Molecular and morphological evaluation of doubled-haploid lines in maize. 2. Comparison with single-seed-descent lines
Molecular and morphological evaluation of doubled-haploid lines in maize. 2. Comparison with single-seed-descent lines
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DOI：
10.1007/bf00223777
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发表时间：
1993-10
影响因子：
5.4
通讯作者：
A. Murigneux;S. Baud;M. Beckert
中科院分区：
文献类型：
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作者：
A. Murigneux;S. Baud;M. Beckert
对玉米双单倍体（DH）和单粒系（SSD）进行了定量遗传性状和RFLP标记的比较。农业形态性状分布的比较不能对两种生殖系统的相似性得出明确的结论。我们使用了100多个RFLP标记来提供亲本等位基因频率和重组分数的精确描述。两个DH群体的比较表明，非随机减数分裂重配受两亲本花药培养能力差异的影响。对于由杂交DH5 × DH7衍生的DH系，在花药培养中涉及两个响应系，分离扭曲（P< 0.05）影响不到20%的基因组，每个亲本的偏差占一半。由A188 × DH7杂交而来的DH系，其中A188为无反应系，显示出两倍以上的扭曲水平，并且在几乎所有扭曲位点上都发现了过量的DH7等位基因。对于大多数基因组，两个DH群体之间的重组分数是均匀的。用同一杂交A188 x DH7的DH和SSD系计算的基因组大小也相似，这表明在花药培养过程中没有发生对重组配子的选择。5次减数分裂（SSD）后观察到的重组分数平均是1次减数分裂（DH）后的2倍。对于大于20%的重组分数，没有观察到差异。尽管在分子水平上对材料进行了精确的描述，但对于某些形态特征的差异是否是分离比和/或重组频率差异的结果，还不能得出明确的结论。然而，农业形态评价显示两种类型的品系之间的差异范围很窄，这表明在育种计划中使用DH品系是可能的。
Doubled-haploid (DH) and single-seed-descent (SSD) lines in maize have been compared for quantitatively inherited traits and for RFLP markers. The comparisons of the distributions for agromorphological traits do not allow definite conclusions to be drawn on the similarity of the two reproductive systems. We have used more than 100 RFLP markers to provide a precise description of the parental allele frequency and the recombination fractions. A comparison of two DH populations shows that non-random meiotic reassortment is influenced by differences in the anther culture capacities of the two parental lines. For the DH lines derived from the cross DH5 x DH7, involving two responsive lines in anther culture, the distortion in segregation (P< 0.05) affected less than 20% of the genome with half of the deviations towards each parent. DH lines derived from the cross A188 x DH7, where A188 is a non-responsive line, showed more than twice this level of distortion and an excess of DH7 alleles was found for almost all of the skewed loci. The recombination fractions were homogeneous between the two DH populations for most of the genome. The genome sizes calculated with the DH and the SSD lines derived from the same cross, A188 x DH7, were also similar, which suggests that no selection against recombinant gametes occurs during anther culture. The observed recombination fraction after five meioses (SSD) is on average twice as large as after one meiosis (DH). No difference is observed for recombination fractions greater than 20%. Despite a precise description of the material at the molecular level, it has not been possible to make a definite conclusion as to whether or not the differences in some morphological characters are the consequences of differences in the segregation ratio and/or the recombination frequency. However, the agromorphological evaluation shows a narrow range in differences between the two types of lines and suggests that the use of DH lines is possible in breeding programmes.