Zhang Keliang, Yao Linjun, Zhang Yin, Tao Jun
Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, PR China.
AoB Plants. 2019 Jun 3;11(3):plz026. doi: 10.1093/aobpla/plz026. eCollection 2019 Jun.
(Asteraceae), a noxious weed in many ecosystems worldwide, produces large amounts of heteromorphic (central and peripheral) achenes. The primary aims of the present study were to compare the morphological, dormancy/germination characteristics of dimorphic achenes. Temperatures simulating those in the natural habitat of were used to test for primary dormancy and germination behaviour of fresh central and peripheral achenes. The effects of cold stratification, gibberellic acid (GA) and dry storage on breaking dormancy were tested and the germination percentage of dimorphic achenes in response to osmotic stress was measured. Cold stratification, GA and dry storage significantly increased the germination percentage, suggesting both types of achenes had non-deep physiological dormancy. Variously pretreated central achenes had significantly higher germination percentages than peripheral achenes. Central achenes were more osmotically tolerant than peripheral achenes with a high germination percentage in high polyethylene glycol concentrations. These above differences among dimorphic achenes of increased the species' fitness to adapt to heterogeneous habitats creating an ecological adaptive strategy that may allow to successfully thrive in stressful habitats.
菊科植物是全球许多生态系统中的一种有害杂草，会产生大量异形（中央和外围）瘦果。本研究的主要目的是比较二形瘦果的形态、休眠/萌发特性。利用模拟该植物自然栖息地的温度来测试新鲜中央和外围瘦果的初级休眠和萌发行为。测试了低温层积、赤霉素（GA）和干燥贮藏对打破休眠的影响，并测定了二形瘦果在渗透胁迫下的萌发率。低温层积、GA和干燥贮藏显著提高了萌发率，表明两种类型的瘦果都具有非深度生理休眠。经过不同预处理的中央瘦果的萌发率显著高于外围瘦果。中央瘦果比外围瘦果更耐渗透，在高聚乙二醇浓度下具有较高的萌发率。该植物二形瘦果之间的上述差异提高了物种适应异质生境的适合度，形成了一种生态适应策略，可能使该植物在压力环境中成功生长。
