2003 Volume 53 Issue 1 Pages 7-13
A sweet pea (Lathyrus odoratus L.) cultivar, ‘Grace’, which has tendrils, was crossed with ‘Snoopea purple’ lacking tendrils. The resultant F2 population was used to identify RAPD (random amplified polymorphic DNA) markers linked to a tendril gene. The presence of tendrils was found to segregate in a dominant fashion. A total of 302 random primers were used to screen a pair of bulked DNA samples of the F2 plants. Only two primers, WB32 and WB67, showed polymorphism between the bulked samples. The former generated a DNA fragment specific to the bulked sample with tendrils, while the latter amplified a fragment in the bulked sample without tendrils. Segregation of these RAPD markers was examined in the F2 population. One of them, WB32a was found to be linked to the tendril gene. The marker was then cloned and sequenced. A pair of primers was designed for specific amplification of this marker. The primer pairs amplified a clear and dominant band, SWB32a, and the band was specific to individuals with tendrils. The linkage between the marker, SWB32a and the gene for tendrils was demonstrated in the F2 population in a distance of 7.7 cM. Use of this genetic marker in the breeding of sweet pea cultivars without tendrils was discussed.
