茄子单性结实果实发育规律与营养物质的关系

以茄子单性结实品系D-11和非单性结实品系S8为试材,研究了果实发育、营养成分变化与茄子单性结实的关系。结果表明:D-11品系在不授粉的情况下,仍具有较好的结实性能,其单果重和果实纵横径均接近于授粉后生长的果实,且比S8品系果实增重快、果重大。授粉当天单性结实品系子房中蛋白质含量比非单性结实品系高59%。随着果实的生长发育,D-11和S8品系果实内可溶性糖含量均呈上升趋势,而蛋白质含量则呈下降趋势,两者呈负相关关系。     

茄子单性结实材料D-11的发现

茄子是喜温作物,正常开花结果所需的温度为25—28℃,由于冬季棚室温度较低,最低温常在10℃左右,开花期间由于低温引起授粉受精不良,落花落果严重。生产上常采用生长素防止落花,费工、费时、成本高;易引起药害,产生畸形果、残留部分药剂,降低果实品质和食用价值,不利于无公害茄子生产。茄子单性结实能使子房在未经正常授粉受精的情况下,发育形成正常无子或少子果实,对棚室优质专用品种的选育具有重要意义。茄子天然单性结实材料很少,不易获得。     

茄子(Solanum melongena)MADs-box家族基因SmA GL9的克隆与表达分析

本研究以茄子单性结实品系D-10和非单性结实品系03-2所构建的抑制差减文库(SSH)中差异表达的EST片段fan11为依据,利用RACE技术克隆得到一条与AGL9基因一致性达97.93%的cDNA序列,命名为SmA GL9。生物信息学分析表明,该基因有一个全长726 bp的开放阅读框,编码241个氨基酸,预测蛋白分子量为27.546 2 kD,理论等电点为9.00。保守结构域分析发现该蛋白含有MADS-MEF2-like和K-box两个保守结构域,属MADS-box转录因子。同源进化分析结果显示SmAGL9基因的蛋白质序列与辣椒AGL9基因同源关系相近。RT-qPCR分析表明,低温条件下SmAGL9基因在单性结实和非单性结实的子房和果实发育过程中均有表达,果实发育初期单性结实品系中的表达量显著高于非单性结实品系,推测SmAGL9基因在茄子单性结实子房和果实发育初期具有重要的调控作用。结果可为进一步研究茄子单性结实果实形成的分子机理提供参考。     

pBAR载体构建及其转化罗汉果的分析

为了创制可免除人工授粉的转基因罗汉果雌性品系,利用植物双元表达载体pBI121-Gus,构建幼果实特异启动子2A11与单性结实相关基因rolB的嵌合基因表达载体pBAR (pBI121-2A11-rolB)。以罗汉果雌株叶盘为材料,以EHA105农杆菌介导遗传转化,经PCR扩增,鉴定出阳性植株,对阳性雌株进行扩繁、生根,最后移栽大田,并观察转基因植株的单性结实性状表现。结果显示,成功构建了单性结实相关基因的pBAR嵌合双元表达载体;转化感受态根癌农杆菌EHA105后,进一步转化雌株叶片,经过对叶片分化苗的检测,得到7株阳性植株,转化率为14.29%。为提高成活率,扩繁7株阳性植株,获得37株转基因单性结实植株株系,其中有8株正常开花,占总数的21.62%,正常开花的植株,未经人工授粉,发育成幼果,表现出单性结实性状。本实验在克隆单性结实相关基因和果实特异启动子的基础上,构建嵌合基因载体,通过根癌农杆菌介导的叶盘转化法,获得了转基因罗汉果单性结实雌株系,为后续研究罗汉果单性结实性的遗传、生理、品种综合改良和深入利用提供了基础。     

