继代培养中马尾松生根能力及其与内源激素含量的相关分析  

Rooting Capacity of Pinus massoniana and the Correlations Endohormones Levels during Subcultur

作　　者：王胤[1] 姚瑞玲[1] Wang Yin;Yao Ruiling(Guangxi Forestry Research Institute, Nanning 530002)

机构地区：[1]广西林业科学研究院,南宁530002

出　　处：《林业科学》2020年第8期38-46,共9页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(31960311,31360178);广西科技计划项目(桂科AD17195078,2017GXNSFAA198037,2018GXNSFDA281020,桂科AA17204087-1);广西林业科技项目(桂林科字[2016]第13号)。

摘　　要：【目的】研究长期连续继代培养中马尾松继代芽生根能力与内源激素水平的变化,分析内源激素与生根能力的相关性,为揭示马尾松生根机制,建立高效马尾松无性育苗技术体系提供科学依据。【方法】以26年生桐棉松为研究对象,利用2014—2018年期间繁育的生根能力较强GLM-8基因型的继代芽为试验材料,分别在继代1、3、5、8、10、15、20、30、40次时取样观察生根能力(生根率、根条数)并测定内源激素水平变化,运用线性回归法分析两者相关性,并利用变异分析检验继代培养时间对生根率、根条数、内源激素是否存在显著影响。【结果】1)继代次数对马尾松继代芽生根能力影响显著。初代培养时,继代芽生根率为83.1%、根条数为2.4;继代15~20次时,继代芽生根能力最强,生根率达98.7%,根条数为6.9;而继代40次后,继代芽生根能力显著下降,生根率仅为65.7%、根条数0.5。2)长期连续继代培养中,继代芽内源生长素(IAA)、赤霉素(GAs)、脱落酸(ABA)和玉米素苷(ZR)水平均发生显著变化,其中以IAA、GAs与继代芽生根能力相关性较大。线性回归分析结果表明,IAA/GAs比值与生根率或根条数间呈显著正相关线性关系。3)生根能力差异显著的3种不同继代时间继代芽,在外源萘乙酸(NAA)、IAA和(或)GA合成抑制剂多效唑(PAC)作用下的生根效果不同:继代培养35~40天,外源IAA显著改善继代芽不定根条数,并以4μmol·L^-1 IAA处理下生根效果最佳,而PAC对继代芽表现出明显的生根抑制性;继代培养700~800天,低浓度(1.2μmol·L^-1)萘乙酸(NAA)的促根效果最稳定,外源IAA和PAC均对生根率和根条数产生抑制性,且浓度越高,抑制作用越强;继代培养1400~1600天,IAA、PAC各自显著改善了继代芽根条数或生根率,但其作用浓度存在一定的阈值范围,在4μmol·L^-1 IAA+4μmol·L^-1 PAC交互作用下,生根效果最佳,生根率和根条数分别较对照(NAA)【Objective】In this study,we investigated variations in rooting capacity and endohormones levels of subcultured shoots during long-term successive subculture of Pinus massoniana,and analyzed the correlations between endohormones levels and rooting capacity,in order to reveal rooting mechanisms and provide a theoretical basis for establishing an efficient micropropagation technique of P.massoniana.【Method】The subculture buds of glm-8 genotype,derived from the 26-year-old P.massoniana‘Tongmiansong’stands,with strong rooting ability were obtained from the subculture from 2014—2018,and used as experimental materials.The rooting capacity(rooting root and root number)and endohormones levels were observed in subcultured shoots at the 1st,3rd,5th,8th,10th,15th,20th,30th and 40th subculture,respectively.The correlations between rooting capacity and endohormones levels were analyzed using linear regression,and significant differences in rooting rate,root number as well as endohormones levels among subculture times were tested based on analysis of variance.【Result】1.Subculturing times significantly affected rooting capacity of in vitro shoots in P.massoniana.For subcultured shoots of initial generations,rooting rate was 83.1%and root number was 2.4.The rooting effect of shoots was the best after subculturing of 15~20 times,reaching rooting rate of 98.7%and root number of 6.9,while the rooting ability of shoots dramatically decreased after subculturing of 40 times,when the rooting rate and root number were 65.7%and 0.5,respectively.2.The levels of endogenous indoleacetic acid(IAA),gibberellins(GAs),abscisic acid(ABA)and zeatin riboside(ZR)significantly changed during long-term successive subculture.Among them,IAA or GAs had relatively greater correlation with the rooting capacity than ABA or ZR.Results of linear regression analysis showed that there was a significantly positive linear relationship between IAA/GAs ratio and rooting rate or root number.3.Under the treatments of exogenous naphthaleneacetic acid

关 键 词：马尾松 连续继代 内源激素 不定根发育 无性系 

分 类 号：S718.43[农业科学—林学]