Development of a SCAR marker associated with male sex determination in Garcinia indica Choisy

Abstract

SummaryGarcinia indica is an endemic fruit-yielding tree which is naturally distributed in the Western Ghats regions of India. It is also cultivated as a plantation crop. It is dioecious tree with a long vegetative phase (10 - 12 years). There are no morphological or biochemical markers to differentiate the sex of individual trees before they reach maturity. In the present study, a randomly amplified polymorphic DNA (RAPD) marker was identified, using a pooled DNA approach, which was able to identify male trees. PCR screening of bulked DNA samples from male and female trees, using 150 decamer primers, revealed one primer (OPL-05) that produced a unique band of 1,501 bp in male tree DNA samples only. OPL-05 was then used to screen individual male and female trees in different collections. The 1.5 kbp band was produced in all male samples, but was absent in all female samples. This male-specific PCR fragment was cloned and sequenced and sequence-characterised amplified region (SCAR) primers were designed from the sequence of this unique fragment.The SCAR primers produced a 1,501 bp fragment in all male tree samples, but not in any female tree DNA sample.The SCAR primers were also used to investigate the sex of unknown trees before maturity.