Steadman Kathryn J
Western Australian Herbicide Resistance Initiative, School of Plant Biology, Faculty of Natural and Agricultural Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
J Exp Bot. 2004 Apr;55(398):929-37. doi: 10.1093/jxb/erh099. Epub 2004 Mar 12.
The influence of temperature, light environment, and seed hydration on the rate of dormancy release in Lolium rigidum (annual ryegrass) seeds during hydrated storage (stratification) was investigated. In a series of experiments, seeds were subjected to a range of temperatures (nine between 5 degrees C and 37 degrees C), light (white, red, far-red, and dark), and hydration (4-70 g H(2)O 100 g(-1) FW) during stratification for up to 80 d. Samples were germinated periodically at 25/15 degrees C or constant 15, 20, or 25 degrees C with a 12 h photoperiod to determine dormancy status. Dark-stratification was an alternative, but not equivalent dormancy release mechanism to dry after-ripening in annual ryegrass seeds. Dormancy release during dark-stratification caused a gradual increase in sensitivity to light, but germination in darkness remained negligible. Germination, but not dormancy release, was greater under fluctuating diurnal temperatures than the respective mean temperatures delivered constantly. Dormancy release rate was a positive linear function of dark-stratification temperature above a base temperature for dormancy release of 6.9 degrees C. Dormancy release at temperatures up to 30 degrees C could be described in terms of thermal dark-stratification time, but the rate of dormancy release was slower at < or =15 degrees C (244 degrees Cd/probit increase in germination) than > or =20 degrees C (208 degrees Cd/probit). Stratification in red or white, but not far-red light, inhibited dormancy release, as did insufficient (<40 g H(2)O 100 g(-1) FW) seed hydration. The influence of dark-stratification on dormancy status in annual ryegrass seeds is discussed in terms of a hypothetical increase in available membrane-bound phytochrome receptors.
研究了温度、光照环境和种子水合作用对硬直黑麦草（一年生黑麦草）种子在水合储存（层积处理）期间休眠解除速率的影响。在一系列实验中，种子在层积处理长达80天的过程中，经历了一系列温度（5℃至37℃之间的9种温度）、光照（白色、红色、远红光和黑暗）和水合作用（4 - 70 g H₂O 100 g⁻¹FW）处理。定期在25/15℃或恒定的15℃、20℃或25℃以及12小时光周期条件下对样品进行萌发试验，以确定休眠状态。黑暗层积处理是一年生黑麦草种子干燥后熟的一种替代但不等同的休眠解除机制。黑暗层积处理期间的休眠解除导致对光的敏感性逐渐增加，但在黑暗中的萌发率仍然可以忽略不计。与持续提供的各自平均温度相比，在昼夜温度波动条件下的萌发率更高，但休眠解除不受影响。休眠解除速率是黑暗层积处理温度高于6.9℃的休眠解除基础温度的正线性函数。在高达30℃的温度下，休眠解除可以用热黑暗层积时间来描述，但在≤15℃（萌发概率增加1个单位需要244℃·天）时的休眠解除速率比≥20℃（208℃·天）时慢。在红色或白色光下但不是远红光下进行层积处理，以及种子水合不足（<40 g H₂O 100 g⁻¹FW），都会抑制休眠解除。根据膜结合光敏色素受体可用性的假设增加，讨论了黑暗层积处理对一年生黑麦草种子休眠状态的影响。
