黄瓜黄色子叶突变体遗传及相关AFLP标记

以黄色子叶突变体B180H为母本,颜色正常子叶黄瓜Q12为父本,配制F1、F2、BC1,并通过对6世代子叶叶色特征的观察和统计分析,研究该黄色子叶性状的遗传规律,并利用BSA法、AFLP技术筛选与黄色子叶性状基因紧密连锁的分子标记。结果表明,黄瓜黄色子叶性状是由1对核基因控制的稳定遗传的隐性性状,绿色子叶相对于黄色为完全显性。通过BSA法和AFLP分子标记,应用1 024对引物组合EcoRⅠ-NN/MseⅠ-NNN对黄色、绿色子叶亲本进行筛选,筛选到了1个与黄瓜黄色子叶性状相关的共显性标记E-AG/M-AAG。测序结果表明,片段长度分别为258 bp和257 bp,为发生插入/缺失或突变的同源序列;在黄色子叶个体中只扩增出了258 bp的特异片段,绿色子叶个体中扩增出了257 bp的特异片段或同时扩增出258 bp和257 bp两个特异片段。经组外其他F2单株验证发现,鉴定结果符合率高达96.74%,以Mapmaker 3.0软件分析,该标记与子叶黄色突变位点的连锁距离为3.2 cM。该性状可作为苗期遗传标记性状,在杂交育种和品种纯度鉴定上有极大的利用价值。     

一个与黄瓜单性结实基因连锁的ISSR标记

黄瓜单性结实特性是其重要的经济性状,选育单性结实品种是现代黄瓜育种中重要的目标性状之一.本实验以黄瓜单性结实品系EP-6和非单性结实品系ZR-2为亲本构建群体,采用分离群体分组分析(bulked segregant analysis,BSA)筛选与黄瓜单性结实基因连锁的分子标记.用65条ISSR引物进行PCR扩增筛选,其中引物N92在亲本和DNA池之间扩增出一条大小为850 bp多态性片段,经F2代群体135个单株验证,该片段稳定出现,在单性结实植株中表现为无带,在非单性结实植株中表现为有带,可以作为鉴别单性结实与非单性结实的标记引物.遗传连锁分析表明,该标记与单性结实基因连锁距离为18.9 cM,为黄瓜单性结实基因的分子标记筛选和分子标记辅助育种奠定了初步基础.     

黄瓜抗枯萎病基因连锁分析和定位

为筛选出与黄瓜抗枯萎病相关基因连锁的SSR分子标记,以对黄瓜抗枯萎病为单显性基因的母本WIS2757和感枯萎病父本津研2号及其F1、F2分离群体为试材,通过构建抗、感池对黄瓜枯萎病抗性进行SSR分析。结果表明:通过对278对SSR引物进行筛选,获得在双亲间存在多态性的引物102对,进一步通过抗、感池筛选,获得抗感池DNA间有差异的引物10对。经F2感病群体验证,共获得9个与黄瓜枯萎病抗性基因(Foc-4)连锁的SSR分子标记,并初步将Foc-4基因定位在2号染色体两标记SSR17631和SSR00684之间,距基因Foc-4的遗传距离分别为1.0 c M和0.9 c M,为进一步开发抗枯萎病分子标记及克隆黄瓜抗枯萎病基因奠定了基础。     

与黄瓜抗枯萎病基因连锁的RAPD标记

以黄瓜抗枯萎病亲本WIS2757和感枯萎病亲本津研2号及其F2分离群体为试材,采用分离群体分组分析法(BSA)进行了与黄瓜抗枯萎病基因连锁的分子标记研究。运用RAPD技术,利用780条RAPD引物对抗、感亲本进行筛选,其中有113条引物在两亲本之间表现多态性,但仅有引物S49在两组间多态性标记与亲本的多态性标记相同。经F2单株分析,引物S49扩增出的特异DNA片段与WIS2757抗黄瓜枯萎病基因连锁,遗传距离为14 cM。DNA标记条带大约为300 bp,定名为S49-300。     

瓠瓜耐湿涝相关根系性状遗传规律及分子标记筛选

以耐湿涝瓠瓜材料JZS和不耐湿涝材料T2002及其杂交F2群体为材料,选择湿涝条件下不定根数目作为耐湿涝鉴定指标,分析瓠瓜耐湿涝特性遗传规律,并采用集团混合分离分析法筛选相关分子标记。结果表明,瓠瓜亲本JZS的耐湿涝特性由1对显性单基因控制,F1的不定根数目比耐湿涝亲本JZS增多,表现出超亲优势。在600个RAPD和100对瓠瓜SSR引物中,共有18个引物(14个RAPD和4对SSR)在双亲中显示多态性。最终筛选到瓠瓜SSR引物S87/88,在双亲及基因池间稳定扩增出片段大小为230 bp的差异条带。通过F2153个单株验证,确定表型调查耐湿涝结果与分子标记S87/88鉴定结果相关性极显著(相关系数0.78),利用Mapmaker 3.0软件对分子标记与表型结果进行连锁分析,S87/88与瓠瓜耐湿涝相关的不定根数目基因的连锁距离为8.8 cM,为进一步利用分子辅助育种加速耐湿涝瓠瓜新品种的选育提供有效标记。     

