Soto-Cerda Braulio J, Duguid Scott, Booker Helen, Rowland Gordon, Diederichsen Axel, Cloutier Sylvie
Department of Plant Science, University of Manitoba, 66 Dafoe Road, Winnipeg, MB, R3T 2N2, Canada.
Theor Appl Genet. 2014 Apr;127(4):881-96. doi: 10.1007/s00122-014-2264-4. Epub 2014 Jan 26.
The identification of stable QTL for seed quality traits by association mapping of a diverse panel of linseed accessions establishes the foundation for assisted breeding and future fine mapping in linseed. Linseed oil is valued for its food and non-food applications. Modifying its oil content and fatty acid (FA) profiles to meet market needs in a timely manner requires clear understanding of their quantitative trait loci (QTL) architectures, which have received little attention to date. Association mapping is an efficient approach to identify QTL in germplasm collections. In this study, we explored the quantitative nature of seed quality traits including oil content (OIL), palmitic acid, stearic acid, oleic acid, linoleic acid (LIO) linolenic acid (LIN) and iodine value in a flax core collection of 390 accessions assayed with 460 microsatellite markers. The core collection was grown in a modified augmented design at two locations over 3 years and phenotypic data for all seven traits were obtained from all six environments. Significant phenotypic diversity and moderate to high heritability for each trait (0.73-0.99) were observed. Most of the candidate QTL were stable as revealed by multivariate analyses. Nine candidate QTL were identified, varying from one for OIL to three for LIO and LIN. Candidate QTL for LIO and LIN co-localized with QTL previously identified in bi-parental populations and some mapped nearby genes known to be involved in the FA biosynthesis pathway. Fifty-eight percent of the QTL alleles were absent (private) in the Canadian cultivars suggesting that the core collection possesses QTL alleles potentially useful to improve seed quality traits. The candidate QTL identified herein will establish the foundation for future marker-assisted breeding in linseed.
通过对不同亚麻籽种质资源进行关联分析来鉴定种子品质性状的稳定QTL，为亚麻籽的辅助育种和未来的精细定位奠定了基础。亚麻籽油因其食品和非食品应用而受到重视。及时改变其油含量和脂肪酸（FA）组成以满足市场需求，需要清楚了解其数量性状位点（QTL）结构，而目前这方面受到的关注较少。关联分析是在种质资源库中鉴定QTL的有效方法。在本研究中，我们利用460个微卫星标记对390份亚麻核心种质进行分析，探究了包括油含量（OIL）、棕榈酸、硬脂酸、油酸、亚油酸（LIO）、亚麻酸（LIN）和碘值在内的种子品质性状的数量特征。核心种质在改良的增广设计下于两个地点种植了3年，并从所有六个环境中获得了所有七个性状的表型数据。观察到每个性状都有显著的表型多样性和中等到高的遗传力（0.73 - 0.99）。多变量分析显示，大多数候选QTL是稳定的。共鉴定出9个候选QTL，从油含量的1个到亚油酸和亚麻酸的3个不等。亚油酸和亚麻酸的候选QTL与先前在双亲群体中鉴定的QTL共定位，并且一些位于已知参与FA生物合成途径的附近基因处。58%的QTL等位基因在加拿大品种中不存在（私有），这表明核心种质拥有可能有助于改善种子品质性状的QTL等位基因。本文鉴定的候选QTL将为亚麻籽未来的标记辅助育种奠定基础。
