Abstract Squash leaf curl (SLC) disease causes serious damage in a great diversity of horticultural crops worldwide and is due to infection by different ssDNA bipartite begomoviruses (Family Geminiviridae). Symptoms of leaf yellowing, stunting and curling have been observed in squash crops in the southern region of the Baja California (BC) Peninsula in the northwestern region of Mexico for at least a decade. The damage estimated for all localities showed disease incidence of 73.3% to 97.7% and severity of 49%. Infected plants were collected in three localities in addition to adult whiteflies for species determination. Squash leaf curl virus (SLCuV) was detected in both infected plants and whiteflies by PCR using specific primers that amplified a 601 bp fragment. The full-length DNA-A sequence was 99.1% identical to sequences in GenBank. Phylogenetic studies using the core CP region showed that the BC isolate grouped within a well-defined clade together with SLCuV from the Mediterranean Middle East and USA. The molecular analysis in individual adult whiteflies determined that all populations belonged to Bemisia tabaci (MEAM1) (biotype B) species. No evidence of the Mediterranean (MED) species (biotype Q) was found. The SLC disease has prevailed in squash in the region in several growing cycles and in geographically separated localities. To the best of our knowledge, this is the first report of SLCuV associated with squash plants in BCS, Mexico.

中文翻译：

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墨西哥下加利福尼亚半岛壁球卷曲病毒的发生和地理分布

摘要 南瓜叶卷曲 (SLC) 病对全世界多种园艺作物造成严重损害，并且是由于不同 ssDNA 二分贝戈莫病毒 (Family Geminiviridae) 感染所致。至少十年来，在墨西哥西北部下加利福尼亚 (BC) 半岛南部地区的南瓜作物中观察到叶片变黄、发育迟缓和卷曲的症状。对所有地区估计的损害显示，发病率为 73.3% 至 97.7%，严重程度为 49%。除了成年粉虱外，在三个地点收集了受感染的植物用于物种确定。使用可扩增 601 bp 片段的特异性引物，通过 PCR 在受感染植物和粉虱中检测到南瓜卷叶病毒 (SLCuV)。全长 DNA-A 序列与 GenBank 中的序列具有 99.1% 的同一性。使用核心 CP 区域的系统发育研究表明，BC 分离株与来自地中海中东和美国的 SLCuV 一起分组在一个明确的进化枝内。单个成年粉虱的分子分析确定所有种群都属于烟粉虱 (MEAM1)（生物型 B）物种。没有发现地中海 (MED) 物种（生物型 Q）的证据。SLC 病在该地区的几个生长周期和地理上分开的地方的南瓜中盛行。据我们所知，这是与墨西哥 BCS 南瓜植物相关的 SLCuV 的第一份报告。单个成年粉虱的分子分析确定所有种群都属于烟粉虱 (MEAM1)（生物型 B）物种。没有发现地中海 (MED) 物种（生物型 Q）的证据。SLC 病在该地区的几个生长周期和地理上分开的地方的南瓜中盛行。据我们所知，这是与墨西哥 BCS 南瓜植物相关的 SLCuV 的第一份报告。单个成年粉虱的分子分析确定所有种群都属于烟粉虱 (MEAM1)（生物型 B）物种。没有发现地中海 (MED) 物种（生物型 Q）的证据。SLC 病在该地区的几个生长周期和地理上分开的地方的南瓜中盛行。据我们所知，这是与墨西哥 BCS 南瓜植物相关的 SLCuV 的第一份报告。