陆地棉抗黄萎病、纤维品质和产量等农艺性状的QTL定位

用一个高抗黄萎病的陆地棉品系5026和一个高感黄萎病的陆地棉品种李8为材料,构建一个RIL群体.用5 300对SSR引物筛选亲本多态,获得115个多态位点并进行标记间连锁分析,构建了一张包括20个连锁群全长560.1 cM的陆地棉品种间分子标记遗传图谱.RIL家系分两份:一份种于病圃,在苗期和成株期分别考查各家系的发病情况;一份种于大田,调查各家系的产量和纤维品质相关性状.用复合区间作图法对抗病、产量和纤维品质等性状进行QTL定位:在苗期检测到了3个抗病QTL,成株期检测到了1个抗病QTL,解释的变异系数范围是7.4%～11.8%;检测到2个纤维长度、2个纤维强度、1个纤维细度、1个整齐度、1个短纤维指数和2个纤维伸长率等9个与纤维品质相关性状的QTL,解释的变异范围是6.7%～15.7%;检测到了2个皮棉产量、1个籽棉产量、2个单株果枝数、1个单株铃数、2个铃重、1个籽指、1个衣分和1个衣指等11个产量构成因素的QTL,解释的变异方差范围是4.1%～10.6%,这些结果为棉花抗病育种同时兼顾产量和品质育种提供了非常有用的信息.     

27份中长绒陆地棉种质资源的遗传多样性分析

为研究南疆中长绒陆地棉农艺性状与产量纤维品质的关系，对27个中长绒陆地棉资源的13个性状进行遗传多样性分析、主成分分析、聚类分析。结果表明，27个资源的变异系数在3.77%～21.98%之间，遗传多样性指数在1.69～2.04之间，其中衣分最低，产量最高；主成分提取结果表明，前4个主成分累计贡献率达73.394%,贡献率由大到小依次是：农艺性状因子、品质因子、产量因子、衣分因子；在聚类分析中，5个类群表现出了中长绒陆地棉棉花种质资源的各种因素，筛选出可用作中长绒陆地棉棉花育种亲本的15份高产、优质资源材料。     

作为棉花改良资源的品种杂交衍生原始材料：Ⅱ．遗传效应和基因型值

棉花种质衍生的原始材料可为品种改良提供有益的性状。预测棉花种质衍生原始材料与品种杂交后高代材料农艺性状表现的能力可以促进其在育种计划中的应用。本研究的目的是采用混合线性模型法预测原始材料的中日性衍生系及其与品种杂交的遗传效应。1998和1999年，在2个试验点种植亲本和F2群体，2000年，在2个试验点种植亲本和F3。对试验材料的皮棉产量、产量构成和纤维品质性状进行了评价。应用一种加性一显性加性X加性(ADAA)模型进行遗传分析。     

棉花抗黄萎病品种选育的轮回选择研究——基础群体的构建

利用我国发现并鉴定的陆地棉核雄性不育系—洞Ａ为工具,将国内外现有的十多个抗（耐）棉花黄萎病的品种（系）和种质系导入到二个轮回群体中,拓建了棉花抗黄萎病轮回选择基础群体。从而为同步提高棉花的产量、品质和抗病性打下基础。     

中国低酚棉品种资源群体特点及特异种质筛选

对１４５个国内外不同来源的低酚棉品种（系）的研究表明，中国低酚棉品种资源群体的基本特点是，皮棉产量的变异潜力较大；铃重、衣分、子指、衣指变异度较小，纤维品质性状的变异率表现相似。多数品种（系）的衣分偏低，子指较大，纤维强度低，细度中等，但纤维较长且整齐度好。在产量或品质性状方面，该资源群体含有一些特异种质；国内育成品种（系）在衣分、细度上可更好地提供优异的基因资源，而国外品种（系）在铃重，衣指，纤     

棉花海陆杂交纤维品质性状遗传参数分析

为了研究棉花海陆杂交纤维品质性状的遗传规律,本试验采用5个陆地棉品种（系）作母本与5个海岛棉品种（系）杂交,配制25个杂交组合,随机区组试验设计,重复2次。主要检测杂交种F1代纤维品质性状,以小区平均数进行相应的方差分析及遗传参数估计。结果表明：陆地棉亲本间变异除马克隆值外,其他纤维品质性状均差异显著或极显著,而海岛棉亲本间除伸长率外,其他性状均存在显著或极显著差异;各纤维品质性状双亲互作效应均不显著。另外,遗传参数结果表明：绒长、比强度和马克隆值的遗传变异系数与表型变异系数变化趋势基本吻合,且均大于环境变异系数。整齐度和伸长率的遗传变异系数均小于环境变异系数,说明整齐度和伸长率的变异中环境因素的作用不容忽视。绒长、比强度和马克隆值的广义遗传率较高,在采用海陆杂交改良棉花纤维品质性状时,适宜在早代选择优异株系。     

