广西甘蔗宿根矮化病的发生及病原检测

通过对广西各蔗区采集的样本进行检测,结果表明甘蔗宿根矮化病在广西普遍发生,其发生情况各地差别不大,与品种和宿根性有关。利用电视相差显微镜和PCR技术结合能快速诊断甘蔗宿根矮化病。     

广西甘蔗宿根矮化病研究初报

甘蔗宿根矮化病在广西蔗区普遍发生，目前栽培品种(品系)RSD检出率达100％。发生没有区域差别，各蔗区均有发生，但发生程度与品种和宿根性有关。各品种间带菌量有差异，新植、宿根蔗带菌量也不同，一般新植蔗带菌量比宿根蔗少，宿根蔗比新植蔗发生严重。利用电视相差显微镜、电子显微镜和PCR等检测技术能诊断RSB。     

甘蔗宿根矮化病的I-ELISA快速检测

利用从澳大利亚引进的RSD标准抗原抗体,研究建立了I-ELISA检测甘蔗宿根矮化病（RSD）的方法。通过对田间采集的样本进行检测,同时以电镜负染检测法印证,检测结果一致,表明I-ELISA能简便、快速、准确、有效地检测出RSD,为甘蔗宿根矮化病的诊断和防治、脱毒种苗的生产、对外甘蔗品种／材料交换检疫检测提供了技术支撑。     

甘蔗宿根矮化病研究综述

对甘蔗宿根矮化病(Ratoon Stunting Disease,RSD)的检测方法、经济损失评估、防治技术、抗病育种及我国大陆蔗区发生情况进行综述,并对存在的问题及今后的研究方向进行探讨。     

勐海甘蔗温水脱毒种苗试验研究

选择云南勐海蔗区4个高感甘蔗宿根矮化病(RSD)的主栽品种粤糖93-159、粤糖00-236、ROC22、ROC20进行甘蔗温水脱毒种苗与常规种苗田间种植对比试验研究。结果表明,与常规种苗相比,温水脱毒种苗增产增糖效果显著。新植增产甘蔗558~2532 kg/667m2,增幅9.5%~54.73%;甘蔗糖分提高0.68~1.69个百分点。可见,种植温水脱毒种苗是防治甘蔗RSD最经济有效的措施之一,可大幅度提高甘蔗的产量和糖分,从而显著提高甘蔗生产的经济效益,增加蔗农收入,建议在勐海蔗区加快推广应用。     

广西甘蔗主栽品种梢腐病田间抗性初步评价

为更好地为广西甘蔗品种的合理布局和科学种植提供依据,探讨广西甘蔗主栽品种对梢腐病的田间抗性,根据发病程度,利用病情指数划分的抗性标准,在甘蔗梢腐病发生盛期,对目前广西蔗区13个主栽品种进行梢腐病抗性的田间综合评价。结果表明:宿根蔗感病程度比新植蔗严重。新植蔗表现为高抗的品种3个,抗病9个,中抗1个;宿根蔗表现为高抗的品种4个,抗病8个,中抗1个。综合不同蔗区新植蔗和宿根蔗的抗性表现,高抗品种2个(粤糖94-128、台优),抗病9个(ROC22、粤糖93-159、桂糖31、桂糖03-2287、桂糖42、台98-0432、桂糖29、柳城03-1137、桂糖21),中抗2个(柳城05-136、粤糖60)。新植蔗和宿根蔗抗性表现为同一水平的8个(粤糖94-128、台优、ROC22、桂糖03-2287、桂糖42、台98-0432、柳城03-1137、桂糖21),宿根蔗差于新植蔗的2个(桂糖31、粤糖60),3个变化趋势相反(粤糖93-159、桂糖29、柳城05-136)。不同蔗区梢腐病的发生情况不同,品种在各个蔗区的抗性表现也不同。2015年,广西蔗区主栽品种对梢腐病抗性达到中抗以上水平,说明梢腐病对该榨季广西甘蔗生产为害程度尚不严重。     

