of paclobutrazol onrhizome germination(SPAD)and needle thickness of young C.lanceolata clones were different.The aboveground growth and total biomass accumulation of C.lanceolata were inhibited by paclobutrazol,but the seedling strength index of each clonal plant was improved effectively.【Conclusion】Foliar spraying of paclobutrazol had different effects on different clones of C.lanceolata,and there was a certain dose effect.But in general,the application of paclobutrazol inhibited the plant height and aboveground biomass,and promoted the diameter growth,number of rhizome germination,the occurrence of partial crown,and the increase of seedling strength index.