大豆亲本杂交方式对后代的遗传变异及品系产量表现的影响 Ⅰ.单交与双交的比较研究

1985—1990年用两套亲本的单、双交组合为材料,比较后代表现及选择效果,以明确双交是否较单交更优越。结果表明:单、双交组合F_2代的株高、主茎节数、单株荚数、单株粒数、百粒重、单株粒重的平均表现、标准差及变异系数无大差异。双交组合多数性状的变异幅度处在两个单交组合之间。除第二套组合双交的主茎节数同时显著少于两个单交外,其余性状均未能同时达到显著水平。按相同育种目标入选的高世代品系在生育期、抗倒伏、抗病性方面,双交均可获得与单交相似的选择效果。两个单交组合与相应的双交组合的F_4、F_5品系平均产量、20％高产品系平均产量、前二名高产品系平均产量的差异未能达到显著水平。看来,对产量进行选择,双交并不比单交更优越。     

栽培大豆(G.max)×半野生大豆(G.gracilis)后代主要农艺性状遗传参数的初步分析

本试验利用三个不同结荚习性的栽培大豆(G.max)做母本,分别与三个半野生大豆(G.graeilis)按NCⅡ设计配制的9个杂交组合,估测了F_1、F_2代主要农艺性状的优势指数;F_2代主要农艺性状的平均数、变幅、遗传变异系数、遗传力和预期遗传进度。试验结果表明:F_1代除百粒重、主茎有效节数以外,其余性状均有明显的杂种优势;F_2代除有效分枝、主茎粗以外,其余性状的优势指数均明显下降;F_2代遗传变异幅度大小的趋势为有限组合>亚有限组合>无限组合;生育日数、株高的遗传力高,可在早期世代进行选择;单株粒数、单株荚数、主茎粗的遗传力低,应在较晚世代选择;单株粒重及其主要构成因素均有较大的遗传进度绝对值,无限组合的遗传进度明显低于有限、亚有限组合。     

半矮秆大豆新品种不同栽培方式产量表现及通径分析

半矮秆大豆新品系通过垄作和平作窄行密植产量比较,同一品系垄作高产、平作窄行密植不一定高产。通径分析结果表明：平作窄行密植栽培直接影响单株粒重的性状是单株粒数,其次产百粒重,单独选择任一性状都可提高产量。间接影响单株粒重的性状是单株英数、有效分枝数。垄作栽培直接影响单株粒重的性状是单株荚数,间接影响单株粒重的性状为有效分枝数、单株粒数。矮秆、半矮秆育种Ｆ１￣Ｆ５代主要是针对与产量有关的性状进行选择,     

江汉平原大豆品系表型分析及综合评价

种质资源是大豆育种的基础,理论方法是品种选育的关键。以64份大豆品系为材料,采用变异性分析、相关性分析、因子分析和聚类分析等多元分析方法相结合,对大豆品系的10个农艺性状及产量性状进行研究,筛选适宜江汉平原种植的大豆品系,同时探究影响大豆产量的关键因素,为选育优质高产大豆品种提供种质和理论依据。结果表明,大豆品系10个农艺性状的变异系数为4.19%~46.95%,有效分枝数变异系数最大,蛋白质含量变异系数最小;因子分析将10个农艺性状转化为4个主因子,分别为产量构成因子、株高因子、粒重因子和品质因子,累计贡献率为80.067%。由农艺性状与综合得分相关性分析可知,生育期、株高、主茎节数、单株荚数、单株粒数、单株粒重和蛋白质含量7个农艺性状可作为大豆品系综合评价指标。聚类分析将64份大豆品系分成3个类群,类群Ⅰ31份,类群Ⅱ24份,类群Ⅲ 9份,类群Ⅲ大豆品系综合表现较好,适宜在江汉平原种植。     

60Coγ诱变豌豆M2农艺性状与产量多重分析

为了更好的发掘利用豌豆辐射诱变变异后代资源,本研究分别以3种不同复叶类型豌豆为材料,通过对豌豆诱变M2代农艺性状进行相关分析、多元分析、通径分析、主成分分析,明确豌豆诱变后代产量的决定因子。结果表明不同复叶类型豌豆诱变M2的主要农艺性状的变异丰富,变异系数达0.171-0.8539;且结荚节数、单株荚数、单株粒数均与单株产量呈极显著正相关关系;通径分析结果证实,不同复叶类型豌豆诱变后代选择中,单株粒数及单株荚数对单株产量的影响均很大;主成分分析结果表明：单株荚数、单株粒数、结荚节数是高产型豌豆形态决定因子。豌豆诱变后代单株产量的主要决定因子依次为单株粒数、单株荚数、结荚节数,同时对百粒重给予足够重视。     

