大白菜育性相关基因BRLSP-55的获得与验证

雄性不育的利用是大白菜制种的重要手段,获得大量育性相关基因可为了解大白菜雄性不育分子机制提供线索。采用cDNA-AFLP技术寻找差异条带,利用RT-PCR经序列比对并推测其功能。利用cDNA-AFLP方法从大白菜雄性不育两用系“AB01”的不育和可育花蕾中找到一个仅在可育花蕾中表达,而在不育花蕾中不表达的差异片段;经测序分析表明所得序列大小为351 bp,将其命名为BRLSP-55;并通过RT-PCR方法得到了验证;经序列比对初步判定该基因与拟南芥硫堇蛋白(Thionin Protein)的亲缘关系较近,所获得育性相关基因BRLSP-55可能为一种硫堇蛋白,在大白菜雄性不育机制中可能起重要作用。     

抑制消减杂交法研究复等位基因遗传的

AB01是本课题组培育的复等位基因遗传的核雄性不育大白菜甲型“两用系”,目前已建立了一套该材料的应用技术体系,但其不育分子机制尚不明确。本研究以AB01的不育株和可育株为材料,利用抑制差减杂交技术构建了正反抑制差减cDNA文库,并通过测序及生物信息学手段寻找育性相关基因,以此来推断该材料的不育分子机制。研究中共找到27个差异表达基因,其中25个基因在NCBI数据库中均有同源序列,这些基因中7个与花发育相关,5个与脂类代谢相关,3个与活性氧及能量代谢相关,3个与光合作用及叶绿体合成相关,其余7个为功能未知基因。由此推测复等位基因遗传的核雄性不育大白菜不育的发生与脂类、能量代谢及光合作用有关。     

大白菜育性相关基因1F203片段的分离与表达分析

杂种优势的利用是提高白菜类作物产量的一个重要途径,也是遗传育种工作者集中研究的领域。为克服常规制种缺点,本课题组长期致力于雄性不育材料的创制,并积极在细胞和分子水平上分析其遗传规律。本次试验以大白菜核基因控制的雄性不育甲型两用系"AB01"(本课题组自主创制)可育植株和不育植株各级花蕾为材料,利用抑制消减杂交方法构建正反cDNA文库,并从中筛选出一个大白菜育性相关基因1F203片段;并利用白菜数据库及NCBI对该片段进行同源比对分析,确定其为SKS基因家族中的一员;同时利用RT-PCR技术对该片段进行了时空表达分析,明确其在可育植株成熟花粉中有较高表达。为接下来克隆该片段对应基因的全长序列,分析其生物学信息,研究其蛋白质功能提供帮助。     

植物雄性不育的蛋白质组学研究进展

雄性不育在植物中普遍存在,是作物杂种优势利用的主要途径。已广泛从遗传育种、生理生化、细胞学、分子生物学等方面对植物雄性不育进行了研究。近年来蛋白质组学的相应研究技术不断发展,已广泛应用于植物雄性不育的研究中,为植物雄性不育的分子机理解析提供了重要的依据。本文综述了近年来细胞质雄性不育和细胞核雄性不育的蛋白质组学研究成果,认为植物雄性不育与一些蛋白质的表达上调、下降、缺失或者一些蛋白的新增表达有关,这些蛋白质分别参与了代谢、转录、信号转导、蛋白质合成、淀粉合成、细胞凋亡等重要生理过程,并指出了蛋白质组学在植物雄性不育研究上的不足和发展的方向。     

关于植物细胞质雄性不育概念的商榷

植物细胞质雄性不育(Cytoplasmic male sterility, CMS)是一种不能产生有活力或可育花粉的母性遗传现象.尽管有学者认为CMS与叶绿体DNA有关,但越来越多的证据表明,线粒体DNA(mitochondrial DNA, mtDNA)及其表达产物与CMS直接相关.为了准确地揭示这一类由线粒体DNA及其表达产物引起的CMS分子机制,我们提出了线粒体雄性不育的概念,其含义是指由线粒体遗传物质和细胞核遗传物质的共同作用控制的雄性不育.以区别于以前植物细胞质雄性不育的概念.     

