亚蔬中心绿豆品种（系）抗白粉病评价

采用苗期人工接种鉴定法,在大棚种植条件下对12个亚蔬中心(AVRDC)绿豆品种白粉病抗性进行了鉴定评价。结果显示,VCl560C、V4785和VC2768A三个品种高抗(HR)白粉病,VC6173—14、V1132为中抗(MR)白粉病品种。其它品种对白粉病表现高度感病。在田间种植条件下对亚蔬中心16个抗豆象回交9代品系(BC9)进行了成株期白粉病抗性鉴定。与对照感病品种VCl973、VC1178A相比,VC6459—3—6—37和VC6458—6—3—16对白粉病具有一定抗性,但白粉病感染程度仍很严重,其它14个BC9品系均对白粉病表现高度感病。     

绿豆抗豆象品系及回交亲本抗性鉴定

对亚蔬中心(AVRDC)抗豆象育种2个回交第12代品系(BC12)及其回交亲本进行了豆象抗性评价和比较,结果表明:豆象在绿豆种子表面的产卵量及产卵率,BC12及其回交亲本之间无显著差异;第一代成虫羽化量、羽化率及种子受害量、种子受害率,BC12与其回交亲本存在显著差异(P<0.05)。相关分析结果表明:绿豆种子受害量和一代成虫羽化量成极显著正相关,种子受害量与成虫产卵量无相关关系。而成虫产卵量与一代成虫羽化量成极显著正相关。回交后代与其回交亲本比较分析显示:在种子受害量上,BC12与其回交后代存在极显著差异(p<0.01),这意味着 BC12确实存在抗豆象性能。     

绿豆抗豆象品系及回交亲本抗性鉴定

对亚蔬中心（ＡＶＲＤＣ）抗豆象育种２个回交第１２代品系（ＢＣｌ２）及其回交亲本进行了豆象抗性评价和比较,结果表明：豆象在绿豆种子表面的产卵量及产卵率,ＢＣｌ２及其回交亲本之间无显差异;第一代成虫羽化量、羽化率及种子受害量、种子受害率,ＢＣｌ２与其回交亲本存在显差异（Ｐ＜０．０５）。相关分析结果表明：绿豆种子受害量和一代成虫羽化量成极显正相关,种子受害量与成虫产卵量无相关关系。而成虫产卵量与一代成虫羽化量成极显正相关。回交后代与其回交亲本比较分析显示：在种子受害量上,ＢＣｌ２与其回交后代存在极显差异（Ｐ＜０．０１）,这意味看ＢＣｌ２确实存在抗豆家性能。     

绿豆抗豆象育种品系综合评价

豆象是绿豆主要仓储害虫,目前生产上尚无可直接利用的抗豆象品种。本通过对20个抗豆象育种品系主要农艺性状和营养品质、抗痛虫及抗逆性综合分析,发现参试品系多属早熟、大粒、高蛋白类型,但在抗虫性、耐干旱、耐瘠薄、单株荚数、单株产量、抗叶斑痛、耐盐性等方面存在较大差异,具有广阔的遗传选择余地。筛选出97—28、98—15、97—15、97—17、97—19等农艺性状优良的抗豆象品系。     

2003-2013年小麦品种(系)抗条锈性鉴定及评价

2003-2013年在甘肃省农业科学院植物保护研究所兰州温室和甘谷试验站,分别对来自国内35个相关育种单位的冬春小麦品种(系)5001份,其中冬小麦4291份、春小麦710份,进行苗期混合菌、成株期分小种和混合菌抗条锈性接种鉴定,结果表明:全生育期表现免疫近免疫的有兰天31号等479份,高抗的有兰天23号等76份,中抗的有天选49等291份,分别占9.58％、1.52％和5.82％;成株期表现免疫近免疫的有天选50号等840份,高抗的有兰天27号等47份,中抗的有天选52等311份,分别占16.80％、0.94％和6.22％;苗期表现免疫近免疫的有兰天30号等964份,高抗的有天98102等122份,中抗的有00-30等273份,分别占19.28％、2.44％和5.46％.冬小麦有天选49号等914份材料表现全生育期抗病,占18.28％;有97-473等906份成株期表现抗病,占18.12％;有兰天20号等1225份苗期表现抗病,占24.50％.春小麦有定西41号等113份材料全生育期表现抗病,占2.26％;有陇春28号等125份成株期表现抗病,占2.50％;有0109-1等114份苗期对混合菌表现抗病,占2.28％.先后在甘肃天水汪川良种场对相关材料进行成株期抗条锈性评价,结果发现:1154份从小种圃筛选出的抗病材料中,表现抗病的有兰天31号等745份,占64.56％;105份甘肃陇南生产品种中,到2013年表现抗病的仅有兰天28号、中梁31号等30份材料,占28.57％;后备品系中,00-30-2-1、CP04-20、00127-2-3等抗性表现优异;抗源材料中,仅有贵农775、中四、T.Spelta albun、贵协1、贵协3等少数材料表现抗病,重要抗源材料贵农21、贵农22、南农92R、川麦42、Moro从2011年开始在田间表现感病,逐步失去利用价值.其衍生系品种材料如陇鉴9343、天选43号、中梁29号、兰天17号、兰天24号等也在田间逐步感病,条锈病发生流行压力持续增大.     

