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作 者 ：郭水良,陈国奇,毛俐慧

期 刊 ：生态学报 2008年 28卷 8期 页码：3698~3705

关键词：中国；被子植物；DNA C-值；入侵性；杂草；统计；

Keywords:angiosperm, DNA C-value, invasiveness, weed, statistic,

摘 要 ：统计了中国境内有分布的539种被子植物的DNA C-值，分析了它们在不同分类群、生活型、倍性、生活史类型以及在杂草和非杂草类群中的分布情况，主要结果如下：（1）539种被子植物DNA C-值平均为4.06 pg，其中木本植物的DNA C-值平均为1.84 pg，低于草本植物的平均值（5.02 pg）；（2）双子叶植物（360种）的DNA C-值平均为2.20 pg，极明显地小于单子叶植物（179种）的平均值（7.80 pg）；（3）1年生植物的DNA C-值平均为2.78 pg, 明显小于多年植物的平均DNA C-值（6.65 pg）；（4）134种杂草的DNA C-值平均为1.93 pg，明显小于非杂草草本植物的平均值（6.75 pg），含杂草较多的科，平均DNA C-值相对较小；（5）统计的47种入侵杂草的DNA C-值平均为1.76 pg, 略小于134种杂草的平均DNA C-值（1.93 pg），极显著地小于非杂草性草本植物（6.75 pg）；（6）以科为单位，不同科的DNA C-值存在着极大的差异；（7) DNA C-值与染色体倍性的关系并不明显，但是，随着倍性的增加，基因组变小；（8) 在同一科、属中，与非杂草相比，典型杂草的DNA C-值往往偏小；（9）总体上杂草或杂草性强的植物，它们的DNA C-值比非杂草性植物的要小。但是，也还存在一些例外，例如野燕麦（Avena fatua）的DNA Ｃ-值就高达14.15 pg，而相反，十字花科和葫芦科的一些非杂草栽培植物，却具有很低的DNA Ｃ-值。结论：DNA C-值在预测外来物种的入侵性方面具有一定的应用价值,但是,由于在木本植物和草本植物之间、单子叶与双子叶植物之间、一年生和多年生植物之间，特别是在不同的科之间，植物的DNA C-值较明显的差异，因此，根据DNA C-值预测外来物种的入侵性，应该严格地限于同一科（或属）内的相关物种间的比较。

Abstract:Using nuclear DNA C-values for 539 angiosperms in China, we examined the variation of these values among growth forms and taxonomic groups and the relationship of these values with invasiveness. Mean DNA C-value of the 539 angiosperm species was 4.06 pg. Mean DNA C-value was (1) significantly lower for woody species (1.84 pg) than for herbaceous species (5.02 pg); (2) significantly lower for 360 dicots (2.20 pg) than for 179 monocots (7.80 pg); (3) significantly lower for annuals (2.78 pg) than for perennials (6.65 pg); (4) significantly lower for 134 weed species (193 pg) than for herbaceous non-weeds (6.75 pg) and for several families that have an unusually high proportion of weed species; (5) significantly lower for 47 exotic weed species (1.76 pg) than for 134 native weeds (1.93 pg), but significantly lower than that of “non-weedy” herbaceous species (6.75 pg); (6) lower for weeds than for “non-weedy” species in same genus or family; and (7) in herbaceous species, generally lower for weedy compared to “non-weedy” species, with some exceptions such as Avena fatua, whose DNA C-value is as high as 14.15 pg, contrarily, and some “non-weedy” herbaceous species in Cruciferae and Cucurbitaceae with very low values. DNA C-values varied much greatly among families. The relationship between DNA C-value and ploidy is not clear, whereas the mean DNA per basic genome decreased with increases in inploidy. Conclusion: DNA C-value is of practical value in the forecast of the invasiveness of exotic species. However, such predictions must be made with comparisons within families (or genus) because the DNA C-values vary greatly between woody and herbaceous species, between monocots and dicots, between annuals and perennials, and especially among families.

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