马铃薯重要性状QTL定位及3个抗病性状分子标记辅助选育

马铃薯是我国主要粮食作物之一,马铃薯分子育种研究具有重要意义。在二倍体马铃薯中,重要性状控制基因的QTL定位及克隆已经有大量报道。近年,随着同源四倍体分析软件的开发,四倍体马铃薯的遗传图谱构建和QTL定位也取得了突破性进展。分子标记是马铃薯育种的重要辅助手段,可快速准确筛选出多个优良性状。对马铃薯重要农艺性状的QTL定位和克隆,以及3个抗病性状分子标记辅助选育的研究进展进行概述,为加快马铃薯分子育种研究提供参考和实践依据。     

美洲黑杨×小叶杨杂交F1代驻芽时间QTL定位分析

生长和休眠是多年生植物生命周期中两个重要的生物过程,研究休眠相关的性状对认识林木生长适应性以及提高植物分子育种效率具有重要意义。为了揭示杨树驻芽的遗传机制,本研究以美洲黑杨(Populus deltoides)和小叶杨(Populus simonii)杂交的F_1代群体为实验材料,基于该群体已构建的高密度遗传图谱,利用MapQTL软件中的KW方法对驻芽时间进行了QTL定位。结果在7个连锁群上共检测到15个与杨树驻芽时间相关的QTL,其中12个QTL位于美洲黑杨连锁群LG-1、LG-7、LG-9、LG-11和LG-15,而其他3个QTL位于小叶杨连锁群LG-9和LG-12。结合检测到的QTL在毛果杨(P. trichocarpa)基因组上的位置,共筛选出45个与杨树驻芽相关的候选基因。进一步对这些基因进行GO富集分析和KEGG代谢途径分析,揭示了71%的候选基因在光信号传导和植物激素信号传导中具有潜在的功能。本研究结果为杨树驻芽时间相关基因的挖掘以及相关的基因应用于分子标记辅助育种提供了重要的参考依据。     

马铃薯块茎形状CAPS标记的开发与验证

马铃薯块茎形状(薯形)是选育马铃薯品种尤其是加工品种最重要的性状之一。前人研究表明薯形是由位于第10染色体的单基因Ro控制的,并且圆形对长形为显性。本研究以二倍体马铃薯长薯形基因型10618-01和圆薯形基因型320-02及其213个F₁代薯形分离群体为材料,基于马铃薯基因组相关序列信息结合分离群体分组分析法开发标记,获得了一个CAPS标记1137-CAPSVI。利用该标记对53份不同薯形的四倍体马铃薯高代品系进行验证,结果表明该标记的选择准确率达83.02%,进一步的Pearson双侧相关分析显示其相关性达极显著水平,且该标记对圆薯形材料的选择准确率更高,达91.42%。该CAPS标记的获得对于四倍体马铃薯分子标记辅助育种,加速马铃薯品种尤其是加工专用型品种的选育具有重要意义。     

马铃薯块茎形状基因CAPS标记的开发与验证

马铃薯块茎形状(薯形)是选育马铃薯品种尤其是加工品种最重要的性状之一。前人研究表明薯形是由位于第10染色体的单基因Ro控制的,并且圆形对长形为显性。本研究以二倍体马铃薯长薯形基因型10618-01和圆薯形基因型320-02及其213个F1代薯形分离群体为材料,基于马铃薯基因组相关序列信息结合分离群体分组分析法开发标记,获得了一个CAPS标记1137-CAPSVI。利用该标记对53份不同薯形的四倍体马铃薯高代品系进行验证,结果表明该标记的选择准确率达83.02%,进一步的Pearson双侧相关分析显示其相关性达极显著水平,且该标记对圆薯形材料的选择准确率更高,达91.42%。该CAPS标记的获得对于四倍体马铃薯分子标记辅助育种,加速马铃薯品种尤其是加工专用型品种的选育具有重要意义。     

四倍体马铃薯块茎蛋白含量分子标记的开发与验证

块茎蛋白含量是马铃薯的重要品质性状之一, 相关分子标记的开发研究较少。本研究以马铃薯高蛋白品种大西洋、低蛋白品种定薯1号及包含173份子代的蛋白含量分离群体为材料, 通过高通量简化基因组测序技术与集群分离分析(BSA)相结合, 开发了SCAR8-107标记, 并以此标记对分离群体的74份高蛋白、42份低蛋白子代及54个四倍体马铃薯品种验证表明, SCAR8-107标记在后代分离群体和四倍体马铃薯品种中的检测结果与表型蛋白含量的对应度分别达到了90.51%和72.97%, 经过Pearson’s双侧相关性分析, 相关性均达到了极显著水平。SCAR8-107的开发对于四倍体马铃薯块茎蛋白含量标记辅助选择与加速马铃薯品质育种具有重要意义。     

