马铃薯和蕃茄的融合植物的再生获得成功

在今年4月召开的育种学会上,日本麒麟啤酒公司报告了使马铃薯的栽培种(Sola-num tuberosum,染色体数2n=48)和蕃茄的野生种(Lycopersicon pimpinellifolium,2 n=24)的细胞经融合,所得杂种再生成植株。据报道,他们是将蕃茄野生种所具有的对青枯病和软腐病等病害有抗性的基因导入马铃薯中。这家公司一直致力于马铃薯的育     

猕猴桃果实软腐病的发生及防治措施

本文所介绍的猕猴桃果实软腐病,是一种使生产者特别担心的果实病害。 一、软腐病的症状和病原菌 典型的软腐病斑为近圆形,中央木栓化,大小不一,呈乳白色至乳黄色,周围为深     

非生物因素诱导马铃薯抗真菌病害研究的新进展

真菌病害是限制马铃薯生产的主要因素之一。生产中控制马铃薯真菌病害的主要手段是喷施化学杀菌剂。随着揭示植物抗病性机理的逐步深入,利用生物或非生物因子诱导植物、使其增强抗病性的研究已取得许多令人瞩目的成果,结合本研究室的一些研究工作,着重介绍了利用非生物因素诱导马铃薯抗真菌病害研究的一些新进展,同时就利用非生物因子控制马铃薯真菌病害的前景及存在问题进行了讨论。     

马铃薯抗病基因工程研究

马铃薯是世界上最主要的粮食作物之一,但真菌性病害、病毒性病害和细菌性病害等对马铃薯的危害非常严重,成为制约其产量的主要影响因素之一。近年来,随着基因工程的迅速发展,通过转基因的方法在提高马铃薯抗病性方面取得了较大进展,对其进展进行了综述。     

马铃薯晚疫病和病毒病防治技术

在北方马铃薯病害中晚疫病和病毒病一直是困扰马铃薯产量和品质发展的重要原因,病害损失可达20~40%。本文介绍一下马铃薯晚疫病和病毒病症状、发生规律及防治方法。     

马铃薯内生细菌的分离及其对环腐病菌的拮抗作用检测(简报)

马铃薯是世界四大作物之一,我国是世界上马铃薯种植面积最大的国家,种植面积达6000万亩。近年来,在马铃薯经济良好发展的带动下,马铃薯生产在种植面积和单产水平上有了大幅度提高。然而各种病害随之表现出逐年上升的趋势。环腐病、黑胫病、干腐病是造成北方马铃薯田间和窖存烂薯的主要病害,一般经济损失达20%—30%,严重年份可达50%。马铃薯环腐病害难以防治是因为病菌侵染部     

拟南芥对细菌性软腐病抗性变异分析

由胡萝卜软腐欧文氏菌胡萝卜软腐亚种 Erwinia carotovora subsp.carotovora （Ecc）引起的细菌性软腐病是世界性的重要流行病害,由于缺乏天然抗源,研究进展缓慢,拟南芥成为软腐病抗性研究的主要试材。本文选用 29 份拟南芥材料,制定了病情分级标准,以接种后 48 小时的病情指数作为软腐病抗性的鉴定指标,筛选出抗软腐病材料 CS906 和感病材料 CS20。通过分析抗、感材料接种 Ecc 后 AOS、ERF1-1、PR1、PDF1.2 和 PAL1 等 5 个基因的表达变化,发现 SA、ET 和 MJ 信号途径都参与了拟南芥对 Ecc 的防卫反应,且基因表达模式在抗、感材料中相似,差异体现在表达量上。本研究对深入探讨拟南芥软腐病抗病机制具有重要意义。     