安豆203主要农艺性状与产量的灰色关联度分析

为探索大豆农艺性状与产量的相关性,以山东省大豆品种安豆203为材料,对其9个主要农艺性状与产量进行灰色关联度分析。结果表明:对安豆203的产量影响最大的是株高,关联度为0.819,最小是有效分枝,关联度为0.490,其它性状对产量的影响从大到小依次为主茎节数(0.789),百粒重(0.784),底荚高(0.744),单株粒重(0.739),生育期(0.727),单株粒数(0.724),单株荚数(0.699)。因此,在今后的高产试验和推广应用中,应针对安豆203的特点制定相应的栽培措施,以提高株高,主茎节数为目标,稳定百粒重,充分发挥其高产、稳产潜力。     

南繁大豆种子产量相关性状的灰色关联度分析

为给南繁大豆育制种实践提供理论参考,采用灰色关联度分析法,对15份南繁栽培大豆的单株种子产量与主要农艺性状进行灰色关联度分析。结果表明,南繁大豆的单株种子产量与7个主要农艺性状的关联顺序为:单株荚数(0.815 3)单株粒数(0.772 0)百粒重(0.648 7)株高(0.646 3)主茎节数(0.644 0)有效分枝数(0.628 9)生育期(0.587 1)。因此,为获取更高的大豆种子产量,南繁时应优先考虑单株荚数和单株粒数等农艺性状。     

黄淮海夏大豆产量与主要农艺性状的灰色关联度分析

为探讨大豆主要农艺性状对大豆产量影响的主次关系,运用灰色关联度分析法,对黄淮海地区16 个品种12 点试验进行产量与农艺性状的分析,从而为黄淮海地区大豆育种提供理论依据。结果表明：产量与主要农艺性状的关联度大小依次是单株粒重＞分枝数＞株高＞生育日数＞单株荚数＞单株粒数＞主茎节数＞底荚高度＞百粒重。可见,对大豆新品种选育时,应优先考虑单株粒重,分枝数,株高和生育日数。     

红花主要农艺性状与单株籽粒产量的相关和通径分析

对来自世界各地的48份栽培红花品种的主要农艺性状进行相关和通径分析.相关分析结果表明,9个相关性状对单株籽粒产量影响的顺序:单株粒数＞百粒重＞单株有效果球数＞平均每果粒数＞株高＞一级分枝数＞开花期＞单株无效果球数.多元回归分析表明,百粒重(x1)、单株无效果球数(x3)、单株粒数(x4)、一级分枝数(x6)是影响产量的主要因素,4个因素对产量的多元回归方程为(y=-8.784 3.773 x1 0.067 x3 0.025 x4-0.046 x6(r=0.981**).通径分析表明,单株粒数对单株籽粒产量的直接效应最大,其次为百粒重,二者是红花品种选育的主要目标性状和高产栽培的主攻方向.减少单株无效果球数可大幅提高单株籽粒产量.单株籽粒产量高产株型应是株高、一级分枝数适中,单株粒数、平均每果粒数多,单株有效果球数多、无效果球数少,百粒重高,开花期短者.     

花生农艺性状与产量的灰色关联度分析

通过对花生产量与农艺性状的灰色关联度分析,结果表明.影响花生产量的农艺性状依次为百果重＞百仁重＞单株生产力＞侧枝长＞千克果数＞饱果率＞出米率＞结果枝数＞主茎高＞市斤仁数＞单株结果数＞总分枝＞生育期.在花生高产育种中,应以百果重、百仁重和单株生产力三个影响花生产量的主导因素为主攻目标,提高花生后代的有效选择,加速高产育种进程.在高产栽培中通过选用优良品种,合理密植,采用增加百果重、百仁重和单株生产力等栽培技术措施达到高产目的.     

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.     

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...     

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.