【摘要】 为明确外源喷施禾谷镰孢菌Fusarium graminearum的尿苷二磷酸-半乳糖吡喃变位酶（uridine diphosphate-galactopyranose mutase,UGMA）基因特异性dsRNA对该基因的沉默效率及对禾谷镰孢菌的防控效果，采用喷施诱导的基因沉默技术对UGMA基因进行沉默，通过平板、大麦叶片、小麦胚芽鞘上的抑菌试验及小麦苗期接种试验分析该基因对禾谷镰孢菌生长和致病力的影响。结果表明：外源喷施UGMA基因dsRNA对禾谷镰孢菌PH-1菌株在PDA平板上的生长影响较小，抑制率最高为5.9%；但可显著降低PH-1菌株对小麦胚芽鞘和大麦叶片的致病力，抑制率最高分别为62.0%和28.5%。外源喷施UGMA基因dsRNA能有效降低靶基因的表达水平。小麦苗期接种试验结果表明，施加20μL浓度为200 ng/μL的UGMA基因dsRNA可显著抑制PH-1菌株对小麦根茎部的侵染，抑制率达59.4%。表明UGMA基因可作为备选的RNA农药靶标基因。更多还原

【Abstract】 In order to clarify the silencing efficiency of exogenous dsRNA targeting the uridine diphosphate-galactopyranose mutase(UGMA) gene in fungal pathogen Fusarium graminearum and its effect in controlling Fusarium disease in wheat, we employed spray-induced gene silencing(SIGS) to silence the UGMA gene. The impact on gene expression, mycelial growth and virulence of F. graminearum was tested on PDA plates, barley leaves, wheat coleoptiles, and wheat seedlings. The results demonstrated that exogenous application of UGMA gene ds RNA showed limited effects on mycelial growth of the F. graminearum PH-1 strain on PDA plates(by 5.9%). However, it significantly suppressed virulence on barley leaves(by 28.5%) and wheat coleoptiles(by 62.0%). Gene expression analysis confirmed effective downregulation of UGMA gene transcription. The results of wheat seedling test showed that applying 20 μL of UGMA gene dsRNA(200 ng/μL) significantly inhibited infection of wheat roots and stems by PH-1, with an inhibition rate of 59.4%(with a significance level of P<0.01).The UGMA gene is therefore proposed as a candidate target gene for RNA-based fungicides.更多还原