Inheritance of parthenogenesis in Poa pratensis L.:: auxin test and AFLP linkage analyses support monogenic control
Inheritance of parthenogenesis in Poa pratensis L.:: auxin test and AFLP linkage analyses support monogenic control
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DOI：
10.1007/s001220050868
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发表时间：
1998-07-01
影响因子：
5.4
通讯作者：
Falcinelli, M
中科院分区：
文献类型：
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作者：
Barcaccia, G;Mazzucato, A;Falcinelli, M
研究了肯塔基州早熟禾（Poaplatensis L.）涉及来自无孢子胚囊的未减数卵子的孤雌发育。试图将无融合生殖性状转移到自然的性障碍之外，需要进一步阐明其遗传。用有性无性系与无融合生殖基因型进行控制杂交，通过生长素试验确定（多）二倍体杂种的孤雌生殖能力，再用RAPD和AFLP标记进行混合分离分析，确定与无融合生殖方式有关的遗传连锁群。这种方法使我们能够检测到一个AFLP标记位于6.6 cM的基因，puplant控制孤雌生殖和15.4 cM的基因组窗口周围的目标位点。利用与孤雌生殖基因座共分离的附加RAPD和AFLP标记构建了携带感兴趣基因的草地早熟禾染色体区域的图谱。孤雌生殖和一些AFLP标记，也似乎属于一个紧密连锁块之间的高度显着的连锁加强了这一特性的单基因遗传的假设。如果假设为单基因，则草地早熟禾的无融合生殖多倍体类型对于赋予孤雌生殖的显性等位基因来说是单一的，并且这种遗传模型将进一步得到来自有性×无融合生殖交配的（多）二倍体后代中表现出的孤雌生殖程度的双峰分布的支持。对草地早熟禾无融合生殖的分子标记是实现标记辅助育种和图位克隆策略的重要一步，其目的是研究和操纵其繁殖方式。
Gametophytic apomixis in Kentucky bluegrass (Poa platensis L.) involves the parthenogenetic development of unreduced eggs from aposporic embryo sacs. Attempts to transfer the apomictic trait beyond natural sexual barriers require further elucidation of its inheritance. Controlled crosses were made between sexual clones and apomictic genotypes, and the parthenogenetic capacity of (poly)diploid hybrids was ascertained by the auxin test, A bulked segregant analysis with RAPD and AFLP markers was then used to identify a genetic linkage group related to the apomictic mode of reproduction. This approach enabled us to detect both an AFLP marker located 6.6 cM from the gene that putatively controls parthenogenesis and a 15.4-cM genomic window surrounding the target locus. A map of the P. pratensis chromosome region carrying the gene of interest was constructed using additional RAPD and AFLP markers that co-segregated with the parthenogenesis locus. Highly significant linkage between parthenogenesis and a number of AFLP markers that also appeared to belong to a tight linkage block strengthens the hypothesis of monogenic inheritance of this trait. If a single gene is assumed, apomictic polyploid types of P. pratensis would be simplex for a dominant allele that confers parthenogenesis, and this genetic model would be further supported by the bimodal distribution of the degree of parthenogenesis exhibited in the (poly)diploid progenies from sexual x apomictic matings. The molecular tagging of apomixis in P, pratensis is an essential step towards marker-assisted breeding and map-based cloning strategies aimed at investigating and manipulating its mode of reproduction.