ORIGIN AND EVOLUTION OF FEMALE PLANT FROM AN IDENTICAL MALE PLANT, IN CARICA PAPAYA L.

Abstract

A field study was carried during January 2011 to March, 2013, to confirm the origin and evolution of female plant from an identical male plant in, a dioecious plant, the Carica papaya L. The plants were grown from the seeds of a normal female plant fruit. The grown, plants were identified as XX, XY and XYh (in March - April, 2012) on the basis of male and female flower bearing. The identical male plants, which usually bear only male (unisexual) flowers having calyx, corrolla and androecium, were observed also to bear bisexual flower, having calyx, corrolla, and gynoecium (ovary fused with androecium ). The fruits were set having the bisexual flowers in the identical male (hermaphrodite) plant. These fruits were kept under observation from setting to ripening stage. The ripened fruits were harvested from the identical male plants and 90-95% fruits from these plants were found with the seeds. Plants grown from these male fruit seeds produced all three type of plants i.e., male, female and hermaphrodite. This study indicated that an identical male (XYh) plant produced the female (XX) plant naturally, because of the XXY= XYh condition, which can contribute basic genetic material to male and female plants i.e an identical male (XYh = XXY= 2N +1 = 18+1= 19) produced all three type of plants, the pure male, the hermaphrodite and the female plant, originated from a single source of an identical male, as shown here. XYh = XXY J XY + XX + XXY. The propagation of all three sexes of Carica papaya from a single source of an identical male plant seeds is the first report in the world.