Paternity determination of Ornithogalum seedlings using DNA markers

Summary

This research was initiated to identify the parentage of putative Ornithogalum hybrids using DNA fingerprinting techniques. Seeds were harvested from Ornithogalum thyrsoides hybrid ‘Chesapeake Starlight’ (‘CS’) and five seedlings (SD1-SD5) were selected and evaluated for growth and flowering. These seedlings varied in scape length, flower shape and colour, and the presence or absence of pollen. Ornithogalum conicum, Bokbaai type of O. thyrsoides 7050A, 7050B and a seedling from a cross between O. conicum x O. thyrsoides 7050C which were considered as possible paternal parents of the seedlings were also analysed for DNA fingerprinting.A total of 169 random amplified polymorphic DNA (RAPD) bands were produced, of which 90 (53%) were polymorphic. Based on the p-distance value, O. conicum was initially excluded as a potential source of pollen and Bokbaai type of Ornithogalum 7050A, and 7050B was considered to be the most likely pollen source. However, the possibility that all seedlings could result from self-pollinated progenies of ‘CS’ was not excluded. Five randomly selected primer pairs for amplified fragment length polymorphism (AFLP) analysis generated a total of 298 fragments, of which 191 (63.4 %) were polymorphic bands. The presence of marker 109 in all four seedlings, SD1, SD 2, SD 4, and SD 5 and in O. conicum x 7050C suggests that marker 109 was inherited from 7050C. According to the p-distance and nonmaternal band analysis performed with RAPD and AFLP, it was concluded that the seedlings were not the result of self-pollination, and O. thyrsoides 7050C could be the paternal parent. Ornithogalum species such as O. thyrsoides, instead of O. conicum, should be used in future breeding efforts to breed a paper white flower with cup-shaped florets.