柑橘衰退病毒侵染对‘赣南早’脐橙植株组织结构及光合作用的影响  

Structural and photosynthetic changes in ’Gannanzao’ navel orange plants infected with Citrus tristeza virus

作　　者：易龙[1] 陈毅群 李双花 黄爱军[1] YI Long;CHEN Yiqun;LI Shuanghua;HUANG Aijun(National Navel Orange Engineering Research Center,Gannan Normal University,Ganzhou 341000,Jiangxi,China)

机构地区：[1]赣南师范大学国家脐橙工程技术研究中心,江西赣州341000

出　　处：《果树学报》2020年第4期574-581,共8页Journal of Fruit Science

基　　金：国家自然科学基金项目(31860488);赣州市科技创新人才计划([2018]50)。

摘　　要：【目的】了解柑橘衰退病毒(Citrus tristeza virus,CTV)侵染对‘赣南早’脐橙植株组织微形态结构变化及光合特性的影响,以便进一步探明CTV对寄主的侵染特性和致病机制,为生产上病害的防控提供参考依据。【方法】通过石蜡切片等技术观测感染CTV的‘赣南早’脐橙植株及其健康植株叶片、枝条和根部组织微形态结构,利用紫外可见分光光度计和光合仪分别测定叶片光合色素、丙二醛(MDA)含量、净光合速率和胞间CO2浓度变化,结合叶片叶绿体超微结构电镜观察,分析CTV侵染对寄主组织结构、光合器和生理功能的影响。【结果】受CTV侵染后‘,赣南早’脐橙植株叶片栅栏组织细胞间隙增大、排列松散,枝条木质部出现凹陷点、结构皱缩,根部细胞萎缩、内含物减少,叶绿体结构发生畸变;叶绿素a、b以及叶绿素总含量分别下降23.9%、16.3%和21.4%,MDA含量增加了28.5%,叶片净光合速率下降25.7%,胞间CO2浓度上升12.1%。【结论】通过分析发现CTV侵染后植株组织结构、光合器形态、叶片光合色素和MDA含量、净光合速率和胞间CO2浓度都发生了显著变化,CTV侵染影响植株叶绿体结构和光和能力降低碳水化合物制造能力,影响木质部结构萎缩阻碍光合产物向地下运输,患病植株根部细胞萎缩、内含物减少,致根系吸收和向枝叶输送水分养分能力下降,进而引起枝叶生长衰弱。【Objective】The objective of this study is to evaluate the effects of Citrus tristeza virus(CTV) infection on’Gannanzao’navel orange plants from the perspective of its morphology and photosynthetic characteristics changes, which provides insights on how the pathogen causes damage to the host. The characteristics of CTV infection and the mechanism of the damage it caused in the host plant was analyzed, which could provide some useful information for the prevention and control of CTV.【Methods】One-year-old healthy’Gannanzao’navel orange seedlings were provided by the germplasm resource nursery of National Navel Orange Engineering Research Center. Seedlings were inoculated with CTV and cultured separately in an isolation net. The fresh leaves and roots from eighteen months old culture of’Gannanzao’navel orange plants infected with CTV were collected with non-infected healthy leaves and roots served as a control. Preparing 40 samples per sample tissue and being embedded in paraffin, the leaves and the roots were cut into a thickness of 6 μm slices by using a Leica RM2245 slicing machine and the anatomical structure was observed under a Leica DMIL-LED fluorescence inverted microscope after being stained with saffron. The thickness of the phloem, xylem and medullary part, palisade tissue and spongy tissue of the leaves were measured by using the LAS V4.0 and Image-Pro Plus 6.0 software. Taking 3 rd to 4 th leaves from top to bottom of healthy and CTV-infected plants, the blade tissues of about 1 mm × 1 mm on both sides of the central leaf veins of the leaves were quickly cut, fixed overnight in 2.5% glutaraldehyde at 4 ℃, phosphoric acid buffer(0.1 mol · L-1, pH 7.0) was rinsed three times, 1% osmium tetroxide fixed at 4 ℃ for 2 hours, and penetrated in turn with acetone∶epoxy resin(2∶1), acetone∶epoxy resin(1∶1), epoxy resin overnight for 12 hours at 37 ℃. After being embeded by spur low viscosity resin, the sample was cut into slices by using a Leica EM UC7 slicing machine and the u

关 键 词：'赣南早’脐橙 柑橘衰退病毒 组织结构 叶绿体 光合特性 

分 类 号：S666.4[农业科学—果树学]