甘肃省马铃薯茎基腐病菌遗传多样性研究

Potato crown rot happens in large area and causes serious damage in Gansu province. The diseased plants, tubers and soil samples of potato crown rot were collected from different region in Gansu province ecologically. 305 strains of Rhizoctonia solani were isolated and anastomosis groups were analyzed to identify the distribution and the pathogenicity on the main varieties. The DNA from all the strains will be extracted by GAPDH、TUB2、CHS-1、ACT, then amplified by PCR and sequenced to add up their diversities between haplotype diversity, nucelotide diversity, fixation index and gene flow, and to analysis the genetic variation and variation of population. By means of AFLP、RAPD and ISSR, the sample and its CK were analyzed polymorphically, the phylogenetic tree constructed by UPGMA will be used to determine the diversity, genetic relationship and system development type between groups, and to reveal the relationship between the groups and diversified biotope, parasitic site, geographical distribution, ways of gene exchange and breeding system. The study will genetically explain why potato crown rot happened in large area and caused serious damage, and provide theoretical basis for occurrence, popular and control of this disease.

以甘肃发生面积广且严重的一种新发病害—马铃薯茎基腐病为研究对象，对采集甘肃马铃薯不同生态区典型的茎基腐病株、薯块、土样获得305株茎基腐病菌菌株，进行融合群判定，明确甘肃马铃薯茎基腐病菌融合群类型、构成、分布及在主栽品种上的致病差异；采用GAPDH、TUB2、CHS-1、ACT测序，分析菌株序列的单倍型、单倍型多样度、核苷酸多样性、群体间固定化指数、基因交流值，分析茎基腐病菌种群遗传多样性和遗传分化的程度。采用AFLP、RAPD、ISSR分子标记技术，对菌株进行多态性分析，UPGMA法构建聚类分析树状图，确定茎基腐病菌种群内多样性及各种群间的亲缘关系、系统发育类型，选择模型检验分析茎基腐病菌种群遗传结构，阐明茎基腐病菌种群与多样化的生境、寄生部位、地理分布、种群历史扩张、基因交流途径、繁育系统等相关关系，揭示马铃薯茎基腐病发生复杂、面积广、危害重的遗传基础，为理解病害发生与流行及制定防治策

以甘肃省马铃薯产区重要病害茎基腐病（Rhizoctonia solani）为研究对象，重点研究了茎基腐病菌优势融合群、病害发生规律和防控措施，并取得了初步成果：全面调查茎基腐病发生情况，明确发生特点，预测未来发生发展趋势，集成综合防治技术体系等综合防控措施；总结茎基腐病6种症状类型，掌握了病原菌鉴定技术，为茎基腐病诊断奠定了理论基础；明确了甘肃省马铃薯立枯丝核菌优势种群为AG-3融合群，探索了其垂直与水平分布和季节变化规律。筛选出PDA培养中添加0.1～0.5mg/L IAA、0.1～1.0mg/L GA促进AG-3生长，添加大于5.0mg/L洋葱、大蒜、胡萝卜提取液抑制AG-3生长；以小白花为母本，亲本材料119-8为父本组配杂交选育新品种陇薯5号，对茎基腐病表现为中抗，产量在2500.2kg/667㎡～3085.5kg/667㎡；制定马铃薯茎基腐病预测预报技术与方法的甘肃省地方标准；研制出由凹凸棒粘土、5%戊唑醇、25%福美双、淀粉、微肥、着色剂等配制而成种衣剂，对茎基腐病防效达90.1～95.6%；研究了新型腐殖酸肥料壤动FT对茎基腐病的防效，在5~15g壤动FT/100kg种薯配合腐植酸肥料对主茎、匍匐茎、块茎基腐防效在87.24%~88.51%，增产24.12%~79.12%。明确了整薯较切块播种生长优势明显，出苗率高5~7%，单株根数多2.0~3.2条，芽长0.5~0.8 cm，株高高2.3~2.7 cm，平均单株结薯数多0.8~1.8个，单株主茎数多0.7~1.6个，单薯重高15.5~16.0g，大薯率高12.9~19.9%，商品薯率高20.3~22.9%，增产率18.17%~26.00%，干物质、可溶性总糖、淀粉含量分别高1.59~3.87%、0.17~0.21%、2.10~3.07%；为茎基腐诊断与发生规律奠定理论基础，对其预测预报、绿色防控具有现实指导意义。