甘蔗宿根矮化病菌多克隆抗体的制备

 甘蔗宿根矮化病（Ratoon stunting disase,RSD）是甘蔗生产中最为严重的细菌病害之一,常导致感病品种新植蔗减产10%～15%,宿根蔗减产20%～25%,在干旱的情况下感病品种的宿根蔗产量损失可达60%^［1］。RSD病原菌为 Leifsonia xyli subsp.xyli（Lxx）,寄生于甘蔗木质部导管内,革兰氏阳性^［2］,体外分离培养非常困难。该病害自从1944 年首次在澳大利亚昆士兰州的甘蔗品种Q28 上发现以来,在世界各产区普遍发生,现已广泛分布于各甘蔗种植区。该菌主要通过带菌种茎和砍收工具传播^［3］,已感病的蔗株又无明显的外部症状,从而导致该病害无意识地传播,造成病害蔓延,对甘蔗生产危害极大。甘蔗宿根矮化病的检测方法主要有形态学、血清学、分子生物学等方法,血清学由于具有操作简便、准确性高、灵敏度好,同时能够处理大量样品而在国外被广泛采用。目前国内所用的RSD血清全部依赖于国外进口,检测成本高,使得血清学方法无法在国内普及。为此我们分离纯化了RSD的病原菌并制备了RSD的多克隆抗体,为甘蔗宿根矮化病敏感、稳定和快捷的检测提供了必要的保证。     

甘蔗黄叶病毒的TBIA快速检测

利用从法国引进的甘蔗黄叶病毒(ScYLV)标准抗原抗体,研究建立了TBIA快速检测ScYLV的方法.通过对田间采集的样本进行检测,同时以DAS-ELISA检测法印证,检测结果一致,表明TBIA能简便、快速、准确、有效地检测出ScYLV,且检测效率高,适合于田间大批量样品快速检测.为甘蔗黄叶病的诊断和防治、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.     

Variation in virus populations and growth characteristics of two sugarcane cultivars naturally infected by Sugarcane yellow leaf virus in different geographical locations

Two sugarcane cultivars (R570 and SP71-6163) naturally infected by Sugarcane yellow leaf virus (SCYLV) were each imported from several geographical locations into a sugarcane yellow leaf-free environment (Montpellier, France). Plants were grown as plant cane for 5–6 months and the experiment was repeated for three consecutive years (2003–2005) in a greenhouse. Several sugarcane-growth and disease characteristics were monitored to identify variation in pathogenicity of SCYLV. Depending on their geographical origin, sugarcane cvs R570 and SP71-6163 were infected by SCYLV genotypes BRA-PER or REU, or a mixture of the two. Severity of symptoms did not vary between plants of cv. R570, but variation in disease severity between plants of cv. SP71-6163 from different geographical locations suggested the occurrence of pathogenic variants of SCYLV. For each sugarcane cultivar, differences in stalk length, number of stalk internodes, virus titre in the top visible dewlap leaf, and percentage of infection of leaf and stalk phloem vessels were also found between plants from different geographical origins. However, these differences were not always reproducible from one year to another, suggesting occurrence of different plant responses to SCYLV isolates under varying environmental conditions.