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烟草黑胫病Phytophthora Parasitica Var.nicotianae是一种地方性病原,它对主要的白肋烟产区发生危害。主要依靠有抗病力的白肋烟栽培品种去减少损失,但是可利用的栽培品种只有中等抗病性能。本文介绍在综合群体内进行轮回选择,去获得增进抵抗黑胫病的种质材料.原始群体是在中等抗病白肋烟栽培品种Ky17、Va509、Va528和感病白肋烟栽培品种Ky9、Ky14、Ky15、白肋21和高抗黑胫病的雪茄烟栽培品种Beinhart1000-1之间杂交产生的。本试验在肯塔基州Franklin郡自然发病田中进行三次表型轮回选择抗黑胫病材料.在C_0轮、C_1轮C_2轮期内选择强度分别为3.8％、12.0％、7.2％。1987年在两处,1989年在一处鉴定存活百分数和病害级数disease progression(采用病情指数统计即DI).在C_0轮到C_3轮生长末期平均存活率呈直线增加,分别为12.5％至61.5％,而病情指数则减少,从44.7降到15.3。从C_1轮至C_3轮具有白肋烟性状植株的比例保持恒定。此改良群体提供继续增进黑胫病抗病性能的种质基础。
Tobacco black shank Phytophthora Parasitica Var.nicotianae is a endemic pathogen that harms the major Burley tobacco producing areas. Mainly relying on disease-resistant cultivars of Burley to reduce losses, but available cultivars have only moderate disease resistance. This article describes the alternative selection of germplasm within an integrated population to improve the resistance to black shank disease.The original population was grown on moderately resistant Burley tobacco cultivars Ky17, Va509, Va528 and susceptible Burley tobacco cultivars Ky9, Ky14 , Ky15, rib 21, and highly resistant black shank Cigar cultivar Beinhart 1000-1. In this study, we performed three rounds of phenotypic recurrent selection of anti-shank material in the naturally occurring field of Franklin County, Kentucky, and selected intensities of 3.8%, 12.0% and 7.2% in C0 and C_2 periods, respectively. The survival rate and the disease progression (using disease index statistics, DI) were identified in two places in 1987 and 1989. The average survival rates increased linearly from C0 to the end of the C_3 round of growth, ranging from 12.5% to 61.5 %, While the disease index decreased from 44.7 to 15.3. The proportion of burley tobacco plants from C_1 to C_3 remained constant. This improved group provides a germplasm basis that continues to improve the disease resistance of black shank.