湖北钉螺数量性状研究Ⅲ种群间形态性状变异及其空间相关分析

Study on morphologic quantitative characteristics of Oncomelania hupensis Ⅲ. Morphologic variations and their spatial correlation among snail populations

目的 探讨湖北钉螺种群间形态性状变异及其空间相关性。方法采集10个省的27个现场螺点的钉螺种群标本，分别测量螺壳的形态学指标及钉螺采集点之间的地理距离，分析钉螺种群间形态性状变异及其与地理距离的相关性。结果20个指名亚种（包括1个广西钉螺种群）钉螺种群间欧氏距离的中位数为3．24（95％CI：2．88～3．81）；不包括广西钉螺种群时，中位数为3．15（95％CI：2．86～3．76）。6个滇川亚种钉螺种群间欧氏距离的中位数为1．69（95％CI：1．33～2．27）。无论指名亚种是否包括广西钉螺种群，滇川亚种钉螺种群间的欧氏距离均明显低于指名亚种种群（P〈0．05）。16个肋壳钉螺种群间欧氏距离的中位数为2．86（95％CI：2．56～3．23）；11个光壳钉螺种群间欧氏距离的中位数为2．24（95％CI：2．00～2．43），明显低于肋壳钉螺种群间的欧氏距离（P〈0．05）。27个钉螺种群间形态性状变异与其地理距离存在明显的正相关（P〈0．01），相关系数（r）为0．2791；这种显著的相关性在指名亚种和肋壳钉螺种群中仍然存在（P〈0．01），但在滇川亚种和光壳钉螺种群中却未发现（P〉0．05）。指名亚种包括广西钉螺种群时r为0．2655（P〈0．01），不包括时r为0．2567（P〈0．01），肋壳钉螺种群的r为0．3121（P〈0．01）。结论 湖北钉螺指名亚种种群间的形态性状变异大于滇川亚种，肋壳钉螺种群间的形态性状变异大于光壳钉螺。我国大陆分布的肋壳钉螺种群间的表型变异具有明显的空间结构。

Objective To explore morphologic variations and their spatial correlation among Oncomelania hupensis populations from the mainland of China. Methods Twenty-seven snail populations from ten provinces were collected. The morphologic indices of shells and geographic distances between the snail spots were measured respectively, and the morphologic variations among snail populations and the correlations between morphologic variations and geographical distances were analyzed. Results The median of Euclidean distances was 3.24 （950/00 CI： 2.88-3.81） among 20 snail populations of O. h. hupensis including a snail population from Guangxi Province, and was 3.15 （95% C1： 2.86-3.76） excluding the Guangxi snail population; the median was 1.69 （950/00 CI： 1.33 -- 2.27） among 6 populations of O. h. robertsoni. Whether including a snail population from Guangxi Province or not, the median among O. h. robertsoni was less than that among O. h. hupensis （P〈0. 05）. The medians among 16 ribbed-shell and 11 smooth-shell snail populations were 2.86 （95%0 CI： 2.56-3.23） and 2.24 （95%0 CI： 2.00-2.43） respectively, and the median among ribbed-shell populations was bigger than that among smooth-shell populations （P〈0. 05）. There was a significant correlation between morphologic variation and geographic distance among 27 snailpopulations （P〈0. 01） and the correlation coefficient was 0. 279 1. The significant correlations also were found among O. h. hupensis and ribbed-shell populations, but not found among O. h. robertsoni and smooth-shell populations （P〉0. 05）. The correlation coefficient was 0. 265 5 for O. h. hupensis including a snail population from Guangxi Province, 0. 256 7 not including it; and was 0. 312 1 for ribbed-shell population. Conelusions Morphologic variation among O. h. hupensis is bigger than that among O. h. robertsoni, and morphologic variation among ribbed-shell populations is bigger than that among smooth-shell populations. There is significant spatial structure among ribbed-shell snail populations of Oncornelania hupensis distributed in the mainland of China.