Guzman P, Rojas M R, Davis R M, Kimble K, Stewart R, Sundstrom F J, Gilbertson R L
Department of Plant Pathology, University of California, Davis 95616.
California Crop Improvement Association (CCIA), University of California, Davis 95616.
Plant Dis. 1997 Jul;81(7):831. doi: 10.1094/PDIS.1997.81.7.831B.
During the 1996 growing season (June to September) an outbreak of bean common mosaic was detected in a navy bean field (cv. Snow Bunting) in Colusa County, CA. Early field inspections (August 1996) revealed an incidence of 5 to 10% infection, whereas a late field inspection (September) showed an incidence of 70 to 90% infection. Enzyme-linked immunosorbent assay (ELISA) was performed on 18 leaf samples from symptomatic plants collected from this field with two monoclonal antibodies (Mab): Mab I-2, which detects bean common mosaic necrosis virus (BCMNV) strains (previously necrotic or serotype A bean common mosaic potyvirus [BCMV] strains), and Mab 197, which detects BCMV strains (previously non-necrotic or serotype B BCMV strains) and BCMNV (3). ELISA results indicated BCMNV infection in all 18 samples. In order to confirm ELISA results and to further characterize the viral isolate(s), primary leaves of the differential bean cvs. Black Turtle Soup (BTS) T-39, Topcrop, Amanda, and Sutter Pink were inoculated mechanically with sap prepared from the same leaves used for ELISA. Within 1 week, BTS T-39 and Topcrop plants showed necrotic spots on inoculated leaves and systemic necrosis and death (black root rot symptoms), Sutter Pink showed typical systemic mosaic symptoms, and Amanda showed necrotic spots and restricted vein necrosis on inoculated leaves. These reactions were consistent with infection by the NL-3 strain of BCMNV (1). Reverse transcriptase-polymerase chain reaction was used to amplify a portion of the genome of the virus that contains the 3' end of the coat protein (CP) gene and the 3' untranslated region (UTR). A DNA fragment of approximately 670 bp was amplified and DNA sequence analysis revealed that the nucleotide sequences of the 3' end of the CP and the UTR region of the California BCMNV isolate were 98 and 94% similar to those of the Michigan isolate of the BCMNV NL-3 strain (2), respectively. Together, these results suggest that the outbreak of bean common mosaic in the cv. Snow Bunting navy beans was caused by a pathogroup VI BCMNV isolate, and DNA sequence information suggests that it is similar to the NL-3 strain of BCMNV. This is the first report of BCMNV in California. References: (1) E. Drijfhout et al. Neth. J. Plant Pathol. 84:13, 1978. (2) G. F. Fang et al. Virus Res. 39:13, 1995. (3) G. I. Mink et al. Arch. Virol. S:397, 1992.
在1996年生长季节（6月至9月），加利福尼亚州科卢萨县的一片海军豆田（品种：雪鹀）中检测到菜豆普通花叶病爆发。早期田间检查（1996年8月）显示感染率为5%至10%，而后期田间检查（9月）显示感染率为70%至90%。使用两种单克隆抗体（Mab）对从该田块有症状植株采集的18片叶片样本进行了酶联免疫吸附测定（ELISA）：Mab I - 2，可检测菜豆普通花叶坏死病毒（BCMNV）株系（以前的坏死型或血清型A菜豆普通花叶马铃薯Y病毒[BCMV]株系）；Mab 197，可检测BCMV株系（以前的非坏死型或血清型B BCMV株系）和BCMNV（3）。ELISA结果表明所有18个样本均感染了BCMNV。为了确认ELISA结果并进一步鉴定病毒分离株，用从用于ELISA的相同叶片制备的汁液对鉴别菜豆品种黑龟汤（BTS）T - 39、顶级作物、阿曼达和萨特粉的初生叶进行机械接种。1周内，BTS T - 39和顶级作物植株在接种叶片上出现坏死斑以及系统性坏死和死亡（黑根腐症状），萨特粉表现出典型的系统性花叶症状，阿曼达在接种叶片上出现坏死斑和叶脉局部坏死。这些反应与BCMNV的NL - 3株系感染一致（1）。逆转录聚合酶链反应用于扩增病毒基因组中包含外壳蛋白（CP）基因3'端和3'非翻译区（UTR）的部分片段。扩增出一个约670 bp的DNA片段，DNA序列分析表明加利福尼亚BCMNV分离株CP基因3'端和UTR区域的核苷酸序列分别与BCMNV NL - 3株系的密歇根分离株的相应序列相似性为98%和94%（2）。综合这些结果表明，雪鹀海军豆中菜豆普通花叶病的爆发是由病原组VI的BCMNV分离株引起的，DNA序列信息表明它与BCMNV的NL - 3株系相似。这是BCMNV在加利福尼亚州的首次报道。参考文献：（1）E. Drijfhout等人，《荷兰植物病理学杂志》84:13，1978年。（2）G. F. Fang等人，《病毒研究》39:13，1995年。（3）G. I. Mink等人，《病毒学文献》S:397，1992年。