余甘子采后软腐病菌的分离鉴定及其细胞壁水解酶活性

【背景】药食同源的余甘子果实在采后贮藏过程中极易软腐变质,严重影响其品质和经济价值。【目的】明确引起余甘子果实软腐病的病原菌种类及其生长特性和产细胞壁水解酶活性,为余甘子采后软腐病的控制及延长其贮藏期奠定基础。【方法】采用组织块分离法从采后发病的余甘子果实分离病原菌,按照科赫法则确定分离菌株的致病性;采用形态学特征结合rDNA-ITS序列分析对病原菌进行鉴定,测定病原菌菌丝生长和产孢特性,检测产胞外细胞壁水解酶活性。【结果】从具有软腐症状的余甘子果实中分离得到32株真菌,其中菌株DQ23是余甘子采后软腐病的致病菌,通过形态特征结合rDNA-ITS序列将其鉴定为Penicillium choerospondiatis。其菌丝在酵母膏葡萄糖琼脂培养基(YDA)上生长最快,在马铃薯蔗糖琼脂培养基(PSA)上产孢最多。该菌能有效利用多种碳、氮源,适宜产孢的碳源为蔗糖、葡萄糖,氮源为蛋白胨、牛肉膏、酵母膏。菌丝生长的最适温度和pH范围分别为25°C和3.0-5.0,产孢的最适温度和pH范围分别为25°C和4.0-7.0。光照均利于菌丝生长和产孢。该菌具有分解果胶、纤维素的能力,无分解蛋白质、鞣质的能力。【结论】Penicillium choerospondiatis是余甘子果实软腐病的病原菌,研究结果为该病害的防控奠定了基础。     

大花蕙兰生产中常见病虫害及其防治措施

本文介绍大花蕙兰生产中常见病害(疫病、软腐病、根腐病、炭疽病、叶枯病、毒素病等)和虫害(介壳虫类、粉虱、螨虫类、蚜虫、蟑螂等)的为害特征及防治方法。     

麒麟啤酒公司再生马铃薯和番茄的融合植株成功

日本麒麟啤酒公司融合了马铃薯的栽培种(Solanum tuberosum,染色体数2n=48)和番茄的野生种(Lycopersicon pimpinellifolium,2n=24)的细胞,并将杂种细胞再生成了植株,在4月上旬在东京召开的育种学会上发表了此成果。麒麟啤酒公司正在深入马铃薯的育种,上述工作的目的是向马铃薯导入番茄的野生种所具有的耐青枯病和软腐病以及疫病等的基因。这次使用的马铃薯栽培种是麒麟自己的系统,有细胞培养简单,且能旺盛地再生植物体     

Bacteriophages Isolated in China for the Control of Pectobacterium carotovorum Causing Potato Soft Rot in Kenya

Soft rot is an economically significant disease in potato and one of the major threats to sustainable potato production. This study aimed at isolating lytic bacteriophages and evaluating methods for and the efficacy of applying phages to control potato soft rot caused by Pectobacterium carotovorum. Eleven bacteriophages isolated from soil and water samples collected in Wuhan, China, were used to infect P. carotovorum host strains isolated from potato tubers showing soft rot symptoms in Nakuru county, Kenya. The efficacy of the phages in controlling soft rot disease was evaluated by applying individual phage strains or a phage cocktail on potato slices and tubers at different time points before or after inoculation with a P. carotovorum strain. The phages could lyse 20 strains of P. carotovorum, but not Pseudomonas fluorescens control strains. Among the 11 phages, Pectobacterium phage Wc5 r, interestingly showed cross-activity against Pectobacterium atrosepticum and two phage-resistant P. carotovorum strains. Potato slice assays showed that the phage concentration and timing of application are crucial factors for effective soft rot control. Phage cocktail applied at a concentration of 1 9 109 plaque-forming units per milliliter before or within an hour after bacterial inoculation on potato slices, resulted in C 90%reduction of soft rot symptoms. This study provides a basis for the development and application of phages to reduce the impact of potato soft rot disease.     