环境与植物激素对马铃薯块茎休眠与萌发的影响研究

马铃薯是重要的经济作物,其块茎休眠期的长短一定程度上影响马铃薯的经济效益,而芽的萌发则是打破休眠的标志。目前,由于马铃薯块茎休眠及芽萌发机制尚不明确,严重阻碍马铃薯的种薯生产以及块茎的加工利用。因此,研究马铃薯块茎休眠和芽的萌发机制具有重要的经济价值。综述了植物激素和环境因素对马铃薯块茎休眠及芽萌发的影响,以期为马铃薯的贮藏保鲜和加工利用等提供参考。     

马铃薯淀粉含量相关SSR分子标记的开发及候选基因的初步确定

淀粉含量是衡量马铃薯品质的重要性状之一,本试验以高淀粉四倍体马铃薯野生种‘YSP-4’与低淀粉四倍体马铃薯品系‘MIN-021’杂交获得的F2代分离群体为材料,基于BSA分析技术,开发了2个与马铃薯淀粉含量紧密连锁的SSR分子标记SSR-152和SSR-174,并对其进行单标记分析验证。本研究对这2个标记片段进行了回收、纯化、测序及blastn序列比对发现,与基因XM＿006348370.1的同源性分别为96.63%和98.04%,该基因可能与马铃薯淀粉合成相关基因Patatin和耐旱基因有关,通过调控糖的合成与代谢,进而影响淀粉含量的积累,初步确定为候选基因。这2个标记为马铃薯淀粉相关候选基因的筛选、克隆以及开展分子标记辅助育种等研究奠定了基础。     

影响四倍体马铃薯块茎中糖生物碱含量的上位性互作的鉴定

糖生物碱是一种次生代谢产物，其特点是味道不好，大量食用有毒。应该对马铃薯块茎中的糖生物碱含量进行选择，且DNA标记可以显著促进这一过程。本试验旨在研究马铃薯块茎中糖生物碱总含量（TGA）的遗传控制以及DNA标记。从TGA含量趋异的四倍体马铃薯无性系构建分离群体，该群体有一个高TGA含量的亲本LT7和一个低TGA含量的亲本NT8。我们应用342个ISSR单引物或者是这种引物组合以及36个CAPS引物对，用不同限制性酶进行降解，     

6-BA处理对马铃薯内源激素含量及StTCP15基因表达的影响

TCP基因家族是参与调控植物内源激素的重要转录因子,马铃薯中StTCP15基因受到细胞分裂素、ABA和GA3的诱导表达,并在块茎休眠打破过程中StTCP15基因表达量变化显著。为探究外源6-BA对马铃薯块茎休眠时间、内源激素含量变化及StTCP15基因表达模式的影响,以马铃薯栽培品种‘鄂薯10号’块茎为试验材料,用液相色谱-质谱(LC-MS/MS)和实时荧光定量PCR (RT-qPCR)技术分别测定了10 mg/L6-BA处理下马铃薯块茎内源GA3、ABA、6-BA、IAA的含量及StTCP15基因表达量变化。结果表明外源6-BA处理与对照相比提前1周打破块茎休眠,块茎内源激素含量短时间与对照差异显著,随着时间延长差异减小;在块茎休眠阶段随着贮藏时间的延长处理组与对照组块茎内源激素ABA、GA3和IAA含量升高,6-BA含量下降;休眠打破后ABA和IAA含量降低,GA3和6-BA含量升高;发芽期间4种内源激素含量均升高。RT-qPCR分析结果表明6-BA处理及对照块茎休眠期间StTCP15基因表达量持续升高,休眠解除后表达量下降。StTCP15基因可能参与ABA信号通路,并在马铃薯休眠...     

马铃薯StNCED1基因过表达载体的构建及其遗传转化

马铃薯块茎的休眠和发芽对于块茎生产和加工极为重要,延长块茎休眠期有助于降低块茎水分和养分的消耗,从而提高其应用价值。本研究用PCR方法从马铃薯中克隆了9-顺式-环氧类胡萝卜素双氧合酶(NCED)编码基因St NCED1,并构建了马铃薯块茎特异表达启动子CIPP驱动的St NCED1基因的植物过表达载体p BIC-St NCED1,然后通过根癌农杆菌介导法转化马铃薯栽培品种"陇薯3号"获得转化植株,经卡那霉素抗性筛选得到5株抗性苗,PCR检测证明St NCED1基因已整合到马铃薯的基因组中。qRT-PCR检测表明St NCED1基因在转基因植株试管薯中的表达量分别比未转基因的对照增加2.10~8.09倍。该研究有助于培育块茎休眠期延长的马铃薯新种质。     

Tagging quantitative trait loci for dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in diploid potato originated from six Solanum species

