甘蔗白叶病植原体巢式PCR检测方法的建立及初步应用

甘蔗白叶病(sugarcane white leaf,SCWL)是由植原体引起的重要甘蔗病害[1],广泛分布在印度、泰国等许多国家[1,2].我国甘蔗产区的栽培品种也有SCWL的发生[3].甘蔗是无性繁殖作物,植原体可通过繁殖种苗进行传播,台湾斑纹叶蝉(Matsumuratetlix hiroglyhious)通过咬食感染甘蔗植株的韧皮部可引起该病害[4].     

甘蔗新品种及主栽品种对褐条病的抗性评价

褐条病是为害甘蔗叶部的重要真菌病害,严重发病田块,一眼望去似“火烧状”,一般减产18％ ～35％,蔗糖分降低15％ ～30％[1].该病于1924年在古巴首次发现[2],至今已有20多个国家报道发生此病,常造成不同程度经济损失[3].在中国,尤其近年,感病品种加上多雨高湿导致褐条病在云南及广西等主产蔗区大面积暴发流行,...     

7种除草剂对凤眼莲的防除效果

凤眼莲[Eichhornia crassipes(Mart.)Solms],别名水葫芦、凤眼蓝等,为常年水生草本植物[1],在13～39℃之间均能生存、繁殖[2].在适应条件下,每5 d能繁殖1株新植株[3],8个月就能繁衍成60万株的群体[4].近年来,凤眼莲在广西柳州市区的一些河道、鱼塘、沟渠中逸生严重,影响了当地的生态环境和渔业发展[5].据报道,我国每年利用人工打捞凤眼莲的花费至少达1亿元[6].从生产实践出发,笔者选用了7种常用的除草剂,于2010年在柳州的鱼塘实验区进行了凤眼莲防除试验.     

节节麦、鬼蜡烛——燕麦孢囊线虫的两种新寄主

禾谷孢囊线虫病(cereal cyst nematode,CCN)是由燕麦孢囊线虫Heterodera avenae Wollen.引起的一种重要的小麦病害,在世界上40多个国家均有发生[1].我国于1987年首次发现燕麦孢囊线虫[2],至2012年,已传播到湖北、河南、河北、北京、山东、山西、安徽、江苏、青海、内蒙古、陕西、甘肃、宁夏、天津、西藏、新疆等16个省市自治区[3],危害程度与范围呈逐年加重和扩大的趋势,已对我国小麦生产构成严重威胁.该病造成小麦平均减产20％～40％,严重时高达73％～89％[4].因此,CCN是制约小麦和大麦生产的主要因素之一.     

柳州市蔗根锯天牛的发生及防治对策

蔗根锯天牛[Dorysthenes granulosus(Thomson)],在广西柳州市各县均有分布,主要以幼虫咬食寄主植物地下的根颈部及主根,严重时导致全株死亡.蔗蔸受害率一般为5%～10%,重者达30%～40%,严重影响甘蔗的品质和产量.除为害甘蔗外,幼虫还为害龙眼、柑桔[1]、板栗、桉树、松树、木薯、等经济作物[2],对经济造成重大损失.     

一些植物提取物的抗茵活性筛选

天然产物是药物开发的重要来源[1],从植物中发现抗植物病原菌的活性化合物的研究受到普遍的重视[2],有些植物的提取物甚至可以直接用于防治作物病害[3].     

潜在的检疫性甘蔗有害生物

在推进现代甘蔗产业过程中,有效防控甘蔗病虫害是"双高"甘蔗栽培技术的一个重要环节。目前世界上已发现的甘蔗病害有120种以上,甘蔗害虫上百种,不同国家、不同蔗区甘蔗病虫害种类不同,病菌生理小种、病毒株系也不相同,而许多重要的甘蔗病虫害都是通过种苗传播的。提高对潜在的检疫性甘蔗有害生物认识,有效地阻止危险性病虫随种苗传播蔓延,增强减灾防灾能力,对确保甘蔗品种质量和甘蔗生产安全,促进甘蔗种植业和蔗糖产业持续稳定健康发展具有重要意义。本文重点介绍了几种潜在的检疫性甘蔗有害生物,并提出了相应的防控对策。     