植物抗白粉病的分子机理

随着分子生物学与其相关技术的飞速发展 ,已克隆到了一系列的植物抗病基因和防御基因 ,加深了对植物与病原微生物相互作用分子机制的了解 ,促进了植物抗病分子机理的研究。国内外许多学者对大麦抗白粉病的分子机制进行了较系统的研究 ,在拟南芥菜中也找到了许多抗白粉病基因 ,这些结果对研究其它植物抗白粉病机制提供了线索。本文就该方面的研究进展加以阐述 ,并讨论了抗病机理在抗病育种工作中的应用前景。     

小麦抗白粉病基因Pm23的RAPD标记

小麦抗白粉病基因Pm23对世界上很多麦区流行的白粉病表现高抗或免疫.本研究以Pm23和Chancellor为抗感亲本,用集群分离分析法对抗性基因Pm23进行了RAPD分析,从320个十碱基随机引物中筛选到一个与Pm23紧密连锁的相引相标记OPE051100. 对F2分离群体进行RAPD分析表明,该标记与Pm23基因之间的连锁距离为10.65±3.25 cM.该标记可以有效用于小麦育种分子标记辅助选择中.     

不同棉花品种(系)抗盲蝽田间鉴定与评价

采用目测法调查棉田盲蝽混合种群发生数量,并结合盲蝽对棉花植株的危害程度,对162个供试棉花品种(系)进行了抗盲蝽鉴定及评价。共计筛选获得包括亚洲棉、灵-29、07生试6号等16个对盲蝽具有抗性潜力的棉花品种(系),以及辽阳多毛棉、冀丰989、08生试6号、大铃668、石抗338、HB5 6个对盲蝽敏感的棉花品种(系)。初步建立了棉花品种(系)抗盲蝽田间鉴定与评价技术规程,为棉花抗盲蝽育种提供了种质资源及技术参考。     

甜瓜抗白粉病基因SRAP分子标记筛选

以感白粉病甜瓜A120和抗白粉病甜瓜A119为亲本构建F2代分离群体,采用BSA和SRAP相结合的方法筛选与甜瓜抗白粉病基因相连锁的分子标记.结果显示,294条SRAP引物中有6条引物在抗病与感病池间表现出多态性;对8个高抗和8个高感单株进行扩增,引物me46em51和me3em6分别在高感单株中扩增出210 bp和205 bp的多态性条带,而高抗单株无此扩增带,与抗病、感病池结果一致.采用JoinMap3.0软件进行连锁分析,两标记与抗白粉病基因的连锁距离分别为18.2 cM和23.4 cM,初步推测本实验中甜瓜白粉病抗性为隐性多基因控制.     

小麦抗白粉病基因定位与分子标记

对小麦抗白粉病基因的遗传定位与分子标记进行了综述,介绍了小麦抗白粉病的遗传,并对今后的研究方向进行了讨论。     

Inheritance of powdery mildew (Erysiphe polygoni DC) resistance in mungbean (Vigna radiata L. Wilczek)

