Abstract:

The authors studied the relationship between the stamen feminization phenomenon of the invasive plant Alternanthera philoxeroides and its habitat, and explored its reproductive strategy after entering the invasive site, aiming to supplement the invasion theory of this invasive plant and provide a theoretical basis for its integrated control. In this study, the occurrences of stamen feminization in different habitats and different inflorescence positions were investigated using A. philoxeroides as the study material. The degree of stamen feminization at the stamen level and the frequency of stamen feminization at the flower level were used as parameters to measure the occurrence of stamen feminization in A. philoxeroides. The results show that: (1) stamen feminization occurs commonly in A. philoxeroides, and the degree and frequency of feminization are generally high; (2) the degree of stamen feminization in A. philoxeroides in the three habitats is aquatic (5.5032)> wet (5.2403)> dry (5.2066); the frequency of stamen feminization is also aquatic (86.75%)> wet (77.28%)> dry (76.17%); (3) there is no significant difference in the occurrence of stamen feminization in A. philoxeroides from the top to the bottom. Thus, the phenomenon of stamen feminization in A. philoxeroides tends to occur under conditions of sufficient moistre, and the phenomenon shows a relatively uniform distribution pattern within the inflorescence, which is consistent with its characteristic of asexual reproduction as the main mode of reproduction after entering the invasive site.

Key words: invasive plant, habitat, inflorescence position, stamen feminization, Alternanthera philoxeroides