不同来源棉花种质资源材料主要农艺经济性状鉴定与分析

对来自中国、美国、法国等国家的 1 1 4份棉花种质资源进行了生育性状、产量性状、纤维品质及抗黄萎病、棉铃虫性鉴定。结果表明 ,该批资源具有较强的生育性状选择潜力 ;单株结铃数较多 ,铃重较高 ,衣分偏低 ;纤维较整齐 ,伸长率较小 ,比强度较低。国内品种与国外品种相比 ,具有成熟早、产量、衣分高 ,结铃数多、铃重小的特点。在纤维品质上 ,国内品种的麦克隆值、伸长率、整齐度均超过国外品种 ,但纤维长度、比强度不及国外品种 ,国内品种的抗性优于国外品种。筛选出了一批具有不同优异性状的种质材料 ,为在棉花育种中有目的利用这些材料提供了参考     

棉花陆海染色体片段代换系BC_7F_2群体纤维产量和品质性状表现及相关分析

为了揭示棉花染色体片段代换系BC_7F_2纤维产量性状和品质性状之间的相关关系,筛选纤维品质优异的新材料。以1套陆海染色体片断代换系为材料,对BC7F2高代回交群体的产量性状与纤维品质性状的表性数据进行评价及偏相关分析。结果表明:群体各性状的平均值接近于轮回亲本‘中棉所36’,群体内存在丰富的遗传变异。纤维上半部平均长度超轮回亲本比例为30.25%,断裂比强度超轮回亲本比例为71.25%,衣分超轮回亲本比例为29.38%。总体上单铃重与马克隆值、整齐度指数呈极显著正相关,衣分与上半部平均长度、断裂比强度呈显著负相关,与单铃重呈极显著负相关。从中筛选出部分纤维品质突出的单株,纤维上半部平均长度高于30.00 mm,断裂比强度高于31.00 cN/tex。     

低酚棉种质资源的研究

1988～1990年在保定地区自然条件下。对145个国内外不同来源的低酚棉品种(系)的生育特性、产量表现和纤维品质进行了研究。结果表明,多数品种的熟性差异不大,从播种到吐絮135～140天的品种占91.72％。产量性状中,铃重、衣分、子指和衣指的变异度较小,而子棉和皮棉产量的变异潜力较大。纤维品质性状的变异程度较产量性状小。国内品种与国外引进品种相比,具有较早熟、衣分高、子指小、产量高、纤维长、细度好的特点,而国外品种的棉铃大、纤维强度高。通过鉴定和筛选,获得了数十份具有丰产、大铃、高衣分、长纤维、高强度和细度好等不同种质特性的优异种质资源。     

棉花苗期氮效率对其产量性状和品质性状的影响

为探明不同棉花品种的氮营养代谢特性和培育氮高效棉花品种提供参考,以30个棉花品种为材料,设置施氮和不施氮两个处理,采用漂浮育苗法培育棉苗,对其苗期的氮效率进行了比较研究,并对各品种棉花的产量性状和纤维品质也进行了测定。结果表明,在氮胁迫情况下,棉花苗期植株的叶绿素含量、含氮量、氮积累量及叶绿素饱和ETR值都产生明显的降低趋势;根据苗期测定的20个指标进行的主成分分析结果表明,前3个主成分的累积方差贡献率已达到80%以上,棉苗三叶一心时期的总相对干重、总氮积累量、地上部含氮量、地上部相对含氮量,地下部含氮量和地下部相对含氮量等6个指标可代表所有供试品种所有参评性状的绝大部分信息;根据这6个指标对这30个棉花品种进行了聚类分析,同时根据这些品种的大田产量性状和纤维品质性状也进行了聚类分析,通过对这3种不同聚类结果的综合分析表明,棉花苗期氮效率与成熟后的产量和纤维品质是有一定的影响,苗期氮效率高的‘鄂棉14’、‘泗棉4号’、‘湘棉10号’、‘衡棉4号’和‘川棉56’等棉花品种,成熟后的产量高,纤维品质也相对优良,而‘鲁棉12号’、‘辽棉15’和‘新陆早20’等苗期氮效率低的品种,成熟后的产量较低,纤维品质也相对较差。     

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...