共查询到20条相似文献，搜索用时 609 毫秒
1.
柑桔是桂林市的重要的经济果树,2005年全市共有水果面积19·30万ha,其中柑桔类面积8·46万ha,占全市水果面积的43·83%,产量106·95万t,产值203 191万元。柑桔生产,给我市农民带来了巨大经济效益,对农民脱贫致富,起着举足轻重的地位。近年来,柑桔粉虱Dialeurodes citri(Ashmead)在桂林市柑桔园发生为害十分严重,由原来的局部发生转为普遍发生,其发生为害程度已不亚于柑桔红蜘蛛。柑桔粉虱主要以成虫、幼虫为害春、夏、秋各次新梢叶片及果实,群集在叶背及果实上吸食汁液,被害叶片退绿变黄,并分泌大量蜜露,污染叶片和果实,引发煤烟病,叶片受… 相似文献
2.
柑桔苗疫病是柑桔苗期的重要病害之一 ,在生产上易被误认作柑桔炭疽病或苗木立枯病。笔者通过近几年在广西资源县及其邻近区域一些柑桔育苗基地调查发现 ,该病易造成严重轻济损失 ,且其发生呈上升趋势 ,宜引起重视。1 症状该病主要为害柑桔苗的嫩叶、顶芽和嫩梢 ,有时也可侵染老熟叶片和枝梢。叶片受害初出现暗绿色水渍状斑点 ,随后迅速扩展成近圆形或不规则形大病斑 ,如开水烫伤状 ,颜色也逐渐转变为灰绿色至黑褐色。天气阴雨潮湿时 ,病斑扩展极快 ,病斑一般大至全叶 1/ 3～ 1/ 2以上 ,最后造成全叶腐烂并脱落 ;天气干燥时则病斑缓慢扩展… 相似文献
3.
4.
5.
广西境内,丘陵山地约占全区面积的85％,属亚热带湿润季风气候。经长期实践证明,从南到北均可种植柑桔。因此,充分利用众多低矮坡地种植柑桔等水果,是振兴广西农业,农民群众脱贫致富的有效途径。据1986年统计,全区柑桔种植面积已达60万亩,年产量约13.4万吨,平均亩产仅223公斤。造成产量低下的原因,除栽培管理技术 相似文献
6.
7.
柑桔溃疡病是柑桔最危险的病害之一,为世界性检疫对象。它主要危害柑桔的地上部分(叶片、枝条、皮刺、树干和果实),印度也有危害根部的报道。柑桔溃疡病很少会直接杀死树木,但会导致落叶、落果、树势衰弱和果实生锈斑,这不仅降低了果品的经济价值,并且严重影响了出口外销。1 病害分布及发生历史1.1 病害分布柑桔溃疡病主要分布在亚洲、非洲、马来群岛、大洋洲以及南美洲和北美洲。在中国,广东、广西、福建、湖南、湖北、江西、浙江等省是常发区。1.2 发生历史1913年,柑桔溃疡病在美国的德克萨斯州与佛罗里达州首先被确定为一种新病害,191… 相似文献
8.
在日益频繁的国际贸易和科技交流中,对国外发生的一些严重危害柑桔生产,而又与我国柑桔黄龙病相类似的病害加以调查了解,显得十分必要。现将调查了解的资料综述如下。国际上与我国柑桔黄龙病相类似的病害主要有南非的青果病(greening)我国台湾省的立枯病,菲律宾的叶斑黄病(leafmoftling yellows)、印度的梢枯病(die 相似文献
9.
10.
芒果叶片营养诊断与防治技术 总被引：3，自引：0，他引：3
芒果（ＭａｎｇｉｆｅｒａｉｎｄｉｃｅＬ．）属漆树科芒果属 ,是东方最著名的水果 ,也是５大热带名果之一。芒果果实以其形、色、香、味均极佳而有“果王”之称 ,在热带、亚热带地区著名出口水果中占有重要的地位。我国芒果主要分布在海南、广西、广东、云南、台湾和福建等省（区） ,四川省南部也有引种。随着芒果栽培面积的猛增 ,生产中如何识别、防治缺素症是芒果丰产不容忽视的关键因素之一。从表１可看出 ,芒果缺素在叶片上均表现失绿症状 ,但由于营养元素在植物体内移动性（即再利用）有差异。因此失绿症状可以表现在新梢不同位置的叶… 相似文献
11.
石楠叶斑病病原鉴定及对药物敏感性测定 总被引：1，自引：0，他引：1
石楠(Photinia serrulata Lindl.)是华中地区一种重要的绿化树种。近年来在武汉地区石楠上发现一种新的叶斑病。本文通过组织分离法、致病性测定等从病株分离得到致病病原菌,并通过形态学鉴定、分子生物学鉴定等,最终确定该致病菌为小孢拟盘多毛孢(Pestalotiopsis microspora)。在室内测定了P.microspora对7种常见杀菌剂的敏感性,结果表明,7种杀菌剂对P.microspora的菌丝生长均有抑制作用,但不同杀菌剂之间EC50值相差较大。450 g·L~(-1)咪鲜胺水剂、70%甲基托布津可湿性粉剂、10%苯醚甲环唑水分散粒剂EC50值分别为0.099、0.142和0.631μg·mL~(-1)。25%三唑酮可湿性粉剂EC50值在7种杀菌剂中最大,为37.625μg·mL~(-1)。这是国内外关于P.microspora引起石楠叶斑病的首次报道。 相似文献
12.
