【目的】马铃薯纺锤形块茎类病毒属的多种类病毒可侵染番茄，造成严重病害，威胁产业发展。研发番茄类病毒检测技术可为病害防控提供技术支撑。此外，虽然国外有报道说我国出口的番茄种子上携带类病毒，但仍未有定论，尚需确认，并且有必要弄清楚我国番茄上类病毒的发生情况。【方法】 使用序列比对的方法，比较能够侵染番茄的不同类病毒的基因组序列，找到保守序列，以此为模板，通过体外转录的方法制备RNA探针。通过斑点杂交的方法，测试该探针的检测灵敏度和特异性。另外，利用该通用探针，使用斑点杂交的方法，普查我国番茄上的类病毒发生情况。【结果】能够侵染番茄的6种类病毒：金鱼花潜隐类病毒（CLVd）、辣椒小果类病毒（PCFVd）、马铃薯纺锤块茎类病毒（PSTVd）、番茄顶缩类病毒（TASVd）、番茄褪绿矮缩类病毒（TCDVd）和番茄雄性株类病毒（TPMVd）的基因组序列含有一段长度为61 bp的保守序列。利用该序列制备的RNA探针能够同时检测这6种类病毒，其杂交检测的适宜反应温度为55℃~60℃。虽然该探针的检测灵敏度略低于每种类病毒的特异性探针，但可以满足田间大量样品的快速检测的需求。利用该探针，从我国番茄温室栽培的番茄植株上检测到了PSTVd，这是PSTVd在我国番茄上的首次报道。基因组序列比较分析发现，我国PSTVd番茄分离物的序列与国外茄科作物上PSTVd的序列最为接近，并且感染PSTVd的番茄的种子是从国外进口的。这表明我国番茄上的PSTVd应该是通过进口的番茄种子从国外传入的。【结论】研发出了一种能够同时检测侵染番茄的6种类病毒的通用探针，该探针具有快速灵敏的特点，适用于大量样品的快速检测，为番茄类病毒的监测及防控提供了技术支撑；此外，证实我国温室栽培的番茄上的确有PSTVd的发生，应该是通过种子由国外传入的，因此，需要加强进口种子及繁殖材料的检验和检疫，也要加强田间种植番茄的监测。

The common fig (Ficus carica L.) was one of the earliest horticultural crops to be domesticated.  A number of different viruses can infect fig trees including Fig mosaic virus (FMV) that has been detected in several commercial fig trees in Xinjiang, China.  However, the distribution of FMV and other fig-infecting viruses in China remains unknown.  In the present study, a sample from an ancient fig tree growing in Xinjiang was investigated by electron microscopy (EM) followed by PCR/RT-PCR, and FMV, Fig badnavirus 1 (FBV-1) and Fig leaf mottle-associated virus 1 (FLMaV-1) were detected.  Fig leaf samples (252) from commercial orchards across China were subjected to PCR/RT-PCR, and FMV, FBV-1 and Fig fleck-associated virus (FFkaV) were relatively abundant (44.4, 48.4 and 44%, respectively), while FLMaV-1 and Fig mild mottle-associated virus (FMMaV) were much scarcer (5.6 and 0.4%, respectively), and FLMaV-2, Fig cryptic virus (FCV), and Fig latent virus (FLV) were not detected.  The presence of disease-causing viruses in fig trees presents a significant challenge for fig producers in China.  This study may help to promote actions aimed at controlling fig viruses, especially FMV.

    Cherry virus A (CVA) is a member of the genus Capillovirus, in the family Betaflexiviridae. The infection rate of CVA was high in sweet cherry in China. We determined the complete nucleotide sequences of two isolates of CVA from Tai’an, Shandong Province, China using high fidelity PCR enzymes and specific primer pairs for amplifying long fragments in RT-PCR and RACE. The full-length sequences from isolates ChTA11 and ChTA12 are both 7 382 nucleotide (nt) long, excluding the poly(A) tail, encode two open reading frames (ORFs) and have similar genome organization to the two isolates in GenBank. The complete nucleotide sequence of ChTA11 is 98.2 and 81.2% nt identity to the isolates from Germany and India in GenBank, respectively, and the ChTA12 isolate is 98.2 and 81.0% similar. Analysis of the nucleotide and amino acid sequences showed that the domain of unknown function (DUF1717) is more variable compared with other domains. This is the first report of the complete nucleotide sequences of CVA isolates infecting sweet cherry in China.

China is the largest potato producing country worldwide, with this crop representing the fourth largest staple food crop in China. However, the steady presence of Potato spindle tuber viroid (PSTVd) over the past five decades has a significant economic impact on potato production. To determine why PSTVd control measures have been ineffective in China, more than 1 000 seed potatoes collected between 2009 and 2014 were subjected to PSTVd detection at the Supervision and Testing Center for Virus-free Seed Potatoes Quality, Ministry of Agriculture, China. A high PSTVd infection rate (6.5%) was detected among these commercial seed potatoes. Some breeding lines of potato collected from 2012 to 2015 were also tested for PSTVd infection, revealing a high rate of PSTVd contamination in these potato propagation materials. Furthermore, comparison of the full-length sequences of 71 different Chinese PSTVd isolates revealed a total of 74 predominant PSTVd variants, which represented 42 different sequence variants of PSTVd. Comparative sequence analysis revealed 30 novel PSTVd sequence variants specific to China. Comprehensive phylogenetic analysis uncovered a close relationship between the Chinese PSTVd sequence variants and those isolated from Russia. It is worth noting that three intermediate strains and six mild strains were identified among these variants. These results have important implications for explaining the ineffective control of PSTVd in China and thus could serve as a basic reference for designing more effective measures to eliminate PSTVd from China in the future.