Saleem Rashid, Campbell Shane, Fletcher Mary T, Kalaipandian Sundaravelpandian, Adkins Steve
School of Agriculture and Food Sciences, University of Queensland, Gatton, QLD 4343, Australia.
Queensland Alliance for Agriculture Innovation, University of Queensland, Coopers Plains, QLD 4108, Australia.
Plants (Basel). 2023 May 26;12(11):2112. doi: 10.3390/plants12112112.
Lindl is a little-understood Australian native plant, with irregular field emergence, causing significant poisoning to grazing livestock. The study aims to examine the form of dormancy exhibited by and determine how key environmental conditions, such as alternating temperature and light conditions, moisture availability, substrate pH and burial depth, affect its germination and emergence. The study concludes that has a complex dormancy mechanism. This comprises a physical component that can be partly removed by fruit scarification, a metabolic dormancy that can be overcome by gibberellic acid (GA), and a suspected third mechanism based on a water-soluble germination inhibitor. The results showed that scarified single seeded fruit (hereafter seed) with GA treatment gave the highest germination percentage (86 ± 3%) at 25/15 °C, with good germination rates at other temperature regimes. Light exposure stimulated germination, but a significant proportion of seeds still germinated in the dark. The study also found that seeds could germinate under water-limited conditions and a wide range of pH levels (4 to 8). Seedling emergence was inhibited when seeds were buried below 3 cm in soil. emergence in the field commonly occurs from Autumn to Spring. Understanding its dormancy mechanism and recognizing its triggers for germination will enable better prediction of outbreaks. This can help landholders prepare for emergence and help manage seedbank build-up in pastures and crops.
林德尔是一种鲜为人知的澳大利亚本土植物，田间出苗不规则，会对放牧的牲畜造成严重中毒。该研究旨在研究其表现出的休眠形式，并确定关键环境条件，如交替温度和光照条件、水分可用性、基质pH值和埋藏深度，如何影响其发芽和出苗。研究得出结论，林德尔具有复杂的休眠机制。这包括一个可以通过果实划破部分去除的物理成分、一个可以被赤霉素（GA）克服的代谢休眠，以及一个基于水溶性发芽抑制剂的疑似第三种机制。结果表明，经GA处理的划破单粒果实（以下简称种子）在25/15°C时发芽率最高（86±3%），在其他温度条件下也有良好的发芽率。光照刺激发芽，但仍有很大比例的种子在黑暗中发芽。研究还发现，种子可以在水分有限的条件和广泛的pH值水平（4至8）下发芽。当种子埋在土壤中3厘米以下时，幼苗出苗受到抑制。林德尔在田间通常从秋季到春季出苗。了解其休眠机制并识别其发芽触发因素将有助于更好地预测其爆发。这可以帮助土地所有者为其出苗做好准备，并有助于管理牧场和作物中的种子库积累。
