中国农业科学 ›› 2016, Vol. 49 ›› Issue (16): 3073-3083.doi: 10.3864/j.issn.0578-1752.2016.16.002

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

油菜开花期QTL定位及与粒重的遗传关联性

黄吉祥1,熊化鑫1,2,潘 兵1,3,倪西源1,张晓玉1,赵坚义1   

  1. 1浙江省农业科学院作物与核技术利用研究所/植物有害生物防控国家重点实验室省部共建培育基地,杭州 310021
    2浙江师范大学化学与生命科学学院,浙江金华 321000
    3浙江大学农业与生物技术学院,杭州 310058
  • 收稿日期:2016-02-25 出版日期:2016-08-16 发布日期:2016-08-16
  • 通讯作者: 赵坚义,Tel:0571-86403406;E-mail:2208086097@qq.com
  • 作者简介:黄吉祥,Tel:0571-86403406;E-mail:838107@163.com。熊化鑫,Tel:0571-86403406;E-mail:huaxinxiong_11@163.com。黄吉祥和熊化鑫为同等贡献作者。
  • 基金资助:
    国家重点基础研究发展计划(973计划)(2015CB150200)、七大农作物育种专项(JFYS2016ZY03002156)、浙江省旱粮创新团队项目(2011R50026-7)

Mapping QTL of Flowering Time and Their Genetic Relationships with Seed Weight in Brassica napus

HUANG Ji-xiang1, XIONG Hua-xin1,2, PAN Bing1,3, NI Xi-yuan1, ZHANG Xiao-yu1, ZHAO Jian-yi1   

  1. 1Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences/State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021
    2College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321000, Zhejiang
    3College of Agriculture & Biotechnology, Zhejiang University, Hangzhou 310058
  • Received:2016-02-25 Online:2016-08-16 Published:2016-08-16

摘要: 【目的】明确中国和欧洲油菜开花期主控位点及其对粒重的影响,为早熟油菜品种选育提供科学依据。【方法】以欧洲冬油菜Sollux和中国品种高油605的选系(Gaoyou)杂交F1经小孢子培养产生的DH群体为材料,采用7年9种环境下的开花期表型数据和新版SG图谱定位开花期QTL,并采用条件遗传学和QTL分析相结合的条件QTL定位方法,解析开花期对千粒重QTL的影响,最后对各20个极端开花期株系的基因型和表现型进行性状-标记的符合度测定,为标记筛选用于辅助选育提供依据。【结果】应用WinQTLCart 2.5复合区间作图法,共检测到7个在3种以上环境中稳定表达的控制开花QTL,加性效应值在0.58—3.85 d,解释了表型总变异的84%。8对上位性QTL效应总和为加性总效应的41.8%。QTL与环境互作效应只在少数位点和个别环境中显著。在3个主效QTL峰值或相近位置上定位了4个在拟南芥中调控开花的关键基因FT、API、FLC和FY的6个同源拷贝,为发掘控制这些QTL的候选基因提供了有价值的参考信息。条件QTL分析表明,在4个增重效应均来自Gaoyou的千粒重QTL位点(qSWA2、qSWA3、qSWA4和qSWC2),大粒等位基因效应可能与开花早、籽粒灌浆期长有关。通过选择这些位点的早开花标记基因型有望同时提高种子千粒重,这也部分给出了开花期与千粒重之间极显著负相关的遗传解释,但2个粒重主效位点(qSWA7和qSWC8)的遗传效应不受开花期影响。根据SG群体极端开花期株系在3个效应值最大的QTL(qFTA2、qFTC2和qFTC6)区域标记基因型和开花期表现型的关联分析,筛选获得6个高质量、高吻合度的共显性标记推荐育种应用。qFTA2位点,标记辅助准确率为70%-80%;qFTC2和qFTC6位点的选择效率达到80%-100%。基因型组配分析显示,聚合qFTA2、qFTC2和qFTC6的早开花等位基因,可显著提早开花期,同步增加千粒重但不影响含油量和角果粒数。【结论】7个QTL均显示早开花等位基因来自中国亲本。拟南芥中调控开花关键基因FT、API、FLC和FY的6个同源拷贝定位到3个主效QTL峰值位置。开花迟、早显著影响4个千粒重QTL位点,但2个最重要的粒重位点(qSWA7和qSWC8)不受影响;3个主效QTL(qFTA2、qFTC2和qFTC6)的6个共显性标记可用于早熟基因的转育和早熟材料的筛选。

关键词: 甘蓝型油菜, QTL定位, 开花期, 千粒重, 条件QTL定位

Abstract: 【Objective】The present research aimed to explore the major QTL controlling the flowering time in European and Chinese rapeseed materials, to analyze the genetic influence of flowering time on QTL for 1000-seeds weight, and thus to provide available information for breeding purpose.【Method】The doubled haploid (DH) Sollux/Gaoyou population with 282 lines was used. The data set of flowering time was obtained from nine environments and over seven years. QTL identification of flowering time was performed using WinQTLCart 2.5. The candidate genes underlining QTLs were screened out by transcriptome analysis using RNA-Seq and alignment between QTL regions and Arabidopsis. Further, conditional QTL estimation was adopted to dissect the genetic relationships between flowering time and seed weight. Finally, using selected DH lines with extreme phenotypes of flowering time, an association evaluation between marker genotypes and phenotypes of flowering time was performed. 【Result】 Seven major QTLs were detected, which showing significant at least in three environments. Their additive effects ranged from 0.58-3.85 days and together accounted for around 84% of the phenotypic variation in population. The sum of eight pairs of epistatic loci (additive × additive) accounted for 41.8% of the total additive effects. QTL by environmental interactions were significant only in few environments with small amount of genetic effects. Four critical orthologous genes of Arabidopsis thaliana for flowering time were mapped in the peak positions of three most significant QTL regions (qFTA2, qFTC2, and qFTC6). It provides valuable information to anchor candidate genes underling QTL. The conditional QTL analysis revealed large impact of flowering time on seed weight in four QTLs (qSWA2, qSWA3, qSWA4, and qSWC2). This partly explained the significant negative correlation between flowering time and 1000-seed weight. While the most important two (qSWA7 and qSWC8) showed independent without being interfered. Six markers linked with three major QTLs showed good fitness between marker genotypes and trait phenotypes (70%-100%), indicating their potentials for breeding purpose. The results demonstrated that the combination of early flowering alleles from qFTA2, qFTC2 and qFTC6 by marker assistant selection of ZAAS548, DNAPL, ZAAS619sa, ZAAS616s, ZAAS846a and C6SGFLO-22 induced not only early flowering but also significantly increased 1000-seed weight, while the oil content and seeds per silique between two extreme flowering time groups showed almost the same.【Conclusion】All seven QTLs of flowering time showed Chinese parent Gaoyou induced early flowering. Four important candidate genes homologous to Arabidopsis controlling flowering time (FT, FLC, AP1, and FY) were physically aligned and mapped underlining the peak positions of the three major QTL qFTA2, qFTC2 and qFTC6. The results indicated that the four loci corresponding to seed weight were genetically influenced by flowering time, however, the most important two (qSWA7 and qSWC8) were independent. Six markers linked to the 3 major QTL were of potentials in the practical breeding program.

Key words: Brassica napus L., QTL mapping, flowering time, 1000-seeds weight, conditional QTL mapping