柳州和来宾蔗区黑穗病的发生及甘蔗品种抗性表现

为明确广西柳州和来宾蔗区甘蔗黑穗病的发生情况及品种抗性,2016年采用定点和随机的方法,对广西柳州市和来宾市6个县级蔗区的9个主栽甘蔗品种黑穗病发生情况进行系统调查和抗性评价。结果表明,广西柳州和来宾蔗区新植蔗发病率≤4.41%,宿根蔗发病率≤24.58%,宿根蔗感病较新植蔗严重。柳城05-136在柳州市柳江县发生最严重,其次为柳州市融安县的台优品种。综合各个品种新植和宿根在不同蔗区的抗性表现,ROC16、桂糖40号、粤糖00-236和粤糖93-159表现为高抗,桂柳二号表现为抗,ROC22和桂糖21号表现为中抗,柳城05-136和台优表现为中感。聚类分析结果与田间综合评价的抗性表现一致。不同甘蔗种植区域、不同品种及不同植期存在感抗黑穗病差异性。     

甘蔗宿根矮化病的Ⅰ—ELISA快速检测

利用从澳大利亚引进的RSD标准抗原抗体,研究建立了Ⅰ-ELISA检测甘蔗宿根矮化病(RSD)的方法.通过对田闻采集的样本进行检测,同时以电镜负染检测法印证,检测结果一致,表明Ⅰ-ELISA能简便、快速、准确、有效地检测出RSD,为甘蔗宿根矮化病的诊断和防治、脱毒种苗的生产、对外甘蔗品种/材料交换检疫检测提供了技术支撑.     

甘蔗叶片宿根矮化病的PCR检测

采用PCR方法对甘蔗植株不同生长时期(幼苗期、分蘖期、拔节期、成熟期)、同一植株的不同叶片及同一叶片的不同部位(叶尖、叶中、叶基)分别取样进行宿根矮化病检测。结果表明:在不同甘蔗生长时期常规PCR方法都可以检测出宿根矮化病阳性植株;对呈阳性植株的不同叶片及同一叶片的不同部位检测均呈阳性,说明被检测甘蔗品种植株不同位置叶片对甘蔗宿根矮化病检测效率影响差异不明显。     

甘蔗重要亲本田间自然抗黑穗病测定

甘蔗黑穗病抗病育种是甘蔗抗病育种的主要目标之一,为了解近年广西甘蔗主要亲本抗性情况,选择98个甘蔗亲本在黑穗病高发蔗区广西百色进行了2新3宿田间自然发病测试.试验结果表明黑穗病发生在不同年度、不同时期存在较大差异,宿根蔗下半年的发病率相对较高,新植蔗不宜用于黑穗病抗性评价.黑穗病发病率属较高遗传力性状,受到试验年度、作...     

广西主要蔗区宿根蔗根际土壤微生物群落结构分析

探讨了广西主要蔗区宿根蔗根际土壤微生物的分布情况,结果表明：宿根蔗根际土壤微生物数量总体上表现为：细菌〉真菌〉放线菌。但宜州市和北海市土壤中真菌数量〉放线菌;崇左市土壤中真菌和放线菌相当。     

Incidence of sugarcane ratoon stunting disease in the major cane-growing regions of China