甘蓝型油菜花叶性状的遗传及基因定位

为明确甘蓝型油菜花叶性状的遗传特点,开发与花叶性状连锁的分子标记。以甘蓝型油菜品系2205(圆叶)、1423(花叶)为亲本,构建了3个世代群体:F1、BC1和F2,探讨花叶性状的遗传规律;利用分子标记技术对花叶基因进行定位。结果表明,F1植株叶形表现为花叶,BC1(F1×2205)和F2中花叶与圆叶的植株分离比分别符合1∶1和3∶1,说明甘蓝型油菜的花叶性状受1对不完全显性基因控制。利用集团分离法(BSA)筛选637对SSR引物,共筛选到了3个与花叶基因紧密连锁的SSR标记:CB10079、BNGMS114和BNGMS385。连锁分析发现,这3个连锁标记均位于花叶基因的一侧,其中BNGMS114与花叶基因的遗传距离最近,其遗传距离为2.5 c M。将这3个连锁标记的序列与白菜基因组的序列进行比对,结果发现它们与白菜A10染色体的序列共线性较好,花叶基因位于A10染色体的15.70 Mb下游区段。上述标记的获得为油菜花叶性状的分子标记辅助选择育种以及花叶基因的克隆奠定理论基础。     

与甜瓜嫁接亲和性连锁分子标记鉴定

使用与南瓜类型砧木(“壮士”)嫁接亲和性差异明显的两个甜瓜自交系(85-1和B717)为亲本,配制F2∶3家系群体;利用BSA法构建亲和性优差池,结合PCR技术筛选与嫁接亲和性有关的分子标记.结果表明:使用葫芦科遗传连锁图谱上发表的750对SSR、SRAP和AFLP等分子标记引物扩增,最终筛选出在两个甜瓜材料之间具有多态性的382对引物,其中9对引物分别在嫁接亲和性优差DNA池中扩增出差异性片段.将这些标记用于F2群体的扩增,计算标记与嫁接亲和性遗传连锁距离,两对SSR引物CMN-0616和M103与嫁接亲和性的遗传距离分别为17.6 cm和9.3 cm.这2对引物有望成为鉴定甜瓜嫁接亲和性的辅助引物,从而将嫁接亲和性差异材料从分子角度区别开来,为甜瓜嫁接接穗育种等研究提供参考.     

小滨麦易位系山农0096抗条锈基因的微卫星标记和染色体定位

从普通小麦品种烟农15与八倍体小滨麦杂交后代中选育的小滨麦种质系山农0096,综合性状优良,高抗条锈病,经鉴定为导入了滨麦草染色体的小片段易位系.通过抗性接种鉴定和遗传分析,推测山农0096的条锈病抗性由显性单基因控制,抗条锈病基因来源于滨麦草,暂将其表示为YrSn0096.利用F2分离群体分组法(BSA)对山农0096中的抗条锈病基因进行了微卫星标记分析,从1 261对SSR引物中筛选出引物BARC236-4A能在滨麦草、八倍体小滨麦和山农0096中扩增出特异性DNA片段Xbarc236-4A255bp;利用该标记检测山农0096x辉县红F2群体的单株DNA,根据扩增带型,利用软件MAPMAKER3.0确定标记Xbarc236-4A与滨麦草抗条锈基因的遗传距离为5.0 cM,并将该抗条锈病基因定位在4A染色体上.     

烟草CMV抗性鉴定及抗性基因的SSR标记研究

本研究以抗黄瓜花叶病毒病的烟草品种铁把子和台烟8号,感病品种NC82和中烟15为亲本,构建F1、F2、BC1代分离群体,并对它们进行CMV的接种鉴定和抗性遗传分析,结果表明铁把子和台烟8号对CMV的抗性是由1对隐性基因控制的.依据混合群体分组分析法(BSA),从F2代群体植株中选取DNA建立黄瓜花叶病毒病的抗病基因池和感病基因池,利用135对SSR引物进行分子标记和分析,得到标记SM1350与来源于铁把子的CMV抗性基因间的遗传距离为8.64 cM,标记SM2270与来源于台烟8号的CMV抗性基因间的遗传距离为3.92 cM.     

与黄瓜抗黑星病相关基因紧密连锁的SSR标记

本研究以黄瓜抗黑星病母本Q6和感黑星病父本F51及其F2代分离群体为试材,采用BSA法和SSR技术建立了对黑星病的抗病组和感病组,SSR引物CSWCTT02D在抗感组间表现多态性,且呈共显性.经162个F2单株验证,在高抗单株和高感单株中分别仅扩增出246 bp和256 bp的特异片段,而在中间类型个体中同时扩增出了两个特异片段.连锁分析结果表明,该标记与黄瓜黑星病抗病相关基因紧密连锁,距离为3.1 cM.测序结果显示,两个片段的差异在于10个碱基的插入或缺失.     

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.     

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.     

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.     

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.