四倍体西瓜抗枯萎病菌生理小种1的机理  

The Mechanism of Resistance to Fusarium oxysporum f.sp.niveum Race 1 in Tetraploid Watermelon

作　　者：姬万丽 朱红菊[1] 路绪强[1] 赵胜杰[1] 何楠[1] 耿丽华[2] 刘文革[1] JI WanLi;ZHU HongJu;LU XuQiang;ZHAO ShengJie;HE Nan;GENG LiHua;LIU WenGe(National Cucurbits and Fruits Improvement Center,Zhengzhou Fruit Research Institute,Chinese Academy of Agricultural Sciences,Zhengzhou 450009;National Engineering Research Center for Vegetables,Beijing 100097)

机构地区：[1]中国农业科学院郑州果树研究所国家瓜果改良中心,郑州450009 [2]国家蔬菜工程技术研究中心,北京100097

出　　处：《中国农业科学》2018年第19期3750-3765,共16页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31672178);国家重点研发计划(2018YFD0100704);中国农业科学院科技创新工程专项经费(CAAS-ASTIP-2018-ZFRI);国家西甜瓜产业技术体系(CARS-26-03)

摘　　要：【目的】近年来由于西瓜重茬种植面积的不断增加及连作障碍的发生导致枯萎病在西瓜上迅速蔓延,该病害已经成为限制西瓜生产的主要因素之一。田间观察发现四倍体西瓜比其同源二倍体西瓜抗枯萎病。本研究通过对比四倍体与二倍体抗性差异,揭示四倍体西瓜抗枯萎病的机理,为西瓜多倍体育种和抗病育种提供理论依据。【方法】以同基因型的郑州3号二倍体和四倍体西瓜幼苗为材料,在一叶一心时期接种枯萎病菌生理小种1(Fusarium oxysporum f.sp.niveum race 1,Fon 1),比较不同倍性西瓜苗期枯萎病抗性差异;运用绿色荧光蛋白标记技术观察枯萎病菌的侵染过程;并分析过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、丙二醛(MDA)、总酚及类黄酮等与抗病相关代谢物质活性/含量差异,及PR3、MPK7、PAL、MYB基因表达变化。【结果】西瓜苗期接种枯萎病菌后,二倍体西瓜幼苗4 d发病,10 d时大部分枯死;四倍体西瓜幼苗7 d开始发病,13 d时大部分枯死,四倍体相对其同源二倍体延后3 d发病。枯萎病菌侵染过程对比发现,病菌在二倍体和四倍体西瓜中的侵染路径相同;此外不同倍性西瓜根系分生孢子的萌发率无明显差别,但是随着病菌的侵染,枯萎病菌在四倍体幼苗中的侵染速度明显较慢,细胞间菌丝较少;枯萎病菌在四倍体西瓜幼苗维管束中的定殖率比其同源二倍体低,且在幼苗根部差异显著、叶柄部差异极显著,病菌在四倍体植株茎部及叶部的扩展得到了一定的限制;枯萎病菌在四倍体西瓜中的侵染过程明显滞后,与枯萎病的发病症状相吻合。接种枯萎病菌后,四倍体西瓜幼苗根系POD、PAL活性均呈增加的趋势,且四倍体幼苗根系POD活性增加的幅度比二倍体大,病菌侵染后四倍体根系生成了更多的PAL和POD以增强植物抗病能力,保护细胞免受伤害;四倍体西瓜根系中总酚、类黄酮含量的增加量�【Objective】The Fusarium wilt disease caused by the continuous cropping obstacles is one of the main factors which limits the production of watermelon in recent years.Field observation shows that tetraploid watermelon is more resistant to Fusarium wilt disease than autodiploid watermelon.The objective of this study is to reveal the mechanism of resistance to Fusarium wilt in tetraploid watermelon by comparing the resistant differences of diploid and tetraploid watermelon,and to provide a theoretical basis for polyploidy breeding and disease resistance breeding of watermelon.【Method】The diploid and autotetraploid watermelon seedlings of Zhengzhou No.3 were used as materials in this research,the differences of the resistance to Fusarium wilt of different ploidy watermelon seedlings were compared after inoculating with Fusarium oxysporum f.sp.niveum race 1(Fon 1)at one leaf stage,the Fon 1 with green fluorescent protein(GFP)was used to observe the infection process in different ploidy watermelon seedlings,then the activity/content of metabolites related to disease resistance such as peroxidase(POD),phenylalanine ammonialyase(PAL),malondialdehyde(MDA),total phenols,flavonoid and the expression levels of PR3,MPK7,PAL and MYB at different stages of diploid and tetraploid watermelon roots were determined【.Result】After inoculation with Fon 1,for the diploid watermelon seedlings,the Fusarium wilt was observed at the 4th day,and most of the plants died at the 10th day,while the disease was observed at the 7th day,and most of them died at the 13th day in the tetraploid watermelon seedlings.The wilt symptom delayed 3 days in tetraploid watermelon seedlings,tetraploid watermelon seedlings were more tolerant to Fusarium wilt than diploid ones.The infection pathway of Fon 1 was the same in both diploid and tetraploid watermelons.In addition,there was no significant difference in the germination rate of conidia between diploid and tetraploid watermelon roots.However,with the infection of pathogens,the infection speed

关 键 词：西瓜 四倍体 枯萎病菌生理小种1(Fon 1) 抗性机理 

分 类 号：S436.5[农业科学—农业昆虫与害虫防治]