基于RAPD的SCAR标记初步定位油菜温敏雄性不育系K121S的育性转换基因

温敏雄性不育系具有育种程序简单、组配自由、育种周期短等优点,已成为杂种优势利用的重要材料。本研究以芥菜型(Brassica juncea L.)油菜温敏雄性不育系K121S与核不育系1161A获得的BCF1为作图群体,利用混合分组分析法(bulked-segregant analysis BSA)对温敏雄性不育系K121S的育性转换基因(Fc)进行定位。结果表明获得2个基于RAPD的SCAR标记与育性转换基因(Fc)连锁,即是SS503-250和SBA485-482,与育性转换基因的遗传距离分别为3.94 c M和7.09 c M。本研究结果为今后育性转换基因的克隆、测序及生物信息学研究并解析K121S育性转换的分子机制机制提供了条件。     

利用SSR标记鉴定茎瘤芥(榨菜)“涪杂5号”种子纯度

为建立一套丰产抗病型的茎瘤芥杂交品种"涪杂5号"种子纯度的快速鉴定方法,本研究以"涪杂5号"及其双亲为试验材料,采用改良CTAB法快速提取DNA与SSR标记分析相结合,对茎瘤芥杂交种种子纯度进行检测。利用改良CTAB法提取的DNA能够满足SSR分析要求,从600对SSR芸薹属共有引物中筛选出3对共显性SSR标记引物Ol11-G11、Na14-G06和Na14-G10,父母本条带互补,可将杂交种中的假杂株分离开。分别利用其中两对引物相结合,对"涪杂5号"种子群体进行SSR检测,结果发现分子标记鉴定结果与田间鉴定结果基本一致。研究结果表明了利用SSR引物Na14-G06与Na14-G10或Ol11-G11相结合可实现对茎瘤芥杂交种"涪杂5号"种子纯度的快速和准确鉴定,并为其大面积推广和安全生产提供了理论依据。     

辣椒CMS恢复基因的遗传分析及基因定位

本研究以辣椒胞质雄性不育系131BC5A与恢复系139D-21-3为亲本,构建了包含210个单株的F2群体,采用CAPS、SSR及SCAR等分子标记技术,对辣椒胞质雄性不育恢复基因进行遗传分析和基因定位研究。田间调查和遗传分析结果表明,F2群体的表现型中可育与不育的分离比为3:1。采用分离群体分组分析法(BSA),从F2可育群体和不育群体中各随机选取10株,构建可育和不育基因池。研究选用295对引物在亲本间进行多态性筛选,其中43对引物在亲本间表现出多态。通过进一步分析43对引物在基因池间的多态性,筛选出Rf基因连锁标记14个。然后对F2群体的210个单株进行连锁分析,最后将恢复基因定位在SSR标记pep43和pep20之间,约3.9 c M(或498.6 kb)的区间内,与两个标记的遗传距离分别为1.3 c M与2.6 c M。本研究为Rf基因的精细定位和克隆奠定了良好基础,也为辣椒雄性不育恢复系的分子标记辅助选择育种提供了理论参考。     

陆地棉光敏雄性不育基因ys-1的遗传分析与初步定位

【目的】精细定位和克隆陆地棉光敏雄性不育基因。【方法】从陆地棉中040029的航天诱变后代中选育出新型光敏雄性不育系中9106,以中9106与11个陆地棉材料配制杂交组合,初步分析了中9106的杂种优势。以中9106为母本与陆地棉乐土603构建遗传分离群体F1、F2,分析不育性状的遗传特征。利用集团分离分析法筛选简单序列重复(Simple sequence repeat,SSR),并在包含186个单株的中9106×乐土603 F2群体中用上述SSR初步定位不育基因。【结果】中9106为母本×陆地棉乐土603的F1单株育性均表现正常,而F2群体中的可育单株数∶不育单株数符合3∶1的分离比,推测中9106的不育性状受1对隐性核基因控制。利用集团分离分析法从16 544对SSR中筛选到18对与该不育基因连锁的标记。利用中9106×乐土603的F2群体和18对SSR标记,将不育基因定位于D12染色体,位于标记NAU3442与CGR6339之间,遗传距离均为0.2c M,将该不育基因命名为ys-1。【结论】本研究有助于ys-1的精细定位及其克隆。     

YM型小麦温敏雄性不育系不育基因的QTL定位

YM型小麦温敏雄性不育系的不育基因被定位在1Bs染色体片段上, 但已发现的相邻分子标记与该基因的遗传距离较大, 达10 cM以上。为寻找与该基因连锁更紧密的分子标记, 以YM型温敏雄性不育系ATM3314与恢复系中国春杂交的F₂代200株为作图群体, 从1Bs的22个SSR引物中筛选出5个在亲本和F₂代中分离的SSR引物, 构建了1个包含5个标记的1Bs局部遗传连锁图谱。结合F₂代个体的育性调查, 采用复合区间作图法在YM型温敏雄性不育系的1Bs染色体上检测到不育基因的1个主效QTLrfv1-1和1个微效QTLrfv1-2。rfv1-1位于SSR标记Xgwm18和Xwmc406之间, 与两标记的遗传距离分别为6.0 cM和4.6 cM, LOD值为8.80, 加性效应23.87, 显性效应10.44, 可解释表型变异的23.91%; rfv1-2位于Xwmc406和Xbarc8之间, 与两标记的遗传距离分别为4.0 cM和3.4 cM, LOD值为3.10, 加性效应17.59, 显性效应5.99, 可解释表型变异的7.78%。本研究初步定位了YM型小麦温敏雄性不育系1Bs染色体片段上不育基因的QTL, 为进一步准确定位该基因奠定了基础。     