花椰菜细胞质雄性不育(CMS)与可育花粉母细胞不同发育期的比较蛋白质组研究

为了探讨花椰菜细胞质雄性不育机理,利用比较蛋白质组学研究技术,对花椰菜细胞质雄性不育系(CMS)、保持系花粉母细胞减数分裂期、双-三核期及花粉粒时期的蛋白质组差异作了比较,发现CMS在花粉败育期(双-三核期)蛋白质组呈现明显变化,CMS中有4个蛋白质斑点(斑点1,9,19,20)缺失,有7个蛋白质斑点(斑点4,6,7,8,15,17,18)表达量明显减少,有10个蛋白质斑点(斑点2,3,5,10,11,12,13,14,16,21)表达量增加。差异蛋白斑点的质谱分析表明,CMS中的差异蛋白其功能涉及信号转导、能量代谢、蛋白质合成、光合作用与植物的防御与抗性等。该研究结果对于花椰菜不育机理探讨及保持系的选择均有一定参考意义。     

甜菜雄性核不育基因的SRAP标记

采用SRAP技术对甜菜核雄性不育基因进行分子标记的研究,为甜菜育种提供了一条新的途径。以遗传背景相似的可育株和不育株甜菜为材料,用64对SRAP引物组,进行了SRAP分子标记研究。在64对引物组中有2对引物组(即M2E7和M8E8)可分别得到1个育性基因相关的SRAP分子标记,即M2E7-480和M8E8-130,出现频率分别为73%和76%。表明该SRAP标记技术可用于甜菜辅助育种及遗传多样性分析,从而为甜菜雄性不育相关基因的表达提供科学依据。     

大白菜细胞核雄性不育两用系的利用途径探讨

不同来源的大白菜核不育两用系存在不同的遗传机制,其不育株与可育株都各略占50％并存。在利用上,50％不育株可作母本用于配制F_1杂种和核基因互作雄性不育系;50％可育株可用作F_1杂种父本、质核复合雄性不育保持系和核基因互作雄性不育临保系,同时自交还可快速选育自交系。在优势育种上,大白菜核不育两用系具有一定开发潜力和应用前景。     

青麻叶大白菜核基因雄性不育性遗传模式的研究

以稳定遗传的青麻叶类型大白菜甲型两用系2个、乙型可育株系4个及可育品系26个为材料，经过杂交、自交、测交及育性鉴定等手段，对青麻叶类型大白菜核基因雄性不育性的遗传模式进行了验证，并对青麻叶类型材料的育性基因型进行了测定。结果表明，青麻叶类型大白菜核基因雄性不育性的遗传模式符合复等位基因遗传模式；在经过多代纯化的青麻叶材料中，基因型为msms的材料所占比例最大，为65．4％，基因型为Ms^fms的材料所占比例最小，为7．7％，基因型为Ms^fMs^f的材料所占比例居中，为26．9％。     

牦牛、犏牛TB-RBP基因克隆及在睾丸组织中的表达

牦牛与普通牛的种间杂种犏牛雄性不育机理一直是畜牧科学研究的热点之一,对牦牛、犏牛睾丸组织特异表达基因的比对分析,可为犏牛雄性不育分子调控机制提供基因参考。通过对牦牛及杂种犏牛TB-RBP基因进行克隆,并利用实时荧光定量PCR技术对候选基因进行组织表达差异分析。结果表明,克隆获得牦牛TB-RBP基因CDS全序列873 bp,犏牛TB-RBP基因部分CDS区序列587 bp;系统进化树显示不同物种TB-RBP基因编码区序列高度保守,遗传相似性较高;蛋白功能预测TB-RBP蛋白属于Translin结合蛋白家族,对精子发生等生物过程具有重要调控作用。TB-RBP基因在犏牛和牦牛的睾丸组织中均有表达,TB-RBP基因的表达水平在牦牛与犏牛组间差异显著(0.01P0.05),牦牛显著高于犏牛。TB-RBP基因是精子正常发育的关键基因,而在犏牛睾丸组织中表达量较低,表明犏牛雄性不育与精子发生异常有关,为今后开展TB-RBP基因与犏牛雄性不育的相关分析以及基因定位、表达调控和牦牛分子育种奠定了理论基础。     

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.     

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.     

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.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

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...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

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.     

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...