Potato breeding aims at breeding diversified cultivars not only suitable for different purposes, but also resistant to diseases, such as late blight caused by Phytophthora infestans , which is a major constraint in potato production. Resistance to P. infestans has been previously introduced into the diploid hybrid population 98-21 from Solanum verrucosum and Solanum microdontum . In the present study, we assessed the segregation of tuber dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in this population. Quantitative Trait Loci (QTLs) affecting these important quality traits were tagged using the genetic map developed for this population to locate QTLs for late blight resistance. The most prominent QTL for dormancy was detected on chromosome II and explained 7.1% of the variance. The most important QTLs for tuber eye depth, flesh colour, shape and shape regularity were identified on chromosomes X ( R ² = 14.7%), IV ( R ² = 5.8%), II ( R ² = 8.0%) and III ( R ² = 10.4%) respectively. All traits were also affected by minor QTLs. The obtained results improve our understanding of the inheritance of traits relevant for variety development in potato.     

In vitro screening and QTL analysis for drought tolerance in diploid potato

Drought stress is a major abiotic constraint limiting crop production worldwide. Screening for drought tolerance and the traits that enhance drought tolerance is not straightforward in large mapping populations. In this study, we investigated the possibility of screening a mapping population in vitro for PEG-induced water deficit stress and recovery potential. We have measured several shoot and root growth parameters or traits in the C × E diploid potato mapping population. Significant variation was observed for genotype-specific responses to water deficit and recovery potential. Genetic variation and heritability estimates were high to very high for the measured traits depending on growth conditions. In order to identify potato QTLs for drought tolerance and recovery potential an SNP marker-rich integrated linkage map was used. A total of 23 QTLs were detected under control, stress and recovery treatments explaining 10.3–22.4% of the variance for each phenotypic trait. Among these, 10 QTLs were located on chromosome 2. Three QTLs involved in the important trait root to shoot ratio were identified on linkage groups 2, 3 and 8. These loci explained together 41.1% of the variance for this trait, and may be breeding targets for stress tolerance and yield in the field as well. The SNP markers derived from EST sequences underlying these QTLs led to the identification of putative candidate genes for further study in potato. This study constitutes the first knowledge of in vitro screening of a mapping population for drought tolerance in potato.     

甘蓝型油菜产量及相关性状的QTL分析

高产是甘蓝型油菜育种的重要目标之一，产量是多基因控制的数量性状。本文通过QTL作图分析了产量及其相关性状的数量性状位点，以甘蓝型油菜中油821和保604 F₁代小孢子培养获得的DH系为作图群体，构建了由20个连锁群组成的，包括251个分子标记( 2个RFLP标记，72个RAPD标记，91个SSR标记，86个SRAP标记)的遗传连锁图(10个标记没有分配到连锁群中)。图谱的平均图距为6.96 cM，共覆盖油菜基因组1 746.5 cM。在此图谱基础上采取复合区间作图法，检测到与油菜产量及其相关性状有关的QTL共17个。其中控制株高的3个分别位于第4、第9和第10连锁群上，对性状的解释率为9.42%～17.58%；与分枝部位有关的4个分别位于第4、第6和第7连锁群上，其中Bp1 和Bp2 均位于第4连锁群，对性状的解释率为8.13%～15.20%；与主花序有效长有关的3个分别位于第4、第10和第16连锁群上，对性状的解释率为7.49%～23.36%；与一次有效分枝有关的2个分别位于第1、第4连锁群上，对性状的解释率为15.29%～19.58%；与角果总数和千粒重有关的分别位于第4连锁群和第9连锁群上，贡献率分别为17.42%和7.64%；与单株产量有关的3个分别位于第3、第4和第15连锁群，共解释26.60%的表型变异。部分性状的QTL在连锁群上成簇分布,对性状贡献率很大，表现主效QTLs的特点，相应的性状之间也呈显著相关，这表明一因多效或者相关的QTLs之间紧密连锁是性状相关的遗传基础。本研究中与主效QTLs连锁的标记可用于油菜产量性状的分子标记辅助选择。     

