Identification of RAPD markers flanked to Fusarium wilt resistance gene in safflower (Carthamus tinctorius L.).

Abstract

Safflower (Carthamus tinctorius L.) is an important edible oilseed crop grown worldwide. Wilt caused by Fusarium oxysporurn f sp. carthami Klisiewicz and Houston is the major yield losing disease in safflower growing areas. It causes yield loss up to 93 % in susceptible varieties (Sastry and Ramchandram, 1994). The fungus persists in the soil and on plant debris, and is seed-borne in internal tissue of the hull and seed coat. Repeated planting of safflower in the same field enhances the fungus inoculum in the soil and the disease becomes serious. The wilting starts from the early seedling stage and continue up to the maturity of the crop. Screening the breeding material in wilt sick plot is crucial to identify resistant genotypes in resistance breeding programme. Standardized wilt inoculum load has to be maintained in wilt sick plot to ensure uniform disease incidence, otherwise, there would be chances of selecting false resistant types which would later hamper the resistance breeding programme. Also screening in sick plot takes about 120 days for recording of observations at different stages. To surmount these practical problems, attempts were made to identify molecular markers flanked to wilt resistant gene in the cultivateg species (c. tinctorius L.).