Development of SCAR Marker for Identifying Male Trees of Ginkgo biloba using Multiplex PCR

摘要

Ginkgo (Ginkgo biloba L.) is one of the most appropriate roadside trees because of a good transplantation nature and ability to grow well in urban environment. Ginkgo is a dioecious species. Sex discrimination of ginkgo is possible through comparing morphological characters of reproductive organs. However, it needs more than about twenty years for reproductive organs to appear after sexual maturity. Until now, ginkgo trees for roadside plantation have been planted without discriminating the sex because ginkgo trees have been usually planted before sexual maturity. Ginkgo nuts from the female ginkgo trees planted along the roadside emit a foul odor, and make much pollution on the streets. Thus in this study a novel SCAR marker (SCAR-GBM) for the early sex discrimination was developed. Primers were developed on the basis of the sequence of male-specific RAPD variants reported previously. False-negative problem of SCAR marker, probably caused by dominant nature, was resolved by using multiplex PCR using primers of both the SCAR-GBM and a universal primer set of atpl region in mitochondria DNA, which resulted in improved discrimination efficiency. The results showed that DNA bands of 1,039 bp were commonly amplified by the atp primer set in male andfemale trees, and SCAR-GBM markers of 675 bp were specifically amplified only in male trees. Reproducible and specific discrimination of the multiplex PCR was finally confirmed by applying multiple male and female individuals.