Genetic Characterization of a New Growth Habit Mutant in Tomato (Solanum lycopersicum)

A mutant tomato cultivar (HT10-3-2) with indeterminate growth habit was obtained from a cultivar (T10-3-2) with determinate growth habit. The character of indeterminate growth habit in HT10-3-2 could be inherited stably. Unlike other normal growth habit cultivars, which are controlled by the SELF PRUNING gene, it was shown here that HT10-3-2 has no mutation in the sp gene. Two hundred random amplified polymorphic DNA (RAPD) primers were used to screen for polymorphism between the two genotypes from genomic DNA, and a polymorphic fragment (S168₁₄₅₈) was obtained and subsequently sequenced. However, Basic Local Alignment Search Tool searches indicated that the sequence of this RAPD fragment shares no significant homology with known sequences in GenBank. The RAPD marker (S168₁₄₅₈) was converted to a sequence characterized amplified region (SCAR) marker, SCA168₁₄₅₃. The SCAR marker was tested using an F₂ population derived from the cross of T10-3-2 and HT10-3-2 and the results showed that this marker was closely linked with the unknown factor influencing the growth habit in HT10-3-2.