抗风桐(Pisonia grandis)的生态生物学特征

对收集于广西桂林的17份野生毛葡萄种质和24份栽培葡萄种质,分别使用12条ISSR和12条SCoT引物进行了遗传多样性和亲缘关系检测。结果表明：两种分子标记均能产生较丰富的多态性片段,可有效应用于葡萄的遗传多样性检测,但在聚类分析结果上表现出一定的差异性,SCoT分子标记能更好地区分野生种质和栽培品种,说明SCoT分子标记在葡萄遗传多样性检测和系统进化研究上可能更有优势。从SCoT聚类结果上看,广西植物研究所收集的3个野生毛葡萄种质zws1、zws2和zws3相对其它野生种质而言,更偏向于与栽培种质聚为一类,说明这一类野生毛葡萄可能是这些栽培品种的原始亲本来源之一。不同的野生种质聚为多个类群,并表现出明显的地域特性,但遗传距离相对较远,说明桂林野生毛葡萄资源具有丰富的遗传变异。栽培品种没有明显的聚类特点,可能因为所选用的栽培品种的地域代表性并不是很强,也可能是因为栽培品种在不断的人工杂交选育过程中,遗传背景趋向一致,遗传多样性降低。该研究证明SCoT分子标记在葡萄遗传多样性研究上具有一定的优势。该研究结果为桂林毛葡萄资源的保护、利用和品种选育提供了理论依据,也为葡萄的系统进化研究提供了参考。

Ecological and biological characteristics of Pisonia grandis

As a predominant and fast growth species in the Xisha Islands, Pisonia grandis (Nyctaginaceae)with important ecological, medicinal and ornamental values plays an important role in wind prevention and sand-fixation. In this study, we examined the morphological and physiological characteristics, nutrient composition of P. grandis growing on Yongxing Island, Xisha Islands. The results showed that P. grandis was a heliophyte, which was characterized with large leaf thickness, small specific leaf area, well developed palisade tissue and sparse intercellular spaces in pongy tissue. Because of these characteristics, P. grandis could obtain light energy and water effectively. The high activities of superoxide dismutase and catalase, the high content of proline, while the low content of malondialdehyde indicated that P. grandis had drought resistance. In addition, the content of nutrient elements were high for plant leaves but low for rhizosphere soil, suggesting that P. grandis was able to use nutrient elements of rhizosphere soil effectively and had strong tolerance to barren soil. P. grandis was a fast growing plant, and had good adaptability to different environments. Water and mineral nutrition should be added to improve its growth in cultivation. In a word, P. grandis can adapt to the environmental stress, such as strong light, drought and infertility. Therefore, P. grandis can be used as an important tree species of vegetation restoration in tropical coral island.