油菜Pol-CMS Rfp候选基因区域SSR标记开发与应用

波里马细胞质雄性不育系(Pol-CMS)的育性受环境温度影响较大,在杂交制种过程中易自交结实产生假杂种,从而影响杂交种的纯度质量,在生产上对母本假杂种的检测是杂交种纯度鉴定的关键。本研究利用已公布的Pol-CMS候选恢复基因Rfp编码序列,通过在白菜型油菜和甘蓝型油菜基因组进行同源序列比对,然后基于Rfp候选基因区域同源序列开发恢复基因的特异SSR标记,并应用于油菜杂交种纯度鉴定研究。研究结果表明,利用已公布Pol-CMS恢复基因1 953 bp编码序列获取Rfp在基因组所在区段,在该区域及上、下游15K区域共获得32个SSR位点;其中,1个位点在供试的Pol-CMS不育系和恢复系间具有多态性,该标记为共显性标记,在不育系中的扩增产物大小为162 bp,在恢复系中为184 bp;与不育系相比,恢复系的扩增序列存在一个15 bp和一个7 bp的片段插入;在‘沣油737’的F2分离群体中,该标记与育性恢复性状呈共分离遗传;利用该标记对‘沣油737’、‘沣油320’和‘沣油958’杂交制种样品的纯度鉴定结果与田间育性鉴定结果一致,表明本研究开发的SSR标记为Rfp基因紧密连锁的共显性标记,在...     

水稻光温敏核雄性不育系选育研究

作者通过总结从事水稻光温敏核雄性不育系选育实践，就光温敏核性不育基因来源，育性转换监界温度，世代选择方法以及实用型光温敏核雄性不育系应具备的几个重要农艺性状选择指标等方面阐述了自己的研究体会。     

甜玉米雄性不育突变体ms2020的表型分析和基因定位

为将雄性不育基因应用于甜玉米杂交制种中，达到降低劳动成本且保证种子纯度的目的。以来源于甜玉米自交系K78的雄性不育自发突变体male sterility 2020(ms2020)为材料，构建ms2020与甜玉米自交系M08的F₁及相应的F₂遗传群体，通过表型鉴定、遗传分析和基因定位研究ms2020甜玉米雄性不育突变体。表型鉴定结果表明：F₁群体均表现为雄性可育，F₂群体出现了育性分离。不育植株能够正常抽雄，但花药不开裂、散粉异常，花药变小且颜色淡黄；1%I₂-KI染色发现不育植株的花药内包含不能正常着色的败育花粉粒。遗传分析结果表明：育性正常植株与不育植株的比例符合3∶1,表明ms2020雄性不育突变体是由单基因控制的隐性突变体。利用BSA技术，初步将目的基因定位在7号染色体短臂上；随后利用初定位区间内的20对SSR标记对不育基因进行定位，将不育基因精细定位在标记S1和W10之间，物理距离为11.30 kb。该区间内包含Zm00001d018802和Zm00001d018803...     

影响温敏核不育水稻育性转换的低温敏感度QTL定位

光温敏核不育水稻的育性光温敏感度对两系杂交水稻的繁殖与制种有重要影响。为了定位影响温敏核不育水稻育性转换的低温敏感度QTL,以冷繁结实率存在明显差异的2个温敏核不育水稻N38S和N727S为亲本构建的F_2群体为作图群体,利用人工气候箱的低温处理和SSR标记技术,结合Mapmaker 3.0及WinQTLCart 2.5软件分析,检测低温敏感度QTL位点。结果显示,共检测到3个低温敏感度QTL,其中QTL1位于水稻第1染色体的PSM12与RM583之间,QTL2和QTL3分别位于第4染色体的PSM194与RM273之间和RM273与PSM103之间,它们加性效应均为负值,对育性转换的贡献率分别为7%,16%,3%。基于分子标记的位置信息可知,3个QTL位点与已定位的光温敏核不育水稻育性相关基因不等位。综上,QTL1、QTL2和QTL3可能是新基因位点,N727S携带的等位基因起到提高繁种产量的作用,在利用分子标记辅助选择时,应选择N727S的标记类型。这3个低温敏感度QTLs的定位可能对于温敏核不育水稻进行易于转育繁种的分子标记辅助选择具有重要意义。     

油菜温敏雄性不育系373S的选育

发现和选育新型光温敏雄性不育材料,有利于深入揭示植物雄性不育的发生机制,丰富油菜杂种优势利用的方法。笔者报道一种新发现的环境敏感雄性不育系373S的选育过程及其育性随温度、日长的变化基本规律。2002年在一个天然雄性不育群体后代中发现1株嵌合不育株,经过连续自交,育成环境敏感不育系373S。2004—2006年在陕西杨凌进行分期播种试验,并进行了温度、光照脉冲处理试验。结果表明：373S是主要对温度敏感的雄性不育系,低温可育而高温不育,开花前2~9d的平均温度对育性影响显著,而日长对育性影响不明显,花蕾长度约2~3mm是育性转换的敏感时期。用一系列品种与373S测交,F1均为100%可育,在F2代温敏不育株出现几率很高,可以达到7.1%~14.6%。进一步精确分析373S光温反应特征、改良其农艺及品质性状、寻找适宜制种生态区的工作正在进行当中。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.