Venkataravanappa V, Reddy C N Lakshminarayana, Shankarappa K S, Reddy M Krishna
Central Horticultural Experiment Station (CHES), Chettalli, Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bengaluru, India.
Department of Plant Pathology, College of Agriculture, GKVK, University of Agricultural Sciences, Bangalore, Karnataka, India.
Iran J Biotechnol. 2019 Jan 11;17(1):e2134. doi: 10.21859/ijb.2134. eCollection 2019 Jan.
Spine gourd (Momordica dioica Roxb. Willd) is one of the important cucurbitaceous crops grown across the world for vegetable and medicinal purposes. Diseases caused by the DNA viruses are becoming the limiting factors for the production of spine gourd reducing its potential yield. For the commercial cultivation of the spine gourd, propagation material used by most of the growers is tuberous roots and stem cuttings, which in turn results in an increased occurrence of the mosaic disease. There is a need for understanding the causal agent; through characterization of which will lead to the designing management strategies for the spine gourd mosaic disease control.
Characterization of a begomovirus and its satellites associated with mosaic disease on spine gourd.
Total DNA was extracted from spine gourd samples exhibiting symptoms typical to the begomoviruses infection (mosaic mottling, leaf curl) and was tested by PCR using begomovirus specific primers. Furthermore, the complete genome of begomo viruses (DNA A, DNA B, alpha satellite, and beta satellite) was amplified by rolling circle amplification (RCA) method.
The full-length sequences of DNA A, DNA B, alpha satellite, and beta satellite isolated from symptomatic spine gourd were determined. The full length genomes (DNA A and DNA B) of the Tomato leaf curl New Delhi Virus (ToLCNDV) infecting spine gourd were compared with the other begomovirus genomes available in the data base. The sequence analysis has revealed that DNA A and DNA B components of the begomovirus infecting spine gourd share 95.4-96.2 and 86.7-91.2% identical sequence (i.e., nucleotide (nt) identity) with that of ToLCNDV infecting potato and cucurbits in the Indian subcontinent isolates reported earlier (available in GenBank), respectively. Further, alpha satellite and beta satellite were also detected in the begomovirus infected spine gourd samples. The recombination analysis of the DNA A, DNA B, beta satellite, and alpha satellite of the begomovirus infecting spine gourd showed the associated begomovirus and satellite DNAs were driven from the different begomoviruses, leading to emergence as a new variant of the begomovirus infecting spine gourd.
The commercial cultivation of the spine gourd by most growers depends on the tuberous roots and stem cutting. The occurrence of begomovirus in spine gourd gives an alarming signal against utilization of such infected plant materials in the crop breeding and improvement programs. Using the clean virus-free vegetative propagation material is considered as one of the most important methods for controlling viral diseases. The study is highly useful for detection of the begomovirus infecting spine gourd in the detection of the virus infection in the clonally propagated planting material.
蛇瓜（Momordica dioica Roxb. Willd）是一种重要的葫芦科作物，在世界各地种植，兼具蔬菜和药用价值。由DNA病毒引起的病害正成为蛇瓜生产的限制因素，降低了其潜在产量。对于蛇瓜的商业化种植，大多数种植者使用的繁殖材料是块根和茎插条，这反过来又导致花叶病的发病率增加。有必要了解其病原体；通过对其进行特征描述，将有助于设计控制蛇瓜花叶病的管理策略。
对一种与蛇瓜花叶病相关的双生病毒及其卫星分子进行特征描述。
从表现出典型双生病毒感染症状（花叶斑驳、叶片卷曲）的蛇瓜样本中提取总DNA，并使用双生病毒特异性引物通过PCR进行检测。此外，通过滚环扩增（RCA）方法扩增双生病毒（DNA A、DNA B、α卫星和β卫星）的完整基因组。
测定了从有症状的蛇瓜中分离出的DNA A、DNA B、α卫星和β卫星的全长序列。将感染蛇瓜的番茄曲叶新德里病毒（ToLCNDV）的全长基因组（DNA A和DNA B）与数据库中其他双生病毒基因组进行了比较。序列分析表明，感染蛇瓜的双生病毒的DNA A和DNA B组分与先前报道的印度次大陆分离株中感染马铃薯和葫芦科作物的ToLCNDV分别具有95.4 - 96.2%和86.7 - 91.2%的相同序列（即核苷酸（nt）同一性）。此外，在感染双生病毒的蛇瓜样本中还检测到了α卫星和β卫星。对感染蛇瓜的双生病毒的DNA A、DNA B、β卫星和α卫星的重组分析表明，相关的双生病毒和卫星DNA来自不同的双生病毒，导致出现了一种感染蛇瓜的双生病毒新变种。
大多数种植者对蛇瓜的商业化种植依赖于块根和茎插条。蛇瓜中双生病毒的出现为在作物育种和改良计划中使用此类受感染的植物材料敲响了警钟。使用无病毒的清洁营养繁殖材料被认为是控制病毒病害的最重要方法之一。该研究对于在克隆繁殖的种植材料中检测病毒感染时检测感染蛇瓜的双生病毒非常有用。
