三种湿地濒危水韭叶片对干旱胁迫的生理响应

The Physiological Response of Leaves of Three Kinds of Endangered Isoetes under Drought Stress

为进一步研究水韭濒危原因,选择中华水韭(Isoetes sinensis)、东方水韭(Isoetes orientalis)和云贵水韭(Isoetes yunguiensis),将3种水韭栽种于盆中,使其健壮植株自然失水,比较在不同干旱条件下叶片的多项生理指标变化。结果表明,3种水韭生理指标的变化趋势基本相同,相对电导率和渗透调节物质含量都上升,净光合速率和叶绿素含量都下降,保护酶含量先上升后下降;3种濒危水韭的抗干旱能力最强的是中华水韭,其次为东方水韭,最弱的为云贵水韭;3种水韭都能通过调节自身生理代谢,在一定程度上抵抗干旱胁迫造成的伤害。短期的干旱不是中国水韭濒危的主要原因。

Isoetes is highly endangered in China, but the reason has yet to be found. This paper first reports the relationships between soil drought stress and the endangering statuses of Isoetes because of which also exsits terrestrial drought-tolerant species. In this study, the robust plants of Isoetes sinensis, Isoetes orientalis and Isoetes yunguiensis are in potted experiment under natural dehydration conditions, and compared to some physiological indexes in different of drought stress conditions. The results indicated that all the three kinds of quillworts showed same trends of physiological responses to dehydration, which include increases of electric conductivity, osmoregulation, decreases of photosynthetic rate, chlorophull content, and the first rising and then falling trend for protective enzymes. All the three quillworts showed the drought resistant ability to survive the dehydration by adjusting their metabolism, while Isoetes sinensis had the strongest ability, and Isoetes orientalis the next. Considering the habitat status, this study indicates that the short-term drought should not be treated as the main cause for the endangering status of quillworts in China.