Sex Identification in Polygamodioecious Simarouba (Simarouba glauca DC) Using RAPD and ISSR Markers

Abstract

Simarouba (Simarouba glauca DC) is polygamodioecious perennial, popularized as an important oilseed tree crop for cultivation on wasteland. In simarouba only female plants are valued for commercial production of fruits and seeds, therefore early sex identification of male and female genotypes before planting becomes essential, as excess of male plants can be discarded at seedling stage. To distinguish male genotypes from female genotypes early in the seedling stage, 69 random amplified polymorphic DNA (RAPD) primers and 12 inter-simple sequence repeat (ISSR) primers were used to screen DNA bulk samples from 5 male and 15 female plants. Fifty three out of the 69 RAPD primers resulted in 373 reproducible RAPD bands with an average of 7 fragments amplified per primer. Five RAPD primers (OPC 06, OPC 16, OPD 15, OPE 05 and OPD 12) and two ISSR primers (ISSR 824 and ISSR 864) produced distinguishing banding pattern for male and female bulk samples. These seven markers were then used to screen individual 5 male and 15 female plants; RAPD primer OPE 05 consistently reproduced a male-specific fragment (521 bp), which was absent in all female plants. These results indicated that marker OPE-05521 may be a male-specific marker and may be used for sex characterization in simarouba at an early stage of plant growth.