Ratoon stunting disease (RSD), caused by Leifsonia xyli subsp. xyli (Lxx), is one of the most important diseases that limits sugarcane production worldwide. A scientific understanding of the distribution, occurrence, and damage of RSD in cane-growing areas will provide basal information for the application of effective RSD control strategies. In the present study, the occurrence and distribution of RSD were surveyed in the 21 cane-growing regions of Yunnan and Guangxi Provinces of China from 1270 samples using a PCR-based assay. The results showed that 949 samples (74.7% out of 1270) were positive for the presence of RSD. In Yunnan and Guangxi provinces, RSD was detected in all 21 cane-growing areas at rates of 65.5–88% and in the 33 main cultivars at rates of 48.9–100%. The results also showed that plant crop and ratoons from both irrigated and rainfed fields were infected with RSD. Thus, RSD has become an established disease that seriously restricts the development of the cane-sugar industry in China due to cane yield loss, a shortened ratoon period, and cultivar degeneration. Effective control of RSD presents a major challenge to the further development of the sugarcane industry in China. The results of our survey indicated that under the field condition, the main cultivars grown over large areas, including Guitang 94-119, Yuetang 93-159, Yuetang 00-236, and Guitang 11 showed high RSD incidence rates, suggesting that the focus on these cultivars should be the production, propagation, application and extension of healthy, bacteria-free seedlings. Relatively low RSD incidence rates were found in the cultivars Liucheng 03-1137, Liucheng 05-136, Yuanlin 1, ROC22, and F95-8899. Further research is required to determine if these cultivars are resistant and can be used to reduce the incidence of the disease and for breeding RSD resistant sugarcane cultivars. Sequencing of 100 PCR products selected randomly from sugarcane samples that tested positive for RSD showed that all 100 sequences were identical and highly homologous to the previously published Lxx 16S–23S spacer region in GenBank (99.54–100% similarity).     

甘蔗宿根矮化病研究进展

对国内外甘蔗宿根矮化病的症状、病原菌、病原菌的检测、发病规律以及防治措施等研究进展进行综述,为我国研究甘蔗宿根矮化病提供参考。     

PCR detection of ratoon stunting disease pathogen and natural resistance analysis in sugarcane core germplasms

Exploring and utilizing resistant germplasm resources plays a pivotal role in breeding for disease resistance, while screening resistant germplasm is important for selecting and breeding varieties resistant to disease. In the present study, we used PCR to detect the ratoon stunting disease (RSD) bacterium Leifsonia xyli subsp. xyli (Lxx) in 137 sugarcane core germplasms from the National Nursery of Sugarcane Germplasm Resources (NNSGR, Kaiyuan, China) in 2009, 2010 and 2011. A total of 21 germplasms that tested negative for Lxx in 2009 and 2010 were selected for further Lxx detection after being subjected to artificial inoculation in 2011 and 2012. The 21 core germplasms that were negative for Lxx after natural infection and artificial inoculation can provide elite resistance source materials and reference frames for the effective breeding of RSD-resistant sugarcane varieties. Under natural conditions, 116 (84.67%) and 21 (15.33%) out of 137 germplasms were positive and negative for Lxx, respectively, as determined by PCR detection, which suggests that a relatively high ratio of sugarcane core germplasms was sensitive to RSD, while few were resistant to RSD. The sequencing and analysis of 30 randomly selected PCR products showed that all 30 sequences were identical or highly homologous to the corresponding Lxx genome region published in GenBank (99.54–100% similarity). Lxx can be detected effectively and precisely by PCR. We therefore recommend PCR as a rapid, low cost and simple procedure to score sugarcane core germplasms for RSD resistance.     

52个甘蔗品种在广西受病毒侵染情况

为明确国家糖料体系甘蔗集成示范及区试品种在广西被病毒侵染情况,2017年从广西北海、南宁、崇左、百色、来宾、柳城、桂林等地集成示范及区试的52个甘蔗品种上采集带有甘蔗花叶病、甘蔗黄叶病和甘蔗杆状病毒病显著病症或不显病症叶片样品,采用特异引物通过RT-PCR和PCR方法进行5种病毒检测（甘蔗黄叶病毒、甘蔗线条花叶病毒、高粱花叶病毒、甘蔗花叶病毒和甘蔗杆状病毒）。结果表明,SCYLV的平均检出率为25.00%;SCSMV的平均检出率为7.97%;SrMV的平均检出率为7.69%;SCMV的平均检出率最低,为7.42%;SCBV的平均检出率最高,为68.41%,远远高于其他病毒。7个地方的甘蔗受病毒混合侵染现象普遍存在,北海的病毒混合侵染率甚至高于单一病毒侵染率。52个甘蔗品种在广西受5种病毒的总侵染率为79.67%,对甘蔗的生产安全存在着严重的潜在威胁,建议推广种植甘蔗脱毒种苗来缓解甘蔗病毒病害的危害。     

