GEOGRAPHICAL VARIATION IN THE BREEDING SYSTEMS OF AN INVASIVE PLANT, EICHHORNIA CRASSIPES, WITHIN CHINA

Abstract

Knowledge about the breeding systems of invasive weeds is crucial for invasion management. Eichhornia crassipes, a noxious clonal plant, has a complex breeding system that includes clonal reproduction and a special sexual reproduction mode, tristyly, and a complex mating system that consists of three floral morphs that differ in the length of styly and stamens. In this paper, we compared the breeding systems of 40 Eichhornia crassipes populations in 24 localities throughout China by investigating the relative level of sexual and clonal reproduction, number of floral morphs and the variances in floral syndrome (especially the position of sexual organs) for each population. A Mann-Whitney test was used to detect whether the variation in the position of the sexual organs were significant among each other and the typical floral morphs. The seed-set ratio of each floral morph was investigated extensively in a Chongqing population that had a high number of floral morphs.