Identification of Linked Markers for Delayed Fruit Ripening in Tomato Using Simple Sequence Repeat (SSR) Markers

Tomato (Solanum lycopersicum L.) is an important vegetable crop and acts as model plant for fruit development studies. Besides that, post-harvest damage is a devastating phenomenon often associated with ripening process in tomato which in turn leads to greater yield loss. Understanding the genetics, molecular and biochemical pathways is the key to overcome the existing situation. In the present study, we have identified a delayed ripening mutant and used in identification of linked marker for delayed fruit ripening. Initially, BML-03 (delayed ripening mutant line) was crossed with BIL-29 (normal ripening inbred line) to produce F2 population. Bulked segregate analysis was carried out using 245 SSR markers. Out of which, five SSRs were found to be polymorphic between parental lines and respective bulks along with a segregating genotype of mapping population. A population of 227 F2 plants was screened with five polymorphic SSR markers and the data were used in linkage analysis. Three SSR markers were found to be co-segregating with the delayed ripening phenotype and resulted in a linkage map which covered the map distance of 3.4 cM. Out of 3 markers TGS0070 was found to be closely linked to the fruit ripening locus and was successfully validated using other ripening specific F2 population BML-28 x BIL-3.