传染性囊病变异株病毒BK912的培育及鉴定

用由国外引进的ＩＢＤ变异株鸡胚适应毒经ＣＥＦ传代适应后所获得的ＢＫ９１２Ｆ。毒液进行了病毒理化特性试验和形态学观察,并与标准Ｉ型毒ＣＪ８０１ＢＫＦ株进行了抗原相关性检测。实验证明,ＢＫ９１具有ＩＢＤＶ的基本特性且与标准１型毒ＣＪ８０１ＢＫＦ株处于不同血清亚型,以２０００ＴＣＩＤ５０／０．２ｍｌ的ＢＫ９１２冻干活疫苗免疫ＳＰＦ鸡后能完全抵抗美国标准弯异株强毒１０８４Ａ的攻击,一系列试验有ＢＫ９１２仍     

用平反式超滤机浓缩鸡新城疫病毒及法氏囊病毒试验效果观察

采用ＵＦ－１型工业平板式超滤机对鸡新城疫病毒（ＮＤＶ）及法氏囊病毒（ＩＢＤＶ）进行了初步的浓缩试验。该调和浓缩工艺简单、效率高，浓缩液ＨＡ液价与未浓缩液比较按浓缩比率相应上升。用浓缩液与未浓缩液制成灭活疫苗免疫鸡，均可获得１００％抵抗ＮＤ及ＩＢＤ的保护力，以浓缩苗免疫的ＤＮ ＨＩ抗体及ＩＢＤ中和抗体滴度明显高于未浓缩苗。试验表明，浓缩苗安全有效，并优于未浓缩苗。     

鸡传染性囊病二价活疫苗攻击保护滴度的测定

使用ＳＰＦ雏鸡进行鸡传染性囊病二价活疫苗的攻击保护滴度的测定。ＳＰＦ雏鸡１４日龄免疫，于免疫后７ｄ、８ｄ、９ｄ、１０ｄ、１２ｄ、１４ｄ采血进行ＩＢＤ中和抗体的测定，同量分别进行标准Ｉ型强毒ＣＪ８０１株和标准变异株强毒１０８４Ａ株的攻击，建立抗体滴度与攻击保护率之间的直线回归方程。二价苗免疫后１４ｄＩＢＤ中和抗体滴度达到２９６８（ＧＭＴ），其对ＣＪ８０１株和１０８４株的攻击保护率分别为８９．２１％和     

用平板式超滤机浓缩鸡新城疫病毒及法氏囊病毒试验效果观察

采用ＵＦ１型工业平板式超滤机对鸡新城疫病毒（ＮＤＶ）及法氏囊病毒（ＩＢＤＶ）进行了初步的浓缩试验。该设备浓缩工艺简单、效率高,浓缩液ＨＡ效价与未浓缩液比较按浓缩比率相应上升。用浓缩液与未浓缩液制成灭活疫苗免疫鸡,均可获得１００％抵抗ＮＤ及ＩＢＤ的保护力,以浓缩苗免疫的ＮＤＨＩ抗体及ＩＢＤ中和抗体滴度明显高于未浓缩苗。试验表明,浓缩苗安全有效,并优于未浓缩苗。     

鸡传染性法氏囊病超强毒901株的分离和鉴定

从暴发鸡传染性法氏囊病死亡率６３．５１％的病死鸡中，分离出一株ＩＢＤ病毒９０１株，经检测，９０１株是一株ＩＢＤＶ超强毒株，可使３１日龄健康雏鸡７１．４％死亡，１０日龄ＳＰＦ鸡胚和３０日龄ＳＰＦ雏鸡１００％死亡。死亡鸡再现了自然暴发ＩＢＤ的典型病变。     

IB(M41株)种毒代次和免疫原性的关系

评估不同代次IBV M41株种毒是否可以作为生产用种子。将M41株种毒用SPF胚连传8代,从中选出第3、第5、第7代,测定其EID50。并用此3代M41株鸡胚尿囊液制毒的油乳苗免疫易感鸡,以HI试验检测其抗体水平。3种疫苗免疫鸡均保护9/10以上,对照鸡全发病;对免疫后与免疫前HI抗体水平的比较表明,免疫后抗体平均滴度提高3倍以上。不同代次的M41毒株的免疫原性仍然保持良好,可以正常用来制造疫苗和建立种子批。     

鸡传染性支气管炎弱毒苗与灭活苗的免疫效果评价

采用鸡传染性支气管炎弱毒疫苗及肾型和呼吸型毒株的灭活苗对鸡进行了免疫，根据鸡免疫后的抗体水平动态变化和攻毒后鸡肾脏和气管水平上的保护力，比较了传染性支气管炎弱毒苗H120与两个不同致病型毒株灭活苗的免疫效果。试验结果表明，弱毒苗虽可诱导较高水平的抗体，但免疫效果较灭活苗差。     

大蒜发芽叶培养体细胞胚发生

将大蒜发芽叶培养于ＭＳ（１／２ＮＨ４ＮＯ３＿＋２，４－Ｄ２ｍｇ／Ｌ＋ＫＴ０．５ｍｇ／Ｌ上，形成愈伤组织。愈伤组织继代后，转移到ＭＳ（ＫＮＯ３２５２５ｍｇ／Ｌ＋（ＮＨ４）２ＳＯ４１６５０ｍｇ／Ｌ，无ＮＨ４ＮＯ３）＋ＫＴ２ｍｇ／Ｌ＋６－ＢＡ４ｍｇ／Ｌ＋Ａｄｅｎｉｎｅ２ｍｇ／Ｌ＋ＩＡＡ０．０１ｍｇ／Ｌ培养基上，２５天后，形成体细胞胚并能再生植株。其中，胚状体发生的必要条件是ＮＯ３／ＮＨ＾＋４＞１，ＫＴ／     

鸡传染性鼻炎二价油乳剂灭活疫苗的近期免疫效力检验

应用３批鸡传染性鼻炎价油乳剂灭活疫苗进行了安全性和近期免疫效力检验,安全性试验采用１５只鸡进行,胸肌注射疫苗４￣５ｍＬ／只后,逐日观察,结果鸡只食欲、精神未见异常,２周后观察,注射部位未发现明显异常和病变。用该疫苗免疫（０．５ｍＬ／ｋｗ ）后的鸡只对Ａ型高致病力菌株的攻击保护率可达１００％,对Ｃ型高致病力菌株的攻击保护率为９３．３％。采用Ｂ－ＥＬＩＳＡ和ＳＰＺＡ对鸡群的抗体水平的评估表明该疫苗可激发产生较高的抗体水平。     

鸡新城疫、传染性支气管炎、减蛋综合征、传染性脑脊髓炎四联油佐剂灭活疫苗的研究

用NDV La Sota株、IBV M41株、EDS76V HSH23株、AEV Van Roekel株为种毒，分别接种鸡胚或鸭胚，制备各种病毒抗原液，经福尔马林灭活后，采用FIL TRON盒式超滤系统对制苗病毒抗原液进行浓缩，然后按一定比例混合，以司本80及吐温80为乳化剂，10号白油为佐剂，制成ND-IB-EDS76-AE四联灭活疫苗。对四联苗各项技术指标进行了测定，证明本疫苗安全、无任何副作用；免疫10～14d后产生免疫力；ND部分效检，攻毒100％保护，每羽份含ND效价达50～123PD50；IB部分效检，免疫21～28d后攻毒保护率达80％～100％，IBHI效价≥1：64；EDS76效检。免疫后21d HI效价≥1:128;AE效检,保护率达80%～100%。     

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...