水稻播种期与灰飞虱虫量及条纹叶枯病发病关系的研究

水稻条纹叶枯病(Rice Stripe Virus ,RSV)是由灰飞虱(Laodelphax striatellus Fallen)传播的一种重要的水稻病毒病[1].近年来,在浙北地区发生为害加重[2],仅嘉兴市2007年发病面积就达1.76万hm2,对当地水稻生产带来严重威胁.为此,笔者于2006～2007年间开展了水稻播种期与条纹叶枯病发生关系的试验,以期为改进防控该病的技术措施提供依据.     

广东省黄瓜绿斑驳花叶病毒分子检测及防疫

黄瓜绿斑驳花叶病毒(Cucumber green mottle mosaic virus,CGMMV)危害多种葫芦科作物[1],是我国农业植物检疫性有害生物[2].近年来,我国检疫部门多次从进境的瓜类种子中检出该病毒[3],并在广西[4]、辽宁[5]、河北、北京[6]、甘肃[7]等地棚室保护地及田间栽培的瓜类作物上发现疫情.2005-2008年,作者在广东省发现多起疫情,为此,对该病毒进行了分子检测及疫情控制.     

柑橘木虱对福建茶和芸香科植物的选择性及其耐饥渴能力

柑橘木虱Diaphorina citri(Kuwayama)是柑橘的重要害虫,也是传播柑橘黄龙病菌的唯一昆虫媒介,给柑橘生产造成很大损失.相关研究表明,芸香科Rutaceae植物是柑橘木虱的主要寄主[1].受全球性暖冬气候的影响,木虱的生存空间和寄主范围逐渐扩大[2],导致黄龙病大面积发生.国内外对柑橘木虱生物学特性、逆境耐受性等做过一些研究[3].而关于柑橘木虱耐饥渴能力和寄主选择性的报道较少,为此,作者选取7种常见的芸香科植物,在室外条件下研究柑橘木虱对各种寄主的选择性,并在室内条件下检测其耐饥渴能力,以期为柑橘木虱的综合防治提供参考.     

云南蔗区发现由植原体引起的检疫性病害甘蔗白叶病

By used of nested-PCR, the 16S rDNA sequence of phytoplasma associated with sugarcane white leaf (SCWL) in 48 suspected SCWL samples from Baoshan and Lincang of Yunnan were amplified with two primer pairs MLOX/ MLOY and P1/P2. The sequencing showed that the fragment size of 17 Baoshan suspected SCWL samples were all 210 bp and their sequences were all identical (GenBank: KC662509); the fragment size of 10 Lincang suspected SCWL samples were all 202 bp and their sequences were all identical (GenBank: KF431837). The Blast result indicated that the sequences obtained in this study were derived from the 16S-23S ISR intergenic spacer region of phytoplasma that causes SCWL and were highly homologous (99.05%-100% similarity) to the corresponding genome region registered in GenBank. Plant height, stalk diameter, millable stalk rate and single stalk weight were significantly reduced by infection of SCWL,which caused destructive damage to sugarcane.     

国外引进甘蔗材料白叶病植原体巢式PCR检测及其序列分析

为有效防止引起重要危险性检疫病害甘蔗白叶病(SCWL)的植原体病原随引进甘蔗材料侵入我国,确保我国甘蔗生产安全,本研究对从缅甸、菲律宾、法国和泰国引进的22个甘蔗材料进行了SCWL植原体巢式PCR检测,并对阳性样品的巢式PCR产物进行了测序及序列分析。结果表明,18个甘蔗材料呈SCWL植原体阳性,阳性检出率为81.8%。所有SCWL阳性样品的16S-23S基因间隔区片段长210bp,与GenBank中已有的其他SCWL植原体分离物(登录号HQ917068、AB646271)的同源性为99.8%~100%,并在系统发育树中聚为一个类群。根据SCWL的巢氏PCR检测及其序列分析结果,对呈阳性的材料及时进行了集中销毁处理。     

