Sex detection of Kokum (Garcinia indica Choisy) by RAPD markers

Abstract

Kokum (Garcinia indica) is one of the most important indigenous and underexploited trees of tropical rain forests of Konkan region of Maharashtra. The fruit rinds of kokum are used as a garnish to give an acid flavor to the curries and also for preparing syrup as a thirst quenching summer drinks. Since sex is the queen problems in evolutionary biology [1], understanding the molecular factors behind sex expression has immense importance both in basic and applied research. The evolution of sex in plants, in particular has been hypothesized variously as the plant display a great variety of sexual phenotypes [2]. In general there are three major sex strategies in angiosperms, viz., hermaphrodite, monoecious and dioecious. The evolution of dioecy directly from a hermaphrodite species is considered unlikely since the occurrence and establishment of two independent mutations, one for male and other for female sterility, most occur simultaneously and the mutant genes (or multiple loci) must be tightly linked so that the generation of hermaphrodites does not occur by recombination [3]. Determination of sex in kokum is of utmost importance from the commercial agricultural point of view, since the sexuality cannot be distinguished prior to floral initiation. In kokum, selection of the appropriate sex type of the progeny for commercial planting would be beneficial, since only the female and hermaphrodite plants are grown for fruit [4]. The available morphological markers are not sufficient to identify sex at seedling stage.