Correlation between distyly and ploidy level in Damnacanthus (Rubiaceae)
Correlation between distyly and ploidy level in Damnacanthus (Rubiaceae)
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DOI：
10.3732/ajb.91.5.664
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发表时间：
2004-05-01
影响因子：
3
通讯作者：
Nagamasu, H
中科院分区：
文献类型：
--
作者：
Naiki, A;Nagamasu, H
对小豆花科9种5变种14个类群的661个个体进行了体细胞染色体的检测。首次报道了13个分类群的染色体数目。二倍体（2n = 22）和四倍体（2n = 44）计数。本文首次报道了4种昆虫的分布情况，分别为angustifolius、d.h enryi、d.l abordei和d.p officinarum。染色体数目与糖尿病的发生有很强的相关性。在不同的分类群中，二花群为二倍体，单态群为四倍体。观察到的单形种群的花有长花柱和短雄蕊，很少有例外。多倍体化可能导致二瓣花分裂为单形花。在籼稻中，来自四倍体群体的叶片往往比来自二倍体群体的叶片大。四倍体籼稻居群比二倍体籼稻居群在北方分布更广。在日本发现了三种同域分布类型：二倍体和四倍体，两个二倍体和两个四倍体。在现有染色体数目研究的基础上，对籼稻品种分类进行修订。
Somatic chromosomes were observed in 661 individuals of 14 taxa, nine species and five varieties, of Damnacanthus (Rubiaceae). Chromosome numbers are reported for the first time for 13 taxa. Diploid (2n = 22) and tetraploid (2n = 44) counts were obtained. Distyly is reported for the first time for four species, D. angustifolius, D. henryi, D. labordei, and D. officinarum. A strong correlation exists between chromosome number and occurrence of distyly. Regardless of taxa in Damnacanthus, distylous populations are diploid, and monomorphic populations are tetraploid. Flowers of the monomorphic populations observed have a long style and short stamens with few exceptions. Polyploidization may have caused the breakdown of distylous to monomorphic flowers. In D. indicus, leaves from the tetraploid populations tend to be larger than those from the diploid populations. Populations of tetraploid D. indicus were distributed in more northern areas than those of the diploid. Three types of sympatric distribution were found for the varieties of D. indicus in Japan: diploid and tetraploid, two diploids, and two tetraploids. Based on the present chromosome number study, the taxonomy of the varieties of D. indicus should be revised.