基于田间表型和Bru1基因检测分析甘蔗褐锈病抗性遗传

Analysis of Brown Rust Resistance Inheritance Based on Field Phenotypes and Detection of Bru1 Gene in Sugarcane

由黑顶柄锈菌(Puccinia melanocephala)引起的甘蔗褐锈病具有产孢量大、流行性强的特点,可导致甘蔗产量和蔗糖分的严重损失,了解抗病性遗传有助于抗锈病育种中的亲本选择和组合配制,而有效的抗性鉴定技术则是分离个体选择所必需的。本研究以甘蔗分离群体为材料,利用表型与抗褐锈病主效基因Bru1检测相结合,研究甘蔗褐锈病抗性遗传倾向并评价Bru1基因检测与表型抗性的关联性。结果显示,发病盛期,感病个体中,Bru1基因未检出率为96.7%,但未感病个体中,Bru1基因的检出率仅为66.0%,且高抗组合CP84-1198×云蔗89-7群体中的未感病个体,该基因检出率为0,尽管也发现有2个组合的未感病个体中,该基因的检出率为100%。说明由Bru1基因控制的抗性可根据该基因的检测结果判断其抗/感病性,同时,甘蔗基因池中还存在其他未知的控制抗病性状的主效基因。值得强调的是,父母本的抗病性均影响杂交后代的抗病性,但以抗病亲本为父本的组合,其分离群体的感病个体明显减少,说明父本对杂交后代的褐锈病抗性影响可能更大。

With characteristics of high pathogenic spore yield and strong popularity,sugarcane brown rust caused by Puccinia melanocephala leads to a serious loss in sugarcane yield and sucrose content.An understanding of the inheritance of brown rust resistance will contribute to parent selections and combination arrangements,while an efficient technique for resistance identification is necessary for selection of segregated individuals.Combination phenotypic survey with Bru1 gene detection,the segregated population derived from crossing combinations with different brown rust resistances was used to explore rust resistance inheritance and evaluate the efficiency of Bru1 gene detection.The undetected rate of Bru1 gene in the individuals with rust sensitivity at the stage of prosperous epidemic peak was 96.7%,while the detected rate in all uninfected individuals was only 66.0%in spite of two from four combinations showed 100.0%in resistant individuals.It indicates the disease sensitivity and resistance can be estimated based on the detection of Bru1 gene in the genetic background with rust resistance regulated by Bru1.In addition,none of the healthy individuals in the segregated population derived from combination of CP84-1198×Yunzhe 89-7 have Bru1 gene been detected,suggesting the new resistance genes,different from Bru1,are present in sugarcane gene pool.In addition,both maternal and paternal components affected the rust susceptibility of their offspring,but male parent other than female parent tended to transmit a higher frequency of rust-susceptible genes.