A rise of ploidy level induces the expression of apomixis in Paspalum notatum
A rise of ploidy level induces the expression of apomixis in Paspalum notatum
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DOI：
10.1007/s004970100070
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发表时间：
2001-05-01
影响因子：
--
通讯作者：
Bovo, OA
中科院分区：
文献类型：
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作者：
Quarin, CL;Espinoza, F;Bovo, OA
百喜草（Paspalumnotatum）的常见小种为四倍体（2n=4x=40），通过无孢子无融合生殖繁殖。百喜草三白草是相应的二倍体（2n=2x=20）有性种族，由于自交不亲和而进行杂交。用秋水仙素处理自然二倍体群体中的三个单株，诱导染色体加倍。胚胎学研究表明，其中一株同源四倍体植株进行了有性繁殖。另外两个同源四倍体为兼性无融合生殖。这些结果表明，在二倍体水平上存在一个未表达的无融合生殖基因。该性状的表达是倍性依赖的。倍性依赖性既可以通过某些转录因子作用于控制无融合生殖的基因座，也可以通过需要较高等位基因剂量的次级基因座影响主基因座的表达。
The common races of bahiagrass, Paspalum notatum, are tetraploid (2n=4x=40) and reproduce by aposporous apomixis. Paspalum notatum var. saurae is the corresponding diploid (2n=2x=20) sexual race that outbreeds due to self-incompatibility. Chromosome doubling was induced by colchicine treatments in three individual plants from a natural diploid population. Embryological studies demonstrated that one of the induced autotetraploid plants reproduced sexually. The other two autotetraploids were facultative apomicts. These results indicate that an unexpressed gene(s) for apomixis exists at the diploid level. The expression of the trait is ploidy-dependent. The ploidy dependency may act either on the locus controlling apomixis through some transcription factors or via a secondary locus which requires a higher allele dosage to affect the expression of the main locus.