Wangai A W, Pappu S S, Pappu H R, Okoko N, Deom C M, Naidu R A
National Plant Breeding Research Center, Njoro, Kenya.
Department of Plant Pathology; University of Georgia, Coastal Plain Experiment Station, Tifton 31793.
Plant Dis. 1999 Aug;83(8):782. doi: 10.1094/PDIS.1999.83.8.782A.
Groundnut (Arachis hypogaea L.) is an important food crop in sub-Saharan Africa. One of the major production constraints is groundnut rosette disease, which is caused by a complex of two viruses, groundnut rosette assistor luteovirus (GRAV) and groundnut rosette umbravirus (GRV) together with the associated satellite RNA (satRNA) (1). Two main forms of the disease have been described: chlorotic and the green rosette. Variants of the satRNA have been shown to be largely responsible for the different forms of the disease (1). Chlorotic rosette has been the predominant form in all of sub-Saharan Africa while green rosette has been reported in the western and southern regions of Africa (2). During the 1997-1998 crop season, disease surveys conducted in Kenya showed the incidence of the rosette disease in farmers' fields to be 24 to 40% in a total of 23 fields surveyed in the western regions of the country (Homabay, Kendubay, Kisumu) and 30% in 8 fields sampled in the Rift Valley (Cheplamus, Marigat) regions. Representative peanut plants showing rosette symptoms were analyzed for the presence of GRV by reverse transcription polymerase chain reaction (RT-PCR). With primers specific to a portion of ORF4 of GRV RNA (3), RT-PCR gave a product of expected size (approximately 300 bp). The PCR product was cloned in pGEM-T vector and sequenced. The sequenced region showed 89% nucleotide sequence identity with published GRV sequences. Green rosette was observed on groundnut cultivars Nyaela Red and Homabay Local in the Kendu Bay region. The incidence of the green rosette was 5.3% of the plants with rosette symptoms. References: (1) A. F. Murant and I. K. Kumar. Ann. Appl. Biol. 117:85, 1990. (2) R. A. Naidu et al. Ann. Appl. Biol. 132:525, 1998. (3). M. E. Taliansky et al. J. Gen. Virol. 77:2335, 1996.
花生（Arachis hypogaea L.）是撒哈拉以南非洲地区一种重要的粮食作物。主要生产限制因素之一是花生丛簇病，该病由两种病毒的复合体引起，即花生丛簇辅助黄症病毒（GRAV）和花生丛簇伞形病毒（GRV），以及相关的卫星RNA（satRNA）（1）。已经描述了该病的两种主要形式：褪绿型和绿色丛簇型。已证明satRNA的变体在很大程度上导致了该病的不同形式（1）。褪绿型丛簇病在整个撒哈拉以南非洲地区一直是主要形式，而绿色丛簇病在非洲西部和南部地区有报道（2）。在1997 - 1998作物季期间，在肯尼亚进行的病害调查显示，在该国西部地区（霍马贝、肯杜贝、基苏木）总共23块调查农田中，农民田地中丛簇病的发病率为24%至40%，在裂谷地区（切普拉姆斯、马里加特）8块采样农田中的发病率为30%。通过逆转录聚合酶链反应（RT-PCR）分析表现出丛簇症状的代表性花生植株中GRV的存在情况。使用针对GRV RNA ORF4一部分的特异性引物（3），RT-PCR产生了预期大小的产物（约300 bp）。将PCR产物克隆到pGEM-T载体中并进行测序。测序区域与已发表的GRV序列显示出89%的核苷酸序列同一性。在肯杜贝地区的花生品种尼亚埃拉红和霍马贝本地品种上观察到了绿色丛簇病。绿色丛簇病在有丛簇症状的植株中的发病率为5.3%。参考文献：（1）A. F. 穆兰特和I. K. 库马尔。《应用生物学年鉴》117:85，1990年。（2）R. A. 奈杜等人。《应用生物学年鉴》132:525，1998年。（3）M. E. 塔利安斯基等人。《普通病毒学杂志》77:2335，1996年。
