【作者】 石军；

【导师】 马炳田； 李仕贵；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2007， 硕士

【摘要】 稻瘟病是目前影响水稻高产、稳产最关键的因素之一。本试验设计9个稻瘟菌毒性相关基因的特异性引物，通过PCR扩增分析了单孢分离培养的不同地理来源的44个菌株，获得了其指纹图谱；利用18个LTH单基因鉴别寄主鉴定了其中31个菌株的致病型；研究了指纹图谱与致病型之间的关系，为研究稻瘟病致病型群体结构及变化规律、阐明稻瘟菌遗传宗谱与致病型之间的关系打下基础，并为水稻抗稻瘟病育种提供科学依据。主要研究结果如下：1．九对毒性相关基因的特异性引物在大部分菌株中扩增得到一条与理论长度接近的特异性扩增片段，部分菌株未产生条带。根据无毒基因划分的指纹类型为8种，根据致病基因划分的指纹类型为6种。54.5％菌株能扩增到所有特异性片断。2．用SPSS11.5聚类分析，根据31个菌株在18个丽江新团黑谷近等基因系上的抗感反应，在Lable Number 10的位置，将菌株分为7种致病类型，其中有20个菌株属于H1型，占供试菌株的64.5％，其余菌株分属H2～H7类型。3．据本研究结果，通过毒性相关基因的特异性引物划分出的指纹类型与用菌株在丽江新团黑谷近等基因系上的抗感反应划分出的致病型之间不存在明显对应关系。4．选取Avr-pita，PWL2，PWL3，MPG1四个毒性相关基因的特异引物，以8号菌株基因组DNA为模板进行PCR扩增，并对扩增出的特异性条带进行测序和氨基酸结构分析表明：与PWL2原始片断相比，测序片断在857位发生了G→A的单碱基突变，从而导致氨基酸在第91位发生了由D→N的变化；与PWL3原始片断相比，测序片断在315bp位发生C→T的单碱基突变，从而导致氨基酸在第11位发生由T→I的变化；MPG1与原始片断一致；Avr-pita片断共有11处碱基发生改变，从而导致编码的氨基酸发生6处改变，其中一处为三个连续碱基的插入突变。更多还原

【Abstract】 Rice blast disease is one of the major factors threatening high and stable production of rice. Nine pairs of specific primers of rice blast virulence genes were designed for PCR amplification, by which the 44 strains from different geographical regions were analyzed and their finger-printings were obtained. The pathogenicities of 31 strains were identified by using 18 LTH NILs, and the relationship between pathogenicity and fingerprinting was studied at the same time. The current study laid a foundation for studying the group structural variance of rice blast pathogenicity, which elucidated the relationship between genetic lineage and pathogenicty, and provided scientific information to transgenic breeding.Ⅰ. A specific fragment, whose length was similar to that of theoretic result, had been obtained by amplifying the fragment of virulence genes relate to 9 pairs of specific primers. But the fragment was not amplified in some strains. The strains could be classified into 8 types according to non-virulence genes and 6 types according to virulence genes. 54.5% of the strains belong to the some group in which the specific fragment could be amplified.Ⅱ. Clustering analysis was performed according to the resistance-susceptibility response of the 18 LTH NILs. All the 31 strains could be grouped to 7 pathotypes at the site of Lable Number 10.20 strains belonged to type H1, accounting for 64.5% of the whole strains, and the others belonged to types H2-H7 respectively.Ⅲ. The finger-printing classified according to specific primers of related virulence genes was not correlated with the pathotype classified according to resistance-susceptibility reaction of LTH NILs.Ⅳ. The specific fragments in No. 8 strain were amplified with the specific primers relative to Avr-pita, PWL2, PWL3, MPG1, and were sequenced,blast.Results indicated that the 857th site of the specific fragment was mutated from G to A compared to the original fragment of PWL2, resulting in the change of amino acid at the 91st site from D to N. The single gene mutation was occurred at the 315th site of the specific fragment compared to the original fragment of PWL3, causing the change of amino acid at the 11th site from T toⅠ. No change in MPG1. 11 bases of the Avr-pita fragment changed, causing the change of amino acids at 6 different sites(one of the 6 was inserted by 3 consecutive bases).更多还原