广西甘蔗花叶病SCMV调查初报

为探明甘蔗花叶病SCMV在广西蔗区的发生情况,给甘蔗健康种苗生产提供科学依据,从广西各主要蔗区对不同品种采集表现花叶症状的甘蔗样品,采用1对病毒CP基因引物(SCMVF4:5′-GTTTTYCACCAAGCTGGAACAGTC-3′;Y=CorT,SCMVR3:5′-AGCTGTGTGTCTCTCTGTATTCTC-3′),进行一步法RT-PCR检测。结果表明:69.4%的样品为阳性。选取8份代表性样品,对经SCMVF4/SCMVR3扩增获得的病毒CP基因片段进行直接测序,所得序列经Blast比对确认均为SCMV CP序列。在所调查的品种中,主栽品种ROC22最易受SCMV侵染,其它台糖系列如台糖16、台糖28、台糖95-889、台优,柳城03-182、柳城03-1137及广西甘蔗研究所许多品系均检测到SCMV。目前甘蔗花叶病SCMV已在广西主要蔗区普遍发生。     

基于PCR和巢式PCR技术的甘蔗黑穗病早期检测

为了探索甘蔗黑穗病早期检测的可能性,应用本实验室已建立的甘蔗黑穗病菌PCR和巢式PCR检测技术,对经人工接种甘蔗黑穗病菌冬孢子的植蔗叶片进行检测,并调查采样植株的黑穗病实际发生情况。结果表明,黑穗病实际发生率80％（16/20）,PCR检测阳性率35％（7/20）,巢式PCR检测阳性率70％（14/20）,PCR和巢式PCR检测为阳性的样品,其植株黑穗病发生率几乎为100％。这一结果表明了甘蔗黑穗病菌PCR和巢式PCR可用于甘蔗黑穗病早期检测,但巢式PCR检测结果与黑穗病的实际发生情况比较吻合,更适合于甘     

甘蔗健康种苗培育体系的建立

通过热处理、温热处理结合茎尖分生组织培养建立有效的甘蔗(Saccharum L.)健康种苗生产的技术体系。以经过热处理和温热处理的甘蔗带芽茎段萌生的腋芽为外植体,取其茎尖分生组织接种于MS BA1.0mg/L NAA0.1mg/L PVP200mg/L 蔗糖30g/L的培养基上培养10￣20d可诱导其产生完整的小芽,再把产生的新芽切割下来接种于MS 6BA1.0mg/L KT0.5mg/L 蔗糖30g/L的培养基上培养20d后便可形成由3￣5个芽组成的丛生芽,丛生芽在继代培养过程中每15￣20d可增殖3￣5倍。把丛生芽分割成单株并接种于1/2MS NAA1mg/L 蔗糖20g/L培养基上培养10￣20d可诱导小芽形成完整的根系,小植株移栽成活率可达98%。植株生长健壮、整齐、无变异,经分子检测证明小植株能脱去宿根矮化病和花叶病的病原。该体系的建立为甘蔗健康种苗的工厂化育苗奠定了坚实的基础。     

桂北果蔗甘蔗杆状病毒的分子检测与分析

从桂北主栽果蔗区采集表现褪绿斑点或花叶及无症状的未脱毒拔地拉、青皮果蔗、紫皮果蔗、罗汉果蔗、广东黄皮、同安果蔗及脱毒拔地拉等7个品种蔗叶样品88份,用SCBV检测引物对采集的样品进行PCR检测分析。检测结果显示:有2份为SCBV阳性,检出率2.3%,均为未脱毒果蔗拔地拉,其中1份叶片无明显的症状;脱毒拔地拉、青皮果蔗、紫皮果蔗、罗汉果蔗、广东黄皮、同安果蔗检测均为阴性。表明桂北果蔗区存在SCBV侵染。