Reproductive traits and sex ratio bias in the dwarf willow Salix herbacea

• Main Author: Zhao, Minchun
• Format: Bachelor Thesis
• Language: English
• Published: Uppsala universitet, Institutionen för biologisk grundutbildning 2024
• Subjects: Salix herbacea; reproductive traits; sex ratio bias; variance component analysis; mixed-model analysis; correlation analysis; Botany; Botanik
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-533977

Sex ratio is very important for the evolution of dioecious plants. It can influence the reproductive success of plants. Sex ratio bias is common among reproductive individuals. Studying the reproductive traits can help to understand possible mechanisms that could influence the generation and maintenance of sex ratio bias. However, few studies have reported the relationship between reproductive traits and sex ratio bias. We investigated 29 full-sib families of the dwarf willow Salix herbacea L. S.herbacea exhibits an overall female sex ratio bias but also strong variation in sex ratio among families. We used variance component analysis to investigate from which morphological level the variation of reproductive traits (cumulative catkin number over four growth periods, annual catkin number in the fourth growth period, flower number, ovule number) came from. And we used mixed models to test the influence of family, sex and the sex by family interaction on reproductive traits. Besides that, we also tested the correlation between sex ratio and reproductive traits. Our results suggest that genetic factors can influence the degree of sexual dimorphism of S. herbacea in the different families Flowers from families with higher sex ratios had more ovules, sex ratio and the ovule number co-varied across families.