Data/hora: 03/06/2024 02:13:31

Provedor de dados: 	Acta Botanica Brasilica	
País: 	Brazil	
Título: 	Pollen has higher water content when dispersed in a tricellular state than in a bicellular state	
Autores: 	Williams,Joseph H.; Brown,Chandler D.	
Data: 	2018-09-01	
Ano: 	2018	
Palavras-chave: 	Desiccation stress; Evolution of development; Pollen dispersal; Pollen germination; Pollen hydration; Spore dormancy; Trade-off.	
Resumo: 	ABSTRACT Pollen is generally dispersed in a sexually immature and somewhat dehydrated, metabolically quiescent state. Yet, in some species, pollen at anthesis is well-hydrated and metabolically active, and in 30 % of angiosperms pollen is dispersed after having formed its sperm cells. Pollen water content and sexual maturity may be correlated, either because both are subject to trade-offs between dispersal viability and post-pollination performance, or because the traits display developmental linkages. We inferred relative water content of sexually immature (“bicellular”) and sexually mature (“tricellular”) pollen of 30 species of angiosperms using a hydration index (HI) that ranges from zero to one, based on how near fresh pollen volume is to its minimal (dehydrated) or maximal (hydrated) volume. Tricellular pollen had 30 % higher HI than bicellular pollen (P &lt; 0.005), after controlling for initial pollen size (larger pollen had higher HI; P &lt; 0.05). A literature survey of 344 species indicated that the tricellular and hydrated states were strongly associated, although all four trait state combinations were present (P &lt; 0.0001). Our results suggest that a common mechanism for the repeated origins of tricellular pollen has been via the loss of controlled pollen dehydration, which enables either accelerated or extended pollen development.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062018000300454	
Editor: 	Sociedade Botânica do Brasil	
Relação: 	10.1590/0102-33062018abb0129	
Formato: 	text/html	
Fonte: 	Acta Botanica Brasilica  v.32 n.3 2018	
Fonte: 	info:eu-repo/semantics/openAccess