半红树植物黄槿的生态生物学特性研究

Ecological and biological characteristics of Hibiscus tiliaceus， a mangrove associate in China

关键词:  黄槿  生态及生物学特性  开发利用

Key words:  Hibiscus tiliaceus  ecological and biological characteristics  exploitation and utilization

摘要:

黄槿是一种具有重要生态、药用和观赏价值的半红树植物，在海岸生态系统中发挥重要作用。对其生态及生物学特性进行研究表明：黄槿属典型阳生性植物，具有较高的光合潜能，适于在热带亚热带地区光照充足的环境中生长。其叶绿素荧光的光合电子传递速率-光响应曲线（RLC）显示，黄槿的相对电子传递速率（rETR）随光合有效辐射（PAR）的升高而逐渐增加，并在PAR 2 751 μmol•m 2•s 1时达到最大值，说明其光合系统II在强光照下也能保持较高的电子传递效率。黄槿叶绿素荧光参数显示其具有较高的能量利用效率，叶绿素a/b值（2.44∶1）略低于理论值（3∶1）。黄槿对营养元素的利用率较高，植株体内N、P、K、Ca、Na、Mg的加权平均养分含量分别为1.23%、0.23%、1.34%、0.42%、0.24%、0.41%。P含量偏低，在其栽培过程中应及时补充P元素。该研究结果将对黄槿的引种、栽培及开发利用提供重要的理论依据。

Abstract:

Hibiscus tiliaceus is a mangrove associate species with high medicinal，ecological and ornamental values and plays an important role in coastal ecosystem. The study on the ecological and biological characteristics of H.tiliaceus showed that it was a typical heliophyte with high photosynthetic capacity and preferred to grow under sunny condition in tropical and subtropical regions. The chlorophyll fluorescence rapid light response curves of H.tiliaceus showed that relative electron transport rate(rETR)increased with elevated photosynthetically active radiation(PAR)and reached its maximum value at 2 751 μmol•m 2•s 1，indicating that its photosystem Ⅱ maintained relatively high electron transport rate in high radiation condition. Measurement of chlorophyll fluorescence parameters showed that it had a relatively high level of energy use efficiency. The chlorophyll a/b ratio(2.44∶1) was slightly lower than theoretic value(3∶1). H.tiliaceus had a high level of nutrient utilization efficiency. The weighted nutrient concentrations of N，P，K，Ca，Na and Mg in H.tiliaceus were 1.23%，0.23%，1.34%，0.42%，0.24% and 0.41%，respectively. The concentration of phosphorus(P)in the plant was relatively low，so it should be added in cultivation. The results from the current study would be very useful for introduction，cultivation，exploitation and utilization of H.tiliaceus.