Effect of certain cultural practices on susceptibility of potato tubers to soft rot disease caused by Erwinia carotovora pv. carotovora

Erwinia soft rot causes destructive and serious damage to many vegetable crops including potato in the field, transit and storage periods. The effect of certain cultural practices on the susceptibility of potato tubers to soft rot bacteria was studied and the results of this work can be summarised in the following: potato tubers harvested on 1 May first exhibited the highest disease incidence compared with those harvested on 15 May or 30 May. Harvesting on 15 June resulted in the lowest disease infection. The application of high levels of nitrogen fertiliser as urea (46.5%), ammonium nitrate (31%) and ammonium sulphate (20.5%) resulted in an increase of the susceptibility of potato tubers to bacterial soft rot disease. In contrast, the addition of phosphorous as superphosphate (15.5%) fertiliser caused the reverse effect. The addition of potassium as potassium sulphate (48%) alone at any of the tested levels showed no effect. The susceptibility of potato tubers to bacterial soft rotting disease was increased by increasing storage periods at 4°C for 1, 2, 3 and 4 months. Spraying copper sulphate exhibited the highest decrease in soft rot incidence disease followed by manganese, zinc and iron. However, spraying of boron increased susceptibility to the disease. Potato tubers obtained from plants sprayed with copper and stored for different periods showed the lowest susceptibility to disease incidence. Tuber sprayed with zinc, iron, manganese and finally boron came next.     

Disease resistance conferred by expression of a gene encoding H2O2-generating glucose oxidase in transgenic potato plants.

Plant defense responses to pathogen infection involve the production of active oxygen species, including hydrogen peroxide (H2O2). We obtained transgenic potato plants expressing a fungal gene encoding glucose oxidase, which generates H2O2 when glucose is oxidized. H2O2 levels were elevated in both leaf and tuber tissues of these plants. Transgenic potato tubers exhibited strong resistance to a bacterial soft rot disease caused by Erwinia carotovora subsp carotovora, and disease resistance was sustained under both aerobic and anaerobic conditions of bacterial infection. This resistance to soft rot was apparently mediated by elevated levels of H2O2, because the resistance could be counteracted by exogenously added H2O2-degrading catalase. The transgenic plants with increased levels of H2O2 also exhibited enhanced resistance to potato late blight caused by Phytophthora infestans. The development of lesions resulting from infection by P. infestans was significantly delayed in leaves of these plants. Thus, the expression of an active oxygen species-generating enzyme in transgenic plants represents a novel approach for engineering broad-spectrum disease resistance in plants.     

Transgenic Potatoes Expressing a Novel Cationic Peptide are Resistant to Late Blight and Pink Rot

Potato is the world's largest non-cereal crop. Potato late blight is a pandemic, foliar wasting potato disease caused by Phytophthora infestans, which has become highly virulent, fungicide resistant, and widely disseminated. Similarly, fungicide resistant isolates of Phytophthora erythroseptica, which causes pink rot, have also become an economic scourge of potato tubers. Thus, an alternate, cost effective strategy for disease control has become an international imperative. Here we describe a strategy for engineering potato plants exhibiting strong protection against these exceptionally virulent pathogens without deleterious effects on plant yield or vigor. The small, naturally occurring antimicrobial cationic peptide, temporin A, was N-terminally modified (MsrA3) and expressed in potato plants. MsrA3 conveyed strong resistance to late blight and pink rot phytopathogens in addition to the bacterial pathogen Erwinia carotovora. Transgenic tubers remained disease-free during storage for more than 2 years. These results provide a timely, sustainable, effective, and environmentally friendly means of control of potato diseases while simultaneously preventing storage losses.     

