小麦纹枯病抗性QTL遗传分析

以Niavt14和徐州25杂交的重组自交系遗传群体为材料,研究小麦纹枯病抗性QTL。通过3年表型数据分析,结合构建的重组自交系遗传图谱,共检测到3个与纹枯病抗性相关的QTL。其中,染色体2B上检测到2个,分别是Qses.jaas-2b1、Qses.jaas-2b2。Qses.jaas-2b1在连续2年田间接种鉴定中可解释5.46%和8.56%的表型变异,Qses.jaas-2b2在连续3年的田间纹枯病接种鉴定中可解释6.04%、8.10%、12.92%的表型变异。在染色体7D上检测到1个抗性QTL:Qses.jaas-7d,最高可解释11.25%的表型变异。说明与纹枯病抗性相关的QTLs有可能存在于小麦染色体2B和7D连锁群上。     

Mapping QTLs Affecting Economic Traits on BTA3 in Chinese Holstein with Microsatellite Markers

It had been demonstrated that the strong and highly significant quantitative trait locus（QTL） can affect protein percentage on Bos Taurus Autosome 3（BTA3） at the position 52 cM, near the microsatellite DIK4353, with the 95% confidence interval spanning from 25 to 57 cM in Chinese Holstein population using QTL-express, MQREML, and GRIDQTL softwares. This study herein focused on such region of fine mapping QTLs for milk production and functional traits with 16 microsatellite markers with coverage of 33 cM between the markers BMS2904 and MB099 on BTA3 in a daughter-designed Chinese Holstein population. A total of 1 298 Holstein cows and 7 sires were genotyped for 16 microsatellites with ABI 3700 DNA sequencer. The variance components QTL linkage analysis（LA） and linkage-disequilibrium（LD） analysis（LA/LD） was performed to map QTLs for 7 traits, i.e., 305-d milk yield, fat yield, protein yield, fat percentage, protein percentage, somatic cell score and persistency of milk yield. Four strong and highly significant QTLs were detected for fat yield, fat percentage, protein percentage and somatic cell score at the position 40, 30, 27 and 26 cM, respectively. Two minor QTLs for milk yield and persistency of milk yield were identified at 42 and 46 cM, respectively. These findings provided a general idea for the fine mapping of the causal mutation for milk production and functional traits on BTA3 in the future.     

Assessment of QoI resistance in Plasmopara viticola oospores

QoI fungicides, inhibitors of mitochondrial respiration at the Qo site of cytochrome b in the mitochondrial bc(1) enzyme complex, are commonly applied in vineyards against Plasmopara viticola (Berk. & MA Curtis) Berl. & De Toni. Numerous treatments per year with QoI fungicides can lead to the selection of resistant strains in the pathogen population owing to the very specific and efficient mode of action. In order to evaluate the resistance risk and its development, two different methods, biological and molecular, were applied to measure the sensitivity of oospores differentiated in vineyards, both treated and untreated with azoxystrobin, from 2000 to 2004. Assays using oospores have the advantage of analysing the sensitivity of bulked samples randomly collected in vineyards, describing accurately the status of resistance at the end of the grapevine growing season. Both methods correlated well in describing the resistance situation in vineyards. QoI resistance was not observed in one vineyard never treated with QoI fungicides. In the vineyard where azoxystrobin had been used in mixture with folpet, the selection of QoI-resistant strains was lower, compared with using solely QoI. In vineyards where QoI treatments have been stopped, a decrease in resistance was generally observed.     

草坪草分子遗传图谱的构建与应用研究进展

 草坪草分子遗传图谱的构建始于２０世纪９０年代,构建高密度的分子遗传图谱研究将有助于提高草坪草的育种水平。近年来,分子标记技术的发展加速了草坪草分子遗传图谱构建的研究。然而与农作物相比,草坪草分子遗传图谱构建的研究还相对滞后。增加作图群体的数量、提高分子遗传图谱的饱和度、抗逆性ＱＴＬ 的定位以及中国本土暖季型草坪草资源开发利用等方面,是我国今后草坪草分子遗传图谱构建研究的重要发展方向。     

利用高密度遗传图谱发掘水稻抽穗期新位点

水稻抽穗期是决定水稻种植地区及其季节适应性的关键因素,发掘控制水稻抽穗期相关的新主效QTL至关重要。利用包含527个bin标记的高密度遗传连锁图谱,通过靶向测序基因型检测技术对水稻“空育131/小白粳子”衍生的RIL群体进行抽穗期基因型分析。通过对双亲和RIL群体的基本统计分析发现,双亲抽穗期呈极显著差异,表型处于RIL群体范围内,RIL群体有明显的超亲分离现象,符合正态分布。利用IciMapping 4.2软件的完备区间作图法,在水稻第1、3和7号染色体上共检测到4个QTL,其中3个QTL区间内分别含有与抽穗期相关的已知基因OsGI、Hd6和Ghd7,而qHD-3-1是控制水稻抽穗期的新位点。     

