Genetic mapping of the Lablab purpureus genome suggests the presence of 'cuckoo' gene(s) in this species

A linkage map of Lablab purpureus consisting of 127 RFLP and 91 RAPD loci w as constructed in an F-2 population of 119 individuals. This population was derived from a cross between 'Rongai' (an annual cultivar) and CPI 24973 ( a perennial wild accession). The map comprises 17 linkage groups and covers 1610 centiMorgans (cM) with an average distance of 7 cM between markers. S evere segregation distortions were observed, with the very extreme situatio n where no paternal type was recovered from the mapping population. These r esults strongly suggest the presence of a gene conferring preferential tran smission from the maternal parent 'Rongai'. It was also clear that, while t he majority of RAPD markers are valuable when used together with RFLP or ot her stringent marker systems, they could be problematic when used solely in mapping exercises.