马铃薯内生细菌的分离及其对环腐病菌的拮抗作用检测（简报）

马铃薯是世界四大作物之一,我国是世界上马铃薯种植面积最大的国家,种植面积达6000万亩。近年来,在马铃薯经济良好发展的带动下,马铃薯生产在种植面积和单产水平上有了大幅度提高。然而各种病害随之表现出逐年上升的趋势。     

细胞和分子技术在甘薯茎线虫病抗病育种中的应用

甘薯茎线虫病是我国北方甘薯薯区的重要病害之一。为进一步研究甘薯茎线虫病育种中线虫和甘薯的抗感关系,利用细胞培养技术建立发根农杆菌转化甘薯发根,用该发根培养马铃薯腐烂线虫,构建植物寄生线虫培养和抗性鉴定的技术平台;用聚合酶链式反应(polymerase chain reaction,PCR)分子标记技术筛选甘薯茎线虫病抗感品种的分子标记,并对发根培养马铃薯腐烂线虫体系和分子标记辅助选择抗甘薯茎线虫病品种技术进行了展望。     

Characterization of blackleg and soft rot from potato in northern Thailand

Blackleg and soft rot of potato cause economic loss through reduced yield and quality. The causal agents of bacterial blackleg and soft rot of potato were identified based on biological data and sequence analyses of the 16S rDNA gene. Between 2016 and 2018, diseased potato stems and tubers were collected in Chai Prakan District, Chiang Mai Province, and Chiang Khum District, Pa Yao Province. The symptoms included black stem lesions, soft rot on tubers, wilting, break down of the stem vascular ring and foliar yellowing. Of 13 bacterial isolates, five were identified as Pectobacterium carotovorum subsp. brasiliense, four‐Dickeya dadantii, two‐Pseudomonas putida and two‐Bacillus altitudinis. Pathogenicity tests of P. carotovorum subsp. brasiliense and D. dadantii resulted in lower leaves turning yellow and wilting followed by blackleg symptoms on lower stems and maceration of tuber tissue. Symptoms caused by P. putida were yellowing and wilting of leaves. B. altitudinis caused yellowing of the lower leaves and wilting followed by drying of leaf tissue. This is a first report of these bacterial pathogens causing blackleg and soft rot of potato in Thailand.     

Bacteriocin-like substance inhibits potato soft rot caused by Erwinia carotovora

Soft rot is a major problem encountered in potatoes during postharvest storage. The soft rot bacterium Erwinia carotovora was inhibited by a novel bacteriocin-like substance (BLS) produced by Bacillus licheniformis P40. The BLS caused a bactericidal effect on E. carotovora cells at 30 microg mL(-1). Transmission electron microscopy showed that BLS-treated cells presented wrinkled bacterial surfaces and shrinkage of the whole cell, indicating plasmolysis. Erwinia carotovora cells treated with BLS were analyzed by FTIR showing differences in the 1390 cm(-1) and 1250-1220 cm(-1) bands, corresponding to assignments of membrane lipids. BLS was effective in preventing E. carotovora spoilage on potato tubers, reducing the symptoms of soft rot at 240 microg mL(-1) and higher concentrations. Soft rot development was completely blocked at 3.7 mg mL(-1). This BLS showed potential to protect potato tubers during storage.     

The Role of Polyphenol Oxidase and Peroxidase in Potato Tuber Resistance to Soft Rot Caused by Erwinia carotovora

Tubers from somatic hybrids produced by protoplast fusion between Solanum brevidens, a diploid, non-tuber-bearing wild species, and a tetraploid S. tuberosum showed resistance to decay caused by soft rot Erwinia. Tubers of the S. tuberosum fusion parent and potato cultivar Russet Burbank are susceptible to bacterial soft rot. Tubers of somatic hybrids indicated higher levels of activities of polyphenol oxidase and peroxidase than tubers of the parental line of S. tuberosum and cultivar Russet Burbank. This is true for intact tubers and also for injured or inoculated tubers. Polish commercial potato cultivars indicated a higher susceptibility to soft rot than somatic hybrids. However, there were some differences in susceptibility to soft rot between Polish commercial potato cultivars, only slight differences were observed in the activities of the polyphenol oxidase and peroxidase between Polish cultivars. A relation between soft rot resistance and the activity of each enzyme was not found for intact, injured or inoculated tissue of commercial cultivars. On the contrary, the activities of both enzymes were significantly higher in the periderm than in the medullary tissue of somatic hybrids, the parental line and the commercial cultivars.