Zhang Hao, Hu Mingfang, Ma Hongyuan, Jiang Li, Zhao Zhenyong, Ma Jinbiao, Wang Lei
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.
University of Chinese Academy of Sciences, Beijing, China.
Front Plant Sci. 2021 Apr 12;12:630338. doi: 10.3389/fpls.2021.630338. eCollection 2021.
The period between seed germination and seedling establishment is one of the most vulnerable stages in the life cycle of annuals in the saline environments. Although germination characteristics of seeds have been reported, the comparative germination patterns of dimorphic seeds and seedling growth to different abiotic stresses remain poorly understood. In this study, germination responses of dimorphic seeds to light and temperature were compared. Meanwhile, responses of dimorphic seeds and thereafter seedlings of to different concentrations of NaCl and NaSO were also tested. The results showed that the light did not significantly affect germination percentage of brown seeds, but significantly promoted germination of black seeds. Brown seeds could reach high germination percentage over a wide temperature range, however, germination of black seeds gradually increased with the increase of temperature. Brown seeds had higher germination percentage and velocity than black seeds under the same salt conditions. However, black seeds had higher recovery germination than brown seeds when transferred to deionized water. Young seedlings had lower salt tolerance than germinating seeds. At the same concentrations, NaSO had stronger inhibitory effect on seed germination and seedling growth than NaCl. This study comprehensively compared germination traits of dimorphic seeds and seedling growth of , and then developed a conceptual model to explain their adaptation to harsh saline environment.
种子萌发和幼苗建成阶段是盐生环境中一年生植物生命周期中最脆弱的阶段之一。尽管已有种子萌发特性的报道，但对于二型种子的比较萌发模式以及幼苗对不同非生物胁迫的生长情况仍知之甚少。本研究比较了二型种子对光照和温度的萌发响应。同时，还测试了二型种子及其后的幼苗对不同浓度NaCl和Na₂SO₄的响应。结果表明，光照对棕色种子的萌发率没有显著影响，但显著促进了黑色种子的萌发。棕色种子在较宽的温度范围内能达到较高的萌发率，然而，黑色种子的萌发随着温度的升高而逐渐增加。在相同盐条件下，棕色种子的萌发率和萌发速度高于黑色种子。但是，当转移到去离子水中时，黑色种子的恢复萌发率高于棕色种子。幼苗的耐盐性低于萌发种子。在相同浓度下，Na₂SO₄对种子萌发和幼苗生长的抑制作用比NaCl更强。本研究全面比较了二型种子的萌发特性和幼苗生长情况，进而建立了一个概念模型来解释它们对恶劣盐生环境的适应性。
