| Wheat scab is one of the important diseases of wheat in Anhui province. In this thesis, preservation, inoculation method, the mycelium culture traits, growth rate, sporulation, and virulence of different ecological zones Fusarium graminearum strains were studied. Molecular genetic diversity of23strains was also analyzed by RAPD and ISSR. This study provided certain foundation for wheat scab resistance identification and breeding for disease resistance. The main results are as follows:1. Optimization selection of preservation methodMycelium growth rate, sporulation and virulence of strain stored by grain of barley, wheat grain, corn kernels solid media material with five kinds of moisture content:50%-60%,40%-50%,30%-40%,20%-30%,10%-20%, at5°C and-15°C were tested at different time periods for keeping. The results showed that: Viability of the pathogen preserved in the barleycorn culture was the best among the three kinds of solid media. The mycelium growth rate were1.83,1.80,1.88,2.02,1.76(cm/d) respectively, the mean was1.85cm/d by keeping three months at5°C in barleycorn culture. The sporulation were29,42,55,127,95(10~4m acroconidia/ml) respectively, the mean was69.6×10~4macroconidia/ml The average mycelium growth rate, sporulation of strains kept by wheat and corn cultivation with five kinds of water content were:1.59cm/d,20.6×10~4m acroconidia/ml and1.62cm/d,20.2×10~4macroconidia/ml. Sporulation of F.graminearum saved under the conditions of low water content was more than that of the high water content. It was contaminated easily under the high water content.Mycelium growth rate, sporulation, virulence under different storage temperature were compared, mycelium growth rate was slightly better at5℃, sporulation and virulence were better under-15℃. The mycelium growth rate were1.88,1.87,1.76,2.19,1.54(cm/d) respectively stored by barleycorn culture with moisture content of10%-20%under5℃, the mean was1.85cm/d and the mean was1.78cm/d under-15℃. The sporulation were161,169,95,54,60(10~4macroconidia/ml) respectively, the mean was107.8×10~4macroconidia/ml and the mean was159×10~4macroconidia/ml under-15℃for every month.The reaction index and daily expand speed of the strains kept by barleycorn with medium moisture content of10%-20%under-15℃of1-18months was best after inoculating to yangmai158.2. Inoculation methodTwo kinds of inoculation method: injection and spray, three kinds of treat after inoculation: natural, bundling, and bagging, and injection vaccination in different parts of wheat spike (25%,50%and75%) were comparative studied. The results showed that it was no significant differences of the disease index between the two inoculation methods, it was more orderly on incidence of wheat scab by vaccination. It was useful for wheat scab on treatment of bagging. The condition index was0.77by spray bagging inoculation, followed by bundling (0.49), natural (0.44). The disease index of vaccination bagging inoculation was0.78, followed by bundling (0.51), natural (0.47). The disease indexes were0.78,0.77,0.78by vaccination inoculation at25percent,50percent and75percent of wheat.3. Biological characterization of F. graminearum in AnhuiMycelium culture traits, growth rate, sporulation, and virulence and other biological characteristics of wheat scab strains collected from23places in Anhui (the southern:xuanzhou, anqing, nanling, fancang, wuhu thecentral: caohu, jinzhai, liuan, shouxian, huoqiu, changfeng, mingguang, fengyang thenorthern: xinmaqiao, maoji, fengtai, yingshang, fuyang, mengcheng, guoyang, suzhou, dangshan.) were studied. The results showed that: The color contained light red, red, dark red and red with yellow of the colony of F.graminearum in PDA medium. There were some differences with mycelium growth rate and sporulation of different strains. The average mycelium growth rates of F.graminearum in Northern Anhui were2.53cm/d,2.39cm/d, and2.50cm/d, slightly greater than that in the southern. The average sporulations of F.graminearum in Northern Anhui were196×10~4macroconidia/ml,132×10~4macroconidia/ml,74.8×10~4macroconidia/ml, significantly higher than the southern. Northern Anhui strains were virulent, the virulence of the strains of the central and southern was weak and middle virulent. From south to north, according to the average disease reaction index and average sporulation correlation analysis of the four local strains, come to the relationship: y=0.052x+2.1485R2=0.8434, it had a certain degree of correlation between sporulation and virulence.4. Anhui F. graminearum genetic diversity analysisPCR analysis on23strains of F. graminearum in Anhui was carried on by ISSR and RAPD. The results showed that: Anhui F.graminearum had a wealth of genetic diversity, amplified strip polymorphism rates were98%and82%. ISSR-PCR and RAPD-PCR data were dealt with the method of UPGMA. The strains were divided into four categories with0.69and0.79for the threshold respectively.The phylogenetic relationship of F. graminearum collected from the Nanling Maoji, Mingguang, Yingshang of Fuyang, Huoqiu, guoyang were close fancang, the phylogenetic relationship of F. graminearum strains fengyang, caohu were close Shouxian, anqing, mengcheng were close Wuhu, jinzhai, changfeng, xinmaqiao were close. The results showed that there was no significant correlation between genetic distance and virulence or location in Anhui Province. |
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