不同环境基于高密度遗传图谱的稻米外观品质QTL定位

为解析稻米外观品质遗传基础, 挖掘稳定存在的控制稻米外观品质性状的QTL, 本研究以籼稻品种V20B和爪哇稻品种CPSLO17作为亲本, 构建包含150个重组自交家系(recombinantion inbred line, RIL)的RIL作图群体, 进行外观品质性状QTL定位分析。利用特定位点扩增长度测序(SLAF-seq)技术, 构建了一个由12个连锁群包含8602个标记, 平均间距为0.29 cM的高密度遗传图谱。采用IciMapping 4.0软件的ICIM-ADD方法在3种环境(贵阳、贵定、三亚)对4个外观品质性状(粒长、粒宽、垩白度和垩白粒率)进行QTL (quantitative trait locus)定位分析。结果表明: 3种环境共检测到9个粒长QTL、6个粒宽QTL、3个垩白度QTL和4个垩白粒率QTL; 有5个QTL在多个环境被重复检测到, 其中3种环境都定位到的粒宽QTL qGW5-1和垩白度QTL qCha5-1为同一定位区间(第5染色体的Marker1642127-Marker1514505); 此外, 垩白度QTL qCha5-2的定位区间(Marker1554573-Marker1554589)和垩白粒率QTL qCGP5-2也是一样的。序列比对发现QTL qCha5-1定位区间仅51.5 kb, 是新的垩白性状主效QTL。本研究结果不仅为挖掘新的外观品质性状基因奠定基础, 也有助于开发新的分子标记进行水稻外观品质性状遗传改良。     

Comparative analysis of Australian and Canadian barleys for seed dormancy and malting quality

The association between high malting quality and pre-harvest sprouting (PHS) susceptibility is a key challenge when developing new malting barley varieties. A new malting barley variety Baudin has successfully combined high malting quality and PHS tolerance. A doubled haploid population was developed for mapping PHS tolerance and seed dormancy from a cross of Baudin?×?AC Metcalfe using 233 molecular markers. Three QTLs were mapped for seed dormancy based on the standard germination test at 24, 48 and 72?h. One major QTL was mapped to the long arm of chromosome 5H controlling seed dormancy and PHS tolerance from Baudin. Two other minor QTLs were identified from Baudin on chromosomes 3 and 7H. QTL/QTL interaction was detected for seed dormancy between chromosomes 3 and 5H. The PHS tolerance allele of the 5H QTL from Baudin contributes to higher malt yield without significant impact on diastatic power, beta-glucan content and wort viscosity. QTL from Baudin provide new sources to integrate PHS tolerance and high malting quality.     

Identification of drought responsive QTLs during vegetative growth stage of rice using a saturated GBS-based SNP linkage map

Drought is a major abiotic constraint for rice production worldwide. The quantitative trait loci (QTLs) for drought tolerance traits identified in earlier studies have large confidence intervals due to low density linkage maps. Further, these studies largely focused on the above ground traits. Therefore, this study aims to identify QTLs for root and shoot traits at the vegetative growth stage using a genotyping by sequencing (GBS) based saturated SNP linkage map. A recombinant inbred line (RIL) population from a cross between Cocodrie and N-22 was evaluated for eight morphological traits under drought stress. Drought was imposed to plants grown in 75 cm long plastic pots at the vegetative growth stage. Using a saturated SNP linkage map, 14 additive QTLs were identified for root length, shoot length, fresh root mass, fresh shoot mass, number of tillers, dry root mass, dry shoot mass, and root-shoot ratio. Majority of the drought responsive QTLs were located on chromosome 1. The expression of QTLs varied under stress and irrigated condition. Shoot length QTLs qSL1.38 and qSL1.11 were congruent to dry shoot mass QTL qDSM1.38 and dry root mass QTL qDRM1.11, respectively. Analysis of genes present within QTL confidence intervals revealed many potential candidate genes such as laccase, Calvin cycle protein, serine threonine protein kinase, heat shock protein, and WRKY protein. Another important gene, Brevis radix, present in the root length QTL region, was known to modulate root growth through cell proliferation and elongation. The candidate genes and the QTL information will be helpful for marker-assisted pyramiding to improve drought tolerance in rice.     

A limited set of starch related genes explain several interrelated traits in potato

To understand the molecular basis of potato starch related traits and the underlying starch biosynthesis and degradation, a Quantitative Trait Locus (QTL) analysis in combination with a candidate gene approach was performed. The diploid mapping population C × E, consisting of 249 individuals, was assayed over two consecutive years, for chipping colour, cold induced sweetening, starch content, starch granule size, starch gelling temperature, starch enthalpy, amylose content and degree of starch phosphorylation. QTLs were observed for all traits, except enthalpy on eight out of the twelve potato chromosomes. Several QTLs were found to be consistent over 2 years. Clustering of co-localizing QTLs was observed on some chromosomes, indicating common genetic factors for the different traits. On chromosome 2, Soluble Starch Synthase 2 mapped on the same position as QTLs for starch phosphorylation, starch gelling temperature and amylose content. α-glucan, water dikinase co-localizes on chromosome 5 together with QTLs for starch phosphorylation and cold induced sweetening. Furthermore, the genes coding for two phosphorylases (StPho1a and StPho2) coincide with QTLs for starch gelling temperature, chipping colour and starch granule size on chromosome 2 and a QTL for starch phosphorylation on chromosome 9, respectively. The results suggest allelic variation acting on the genetics of the different traits.