Detached mungbean (Vigna radiata L.Wilczek) leaves were inoculated with a conidial suspension of a local isolate (TI-1) of the powdery mildew pathogen (Erysiphe polygoni DC) under controlled environment conditions. Based on the latent period and severity of the infection, a rating scale of 0–5 was used to classify the host pathogen interactions. Reactions 0, 1 and 2 were considered resistant and referred to as R0, R1 and R2 while 3, 4 and 5 were classified as susceptible (S). RUM lines (resistant to powdery mildew) and their derivatives are crossed with several susceptible (reaction types 3–5) genotypes and the inheritance of the resistance was studied in the F₁, F₂ and F₃ generations. The results showed that powdery mildew resistance in mungbean is governed by two dominant genes designated as Pm-1 and Pm-2. When both Pm-1 and Pm-2 were present, an R0 reaction was observed after inoculation with TI-1. The resistant reaction was R1 when only Pm-1 was present and R2 in the presence of Pm-2. In the absence of both Pm-1 and Pm-2, susceptible reactions 3, 4 and 5 were observed.     

A high-resolution genetic map and a diagnostic RFLP marker for the Mlg resistance locus to powdery mildew in barley

The semi-dominantly acting Mlg resistance locus in barley confers race-specific resistance to the obligate biotrophic fungus Erysiphe graminis f.sp. hordei. A high-resolution genetic map was constructed at Mlg based on a cross between the near-isogenic barley lines Pallas BC₅ Mlg and Pallas mlg. A total of 2000 F₂ progeny were inspected by cleaved amplified polymorphic sequence (CAPS) analysis, defining a 4.47 cM interval encompassing the resistance locus. Pathogen challenge of the segregants with multiple powdery mildew isolates uncovered a novel resistance specificity in Pallas BC₅ Mlg. Probes from within 4.0 cM of Mlg were mapped in rice, revealing orthologues on five different rice chromosomes and suggesting multiple breaks of chromosomal collinearity in this region between the two grass species. The most tightly Mlg-linked RFLP marker, MWG032, was shown to reliably detect the presence of the resistance allele in a collection of 30 European barley cultivars. Received: 23 March 2000 / Accepted: 20 April 2000     

Resistance to oat powdery mildew in Britain and Europe: a review

The evolution of virulence in UK oat powdery mildew (Blumeria graminis f.sp. avenae) populations is presented along with comparative information on the deployment of resistant cultivars. Virulence frequencies have followed classical gene‐for‐gene principles, and there are no effective resistance genes currently deployed in cultivars grown in the UK. The incidence of powdery mildew in continental Europe and pathogen variation is reviewed as well as other strategies for the control of this disease. New resistant sources have been identified and are being used in breeding programmes throughout Europe.     

Regulation of resistance and susceptibility in wheat–powdery mildew pathosystem with exogenous cytokinins

Dose–response relationship between resistance of wheat seedlings (Triticum aestivum, cultivar Zarya) to Erysiphe graminis f. sp. tritici Marchal. (Syn. Blumeria graminis), a causal organism of wheat powdery mildew and exogenous zeatin has been investigated. Two-week-old seedlings were inoculated with the pathogen. Zeatin or zeatinriboside were added to the nutrient solution immediately after inoculation. The dose–response curve of cytokinin in the most cases was multiphasic, with peaks of increased susceptibility occurring at 0.25–1.5 and 1.5–9 μM cytokinin, separated by a region of increased resistance at 0.5–3 μM cytokinin. The change in mineral nutrition or simultaneous treatment with thidiazuron revealed alterations of the dose–response curve ranging from a curve with maximum of resistance to a curve with maximum of susceptibility. Both multiphase nature of dose–response and its variability were proposed as possible explanations for earlier observed discrepancies in experimental data on modification of disease resistance by cytokinins. A mathematical model for two metabolic processes with substrate inhibition connected in-series was suggested to explain the multiphase dose–response. In this model, the product of the first reaction was used as substrate for the second reaction. Numerical experiments showed the changes in the shape of dose–response curve with changes in parameters dependent of cytokinin metabolism.     

