RETRACTED ARTICLE: The role of seed appendage in improving the adaptation of a species in definite seasons: a case study of Atriplex centralasiatica

Abstract

BackgroundAs a common accompanying dispersal structure, specialized seed appendages play a critical role in the successful germination and dispersal of many plants, and are regarded as an adaptation character for plants survival in diverse environments. However, little is known about how the appendages modulate the linkage between germination and environmental factors. Here, we tested the responses of germination to seasonal environmental signals (temperature and humidity) via seed appendages using Atriplex centralasiatica, which is widely distributed in salt marshlands with dry-cold winter in northern China. Three types of heteromorphic diaspores that differ in morphology of persistent bracteole and dormancy levels are produced in an individual plant of A. centralasiatica.ResultsExcept for the nondormant diaspore (type A, with a brown seed enclosed in a persistent bracteole), bracteoles regulated inner seed dormancy of the other two dormant diaspore types, i.e., type B (flat diaspore with a black inner seed) and type C (globular diaspore with a black inner seed). For types B and C, germination of bracteole-free seeds was higher than that of intact diaspores, and was limited severely when incubated in the bracteole-soaking solution. Dormancy was released at a low temperature (< 10 °C) and suitable humidity (5–15%) condition. Oppositely, high temperature and unfit humidity induced secondary dormancy via inhibitors released by bracteoles. Type C with deeper dormancy needed more stringent conditions for dormancy release and was easier for dormancy inducement than type B. The germination windows were broadened and the time needed for dormancy release decreased after the bracteole flushing for the two dormant types in the field condition.ConclusionsBracteoles determine the germination adaptation by bridging seeds and environmental signals and promising seedlings establishment only in proper seasons, which may also restrict species geographical distribution and shift species distributing ranges under the global climate change scenarios.

The environmental adaptation strategy of seed germination, and roles of the seed pappus on dispersal and hypocotyl hairs on seedling anchorage inTamarix ramosissima

“…T. ramosissima seeds are extremely small and have hairy appendages ( Zhang et al . 2002 ), which are considered adaptations for survival in adverse environments ( Wang et al . 2019 ).…”

Effects Of Diaspore Bracts And Cations On Germination Of Ceratoides Arborescens (Losinsk.) Tsien Et C.g. Ma Under In Vitro Culture

“…The dead coverings of seeds from different species are very diverse and reflect the adaptive characteristics of seed dispersion in a variety of different environments (Webb et al 2009, Wang et al 2019. Previous studies have exported the effect of dead layers on seed germination was species-specific, and showed that dead coverings could increase (Ueno and Miyoshi 2005), decrease (Fandrich and Mallory-Smith 2006), or have no influence on seed germination characters.…”

Dormancy and germination of the trimorphic achenes of a cold desert annual: spreading the risk over time

“…Many studies have been conducted on the ecology of species with dimorphic diaspores (reviewed in Baskin et al 2013 , 2014 ). However, there are fewer such studies on species that produce three diaspores ( Venable et al 1987 ; Wei et al 2007 ; Wang and Wei 2007 ; Cheng and Tan 2009 ; Sun et al 2008 , 2009 ; Ma et al 2018 ; Mamut et al 2018 ; Wang et al 2019 , 2020 ).…”