Field Screening and Marker Assisted Selection of Late Blight Resistant Potato Lines

Abstract

Late blight (LB), caused by Phytophthora infestans (Mont.) de Bary, is the most destructive disease of potato. The main objective of this study was to evaluate 72 potato lines, derived from crosses of the recipient cv. ACI Pakri-1 (female) and a LB resistant donor variety (male), against LB disease. Parent materials, LB susceptible varieties Diamant and BARI Alu-40 and LB resistant variety BARI Alu-77 were used as check varieties. The experiment was conducted with three levels of inoculums pressure (i) LB inoculation & no fungicide, (ii) No LB inoculation & no fungicide and (iii) No LB inoculation & fungicide. LB infection was assessed at 10 day intervals by scoring the percentage of foliage destruction. Subsequently, the area under the disease progress curve (AUDPC), relative AUDPC and susceptible scale value were estimated. Three categories of potato lines were selected considering level of LB infection and tuber appearance -(a) LB resistant -8 lines, (b) LB tolerant -14 lines, and (c) LB susceptible -14 lines. The foliage destruction of selected LB resistant