【作者】 马星霞；

【导师】 赵纯森； 廖玉才；

【作者基本信息】 华中农业大学 ， 植物病理学， 2001， 硕士

【摘要】 1997—2001年间，从湖北、湖南、江西、浙江、安徽、黑龙江、河南、江苏、陕西、四川、河北、上海等省市共采集赤霉病穗标样600多个，分离纯化得到357株单孢菌株，经鉴定分别属于镰刀菌属的5个种。其中禾谷镰孢(Fusarium graminearum Schw.)344株，弯角镰孢(F. camptoceras)5株，半裸镰孢(F. semitectem)4株，三线镰刀菌(F. tricinctum)3株，黄色镰刀菌(F.culmorum Sacc.)1株。禾谷镰孢占绝对优势。 根据来源、培养性状选择123株菌株用于田间致病力鉴定，以CMC液培养分生孢子，采用剪颖滴注法于扬花期在三个不同品种(高抗品种苏麦三号(R)、中抗品种扬麦158(MR)和感病品种安农8455(S))上分别接种，10天后进行病情调查。分析结果显示：不同来源的各个菌株在不同品种上致病力差异达到极显著水平(菌株间和品种间P值均为0.0001)；菌落扩展速度与菌株致病力显著相关(P=0.0029)，基质颜色、菌丝生长状况、产孢量与致病力不相关；禾谷镰刀菌相对其他种镰刀菌致病力较强。 根据菌株来源、培养性状、PCR分析及致病力鉴定结果筛选出致病力较强、PCR为一条500bp带的禾谷镰孢菌株XZ-01(采自湖北省新洲地区)与致病力弱、PCR为一条450bp带的禾谷镰孢菌株LY-01(河南洛阳)、137(江苏东辛农场)及SL-05(陕西商洛)进行子囊孢子单孢杂交，得到XZ-01与LY-01的杂交菌株3株，杂交率为4.7％；XZ-01与SL-05的杂交菌株2株，杂交率为3.7％；XZ-01与137配对53对，但没有得到杂交菌株。 将其中杂交菌株之一34④(亲本分别为XZ-01与SL-05)培养子囊孢子，进行单孢分离，随机选取95个单子囊孢子菌系，培养各菌系分生孢子，接种在感病品种安农8455上进行致病力检测，以亲代XZ-01、SL-01和杂交菌株作对照，分析其致病力分化，结果表明：与亲代XZ-01致病力同为“中”级的有44株，与亲代SL-05致病力同为“弱”级的同样有44株，致病力表现“强”的有7株，致病力分化比例是44：44：7。更多还原

【Abstract】 357 single-spore isolates were obtained from more than 600 scabby wheat ear, which were collected from 37 locations of Hubei, Hunan, Jiangxi, Zhejiang, Anhui, Heilongjiang, Henan, Jiangsu, Shanxi,Sichuan,Hebei provinces in China during 1997-2001. These isolates were identified and classified into five Fusarium species. 344 isolates of Fusarium graminearum Schw., 5 isolates of F.camptoceras, 4 isolates of F.semitectem, 3 isolates of F.tricinctum and 1 isolate of F.culmorum were identified. Fusarium graminearum is prevailing in the fields.123 isolates different from sources and cultural characteristics were applied to identification of field pathogenicity. Three wheat cultivars, including Sumai3(HR),yangmai158(MR) and Annong8455(S), were inoculated with the conidia produced in liquid CMC medium by drip spore-suspension method during flowering stage respectively. Pathogenicities of different isolates on different cultivars reach significant difference (P=0.0001). The expansion speed of isolates on wheat had markedly correlation with their pathogenicities(P=0.0029). But the matrix colour, the growth of mycelia ,sporulation had no correlation with the pathogenicities.On basis of source, cultural characteristics, PCR analysis and pathogenicity identification, isolate XZ-01 with highly pathogenecity to wheat and 500bp unique PCR band, was paired with isolate LY-01,137,SL-05 with weak pathogenicities to wheat and 450bp unique band, respectively. The successful single ascospore cross between XZ-01 and LY-01 resulted in 3 cross-isolates ,2 between XZ-01 and SL-05, 0 between XZ-01 and 137.95 ascospores were randomly screened from isolate 34(4),a filial generation of XZ-01 & SL-05. The susceptible cultivar Annong8455 were inoculated with the corresponding conidia produced from colonies of 95 ascospores .The result showed that the pathogenicities of 44 isolates were the same as that of XZ-01, and the other 44 isolates were the same as SL-05. Seven isolates showed high pathogenicities which were different from their parents. The segregations rate of pathogenecity is 44:44:7.更多还原