Maleki Keyvan, Maleki Kourosh, Soltani Elias, Oveisi Mostafa, Gonzalez-Andujar Jose L
Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210, USA.
Department of Forestry, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan P.O. Box 386, Iran.
Plants (Basel). 2023 Jan 4;12(2):233. doi: 10.3390/plants12020233.
In every agricultural system, weed seeds can be found in every cubic centimeter of soil. Weed seeds, as a valuable trait underlying the fate of weed populations, exhibit differing levels of seed dormancy, ensuring their survival under uncertain conditions. Seed dormancy is considered as an innate mechanism that constrains germination under suitable conditions that would otherwise stimulate germination of nondormant seeds. This work provides new insight into changes in germination patterns along the dormant to nondormancy continuum in seeds with physiological dormancy. Notable findings are: (1) germination synchrony can act as a new parameter that quantitatively describes dormancy patterns and, subsequently, weed population dynamics, (2) germination synchrony is dynamic, suggesting that the more dormancy decreases, the more synchrony is obtainable, (3) after-ripening and stratification can function as a synchronizing agent that regulates germination behavior. Freshly harvested seeds of with type 3 of non-deep physiological dormancy showed the most synchronous germination, with a value of 3.14, while a lower level of germination asynchrony was found for newly harvested seeds of with type 1 of non-deep physiological dormancy, with an asynchrony value of 2.25. After-ripening and stratification can act as a synchronizing factor through decreasing the asynchrony level and increasing synchrony. There is a firm relationship between seed dormancy cycling and germination synchrony patterns, ensuring their survival and reproductive strategies. By germinating in synchrony, which is accompanied by cycling mechanisms, weeds have more opportunities to persist. The synchrony model used in the present study predicts germination behavior and synchrony along the dormant to nondormancy continuum in weed seeds with physiological dormancy, suggesting a useful method for the quantification of germination strategies and weed population dynamics.
在每一个农业系统中，每立方厘米土壤里都能发现杂草种子。杂草种子作为决定杂草种群命运的一个重要特性，表现出不同程度的种子休眠，以确保它们在不确定的条件下得以存活。种子休眠被认为是一种内在机制，它在适宜条件下抑制种子萌发，而这些条件原本会刺激非休眠种子萌发。这项研究为具有生理休眠的种子从休眠到非休眠连续过程中萌发模式的变化提供了新的见解。显著发现有：（1）萌发同步性可作为一个新参数，定量描述休眠模式以及随后的杂草种群动态；（2）萌发同步性是动态的，这表明休眠程度降低得越多，可获得的同步性就越高；（3）后熟和层积处理可作为一种同步因子，调节种子的萌发行为。具有第3类非深度生理休眠的新收获种子表现出最同步的萌发，同步值为3.14，而具有第1类非深度生理休眠的新收获种子萌发异步性较低，异步值为2.25。后熟和层积处理可通过降低异步水平和提高同步性来充当同步因子。种子休眠循环与萌发同步模式之间存在紧密关系，确保了它们的生存和繁殖策略。通过同步萌发（伴随着循环机制），杂草有更多机会得以存续。本研究中使用的同步性模型预测了具有生理休眠的杂草种子从休眠到非休眠连续过程中的萌发行为和同步性，为量化萌发策略和杂草种群动态提供了一种有用的方法。