系谱追踪等位变异法分析籼粳交亲本对衍生后代的遗传贡献

利用16个亲本及特异种质92gk729的39个衍生品系为材料,采用221对SSR标记和系谱追踪等位变异法分析祖先亲本在籼粳杂交各衍生世代的遗传贡献。结果表明：（1）在92gk729中有10对SSR引物位点上出现4个祖先亲本杂交重组的特异条带,有5个重组后的特异位点能稳定传递到衍生后代中,有1个重组后的特异位点在亲本及衍生品系中都没有出现;（2） ketan Nangka、嘉南粳、02428、明恢72对92gk729的遗传贡献率分别为15.09％、21.32％、22.78％和34.64％。4个亲本杂交染色体片段重组后能产生新的特异位点,其遗传贡献率是6.17％;（3）4个祖先亲本在每条染色体上对衍生后代遗传贡献的趋势都是随着衍生代数的递增,遗传贡献率逐渐下降。亲本对各世代衍生品系的遗传贡献率为明恢72＞02428＞嘉南粳＞Kenta Nangka ;（4）采用系谱追踪等位变异法进行数据分析,然后对数据进行聚类,发现同一杂交组合的品系、同一系谱分支存在衍生关系的大部分品系聚为一类,后代亲缘关系相近的高代材料聚为一类。说明该法能够较好地反映祖先亲本对后代的遗传贡献。     

利用DH和IF_2两个群体进行小麦粒重、粒型和硬度的QTL分析

【目的】检测控制小麦粒重、粒型和硬度加性和显性QTL,解释控制这些性状的分子遗传基础。【方法】以小麦品种花培3号、豫麦57构建的包含168个株系的DH群体和由其构建的包含168个株系的IF2群体为材料,结合含有368个位点的分子遗传图谱,对5个环境的DH群体以及2个环境的IF2群体的千粒重、粒型和硬度数据进行QTL分析。【结果】共检测到控制千粒重、粒长、粒径和硬度的35个加性效应和18对上位效应QTL,包括控制千粒重的8个加性效应位点以及5对上位性位点,控制粒长的10个加性效应位点以及6对上位性位点,控制粒径的10个加性效应位点以及6对上位性位点,控制硬度的7个加性效应位点以及1对上位性位点。其中,控制粒重的Qtkw6A在DH和IF2群体中都能检测到,而且既有加性效应又有显性效应,加性效应的贡献率在2个群体内分别为9.39%和11.75%,显性效应的贡献率为1.37%。控制粒径的Qgd6A也在DH和IF2群体中检测到,加性效应贡献率分别为15.02%和15.03%,而且与控制粒长的Qgl6A为同一基因位点,在DH和IF2群体中对粒长的加性效应贡献率分别为14.96%和15.10%。【结论】小麦的千粒重和粒型的遗传主要受加性效应控制,同时也受上位效应影响。硬度主要受位于5D染色体短臂上一个主效基因控制,同时受其它微效基因以及上位性影响。本研究检测到的一些重要QTL可用于相关性状的分子标记辅助选择育种,用IF2群体检测到的显性效应QTL及具有显性×加性、加性×显性及显性×显性效应的QTL可为有关性状杂种优势的研究提供参考。     

Mapping of quantitative trait loci for phytic acid and phosphorus contents in seed and seedling of mungbean (Vigna radiata (L.) Wilczek)

Phytic acid (PA) is the storage form of phosphorus (P) in seeds and plays an important role in the nutritional quality of food crops. There is little information on the genetics of seed and seedling PA in mungbean [Vigna radiata (L.) Wilczek]. Quantitative trait loci (QTL) were identified for phytic acid P (PAP), total P (TP), and inorganic P (IP) in mungbean seeds and seedlings, and for flowering, maturity and seed weight, in an F₂ population developed from a cross between low PAP cultivated mungbean (V1725BG) and high PAP wild mungbean (AusTRCF321925). Seven QTLs were detected for P compounds in seed; two for PAP, four for IP and one for TP. Six QTLs were identified for P compounds in seedling; three for PAP, two for TP and one for IP. Only one QTL co-localized between P compounds in seed and seedling suggesting that low PAP seed and low PAP seedling must be selected for at different QTLs. Seed PAP and TP were positively correlated with days to flowering and maturity, indicating the importance of plant phenology to seed P content.     

大豆脂肪含量遗传分析及QTL定位研究

以高蛋白大豆品种吉育50和高油大豆品种吉农18杂交后获得的F2及其衍生群体为材料,采用主基因+多基因混合遗传模型和QTL IciMapping v2.2完备区间作图法研究大豆脂肪含量的遗传规律.结果表明:大豆脂肪含量表现为多基因遗传模型,主要受多基因控制,多基因遗传率为79.15%;对大豆脂肪含量进行QTL定位和分析,共检测到2个主效QTL和2个微效QTL,分布于12(G)、17(M)和22(F)3个连锁群上,其中包括了1个在2年间稳定存在的主效QTL.     

农作物抗旱育种新进展

概述了通过常规育种、分子标记辅助育种(MAB)和遗传工程(转基因)增强农作物的抗旱性方面的研究进展,并探讨了3种抗旱育种方法的前景。