Morphological and molecular evidences for DNA introgression in haploid induction via a high oil inducer CAUHOI in maize
Morphological and molecular evidences for DNA introgression in haploid induction via a high oil inducer CAUHOI in maize
复制标题
通过高油诱导剂 CAUHOI 在玉米中单倍体诱导中 DNA 渗入的形态学和分子证据
DOI：
10.1007/s00425-009-0943-1
复制
发表时间：
2009-07-01
期刊：
影响因子：
4.3
通讯作者：
Chen, Shaojiang
中科院分区：
文献类型：
--
作者：
Li, Liang;Xu, Xiaowei;Chen, Shaojiang
玉米的母本单倍体诱导现象在多年前就被首次描述，但其潜在的机制仍然不清楚。本研究以玉米自交系Stock-6的高含油量单倍体诱导系ZHHOI为授粉材料，从低含油量玉米杂交种ZD 958中获得母本单倍体。R1-nj是显性标记基因R1-nj的纯合子。通过形态学和细胞学研究鉴定了单倍体。该杂交组合的单倍体诱导率为2.21%。出乎意料的是，许多单倍体籽粒在胚上具有弱着色的紫色，并且一些单倍体籽粒具有高KOC。SSR分析表明，43.18%的单倍体携带有来自于中国大豆的片段，并且有一小部分（平均1.84%）的中国大豆基因组渗入到单倍体中。高KOC的单倍体籽粒中，来自水稻的片段渐渗频率（2.92%）高于低KOC的单倍体籽粒（1.79%），表明水稻的标记基因R1-nj和高油基因在部分单倍体胚发育过程中表达，并证实诱导亲本的DNA渐渗发生在母本单倍体诱导过程中。这些结果表明，染色体消除可能是玉米单倍体诱导的原因，并且可能发生晚期体细胞消除。讨论了单倍体形成的几种可能机制。
The phenomenon of maternal haploid induction in maize was first described many years ago, but the underlying mechanism is still unclear. In this study, the Stock-6-derived, haploid-inducing line CAUHOI with high kernel oil content (KOC), was used as the pollinator to produce maternal haploids from the maize hybrid ZD958 with low KOC. CAUHOI is homozygous for the dominant marker geneR1-nj. Haploids were identified by morphological and cytological investigations. The frequency of haploid induction from this cross was 2.21%. Unexpectedly, many haploid kernels had weakly pigmented purple color on the embryo, and some haploid kernels had high KOC. Simple sequence repeat (SSR) analysis showed that 43.18% of the haploids carried segments from CAUHOI, and a small proportion (average 1.84%) of the genome of CAUHOI was introgressed into haploids. Haploid kernels with high KOC had a higher frequency of segment introgression from CAUHOI (2.92%) than that in haploid kernels with low KOC (1.79%), showing that the marker geneR1-njand high-oil genes from CAUHOI were expressed during the development of some haploid embryos, and confirmed that the DNA introgression from the inducer parent occurred during maternal haploid induction. Together, these results suggested that the chromosome elimination was probably responsible for haploid induction in maize, and late somatic elimination might occur. Several possible mechanisms underlying haploid formation are discussed.