Hu Jiedong, Li Kaihui, Deng Chengjun, Gong Yanming, Liu Yanyan, Wang Lei
CAS Research Center for Ecology and Environment of Central Asia, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Plants (Basel). 2022 Jul 5;11(13):1777. doi: 10.3390/plants11131777.
The semiparasitic weed Maxim. has rapidly spread in the alpine grasslands of northern China over the past twenty years and has caused serious ecological problems. In order to effectively halt the spread of this weed, a thorough understanding of the dormancy type and the seed-germination ecology of is required. We have conducted a series of experiments to investigate the effects of plant growth regulators (gibberellin (GA) and strigolactone synthesis (GR24)), as well as different abiotic (temperature, light, cold stratification, and drought) and biotic (aqueous extracts of three native dominant plants) factors on the seed-germination characteristics of . The seed-germination percentages ranged from 2% to 62% at all of the temperatures that were examined, with the highest occurring at 25/10 °C. The light conditions did not significantly affect the germination percentage. The seed germination was greatly improved after two to eight weeks of cold stratification. The seed germination decreased dramatically with an increasing polyethylene glycol (PEG-6000) concentration, from 55% to 0%, under 10% and 20% PEG-6000. The seed germination was improved at a proper concentration of GA, GR24, and the aqueous extracts of L., L., and (Georgi) Tzvel. Furthermore, in the pot experiment, the seedling emergence of was also improved by the cultivation of these three dominant grasses. These findings indicate that the dormancy type of seeds is non-deep physiological dormancy, and such findings will help in paving the way for the creation of effective weed management strategies, based on a thorough knowledge of germination ecology.
半寄生杂草列当（Orobanche coerulescens Steph.）在过去二十年里在中国北方高寒草原迅速蔓延，引发了严重的生态问题。为有效遏制这种杂草的蔓延，需要深入了解其休眠类型和种子萌发生态学。我们开展了一系列实验，研究植物生长调节剂（赤霉素（GA）和独脚金内酯合成物（GR24））以及不同非生物因素（温度、光照、低温层积和干旱）和生物因素（三种本地优势植物的水提物）对列当种子萌发特性的影响。在所测试的所有温度下，种子发芽率在2%至62%之间，最高发芽率出现在25/10℃。光照条件对发芽率没有显著影响。经过两到八周的低温层积处理后，种子发芽率显著提高。随着聚乙二醇（PEG - 6000）浓度的增加，种子发芽率急剧下降，在10%和20% PEG - 6000处理下，发芽率从55%降至0%。在适当浓度的GA、GR24以及乳白香青（Anaphalis lactea Maxim.）、乳香黄耆（Astragalus galactites Pall.）和阿尔泰狗娃花（Heteropappus altaicus (Willd.) Novopokr.）的水提物处理下，种子发芽率有所提高。此外，在盆栽实验中，种植这三种优势草也提高了列当的出苗率。这些结果表明，列当种子的休眠类型为非深度生理休眠，这些发现将有助于在深入了解萌发生态学的基础上，为制定有效的杂草管理策略铺平道路。
