甘肃贝母种子水提取液对小白菜的化感效应

为进一步探明甘肃贝母种子后熟脱休眠机理,本研究对其种子不同后熟阶段水提取液不同质量浓度下小白菜种子的生物活性进行测定。结果表明,甘肃贝母种子水提取液对小白菜种子萌发及生长具有明显影响,影响程度随其所处后熟阶段的不同而异。在形态后熟阶段,与对照相比,水提取液浓度为2.5 mg·mL^-1时,对小白菜种子发芽率和发芽势均有促进作用,但随着水提取液浓度的提高,小白菜种子萌发和幼苗生长均表现明显的化感抑制效应,化感效应指数RI值逐渐降低,当水提取液浓度为40 mg·mL^-1时,化感抑制效应达到显著水平(P<0.05)。在生理后熟阶段表现出不同的化感效应,各处理组小白菜种子的发芽率均低于对照,但随着水提取液浓度的提高,化感效应呈现先增大后减小的趋势,当水提取液浓度为5 mg·mL^-1时,小白菜苗高、根直径与单苗鲜重均较对照显著提高(P<0.05)。综上表明,甘肃贝母种子内源化感抑制物质在后熟不同阶段具有明显差异,从形态后熟转入生理后熟后,种子内源化感抑制物明显减少。本研究结果为进一步探究甘肃贝母种子中内源抑制物质的种类特性及生产实践中打破其种子休眠提供了科学依据和理论支撑。

Allelopathic Effect of Aqueous Extracts of Fritillaria przewalskii Maxim. Seeds on Brassica chinensis

In order to further explore the mechanism of after-ripening dormancy-release of Fritillaria przewalskii Maxim. seeds, the biological activity of Brassica campestris ssp. chinensis seeds was determined at different concentrations of the aqueous extracts and different after-ripening stages of F. przewalskii. The results showed that the aqueous extracts of F. przewalskii had obvious effects on the seed germination and growth of B. chinensis, and some differences were found between the two stages. At the morphologic after-ripening stage, compared with the control, the germination ratio and germination energy of B. chinensis were promoted when the concentration of aqueous extracts was 2.5 mg·mL^-1. Howerer, with the increase of concentration of aqueous extracts, the B. chinensis seeds showed significant allelopathic inhibition effect on germination and seeding growth, and the response index (RI value) decreased gradually. When the concentration was 40 mg·mL^-1, the allelopathic inhibition effect reached a significant level (P<0.05). In the stage of physiological after-ripening, the opposite allelopathic effect was observed. Although the germination ratio of B. chinensis seeds in each treatment was lower than that of the control, the allelopathic effect increased first and then decreased with the increase of the concentration of aqueous extracts. And when the concentration was 5 mg·mL^-1, the seedling height, root diameter and fresh weight per plant of the B. chinensis were significantly higher than the control(P<0.05). In summary, the endogenous allelopathic inhibitors of F. przewalskii seeds showed significant differences in different stages of after-ripening, which decreased significantly from morphological after-ripening to physiological after-ripening. The results of this study provide a scientific basis and theoretical support for further exploration of the species characteristics of endogenous inhibitors in F. przewalskii seedlings and the breaking of seed dormancy in production practice.