摘要
【目的】甘蔗白条病是影响甘蔗产业的一种重要细菌检疫性病害,选择抗病品种可有效降低病害的发生。了解甘蔗基因型的白条病抗性,规范抗性评价方法,为甘蔗白条病抗病种质资源的选育和利用提供依据。【方法】以桂糖46号分离得到的黄单胞菌株JG43菌株为接种病原,采用截头法人工接种于70个不同基因型的甘蔗上。通过蘸有细菌悬浮液(108 CFU/mL)的剪刀剪切甘蔗生长点上方,并用棉花吸取500μL细菌悬浮液置于斜切面上。分别于接种后14、28、42、56和70 d,对每个甘蔗基因型的发病情况进行调查,计算发病率(incidence,IC)。根据甘蔗白条病严重度评判标准计算病情指数(disease index,DI)和病害进展曲线下面积(area under the disease progress curve,AUDPC)。利用SPSS 25.0软件分别进行方差分析、主成分分析和判别分析。其中,采用一般线性模型和类型Ⅲ的平方和模型进行方差分析,以IC、DI和AUDPC作为因变量,基因型、区组及接种后时间为固定因子。原始数据经过标准化(Z-score)处理后,通过KOM和Bartlett球体检验法进行主成分分析。运用DPS 9.50软件的WPGMA法,计算欧几里得距离(Euclidean metric)进行聚类分析。以聚类分析结果中的不同抗性等级作为分组变量,AUDPC、IC和DI作为自变量,根据Fisher准则进行判别分析,计算分类准确率。【结果】接种14 d,部分基因型叶片开始发病,出现1-2条铅笔状条纹;接种28 d,条纹数增多且逐步向边缘扩展;接种42 d,叶片黄化或白化症状从边缘逐步向叶脉扩展;接种56 d,叶片向内卷曲枯死;接种70 d时,发病严重的甘蔗整株枯萎死亡。方差分析发现,不同基因型(genotype,Gen)、接种后持续时间(days post-inoculation,Dpi)及其互作(Gen×Dpi)对IC、DI和AUDPC均具有极显著影响(P<0.01),其中,总方差的42%归因于接种后时间效应,表明不同接种时间甘蔗基因型的抗性反应存在显著差异。接种56 d,病害的发生达到相对稳定状态,这一时期的病害数据经平均值多重比较后能较好地进行甘蔗基因型间的抗性划分。判别分析与聚类分析的结果基本一致,将70个基因型分为5个不同抗病等级,包括高抗基因型15份、抗病基因型14份、中抗基因型15份、感病基因型11份、高感基因型15份。【结论】通过截头法人工接种进行甘蔗抗白条病鉴定时,以接种56 d基因型的IC、DI和AUDPC作为抗性鉴定评价指标,在聚类分析的基础上增加判别分析,可以提高试验结果的准确性。筛选出中蔗9号、中蔗4号、中蔗2号、GUC19、GUC8、云瑞03-103、云瑞05-649、云瑞05-182、云瑞05-367、云瑞89-159、福农11-601、福农09-4059、桂糖02-467、桂糖08-297、新台糖22号等15个高抗品种,可进一步用于甘蔗抗白条病育种研究。
【Objective】Sugarcane leaf scald disease is an important bacterial disease affecting sugarcane yield.Selection of disease-resistant genotypes can effectively reduce the incidence of this disease.This study aimed to explore the leaf-scald resistance of sugarcane genotypes,standardize resistance evaluation method,and provide a basis for the selection and utilization of germplasm resources of sugarcane.【Method】Xanthomonas albilineans JG43 isolated from Guitang 46,was used as inoculum on 70 different sugarcane genotypes using the decapitation method by placing 500 mL of bacterial suspension on the surface previously cut above the apical meristem with scissors dipped in the inoculum suspension of 108 CFU/mL.The disease incidence(IC)was calculated at 14,28,42,56,and 70 days post-inoculation(Dpi).The disease index(DI)and the area under the disease progress curve(AUDPC)were calculated according to the disease severity of leaf scald in sugarcane.Variance,principal component,and discriminant analysis were performed using SPSS 25.0 software.Among them,a general linear model procedure(PROC)and the square sum model of type III were used to analyze the variance,with IC,DI and AUDPC as dependent variables,genotype,block and days post-inoculation as fixed factors.After the original data were processed by standardization(Z-score),principal component analysis was carried out by KOM and Bartlett sphere test.The Euclidean metric was calculated for cluster analysis using the WPGMA method of DPS 9.50 software.The discriminant analysis was performed to evaluate the clustering results according to Fisher’s criterion.【Result】Some genotypes displayed white pencil lines at 14 dpi,then gradually expanded to the edge at 28 dpi.The leaves began yellowing or albinism from the edge to the veins at 42 dpi,then curled inward and died at 56 dpi.The severely infected plant withered and eventually died at 70 dpi.Variance analysis exhibited highly significant effects for IC,DI,and AUDPC among genotype(Gen),days post-inoculation(Dpi),and their interactions effect(Gen×Dpi)(P<0.01).Approximately 42%of the total sum of square was attributed to Dpi effect,indicating significant differences among genotypes resistance across the days post-inoculation.At 56 dpi,the disease reached a steady plateau,and the data in this period could be better divided among sugarcane genotypes.The results of discriminant and cluster analysis showed that 70 genotypes were divided into five different groups,including 15 highly resistant,14 resistant,15 moderate,11 susceptible,and 15 highly susceptible genotypes.【Conclusion】The resistance of sugarcane genotypes to leaf scald was assessed using the decapitation method,the IC,DI and AUDPC at 56 dpi were used as the evaluation indicators.The combined method of clustering and discriminant analysis could improve the accuracy of clustering results.Fifteen genotypes of high resistance to leaf scald were assessed and used for the sugarcane breeding program in China,including Zhongzhe 9,Zhongzhe 4,Zhongzhe 2,GUC19,GUC8,Yunrui 03-103,Yunrui 05-649,Yunrui 05-182,Yunrui 05-367,Yunrui 89-159,Funong 11601,Funong 09-4059,Guitang 02-467,Guitang 08-297,ROC22.
作者
杜金霞
李奕莎
李美霖
陈文浛
张木清
DU JinXia;LI YiSha;LI MeiLin;CHEN WenHan;ZHANG MuQing(College of Agriculture,Guangxi University/State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources/Guangxi Key Laboratory of Sugarcane Biology,Nanning 530005)
出处
《中国农业科学》
CAS
CSCD
北大核心
2022年第21期4118-4130,共13页
Scientia Agricultura Sinica
基金
广西科技基地和人才专项(2020AC18001)
国家糖料产业技术体系(CARS170109)。
关键词
甘蔗
白条病
抗性鉴定
聚类分析
主成分分析
判别分析
sugarcane
leaf scald
disease resistance
cluster analysis
principal component analysis
discrimination analysis