Abstract Detail

Ecology

Mozumdar, Kallol [1], Gowda, Vinita [2], Iyer, Priya [3].

Resource-dependent sex allocation in Andromonoecy.

Plants possess some of the most diverse sexual systems available in biology. Sexual systems in plants have been suggested to have evolved as a dynamic response to both environmental and genetic cues. However, understanding factors that can influence the sex of flowers especially factors such as soil nutrients, water and similar abiotic factors have been addressed in many studies but remains to be an underexplored field of research. The sex allocation theory explains the prevalence of various sexual strategies in plants. It suggests that reproductive strategies will be selected based on the trade-off between allocation to male and female reproductive functions.  While most theories focus on trade-offs between male and female sexes, theories focusing on sex-specific trade-offs among specialized sexual systems such as andromonoecy are rare. Andromonoecy is defined as a sexual system where the plant produces both staminate and perfect flowers. One of the most widely studied hypotheses that explain the maintenance of andromonoecy in plants is the optimal resource allocation theory. This suggests that under resource limitation, the plant will invest more into male function as it is energetically cheaper in comparison to female function. To get a better understanding of the allocation strategy, we designed mathematical models for sex allocation in andromonoecious plants. With the help of these models, we address the following questions: (1) How does resource availability influence the sex ratio and allocation pattern of an andromonoecious plant?   (2) What is the sex-specific allocation strategy when resources are limited and pollinator visitation rates may be affected by floral display size? Our models predict that with increasing resource availability, the plant will show an increase in hermaphrodite-to-male flower ratio and a female-biased allocation. We also observed that, if female fitness is limited by pollinator visitation, producing more male flowers will indeed increase the plant's female fitness. Our study is the first to show resource-dependent sex allocation in andromonoecious plants and allows us to understand parameters that may affect at least one of the sexual strategies in plants. We conclude with a comparison of our theoretical model with empirical observations from Murdannia simplex (Commelinaceae), an andromonoecious plant from the Kaas plateau, Maharashtra, India. We propose that our models best explain the sex-specific shifts in andromonoecious plants and encourage them to be tested with empirical data from different plant sexual systems.  

1 - Indian Institute of Science Education and Research Bhopal, Biological Sciences, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, 462066, India
2 - IISER Bhopal, Room 223, AB3, Dept. Of Biological Sciences,, IISER- Bhopal, Bhopal Bypass Road, Bhauri,, Bhopal, MP, 462066, India
3 - Indian Institute of Science Bangalore, Centre for Ecological Sciences, CV Raman Rd, Bengaluru, Karnataka, 560012, India

Keywords:
andromonoecy
Resource allocation trade-offs
Mathematical modelling
Evolutionarily Stable Strategy.

Presentation Type: Oral Paper
Session: ECO7, Ecology: Reproductive Biology
Location: /
Date: Thursday, July 22nd, 2021
Time: 4:00 PM(EDT)
Number: ECO7005
Abstract ID:1100
Candidate for Awards:Ecological Section Best Undergraduate Presentation Award