Mapping oligogenic resistance to powdery mildew in mungbean with RFLPs

We have used restriction fragment length polymorphisms (RFLPs) to map genes in mungbean (Vigna radiata) that confer partial resistance to the powdery mildew fungus, Erysiphe polygoni. DNA genotypes for 145 RFLP loci spanning 1570 centimorgans of the mungbean genome were assayed in a population of 58 F₂ plants. This population was derived from a cross between a moderately powdery mildew resistant (VC3980A) and a susceptible (TC1966) mungbean parent. F₃ lines derived from the F₂ plants were assayed in the field for powdery mildew response and the results were compared to the RFLP genotype data, thereby identifying loci associated with powdery mildew response. A total of three genomic regions were found to have an effect on powdery mildew response, together explaining 58% of the total variation. At 65 days after planting, two genomic regions were significantly associated with powdery mildew resistance. For both loci, the allele from VC3890A was associated with increased resistance. At 85 days, a third genomic region was also associated with powdery mildew response. For this locus, the allele from the susceptible parent (TC1966) was the one associated with higher levels of powdery mildew resistance. These results indicate that putative partial resistance loci for powdery mildew in mungbean can be identified with DNA markers, even in a population of modest size analyzed at a single location in a single year.     

Evaluation of biocontrol agents and potassium silicate for the management of powdery mildew of zucchini

Investigations were conducted under greenhouse and field conditions to evaluate the effects of potential biocontrol agents (BCAs) and soluble silicon (Si) on powdery mildew of zucchini caused by Podosphaera xanthii. Five BCAs were applied as foliar sprays to zucchini leaves and Si was drenched weekly into the rhizosphere of these plants.In the greenhouse, all BCAs provided significant control of powdery mildew with fungal isolates, reducing disease levels by up to 90%. Si alone reduced powdery mildew by as much as 35% and improved the efficacy of most of the biocontrol agents. Higher disease pressure reduced the efficacy of Si on powdery mildew but did not affect the performance of the BCAs. In the field, a disease reduction of 10–70% was achieved by BCAs and Si. Lower temperatures and high humidity ranges were suitable for optimal performances. The efficacy of the bacterial BCA, Serratia marcescens – B15 and silicon diminished at temperatures above 25 °C. The fungal BCAs (Clonostachys rosea – EH and Trichothecium roseum – H20) were better suited to higher temperatures (25–30 °C) and were tolerant of low RH values. Application of K₂SiO₂ to zucchini roots increased the level of Si in the leaves, which was responsible for suppression of the disease.     

Cytological characterization,powdery mildew resistance and storage protein composition of tetraploid and hexaploid 1BL/1RS wheat-rye translocation lines

Summary Progenies of a tetraploid 1BL/1RS wheat-rye translocation line, CV 256, selected from the cross Cando x Veery, were analyzed by means of Giemsa C-banding. CV 256 is cytologically stable for the presence of the 1BL/1RS translocation but still segregating for A- and B-genome chromosomes of Cando and Veery. In CV 256, nucleolar activity of the 1RS NOR locus is suppressed, as judged by the absence of a secondary constriction in that rye segment and the capability of organizing nucleoli. PAGE analysis of prolamins confirmed the presence of two 1RS secalins in all single seeds analyzed. SDS-PAGE analysis of reduced glutenins of single seeds indicated that some seeds contained the Cando Glu-B1 locus (subunits 6+8), some contained the Veery Glu-B1 locus (subunits 7+9) while others contained all four subunits, indicating that the material was heterozygous. Pm8 resistance is expressed in the tetraploid 1BL/1RS translocation line based on the reactions of six well-defined powdery mildew isolates. However, Pm8 resistance is not expressed in the hexaploid wheat cultivars Olymp, Heinrich and Florida, which also contain the 1BL/1RS translocation. Obviously, the existence of the 1BL/1RS translocation is not a proof for the expression of the associated genes. PAGE results did not show a clear linkage between powdery mildew resistance and the presence of 1RS secalins.     

Development and molecular cytogenetic analysis of wheat-Haynaldia villosa 6VS/6AL translocation lines specifying resistance to powdery mildew

Several Triticum aestivum L.-Haynaldia villosa disomic 6VS/6AL translocation lines with powdery mildew resistance were developed from the hybridization between common wheat cultivar Yangmai 5 and alien substitution line 6V(6A). Mitotic and meiotic C-banding analysis, aneuploid analysis with double ditelosomic stocks, in situ hybridization, as well as the phenotypic assessment of powdery mildew resistance, were used to characterize these lines. The same translocated chromosome, with breakpoints near the centromere, appears to be present in all the lines, despite variation among the lines in their morphology and agronomic characteristics. The resistance gene, conferred by H. villosa and designated as Pm21, is a new and promising source of powdery mildew resistance in wheat breeding.This research was supported by grants from the National High-Tech R and D Program and the National Science and Technology Commission