Flower-level developmental plasticity to nutrient availability in Datura stramonium: Implications for the mating system

IVAN CAMARGO; JULIETA NATTERO; SONIA CAREAGA; JUAN NÚÑEZ-FARFÁN

ANNALS OF BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2017 vol. 120 p. 603 - 615

0305-7364

?Backgrounds and Aims: Phenotypic plasticity studies have mainly focused on (1) the effects of environmental variation on whole-plant traits related to the number of modules rather than on (2) phenotypic consequences of environmental variation for the traits of individual modules. Since changes in the plant mating system are expected due to environmental and developmental factors, we used the second approach to investigate (1) how within-individual variation in herkogamy-related traits are affected by the environment during plant development in Datura stramonium (Solanaceae), a predominantly self-fertilizing annual herb with a hypothesized persisting mixed mating system, and (2) which morphological traits promote an increased self-fertilization.?Methods: Two Mexican populations of D. stramonium with contrasting ecological histories were compared under low-, mid- and high-nutrient availability to investigate genetic, environmental, flower position order and its interaction effects on flower size, corolla, stamen, pistil, and herkogamy length.?Key Results: Populations showed differences in familial variation, plasticity and familial differences in plasticity in almost all traits analyzed. Almost all traits showed variation among families in flower position in the Ticumán population, whereas the Pedregal population showed differences in within-individual variation to nutrient availabilities. Populations showed contrasting ontogenetic trends in flower size in low nutrient availability; a systematic-ontogenetic trend of reduction in flower size and herkogamy along flower position, which increased the probability of self-fertilization, was detected (Pedregal). ?Conclusions: Beside genetic variation in floral traits between and within populations, environmental variation affects phenotypic floral traits values at the whole plant level as well as among floral position. The interaction between floral position and nutrient environment can affect plant mating system and differs between populations.