Comparative floral development in male and female plants of Palmer amaranth (Amaranthus palmeri).

Autor: Wu W; Department of Plant Sciences, University of California, Davis, 95616, CA, USA., Jernstedt J; Department of Plant Sciences, University of California, Davis, 95616, CA, USA., Mesgaran MB; Department of Plant Sciences, University of California, Davis, 95616, CA, USA.
Jazyk: angličtina
Zdroj: American journal of botany [Am J Bot] 2023 Aug; Vol. 110 (8), pp. e16212. Date of Electronic Publication: 2023 Aug 10.
DOI: 10.1002/ajb2.16212
Abstrakt: Premise: Characterizing the developmental processes in the transition from hermaphroditism to unisexuality is crucial for understanding floral evolution. Amaranthus palmeri, one of the most devastating weeds in the United States, is an emerging model system for studying a dioecious breeding system and understanding the biological traits of this invasive weed. The objectives of this study were to characterize phases of flower development in A. palmeri and compare organogenesis of flower development in female and male plants.
Methods: Flower buds from male and female plants were dissected for light microscopy. Segments of male and female inflorescences at different stages of development were cut longitudinally and visualized using scanning electron microscopy.
Results: Pistillate flowers have two to three styles, one ovary with one ovule, and five obtuse tepals. Staminate flowers have five stamens with five acute tepals. Floral development was classified into 10 stages. The distinction between the two flower types became apparent at stage four by the formation of stamen primordia in staminate flowers, which developed female and male reproductive organs initially, as contrasted to pistillate flowers, which produced carpel primordia only. In staminate flowers, the putative carpel primordia changed little in size and remained undeveloped.
Conclusions: Timing of inappropriate organ termination varies across the two sexes in A. palmeri. Our study suggests that the evolution of A. palmeri from a cosexual ancestral state to complete dioecy is still in progress since males exhibited transient hermaphroditism and females produced strictly pistillate flowers.
(© 2023 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)
Databáze: MEDLINE
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