Apomixis in Coix aquatica Roxb

Abstract

When plants of Coix aquatica Roxb. were grown in isolation or bagged, with removal of staminate spikelets several produced one or two seeds, and one plant formed several seeds. These were presumably formed through apomixis, of the autogamous type. Apomixis occurs side by side with sexual reproduction, and is therefore facultative. The fact that one of the plants grown under the same conditions had higher apomictic seed set than others, and both its apomictic and selfed progeny also showed higher apomictic seed formation suggests that these have greater apomictic potentialities than others. Genetic analysis of apomixis suggests that it is recessive to sexuality, and is probably governed by a number of genes. A few triploids tested did not show any apomictic seed set indicating that polyploidy per se may not be responsible for initiation of apomixis. Except that it is a diploid, C. aquatica seems to fulfil the criteria for apomixis, yet it reproduces predominantly by sexual means.