Mapping Fall Dormancy and Winter Injury in Tetraploid Alfalfa
Mapping Fall Dormancy and Winter Injury in Tetraploid Alfalfa
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DOI：
10.2135/cropsci2014.12.0834
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发表时间：
2015-09-01
期刊：
影响因子：
2.3
通讯作者：
Brummer, E. Charles
中科院分区：
文献类型：
--
作者：
Li, Xuehui;Alarcon-Zuniga, Baldomero;Brummer, E. Charles
苜蓿（Medicago sativa L.）是广泛种植的多年生饲料作物。苜蓿秋眠性一般与冬害呈负相关。为了了解这两个性状的遗传基础，我们使用四倍体苜蓿F-1群体鉴定了控制秋季生长和冬季伤害的数量性状位点（QTL）。总共从78个限制性片段长度多态性（RFLP）、123个简单重复序列（SSR）和48个单核苷酸多态性（SNP）标记中获得了601个标记等位基因。分别为每个亲本构建连锁图谱。两个图谱都包含8个连锁群，WISFAL-6的长度为898 cM，ABI 408的长度为845 cM。利用区间作图，我们确定了15个QTL的跨环境分析和71个QTL的个人环境中的秋季植物高度，冬季伤害，和秋季拍摄，冠，根生物量在四个爱荷华州的环境。在这71个QTL中，有42个QTL位于18个染色体位置，这些位置是在多个环境中为同一性状确定的。结果表明，在地上部干重、冠幅干重和主根干重等性状上均发现了可能的多效QTL，部分解释了这些性状间的遗传相关性。但是，很少有QTL同时与秋株高和冬害相关，支持了本研究中两个性状之间不存在遗传相关的观察结果。这些结果表明，这两个性状可以独立操纵，并可能有效地提高使用标记辅助选择。由于本研究中确定的大多数QTL被定位到至少10 cM的区间，因此需要在其他群体中进行验证和定位，以促进标记辅助选择的应用。
Alfalfa (Medicago sativa L.) is a widely planted perennial forage crop. Fall dormancy is generally negatively correlated with winter injury in alfalfa. To understand the genetic basis of the two traits, we identified quantitative trait loci (QTL) controlling autumn growth and winter injury using a tetraploid alfalfa F-1 population. In total, 601 marker alleles were scored from 78 restriction fragment length polymorphism (RFLP), 123 simple-sequence repeat (SSR), and 48 single nucleotide polymorphism (SNP) markers. Linkage maps were constructed for each parent separately. Both maps contained eight linkage groups (LGs), with a length of 898 cM for WISFAL-6 and 845 cM for ABI408. Using interval mapping, we identified 15 QTL from an across-environment analysis and 71 QTL within individual environments for autumn plant height; winter injury; and autumn shoot, crown, and root biomass across four Iowa environments. Of the 71 QTL, 42 were identified at 18 chromosomal locations that were identified in multiple environments for the same trait. Possible pleiotropic QTL that contributed to dry weight of shoot, crown, and taproot were found, which partially explained the observed genetic correlations between those traits. However, few QTL were related to both autumn plant height and winter injury, supporting the observation of no genetic correlation between the two traits in this study. These results indicated that the two traits could be manipulated independently and, possibly, efficiently improved using marker-assisted selection. Because most QTL identified in this study were mapped to intervals of at least 10 cM, validation and localization in additional populations is needed to facilitate application of marker-assisted selection.