枸杞高密度遗传图谱构建及产量相关性状QTL定位

Lycium bararum L. (Chinese wolfberry) is an important medicinal and edible plant, enriching polysaccharide, zeaxanthin and other functional ingredient with improved anti-oxidation and anti-aging. Unique and rich nutrition of health care functions by Europe and the United States and other Western countries were recognized. The market consumption increased year by year. Although in recent years, China's wolfberry cultivation and development of the rapid development of the current planting area and production rank first in the world, but because of the complex genetic background of Chinese wolfberry, self-incompatibility, high heterozygosity genomes, yield-related traits mostly multi-gene control quantitative traits and so on, and the genetic research of the quantitative traits of Chinese wolfberry is relatively weak, which is more difficult to cultivate new varieties of high yield Chinese wolfberry. In this study, “double-psendotest crosses " mapping strategy, F1 mapping population generated from a cross between ‘Lycium chinense Mill.var.potaninii’ and ‘Lycium bararum L.var auranticarpum’. SSR marker technique and SLAF technique based on NGS technology were used to determine the mapping genotype. Application of Joinmap4.1 software was used to construct high-density genetic map of Chinese wolfberry. Finally, QTL mapping was used composite interval mapping method to analyze the yield traits such as single fruit weight, fruit length, leaf length and leaf width and other yield-related traits. It will reveal the number and effect of the genes controlling the yield-related traits. Hgh-density genetic map would be helpful for molecular-assisted selection of breeding of wolfberry.

枸杞是我国重要药食同源植物，含有多糖、玉米黄素等功效成分，具有抗氧化、抗衰老等功效，独特而丰富的营养保健功能受到欧美等西方国家认可，市场消费量逐年在增加。虽然近年来，我国枸杞栽培生产发展很快，目前种植面积和产量均居世界第一，但由于枸杞遗传背景复杂，自交不亲和，基因组杂合度高，产量相关性状多数为多基因控制的数量性状等特点，且枸杞数量性状遗传研究比较薄弱，为培育高产枸杞新品种增加了难度。本研究采用“双假测交”作图策略，以表型性状差异大、亲缘关系远的‘北方枸杞’和‘宁夏黄果’为亲本，建立F1作图群体，采用SSR标记技术和基于二代测序技术的SLAF技术测定作图群体基因型，应用Joinmap4.1软件构建枸杞高密度分子遗传图谱，最后运用复合区间作图法对单果重、果实纵径、叶长和叶宽等产量相关性状进行QTL定位。揭示控制产量相关性状的基因数量及效应大小，为枸杞分子辅助选择育种奠定坚实的理论基础。

枸杞是我国重要药食同源植物，含有多糖、玉米黄素等功效成分，但由于枸杞遗传背景复杂，自交不亲和，基因组杂合度高，产量相关性状多数为多基因控制的数量性状等特点，且枸杞数量性状遗传研究比较薄弱，为培育高产枸杞新品种增加了难度。本研项目用“双假测交”作图策略，以表型性状差异大、亲缘关系远的‘北方枸杞’和‘宁夏黄果’为亲本建立F1作图群体，利用SSR和SNP标记构建枸杞的分子遗传连锁图谱。共获得12个连锁群，包含2810个标记位点（40个SSR和2770个SNP），覆盖基因组全长的924.53 cM，标记间平均图距为0.33 cM。每个连锁群的标记数在130~383个，每个连锁群长度为47.35~111.36 cM。采用复合区间作图法扫描双亲整合图谱的12个连锁群，对单果重，果实纵径、果实横径、果柄长度、叶长、叶宽、叶厚和也柄长度等8个产量相关性状QTL分别进行QTL定位。定位结果显示，两年联合分析总共检测到11个主效QTLs，分别分布在LG1、LG2、LG4、LG5、LG7、LG8、LG9和LG10连锁群上。项目执行期间共发表5篇论文；授权国家发明专利1项。项目实施进一步揭示控制产量相关性状的基因数量及效应大小，为开展枸杞分子辅助选择育种奠定坚实的理论基础。.