Development of pepper (Capsicum anuum) lines for resistance against Tomato Mosaic Virus (TMV) and Tomato Spotted Wilt Virus (TSWV) via molecular Marker Assisted Selection (MAS)

Pepper have an important place in consumption habits and taking in a big place in world's vegetable exports. As a result when seed companies decided to start breeding activities pepper is among the preferred species. Disease pressure has accelerated the development of resistant material/line and resistant hybrids, because of the difficulties of mechanical testing, the use of molecular markers in plant breeding has accelareted in the last decade. In this study, the marker assisted selection (MAS) method was used. In 2012 autumn season 12 commercial hybrid variety planted, selfed and obtained F2 seeds . The presence of L3, L4 alleles for TMV resistance, and Tsw gene for TSWV resistance were detected using the molecular markers linked to the gene of interests in the selected F2 plant, and among the F3 progenies of the selected plants. The markers were co-dominant CAPS marker SCAC568 for TSWV resistance, and dominant markers 189D23M for the L3 allele and 060I2END for the L4 allele. Two dominant markers linked to L3 and L4 alleles were dominant with an expected segregation ratio of 3: 1 , and a co-dominant marker linked to Tsw resistance with an expected segregation ratio of 1:2:1 in F2 population. Kisquare (X2) analysis was performed to test segregation distortion in the F2 population for both dominant and co-dominant marker results. The codominant marker linked to the Tsw gene segregated 1:2:1 as expected. However, dominant markers linked to L3 and L4 alleles showed significant distortions. Ramification of MAS in pepper breeding is discussed.