摘要
This article is a commentary on Liu et al.(2021).In their recent review in this journal,Liu et al.(2021)argue that sexual differences in the allocation to reproduction by male and female plants may cause sexual differences in their responses to biotic(e.g.herbivory)and abiotic stress(e.g.moisture stress).Their general argument is that the nett reproductive costs are higher for females because they not only flower but must also produce fruits/cones/seeds(their Figure 3).They suggest(their Figure 2)that females can ameliorate their higher costs of reproduction such as by maximizing resource acquisition and resource gain.Many other previous reviews have also argued for higher female costs(Barrett and Hough 2013;Barrett et al.2010;Juvany and Munné-Bosch 2015;Obeso 2002).My aims in this commentary are(i)to note that theory predicts equal sexual allocation to reproduction,(ii)to argue that some of examples cited by Liu et al.(2021)do not suggest the theory is incorrect and finally,(iii)to provide a Cape(South Africa)perspective to show that differences in allocation cannot be invoked ad hoc to explain vegetative or other differences between the sexes.Vegetative differences between the sexes must ultimately be related to differences in sexual function,as is the case in animals,and not to differences in nett allocation to reproduction.