13.
柑桔脂点黄斑病病原菌的研究 总被引：3，自引：0，他引：3
根据对采自江、浙、黔、川、滇等省部分产桔区的病叶进行分离培养和接种的研究,证明上述各地都有柑桔脂点黄斑病发生。本病症状初呈黄斑,后转为脂斑,有时可进而转变成褐色小园星。病原菌为柑桔球腔菌(My-cosphaerella citri Whiteside),无性阶段为柑桔灰色疣丝孢(Stenella citri-grisea (Fisher) Sivanesan),其主要形态特征与J.O.Whiteside报道的美国佛罗里达州柑桔脂斑病病原菌基本相同,但接种后表现的病状有所差异。病菌的假囊壳产生在落地将朽的病叶上,子囊孢子起着初侵染作用;发生在落叶上的分生孢子数量很少,看来再侵染作用不大,但在培养基上可产生较多的无性孢子.接种表明,病菌从寄主的气孔侵入,潜育期1~2个月以上,其长短与柑桔品种有关,在江苏太湖桔区,此菌主要以菌丝体在病叶中越冬,翌年4-9月间落叶上产生子囊孢子传播侵染,春、夏、秋、梢的新叶均可受害,以春梢叶片被害最重. 相似文献
14.
In 2008, a severe bacterial disease was observed in Wenchang, Hainan Province. Symptoms consisted of small circular to elongated brown lesions surrounded by yellow halos. All isolates, which formed white colonies, were gram-negative and each had a single, polar, sheathed flagellum. Isolates were oxidase and catalase positive, negative for arginine dihydrolase, gelatin hydrolysis and starch hydrolysis, and acid production from levan. Sequences of the 16S rDNA gene of the isolates shared 98% sequence identity with that of Burkholderia andropogonis strain LMG2129 (GenBank accession No. NR118985). Pathogenicity tests were conducted and fulfilled Koch's postulates, indicating that these isolates are causative agent of the disease. The results led to the conclusion that the causal pathogen of betel palm bacterial leaf spot was B. andropogonis. It is the first report of B. andropogonis causing bacterial leaf spot of betel palm in mainland China. 相似文献
15.
A new leaf spot disease on Calathea rotundifolia cv. fasciata was observed in Guangdong, China. The pathogen of this disease was identified by pathogenicity, morphological characteristics and multi-gene sequences analysis of ITS, TEF and GAPDH. The result showed that leaf spot of C. rotundifolia cv. fasciata was caused by Bipolaris sivanesaniana. This is the first report of leaf spot disease on C. rotundifolia cv. fasciata caused by B. sivanesaniana.The results of host range determination showed that B. sivanesaniana could also infect Calathea veitchiana and cause leaf spot. This study will facilitate the timely detection and management of Bipolaris leaf spot. 相似文献
16.
2015年春季在昆明市区绿化带种植的中华常春藤上发现一种由细菌侵染而引起的病害,称为中华常春藤细菌性叶斑病。通过发病症状、菌落形态观察、致病性测定、Biolog分析,16S rDNA序列和核糖体DNA内转录间隔区(internal trans-cribed spacer, ITS )序列分析比较,对昆明地区的常春藤叶斑病病原菌及其系统进化关系进行研究。分离病原菌接种中华常春藤叶片完成科赫法则验证,发病初期在叶片表面形成带有黄色叶晕的不规则褐色斑点,后期叶片边缘形成倒V字型坏死并起皱。将菌株CCT1和CCT6测序结果与现有的黄单胞菌菌株的16S rDNA序列和核糖体DNA的ITS序列构建进化树,结果均显示病原菌与野油菜黄单胞菌的序列相似度最大,属于同一支。研究确定该病原菌为野油菜黄单胞菌(Xanthomonas campestris)。这是中国首次报道由X. campestris 引起的中华常春藤叶斑病。 相似文献
17.
18.
Cherry leaf spot disease is one of the most common diseases of sweet cherry. In 2018 and 2019, a leaf spot symptom was observed on sweet cherry in Beijing city, Shandong province and Liaoning province, and the pathogen fungi were isolated from diseased samples. Seven fungal isolates (JZB310197-JZB310203) were identified as Botryosphaeria dothidea according to morphological characteristics and multi-gene (ITS, EF 1-α and TUB2) phylogenetic analysis. To fulfill the Koch′s postulation, pathogenicity assay was carried out on detached leaves and tissue cultured seedlings. The inoculation results showed that all isolates were pathogenic to cherry leaves, proving that B. dothidea was a pathogen of cherry leaf spot disease. This is the first report of B. dothidea causing leaf spot of sweet cherry in China. 相似文献
19.
This study was conducted to identify the pathogens causing a new leaf spot disease on bitter gourd. The diseased leaves were collected from bitter gourd plantations around Nanning, Guangxi province. The pathogen causing this disease was identified by pathogenicity, morphology, and combined gene sequences analysis on ITS, TEF and GPD. The morphological characteristics of the pathogen were similar to that of Bipolaris bicolor. The representative isolate was clustered into one clade in phylogenetic tree with B. bicolor, which indicated that the leaf spot of bitter gourd was caused by B. bicolor. This is the first report of a leaf spot disease caused by B. bicolor on bitter gourd. 相似文献