Abstract
Resource allocation to reproduction can change depending on size, as predicted by the size-dependent sex allocation. This theory is based on the fact that small individuals will invest in the allocation of sex with lower cost of production, usually male gender. In plants, there are some andromonoecy species, presence of hermaphrodite and male flowers in the same individual. Andromonoecy provides a strategy to optimally allocate resources to male and female function, evolving a reproductive energy-saving strategy. Thus, our objective was to investigate the size-dependent sex allocation in Solanum lycocarpum St. Hil. We tested the hypothesis that plants with larger size will invest in the production of hermaphrodite flowers, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure. The studied species was S. lycocarpum, an andromonoecious species. From June 2016 to March 2017 the data were collected in 38 individuals, divided in two groups: the larger plant group (n=18; height=3-5 m) and the smaller plant group (n=20; height=1-2 m).Our data show that there was effect of plant size on the flower production and the sexual gender allocation. The larger plants showed more flowers and higher production of hermaphrodite flowers. Furthermore, in the flower scale, we observed allometric relationship among the flower's traits with proportional investments in biomass, anther size and gynoecium size. Our results are in agreement with size-dependent sex allocation theory and andromonoecy hypothesis related to mechanisms for optimal resource allocation to male and female function.
Highlights
Plants have three essential functions: growth, defense against herbivores and reproduction, and each of these functions needs some resources (Weiner et al, 2009)
Large plants will invest more in hermaphrodite flowers than small plants, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure
The production of flower appeared to be closely linked to plant size, since the number of flowers was significantly greater in plants from the larger group than in plants from lower group (U = 308.000; p < 0.001) (Figure 2)
Summary
Plants have three essential functions: growth, defense against herbivores and reproduction, and each of these functions needs some resources (Weiner et al, 2009). The resources are limited and the essential functions compete for them, which generate a trade-off between the essential functions, leading to a resource differential allocation (Bazzaz et al, 1987), as plants are not able to invest simultaneously in growth, reproduction and defense (Weiner et al, 2009). Sexual allocation is one type of allocation that may occurs in both animals and plants and has as premise that the individual can change his gender taking into account the energy expenditure, opting for the more favorable sex (Warner et al, 1975; Lloyd and Bawa, 1984; Warner, 1988; Vega-Frutis et al, 2014). This allocation has been considered a survival strategy because it affects the plant fitness through the male and female functions (Cao and Kudo, 2008)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