不同品种和植期甘蔗白叶病自然发病率调查

甘蔗白叶病(sugarcane white leaf, SCWL)是由植原体引起的甘蔗毁灭性病害,对甘蔗生产危害极大。为明确不同品种不同植期SCWL的发病规律,2018年对我国SCWL发病最为严重的耿马芒翁和贺派蔗区进行了SCWL田间发病情况调查和巢式PCR检测分析。田间调查结果表明,不同品种田间自然发病率不同,其中粤糖60号平均发病率最高,为73.50%,柳城05-136平均发病率最低,为13.67%;不同植期田间自然发病率也有差异,新植蔗田间发病率最低,为32.38%,3年宿根蔗的田间发病率最高,为64.33%。病原检测结果表明,所有品种的阳性检出率均在90%以上,其中盈育91-59阳性检出率最低,为90.95%,柳城05-136阳性检出率最高,为96.67%,无白叶症状样品的阳性检出率为81.53%,2年和3年宿根的阳性检出率最高,均为96.67%。本研究结果表明SCWL发病率随宿根年限增加而升高,依据白叶症状进行的田间病害调查不能准确反映SCWL的真实发生情况。     

Detection, identification and significance of phytoplasmas in grasses in northern Australia

Sugarcane yields have been severely reduced by white leaf and grassy shoot phytoplasma diseases in many parts of Asia. Australian sugarcane crops are not known to be affected by these diseases, but plant pathogenic phytoplasmas found in other introduced and native grasses in northern Australia could pose a serious threat to the Australian sugarcane industry. To further evaluate this threat, leaves from plants of 20 grass species, with and without symptoms, were collected during field surveys in northern Australia and tested to determine whether phytoplasmas were present and whether symptoms were reliable indicators of phytoplasma presence. Molecular tools were used to detect and characterize phytoplasmas. Four different phytoplasmas were found in seven grass species known to grow near healthy sugarcane crops. All the phytoplasmas were closely related to sugarcane white leaf phytoplasma (SCWL), one of the phytoplasmas that causes disease in sugarcane in Asia. Four of the host plant species and two of the phytoplasmas were new records. The relationship between symptoms and phytoplasma presence was poor. Because some plants with symptoms tested negative for phytoplasmas, a series of surveys was carried out in which flowers, leaves, roots and stems of two known host plant species, Whiteochloa cymbiformis and Sorghum stipoideum, were tested separately on nine occasions during two wet seasons. This was done to investigate the distribution of phytoplasmas within plants over time. Results showed that spatial and temporal variation of phytoplasmas occurred in these two host plant species. Hence, evaluation of disease distribution within a region requires repeated testing of all plant parts from plants without symptoms, as well as those with symptoms. To date, there is no report of a vector capable of transmitting to Australian sugarcane the phytoplasmas found in grasses in this study. If one is present, or occurs in the future, then native and introduced grasses could constitute a large reservoir of phytoplasma for vectors to draw on. This work provides an early warning for the sugarcane industry that the potential for infection exists.     

Identification of sugarcane grassy shoot-associated phytoplasma and one of its putative vectors in India

During a survey of sugarcane fields at the Sugarcane Research Institute, Shahjahanpur, Uttar Pradesh, India, in August–September 2012, 6% to 28% incidence of sugarcane grassy shoot disease was observed in different fields of sugarcane variety CoS 7250. The association of phytoplasma with symptomatic sugarcane was confirmed by direct and nested PCR amplification of phytoplasma ribosomal gene. Four different delphacid leafhopper species, viz. Cofana unimaculata Signoret, Exitianus indicus (Distant), Sogatella kolophon Kirkaldy and Hishimonus phycitis (Dist.) were the prevalent feeding species of the Auchenorrhyncha fauna in the symptomatic sugarcane fields. Out of these four leafhopper species, only E. indicus tested positive for phytoplasma presence. Phylogenetic analysis suggested that the phytoplasmas from sugarcane and E. indicus in the present study were members of 16Sr XI. The confirmation of association of sugarcane grassy shoot phytoplasma in E. indicus population is important to understand the secondary spread of this phytoplasma in sugarcane plants.     

