Weed Seed Dormancy: The Ecophysiology and Survival Strategies

Abstract

This chapter deals with seed dormancy of agricultural weeds, its definitions and types from the physiological and ecological point of view, and physiological and ecological factors inducing dormancy in different weed species. The role of different environmental factors, agricultural practices including herbicides application, selection pressure, and seasonal dormancy, weed density and population regulation, seed phenology, polymorphism, and modifications were emphasized. Factors induce or terminate dormancy and enhance seed germination and dormancy breaking have been mentioned and evaluated in addition to the ecological importance of seed dormancy and herbicide resistance, genetic bases of dormancy, and molecular studies were presented. The role of allelochemicals, stresses, and dormancy and their effects on seed longevity and germination regulation were thoroughly discussed. Dormancy breaking under laboratory conditions, role of plant hormones and other chemicals, and dormancy management in the field were reviewed in addition to information on seed dormancy/longevity and germination stimulants. Seed germination stimulants and inhibitors of parasitic weed and seed dormancy as a weed survival strategy were presented and discussed.

Interspecific competition in germination of bird-dispersed seeds in a habitat with sparse tree vegetation in South Africa

“…africana, G. occidantalis, S. lancea , and E. rigida ) could be partly attributed to the adaptive mechanisms related to a need for the persistence of dispersed seeds through protection against microbes and physiological barriers to their germination (Dalling et al 2011 ). Orthodox seeds tend to dry up to preserve their viability (Hilhost and Toorop 1997), and this requires some treatment to break their dormancy (Qasem 2019 ; Rowarth et al 2007 ). Bewley and Nonogaki ( 2017 ) distinguished between the sequence of the different physiological stages of the germination process, and they contended that, during the imbibition phase of germination in dry seeds (i.e., orthodox), germination may be prolonged if all the essential protein are not available to reinitiate the metabolism in the dormant seeds.…”

Germinación y crecimiento de Vicia magellanica: Implicancias para la restauración de áreas incendiadas en el norte de la Patagonia andina

“…Las semillas de V. magellanica poseen una cubierta externa dura, como muchas otras especies del género Vicia spp. (Qasem 2020). Utilizando una balanza de precisión (0.001 g) y un calibre digital se registró el peso y el diámetro medio, respectivamente, considerando el diámetro mayor de cada semilla, de 20 semillas seleccionadas aleatoriamente del conjunto de semillas seleccionadas para el ensayo.…”

Seed Germination Strategies of Mediterranean Halophytes Under Saline Condition

“…In an attempt to identify the causes and classify the various ways in which dormancy occurs, a wide range of scientific papers are available, some of which are very distant over time (Belderok 1961;Barton 1965;Nikolaeva 1977;Lang 1965;Khan 1977;Bewley 1997;Finch-Savage and Leubner-Metzger 2006;Qasem 2019).…”