Zhang Jian, Yuan Huwei, Yang Qingshan, Li Min, Wang Ying, Li Yujuan, Ma Xiangjian, Tan Feng, Wu Rongling
Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Jiangsu Riverine Institute of Agricultural Sciences, Nantong, Jiangsu 226541, China.
Hortic Res. 2017 Jun 14;4:17024. doi: 10.1038/hortres.2017.24. eCollection 2017.
Willow () is one of the most important ornamental tree species in landscape plants. One species, , is widely used as a shade tree and border tree because of its soft branches and plump crown. Some varieties of were salt tolerant and could grow normally in coastal regions. However, the molecular mechanisms of salt tolerance for have been less clear. Here, we addressed this issue by performing a mapping experiment containing 195 intraspecific F progeny of , derived from salt-sensitive 'yanjiang' and salt-tolerant '9901', grown by cuttings in a 100 mM NaCl solution. Growth performance of these progeny under salt stress was investigated, displaying marked genotypic variability with the coefficients of variance of 28.64-86.11% in shoot and root growth traits. We further mapped specific QTLs contributing to these differences to the genome. Of the 204 QTLs identified, a few were detected to explain a remarkably larger portion of the phenotypic variation than many others. Many detected QTLs were found to reside in the region of candidate genes of known biological function. The discovery of growth QTLs expressed under salt stress provides important information for marker-assisted breeding of salt tolerant varieties and founds the basis for the application of in coastal afforestation.
柳树（）是园林植物中最重要的观赏树种之一。其中一个品种，因其枝条柔软、树冠丰满，被广泛用作遮荫树和边界树。该品种的一些变种具有耐盐性，能够在沿海地区正常生长。然而，柳树耐盐的分子机制尚不清楚。在此，我们通过进行一项作图实验来解决这个问题，该实验包含195个柳树种内F子代，它们源自盐敏感型‘沿江’和耐盐型‘9901’，通过扦插在100 mM NaCl溶液中培养。研究了这些子代在盐胁迫下的生长表现，其在地上部和根部生长性状上表现出显著的基因型变异，变异系数为28.64 - 86.11%。我们进一步将导致这些差异的特定数量性状位点（QTL）定位到柳树基因组上。在鉴定出的204个QTL中，有几个被检测到比许多其他QTL解释了显著更大比例的表型变异。许多检测到的QTL位于已知生物学功能的候选基因区域。在盐胁迫下表达的生长QTL的发现为耐盐柳树品种的分子标记辅助育种提供了重要信息，并为柳树在沿海造林中的应用奠定了基础。