甘蓝型油菜磷脂二酰甘油酰基转移酶(BnPDAT1)表达特性研究

为探究甘蓝型油菜中BnaPDAT1基因表达特性与油脂合成之间的关系。选用2个含油量具有显著差异的甘蓝型油菜双低品系855(49. 72%)和868(35. 06%),以qRT-PCR方法检测BnaPDAT1各拷贝在两品系油菜中的表达规律,同时以薄层层析(TLC)和气相色谱(GC)检测两品系油菜中TAG的积累规律。结果表明:授粉后种子中BnaPDAT1基因及其3个拷贝表达量均呈先升高后降低的趋势,花、叶片中均有BnaPDAT1表达,三拷贝表达存在差异,但表现整体调控的特点。两品系油菜叶(Bna A10. PDAT1除外)和授粉后20 d的种子中BnaPDAT1及其3个拷贝表达量具有极显著差异,其余各时期两品系间表达差异规律不明显,BnaPDAT1在高含油量品系855中授粉后20 d表达量为全生育期最高值(11. 100 9),是868的5. 07倍;叶中表达量8. 858 6,为868的7. 34倍,表达特性与Bna C09. PDAT1相似。两品系油菜种子TAG含量变化均呈S型,授粉20 d后油脂合成进入快速增长阶段,授粉后35 d进入缓慢增长期;授粉后30 d以前TAG含量品系间差异不大,授粉后35 d开始出现差异,授粉后40 d差异进一步扩大并趋于稳定。BnaPDAT1基因表达和种子TAG含量变化没有明显的直接关系,但高含油品系中BnaPDAT1基因表达值明显高于低含油品系。     

园艺作物单性结实功能基因研究进展

单性结实是指植物子房未经授粉受精或其他刺激而能发育形成果实的现象,这种特性在园艺作物生产中能减轻不良环境引起的落花落果,提高坐果率和产量。此外,由于单性结实果实未经授粉受精过程多发育成无籽果实,其可食率和品质也显著提高。因此,强单性结实性是园艺作物良种培育的重要目标之一。植物激素在诱导单性结实形成中发挥了重要作用,本研究总结了植物激素(主要是生长素,细胞分裂素和赤霉素)合成、代谢及信号转导相关基因对园艺作物单性结实性形成的调控机制,为园艺作物单性结实发生机制的深入研究提供参考。     

南方茄子杂交制中的几项关键技术

茄子花粉最适宜定的发育温度为28—30℃，低于17．5℃和高于35℃均不利于授粉受精．阴雨天气容易导致授粉失败和落花蒋果，因此应避免雨天杂交。春季茄子从播种到开花大约为100d，其中苗期为60—70d；秋季从播种到开花大约为50d，其中苗期为25—30d。茄子杂交制种多在露地栽培条件下进行．各地应根据当地的气候确定适宜的播种期，     

茄子单性结实相关基因的挖掘与分析

利用qPCR技术,对茄子单性结实SSH-cDNA文库中的109条EST序列进行表达量分析,研究其在单性结实品系和非单性结实品系中的表达模式。分析表明,在低温条件下,相对表达量有显著差异的EST序列有48条,其中上调表达的EST序列有21条,下调表达的EST序列有27条。通过NCBI对EST序列进行BLASTx比对,得到与其同源性高的序列信息。其中,8条EST与植物激素合成和信号转导相关、4条EST与低温胁迫相关、5条EST与植物代谢过程中的蛋白质和碳水化合物合成相关、5条ESTs无比对结果,可能为新基因。差异表达序列可作为研究单性结实和耐低温的候选基因,为进一步探究茄子单性结实的形成机理,挖掘和利用茄子单性结实相关基因提供参考。     

茄科十字花科等蔬菜杂交制种技术要点

1茄子通过保护地栽培，已成为四季家常菜。属雌雄同花茄科白花授粉作物，杂交制种比其它蔬菜优势强，必须采用人工去雄授粉方法才能得到杂交种。茄子生长最适温度25℃左右，生产制种要选择耐热、耐涝、结实高的自交系为母本。为保证花期相遇和间隔距离，父本一般比母本提前10～15d育苗，使父本提前3～5d开花，以保证母本开花时有足够的花粉量。     

不同温度和薄膜包装对茄子冷害及果实生理变化的影响

进行了不同温度和薄膜包装袋对茄子果实冷害发生、电解质渗透率及果实呼吸强度、果肉Vc含量变化的研究。结果表明：1～3℃下，对照、薄膜包装果实分别在贮藏3，8d后出现冷害症状，且伴随电解质渗透率迅速上升；薄膜包装可使冷害症状推迟4～5d出现，延缓电解质渗透率的增高；在11～13℃及室温下，薄膜包装可明显抑制茄子的呼吸速率，减少果实中Vc的氧化损失。     

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.