短季棉主要农艺性状的遗传分析

中国农科院棉花所宋美珍等入选用5个早熟不早衰的短季棉品种和5个早衰的短季棉品种进行部分双列杂交。通过对亲本、F1和F2代分别于2001年和2002年两年田间试验研究。结果表明：子棉产量、皮棉产量和衣分3个性状以显性效应为主，其次为加性效应，同时还存在极显著的加性上位性与环境的互作效应，单铃重和成铃数以显性效应为主；与早熟有关的诸性状，生育期、始花期、铃期和果枝始节4个性状以加性效应为主。     

短季棉常用亲本早熟性状的遗传及配合力研究

采用9×9不完全双列杂交设计,分析了短季棉早熟及其相关性状的遗传特性、配合力和杂种优势表现,结果表明:短季棉的早熟性状由加性遗传效应和显性遗传效应共同作用,同时有不可忽视的加性、显性效应与环境的互作;全生育期、株高、衣分、铃重、霜前花率有较高的狭义遗传力,为0.262～0.528,特别是衣分和铃重受环境影响较小,可早代和异地选择;而果枝始节受环境条件影响较大;但在同一地区,果枝始节的狭义遗传力较高,为0.244～0.652,作为早熟性的选择指标是可靠的;在研究的9个材料中,有4个短季棉的早熟性的一般配合力较好,46个组合中有16个组合的早熟性及产量性状的特殊配合力均较好,其中以3个三个组合的产量及早熟性的综合性状较优,霜前皮棉较其优良亲本增产15%以上。     

早熟陆地棉主要纤维品质性状的遗传效应及杂种优势研究

通过ADAA模型(加-显-上位性效应)研究了早熟陆地棉2.5%跨长、整齐度、比强度、伸长率、麦克隆值等5项主要纤维品质性状的遗传效应及杂种优势。结果显示,早熟陆地棉纤维品质性状中2.5%跨长、比强度、伸长率和麦克隆值的遗传以加性效应为主,其次为显性效应,其狭义遗传率分别为65.7%、74.2%、39.6%和47.5%,均达到极显著;整齐度以显性效应为主,其次为加性效应;5项性状指标的上位性效应很小或无;F1和F2品质性状无杂种优势,但有一定的群体平均优势。本试验亲本纤维品质性状一般配合力差异较大,为利用新疆早熟棉中优良材料改良其他三类短季棉的品质提供了可能。     

持续高温干旱年份陆地棉农艺和产量性状的遗传效应分析

本文采用NCⅡ交配设计方法,以9个陆地棉品种(系)配置16个杂交组合,利用加性—显性与环境互作的遗传模型(ADE模型),分析亲本和F1在2013年持续高温干旱条件下望江、九江2个环境下的农艺和产量性状,估算了各项遗传方差分量,分析了性状间各项遗传效应的相关性和各性状的杂种优势。结果表明,农艺和产量性状易受环境条件影响,子棉产量、皮棉产量、单株铃数和铃重的遗传主要受显性效应控制,衣分同时受加性和显性效应控制,子指主要受加性效应控制。遗传相关分析表明,子棉产量和皮棉产量与铃重和衣分呈显性正相关;铃重与衣分呈显性正相关,衣分与子指的加性和显性均为负相关。杂种优势分析表明,中棉所63的铃重、衣分、子指、子棉产量和皮棉产量的群体平均优势达极显著水平,其皮棉产量的杂种优势可以利用至F3。     

陆地棉产量性状的遗传分析

采用加性-显性与环境互作的遗传模型,分析陆地棉8个杂交亲本和F128个组合的7个产量性状的两年试验资料,估算各项遗传方并非分量和F1、F2的杂种优势.结果表明,产量性状受加性效应和显性效应共同控制,加性×环境各产量性状均极显著,铃重、衣分、籽指还受显性×环境的极显著影响,7项产量性状的广义和狭义遗传率均达到极显著水准.     

