新型选择性培养基检测土壤棉花黄萎病菌效果初报

介绍了一种用于检测土壤棉花黄萎病菌的选择性培养基。该培养基成份为：鲜棉叶100g,蔗糖5g,琼脂17~20g,40%PCNB0.3g,氯霉素、链霉素和青霉素各0.05g,水1000ml,pH6.4~7.0。该培养基与其它常见分离培养基相比,成份简单、操作简便,检测率显著,抑菌效果好,病菌在其上生长快、菌落典型,是一种较为理想的选择性分离培养基。     

从土壤中分离棉枯萎病菌(Fusarium oxysporum f.sp.vasinfetum (Atk) Synder & Hansen)选择性培养基研究

本文介绍一种用于分离检测土壤中棉枯萎病菌的选择性培养基—植选2号。其成分为:KH_2PO_41g,MgSO_4·7H_2O 0.5g,K_2S_2O_50.2g,KCl0.6g,NH_4NO_3 0.5g,蛋白胨5g,山梨糖10g,蔗糖5g,琼脂20g,蒸馏水1000ml,PCNB 620mg,Oxgall1g,硫酸链霉素300mg,盐酸金霉素75mg。根据棉枯萎病在此培养基上的形态特征,能较容易地识别和检测该病菌。     

一种海洋细菌显色分离培养基优化

针对一种海洋细菌显色分离培养基的成分进行了探究。通过改变科玛嘉海洋细菌培养基中硫代硫酸钠(0.500、0.375、0.250、0.125 g/L),ONPG(1.5、1.0、0.5 g/L),纤维二糖(4.0、3.0、2.0、1.0 g/L)的浓度,观察培养基中海洋细菌菌落形态,菌落面积大小和菌落颜色,统计对比出海洋细菌在不同浓度培养基上生长的状况。结果在硫代硫酸钠浓度为0.25 g/L,纤维二糖浓度为2.0 g/L,ONPG浓度为0.5~1.0 g/L时,培养基上菌落清晰,个体适中且菌落数较多,有较好的检测效果。说明该研究在保证海洋细菌显色分离培养基分离效果前提下,降低了海洋细菌显色培养基配制成本,同时,提升了其对海洋细菌的检测效果。     

诱导富集胞外灵芝酸A的液态发酵培养基研究

使用液态发酵培养基直接诱导富集活性成分可以高效获得食用菌活性物质.本研究设计一种胞外液态灵芝酸A诱导富集培养基,诱导富集三萜类化合物灵芝酸A.通过单因素试验,研究了培养基中的碳源、氮源、生长因子对灵芝酸A产量的影响,确定了最佳诱导富集培养基组分及其浓度.结果表明,灵芝酸A诱导富集培养基配方为:葡萄糖25～30 g/L,组氨酸0.5～0.7 g/L,复合维生素B 10～50 mg/L.     

野生红菇菌丝体的分离

本文以广西浦北县椎林下野生红菇的子实体作为分离材料,对子实体的不同部位进行组织分离和孢子分离,分别接入不同配方的培养基上进行菌丝萌发试验,获得了红菇组织分离纯培养菌丝体。比较了几种不同成分培养基的分离效果,并对所获菌丝体的形态特征进行初步研究。经3代母种扩转,在Ⅰ号、Ⅴ号母种培养基上菌丝生长良好。     

茉莉花粉离体培养萌发及花粉管生长特性研究

为了揭示茉莉花粉育性并为其活力检测提供一种高效方法,研究了取粉时间、基本培养基种类及不同添加物浓度、pH值、温度、光照、时间等因素对花粉离体培养萌发和花粉管生长的影响,并应用扫描电子显微镜观察了花粉在柱头上的萌发情况,以对检测方法进行验证。结果显示,早上8：00-9：00所取花粉活力最高,适宜萌发的培养基为BK（成分为100 mg/L的H3BO3、100 mg/L的KNO3、200 mg/L的MgSO4·7H2O和300 mg/L的Ca（NO3）2·4H2O）＋蔗糖80 g/L＋PEG4000120 g/L,适宜的pH值6．0,最佳培养温度为25～30℃、光照为35～50μmol/（ m2· s）、时间为3～4 h。相关性分析发现,花粉萌发和花粉管生长均与光照强度和培养时间呈极显著正相关（P＜0．01）,与培养基pH值呈正相关、与蔗糖和PEG4000浓度均呈负相关、与培养温度分别呈负相关和正相关,但相关性均未达显著水平（P＞0．05）。研究表明,茉莉花粉总体上活力较低,离体培养萌发不失为一种简单、快速、可靠的检测方法,但应注意对培养条件的选择和优化以达到最佳效果。     

玫瑰黄链霉菌Men-myco-93-63活性成分的初步研究

对拮抗链霉菌Men-myco-93-63固体培养基中活性成分的提取分离进行了初步研究,最后确定乙酸乙酯与丙酮3∶1（V/V）的混合提取剂为最佳提取剂,并明确了该活性成分属于脂溶性。进行了活性成分存在部位的测定试验,结果发现活性成分既存在于菌丝体中,又存在于培养基中。通过HPLC对活性成分进行检测,确定了其中能够进行纯化的组分。     

玫瑰黄链霉菌Men-myco-93-63活性成分的初步研究

对拮抗链霉菌Men-myco-93-63固体培养基中活性成分的提取分离进行了初步研究,最后确定乙酸乙酯与丙酮 3∶1(V/V)的混合提取剂为最佳提取剂,并明确了该活性成分属于脂溶性.进行了活性成分存在部位的测定试验,结果发现活性成分既存在于菌丝体中,又存在于培养基中.通过HPLC对活性成分进行检测,确定了其中能够进行纯化的组分.     

响应面法优化海藻糖合酶产菌的发酵条件

为了优化响应面法海藻糖合酶产生菌pET-30a(+)/TreS的发酵培养基。用Plackett-Burman设计法评价发酵培养基的8个成分对海藻糖合酶的影响,然后用最陡爬坡实验确定重要成分在中心复合设计中的取值变化范围,最后用中心复合设计响应面法求出了重要成分的最佳浓度。结果表明：麦芽糖、蛋白胨和牛肉膏对海藻糖合酶酶活力影响显著(P＜0.05),是重要成分,其最佳浓度分别为：麦芽糖22.07 g/L、蛋白胨5.46 g/L、牛肉膏2.16 g/L。优化后的培养基酶活力达到0.826 U/mL,比基础发酵培养基培养重组菌的酶活力提高了2倍。说明数理统计实验设计及分析的方法成功地用于了海藻糖合酶基因工程菌pET-30a(+)/TreS的发酵培养基优化,为工业化发酵生产海藻糖合酶奠定了理论基础。     

高效毛细管电泳对复合B药片中水溶性维生素含量的快速测定

本文改进了毛细管电泳法同时分离检测多种水溶性维生素的方法,在柱温25℃、电压25kv、40mMpH8.4磷酸二氢钾-硼砂缓冲液的电泳条件下,7min内实现了7种水溶性维生素（VB1、VB12、VB2、VB6、VC、烟酸和叶酸）的良好分离。利用上述的毛细管电泳法对复合B药片中7种水溶性维生素进行了检测,其迁移时间重现性为0.0625%～1.2224%,峰面积重现性为1.82%～4.70%,回收率为96.2%～105.3%检测限为0.03μg/ml。     

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.     

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.     

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.     

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...