Green Global
Foundation   Journal
...an emerging window for scientific research and publication across the globe

MAPPING OF QUANTITATIVE TRAIT LOCI CONTROLLING RESISTANCE TO DARK LEAF SPOT (Alternaria brassicicola) DISEASE IN Brassica oleracea L. (Pages : 11 - 18)

Dark leaf spot and black rot are important diseases in Brassicas worldwide. New sources of resistance to the diseases are urgently needed for sustainable management. Quantitative trait loci (QTL) controlling resistance to Alternaria brassicicola was mapped using cleaved amplified polymorphic sequences (CAPS) and sequence-related amplified polymorphism (SRAP) analysis with disease rating of F3 families from a susceptible broccoli Green commet P09 × resistant cabbage Reiho P01. For dark leaf spot disease, 3rd/4th leaves of 30-day old plants were inoculated by detached leaf inoculation method. A total of 38 CAPS and 60 SRAP primer pairs were screened to assess parental polymorphism against dark leaf spot resistance. Ninety-two markers were distributed in 10 linkage groups (LGs) covering 320.5 cM, with average 3.56 cM interval between markers. The QTL effect was detected significantly in the interval between IPI - FLC3 on LG 7 for dark leaf spot disease resistance explained 43.8 % of the phenotypic variation with LOD score of 4.27. This is the first QTL detected for resistance to A. brassicicola. One non-significant QTL on LG 2 in the interval between CAM – GSA1 (LOD = 2.02) was also detected for resistance to the dark spot disease. The QTL, which was mapped to LG 7, could be useful for marker-assisted selection of dark leaf spot resistance breeding. Download