转基因抗虫棉产量性状的遗传效应及其杂种优势分析

采用加性-显性与环境互作的遗传模型,分析了9个亲本和36个F1的皮棉产量、单株铃数、铃重和衣分的两年资料,估算了转基因抗虫棉各项遗传方差和成对性状间各项遗传效应的相关性.结果表明,转基因抗虫棉的产量性状受加性和显性效应共同控制,皮棉产量、铃重和衣分都以基因的显性效应为主,而单株铃数是以加性效应为主,单株铃数和衣分还具有基因与环境互作效应.遗传相关分析表明,转基因抗虫棉的皮棉产量与单株铃数的基因型和表现型相关系数都比较大而且比较接近;皮棉产量与单株铃数、铃重和衣分的加性相关系数都达到极显著水平,而且皮棉产量与单株铃数、衣分的数值比较大.利用亲本和F1的资料预测了F2基因型值和杂种优势,结果表明,转基因抗虫棉F2的皮棉产量、单株铃数、铃重和衣分的群体平均优势分别为4.0%、5.1%、-1.3%和3.2%,群体超亲优势分别为-7.3%、-6.0%、-4.2%和-0.5%.     

基于部分NCII交配设计的陆地棉产量和纤维品质性状遗传分析

以60份陆地棉品种（系）和由部分双因素交叉式遗传（North Carolina II,NCII）交配设计配制的180个F₁组合为材料,分析产量和纤维品质性状的遗传效应和相关性。结果表明,皮棉产量、衣分、铃数和铃重的加性效应方差分量分别为0.25、0.62、0.20和0.14,显性效应方差分量分别为0.17、0.13、0.07和0.21;纤维上半部平均长度、断裂比强度和马克隆值的加性效应方差分量分别为0.48、0.60和0.48,显性效应方差分量分别为0.05、0.02和0.06。各性状（除马克隆值外）的显性×环境互作效应均高于加性×环境互作。产量性状中,衣分与纤维上半部平均长度、断裂比强度和马克隆值的相关性较强,相关系数分别为-0.35、-0.40和0.48。除铃重之外,陆地棉的产量性状呈现出以加性效应为主的遗传特点;纤维上半部平均长度、断裂比强度和马克隆值的遗传以加性效应为主。部分NCII交配设计可用于同时对大量亲本进行评价。     

陆地棉铃形和纤维品质的遗传和相关研究

采用加性-显性及其与环境互作的遗传模型,对8个陆地棉亲本的F1代15个组合的铃长、铃宽、铃长/铃宽（长宽比）等3个铃形性状以及5项纤维品质指标的两年资料,进行了遗传方差分量分解和成对性状间的遗传效应的相关分析。结果表明,铃形性状和纤维品质性状主要受加性效应的影响,显性效应也有较大作用;铃长与长宽比的广义和狭     

QTL遗传效应正反交差异研究

应用改良AD模型对转基因棉花QTL突变体系进行遗传效应的正反交比较分析,结果表明,农艺性状的主要遗传方差组分分解正反交表现一致,除铃重存在显著的遗传背景加性效应(A2)外,子棉产量、皮棉产量、衣分和铃数均存在显著或极显著的 dQTL加性效应(A1)和显性效应(D1),农艺性状均有显著或极显著的遗传背景显性效应(D2);棉花纤维性状的主要遗传效应正反交之间无显著差异.铃重的dQTL的加性和显性效应与环境的互作存在显著差异.对转基因系、受体及三个品系的dQTL加性效应分解结果也表明,正反交对不同材料各性状的加性效应估计也是一致的.本文还对不同组合正反交时的纯合及杂合显性效应进行预测比较.     

陆海种间杂交铃重和衣分的遗传及其F1群体优势分析

以4个陆地棉品种(系)和3个海岛棉品种为亲本配制不完全双列杂交组合12个,采用包括基因型×环境互作的加性-显性(AD)遗传模型.通过对亲本和F1的2年随机区组试验数据分析,结果为铃重和衣分都存在极显著的加性效应和显性效应.其加性效应和显性效应与环境的互作都很小.铃重以加性效应为主,为 54.3%.显性效应相对较小,为 21.6%.衣分主要由加性效应和显性效应共同控制,其加性效应和显性同等重要.分别是 43.8%和 49.8%.铃重的狭义遗传率和广义遗传率分别为 54.3%和75.8%,衣分的狭义遗传率和广义遗传率分别为 43.8%和 93.6%.铃重和衣分F1均具有显著的负向群体平均优势和群体超亲优势,F1铃重小于中亲值.偏向低亲值;F1表分小于中亲值,接近或小于低亲值.在利用海岛棉的优异性状时,要考虑亲本材料的选择,要考虑到其性状遗传方式的特点,在进行陆海杂交、高代回交辅助选择时必须考虑性状的遗传效应.铃重可以在平世代进行选择,衣分应在中期世代选择效果较好.     

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.     

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.     

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...