4.3 Fitness optimization - an integral view of reproductive
pattern
Reproductive pattern – how reproductive effort is allocated in
different reproductive modes is directly correlated with the fitness of
clonal plants (Wang et al., 2021b). The shift in reproductive pattern in
different ecological conditions, as a representative of adaptive
phenotypic plasticity, likely optimize the fitness of clonal plants in
changing scenarios (Li et al., 2018).
In an integral view, the tested four populations from different
geographic sources showed an adaptive plasticity in reproduction pattern
under different warming conditions. First, population 1 and 3 showed a
maintenance in asexual propagation especially the turion biomass
production under different warming conditions, while the sexual
reproduction was totally lost under warming. This shift in reproduction
pattern seems a non-adaptive plastic response to warming. However, it is
noteworthy that a higher percentage of pleiophyllous turions generated
under warming. Since the scale leaf is correlated with the nutrient
storage, photosynthetic capacity and the axillary bud number thus the
sprouting potential, an increase in the percentage of pleiophyllous
turions likely enhances the fitness and thus compensates the complete
loss of sex (Xie & Yu, 2011; Qian et al., 2014; Adamec, 2018). Second,
population 2 presented an increase in clonal propagation and
simultaneously a decrease in sexual reproduction under warming. A
prominent trade-off between asexual and sexual reproductive modes was
shown in the shift of reproductive pattern (Herben et al., 2015).
Although warming blocked the sexual reproduction and thus impeded the
probable genetic variance in the progeny, the enhancement in the asexual
propagule production is likely beneficial in maintaining the fitness.
Lastly, population 4 also showed a coherent asexual propagation output
under varied warming conditions. However, warming did not alter its
sexual reproduction as no sex reproduction was manifested under both
unwarming and warming conditions. As population 1 and 3, more
pleiophyllous turions were recruited for population 4 under warming, and
the fitness maximization might be realized. Overall, the fitness of the
populations from four different geographic sources is predicted to be
optimized under extreme warming.