寄主植物的功能性状对桑寄生寄主专一性的影响初探

Preliminary Studies on Effects of Host Functional Traits on Host Specificity of Mistletoe Species

摘要:

为探讨寄主多样性和寄主功能性状对桑寄生植物的寄主专一性的影响，调查了西双版纳热带植物园内桑寄生和寄主植物种类。结果表明，桑寄生植物共有2科5属6种1变种，感染隶属于58科190属286种寄主植物1 323株。桑寄生在不同生境的寄生强度具有极显著差异（P<0.01），单一种植园的寄生强度最高，而在森林的分布最少。不同种类桑寄生的寄主范围存在较大差异，专一性程度（H'）为1.92~7.05，多度较高的植物更容易被感染。冗余分析表明，寄主植物的胸径、树皮含水量和树皮粗糙度对不同桑寄生的寄主利用差异有显著影响，而木质密度和树皮pH的影响不显著。因此，不同种类桑寄生在热带植物群落的寄主专一性程度有较大差异，对寄主植物特定功能性状的偏好能解释部分差异。

Abstract:

In order to understand the effect of host diversity and functional traits on host specificity of mistletoe, the mistletoe and host species as well as the degree of host specificity of mistletoe in Xishuangbanna Tropical Botanical Garden were investigated. The results showed that there were 1 323 host individuals, belonging to 58 families 190 genera and 286 species, infected by 6 mistletoe species and 1 variety, belonging to 2 families 5 genera. There was significant difference (P<0.01) in infection density among different habitats, which was the highest in monoculture plantation, and the lowest in forest. The degree of host specificity (H') of seven mistletoe species ranged from 1.92 to 7.05. According to redundancy analysis, the DBH, bark water content and bark roughness of host species were significantly correlated with the distribution of mistletoe on host species, whereas wood density and bark pH had not significant correlation. In conclusion, mistletoe species showed great difference in host specificity in tropical plant community, which could partly explained by the preference on specific host functional traits of mistletoe species.