甘蔗新品种及主栽品种对甘蔗梢腐病的自然抗性

为筛选抗梢腐病的甘蔗品种,于2016—2019年采用田间自然发病率调查方法对我国近年选育的60个新品种及云南省临沧市、普洱市、玉溪市和广西壮族自治区宜州区甘蔗梢腐病高发蔗区的31个主栽品种进行自然抗性评价。结果表明：在60个甘蔗新品种中,35个表现为高抗、抗病和中抗,所占比例为58.3%,其中高抗品种5个、抗病品种15个、中抗品种15个,所占比例分别为8.3%、25.0%、25.0%;在31个甘蔗主栽品种中,15个表现为高抗、抗病、中抗,所占比例为48.4%。目前大面积种植的新台糖25号、粤糖93-159、盈育91-59、柳城03-1137、云蔗03-258、川糖79-15、新台糖1号、桂糖11号、桂糖42号9个主栽品种对甘蔗梢腐病高度感病,而近年选育的粤甘49号、福农11-2907、闽糖11-610、闽糖12-1404、桂糖11-1076五个新品种对甘蔗梢腐病高抗,粤甘46号、粤甘47号、福农09-2201、福农09-6201、福农09-7111、福农10-14405、闽糖06-1405、桂糖40号、桂糖44号、桂糖06-1492、桂糖06-2081、桂糖08-1180、桂糖08-1589、云蔗11-1074和德蔗07-36共15个新品种对甘蔗梢腐病表现抗病。     

Transmission of a sugarcane yellow leaf phytoplasma by the delphacid planthopper Saccharosydne saccharivora, a new vector of sugarcane yellow leaf syndrome

During surveys of sugarcane fields in western and central Cuba from December 2001 to March 2003, the delphacid planthopper Saccharosydne saccharivora was the most prevalent of the Auchenorrhyncha fauna surveyed. Individuals of S. saccharivora collected tested positive for the sugarcane yellow leaf phytoplasma (SCYLP). Saccharosydne saccharivora were reared in cages and used for experimental transmission studies of SCYLP. The S. saccharivora were given acquisition-access feeds of 72 h on SCYLP-infected canes collected from the field followed by an inoculation-access period of 15 days on healthy sugarcane seedlings. Symptoms of yellow leaf syndrome developed on 24 out of 36 plants, 7–12 months postinoculation. None of the 36 healthy seedlings that were inoculated with S. saccharivora fed on phytoplasma-free sugarcane developed symptoms. All phytoplasma-positive sugarcane and S. saccharivora samples showed identical RFLP patterns and had 99·89% similarity in their 16S/23S spacer-region sequences, but only 92·6–93·6% similarity with other phytoplasmas. Sequences were deposited with GenBank [accession numbers: AY725237 ( S. saccharivora ) and AY257548 (sugarcane)]. Phylogenetic analysis suggested that the phytoplasmas from sugarcane and S. saccharivora are putative members of a new 16Sr phytoplasma group. This is the first report of vector transmission of a phytoplasma associated with sugarcane yellow leaf syndrome and the first time that S. saccharivora has been shown to vector a phytoplasma.     

江西甘蔗花叶病田间调查

2007年9-10月对江西甘蔗花叶病(sugarcane mosaic disease)进行了多点田间调查,结果表明江西甘蔗普遍发生花叶病,其中红皮甘蔗花叶病重于青皮甘蔗,两者病丛率分别为59.8%和19.2%,赣北、赣中、赣南3大地区之间的甘蔗花叶病发生轻重无明显差异。     

‘Candidatus Phytoplasma aurantifolia’-related strain associated with tomato yellows disease in China

A new disease of tomato plants with typical phytoplasma disease symptoms such as stunting, yellows, auxiliary shoot proliferation and phyllody was observed in Yunnan Province, southwest China in 2011. By a nested-PCR, phytoplasma were detected using the phytoplasma universal primers specific for 16S rDNA. The results of the 16S rDNA sequencing, computer-simulated RFLP patterns and phylogenetic analysis indicated that the phytoplasma associated with the diseased tomato plants belongs to subgroup A of the peanut witches’-broom group. This is the first report of a 16SrII-A phytoplasma associated with a new tomato disease in China. This new disease was named tomato yellows.