Clonal diversity in the rare Calamagrostis porteri ssp. insperata (Poaceae):: comparative results for allozymes and random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) markers
Clonal diversity in the rare Calamagrostis porteri ssp. insperata (Poaceae):: comparative results for allozymes and random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) markers
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DOI：
10.1046/j.1365-294x.1999.00585.x
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发表时间：
1999-03-01
影响因子：
4.9
通讯作者：
Wolfe, AD
中科院分区：
文献类型：
--
作者：
Esselman, EJ;Jianqiang, L;Wolfe, AD
本文报道了稀有、高度克隆的禾本科植物-小叶章Calamagrostis porteri ssp.利用等位酶和随机扩增多态性DNA（RAPD）和简单重复序列（ISSR）两种PCR标记，对10个供试材料进行了分析。在15个等位酶位点中，只有1个位点发生变异，检测到2个等位基因，均在2个群体中发现，而在另外2个群体中只检测到1种基因型。与等位酶相比，ISSR和RAPD标记在居群内检测到更多的基因型。在所研究的四个种群中，有三个种群的ISSR标记比RAPD标记检测到了更多的多样性。在一个群体中，没有发现RAPD多样性，而在10个植株中发现了8个不同的基因型。这种多样性是存在的，尽管罕见的开花，没有记录的自然种群中发生的种子集和非常低的种子集与实验授粉，所有这些都表明，有性生殖很少发生。该亚种是自交亲和的，但种子发生在自花艾德胚珠低，而且，有高胚败育，无论花粉来源。RAPD和ISSR引物检测到的变异可能反映了过去较高水平的有性生殖，现存种群中非常罕见的有性生殖，体细胞突变，或三者的组合。虽然基于PCR的标记确定人口内的几个多位点基因型，它是不知道这些是否都代表不同的基因产生的有性生殖或体细胞突变的结果在老，多年生和高度克隆的植物。
Four populations of the rare, highly clonal grass Calamagrostis porteri ssp. insperata were examined using allozymes and the two polymerase chain reaction (PCR)-based markers, random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) bands. Only one of the 15 allozyme loci was variable and two alleles were detected, both of which were found in two populations, while only one genotype was detected in the other two populations. ISSR and RAPD markers detected more genotypes within populations than did allozymes. ISSR markers detected more diversity than RAPD markers in three of the four populations examined. In one population, no RAPD diversity was found whereas eight different genotypes were found among the 10 plants with ISSR markers. This diversity is present despite rare flowering, no documented occurrence of seed set in natural populations and very low seed set with experimental pollinations, all of which suggest that sexual reproduction rarely occurs. The subspecies is self-compatible, but seed initiation is lower in self ed ovules; also, there is high embryo abortion regardless of pollen source. Variation detected by RAPD and ISSR primers may reflect higher levels of sexual reproduction in the past, very rare sexual reproduction in extant populations, somatic mutations, or a combination of the three. Although the PCR-based markers identify several multilocus genotypes within populations, it is not known whether these all represent distinct genets generated by sexual reproduction or result from somatic mutations in the old, perennial and highly clonal plants.