Responses of propagule germination and sexual reproduction of submerged macrophytes exposed to cadmium
Responses of propagule germination and sexual reproduction of submerged macrophytes exposed to cadmium
复制标题
沉水植物繁殖体萌发和有性生殖对镉的响应
DOI：
10.1016/j.chemosphere.2018.12.056
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发表时间：
2019
期刊：
影响因子：
8.8
通讯作者：
Li Wei
中科院分区：
文献类型：
--
作者：
Cao Yu;Liu Hui;Sun Junyao;Liu Yang;Jiang Hong Sheng;Wang Wei;Li Wei
沉水植物被认为是浅水湖泊的主要初级生产者。最近，由于环境影响的增加，重金属负荷过大。相对于营养生长方面的研究，重金属对植物繁殖体萌发和繁殖的影响研究较少。通过3个试验研究了镉对沉水植物繁殖体萌发和有性繁殖的影响。在实验I中，使用6种Cd浓度（0、0.05、0.5、1、2.5和5 mg L-1），发现Cd处理对种子萌发的影响很小。在实验II中，镉暴露（5天）在6个镉浓度进行15，30，60，90，和120天之前，指定的发芽日期为洋葱/块茎。刺苦草种子在Cd浓度≥ 2.5 mg L− 1时不能萌发，而眼子菜种子在Cd浓度≥ 2.5 mg L−1时萌发率较低。在实验Ⅲ中，随着Cd浓度从0增加到0.5 mg L-1，水莲和刺叶水莲的果实重量减少，而水莲的果实数量增加，刺叶水莲的果实数量没有增加。总之，镉暴露会影响沉水植物无性繁殖体的萌发和有性繁殖，种子对高达5 mg L-1的镉处理具有耐受性。
Submerged macrophytes are considered the main primary producers in shallow lakes. Recently, they have experienced a decline due to increasing environmental impacts, e.g., excessive heavy metal loads. Compared to extensive studies on vegetative growth, reports on effects of heavy metals on propagule germination and reproduction remain scarce. In this study, three experiments were conducted to investigate the effects of cadmium (Cd) on the propagule germination and sexual reproduction of submerged macrophytes. In Experiment I, six Cd concentrations were used (0, 0.05, 0.5, 1, 2.5, and 5 mg L−1), with seed germination found to be marginally affected by Cd treatment. In Experiment II, Cd exposure (5 d) at the six Cd concentrations was performed 15, 30, 60, 90, and 120 d prior to the designated germination date for turions/tubers. TheVallisneria spinulosatubers did not germinate at ≥ 2.5 mg Cd L−1when exposed to Cd 90 and 120 d prior to germination, whereas thePotamogeton crispusturions remained viable but with a low germination rate at ≥ 2.5 mg Cd L−1. In Experiment III, with an increase from 0 to 0.5 Cd mg L−1, the fruit weight ofOttelia alismoidesandV. spinulosadecreased, whereas the fruit number increased forO. alismoidesbut not forV. spinulosa.Furthermore, the phenology of sexual reproduction for both species advanced under Cd exposure. In summary, Cd exposure affected the germination of asexual propagules and sexual reproduction of submerged macrophytes, with seeds found to be tolerant of Cd treatment up to 5 mg L−1.