Abstract:
Commelina erecta is a successful weed species. The aims of this study were to analyse the morpho-anatomy of the fruit and dimorphic seeds of the weed C. erecta, the dynamics and type of dormancy, and water entry. Flowers and fruits at different development stages were processed using standard anatomical techniques. Besides, experiments of imbibition, germinability and water entry were performed on both seed types. In the fruit of C. erecta, free and coated seeds are developed within dehiscent and indehiscent carpels, respectively. Dehiscent carpels open through a region of mechanical weakness in the dorsal vascular bundle. This region does not form in the indehiscent carpel. The main anatomical differences between the two seed types were observed in the testa and in the number of covering layers. Imbibition experiments showed that the covering of both seed types is water permeable, so these seeds lack physical dormancy and may exhibit physiological dormancy. Germinability experiments showed that the dormancy in free seeds is variable throughout the reproductive season, whereas, in coated seeds, it is high throughout the reproductive season. The embryotega is an area where the hardness of the seed coat is interrupted and facilitates water entry. Differences in the morpho-anatomy of carpels result in the formation of dimorphic seeds with different covering layers and different germination properties. These different properties allow some seeds germinate immediately after falling from the mother plant, and others to be incorporated into the seed bank. These results are useful for designing weed management strategies in agroecosystems.
摘要:
Commelinaeripta是一种成功的杂草物种。这项研究的目的是分析杂草C.erecta的果实和二态种子的形态解剖学,休眠的动态和类型,水进入。使用标准解剖技术加工不同发育阶段的花和果实。此外,吸胀实验,在两种种子类型上都进行了发芽和水进入。在C.erecta的果实中,自由和包衣的种子在开裂和不裂的心皮中发育,分别。开裂的心皮通过背侧维管束中的机械薄弱区域打开。该区域不会在不裂的心皮中形成。在种皮和覆盖层的数量中观察到了两种种子类型之间的主要解剖学差异。吸胀实验表明,两种种子类型的覆盖都是透水的,因此,这些种子缺乏物理休眠,可能表现出生理休眠。发芽性实验表明,在整个生殖季节中,自由种子休眠是可变的。然而,在包衣种子中,在整个生殖季节都很高。胚胎是种皮硬度中断并促进水进入的区域。心皮形态解剖结构的差异导致形成具有不同覆盖层和不同发芽特性的双态种子。这些不同的特性使一些种子在从母株落下后立即发芽,和其他将被纳入种子银行。这些结果对于设计农业生态系统中的杂草管理策略很有用。