Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India.
BMC Genomics. 2024 Oct 15;25(1):966. doi: 10.1186/s12864-024-10866-2.
Mustard is a commercial oilseed crop worldwide infected by a highly infectious turnip mosaic virus (TuMV). In the experimental field at ICAR-IARI, New Delhi, in 2022, a 100% incidence of TuMV infection was observed in brown, black and yellow mustard. A very low aphid population suggested the possibility of seed transmission. Earlier, the virus genome was characterized by high throughput sequencing and it was a recombinant of World-B and Asian-BR isolates. The presence of TuMV in immature seeds was confirmed in eight field-grown genotypes via RT-PCR using CP-specific primers designed from the same genome sequence. TuMV was found to be localized in embryo and cotyledon, indicating its true seed-borne nature. Presence of TuMV was also confirmed by RT-PCR in the grow out plants from seeds of field grown eight infected genotypes and 9 genotypes collected from seed stock, that were grown in an aphid-free growth chamber. Further, out of 24 seedlings of Pusa Gold (seed stock) and Pusa Karishma (seeds from field grown plants), 20 and 17 seedlings were found infected with TuMV, respectively. The internally seed-borne nature of the virus leads to its early establishment at the seedling stage, leading to stunting and leaf-puckering symptoms in the progeny plants. This study is the first evidence of seed embryo infection and seedling transmission of TuMV of all the three species of mustard plants (brown, black and yellow mustard). Seed transmission of TuMV in mustard genotypes have implications for the seed exchange programme of mustard seeds.
芥菜是一种在全球范围内广泛种植的商业性油料作物，易受到芜菁花叶病毒（TuMV）的高度感染。在 2022 年位于新德里的印度农业研究所的实验田中，观察到棕色、黑色和黄色芥菜中 TuMV 的感染率达到了 100%。极低的蚜虫种群表明存在种子传播的可能性。此前，病毒基因组通过高通量测序进行了特征分析，发现其为世界-B 和亚洲-BR 分离株的重组体。通过使用从同一基因组序列设计的 CP 特异性引物，对八个田间生长的基因型进行 RT-PCR 检测，证实了未成熟种子中存在 TuMV。研究发现，TuMV 定位于胚胎和子叶中，表明其具有真正的种子传播特性。从田间生长的 8 个感染基因型的种子和从种子库收集的 9 个基因型的植物中，也通过 RT-PCR 证实了 TuMV 的存在。在无蚜虫生长室中生长的种子中，从 24 株 Pusa Gold（种子库存）和 Pusa Karishma（田间生长植物的种子）幼苗中，分别发现 20 株和 17 株感染了 TuMV。病毒的内部种子传播特性导致其在幼苗阶段早期建立，导致后代植物出现矮化和叶片卷曲症状。这项研究首次证实了 TuMV 对芥菜属三种植物（棕色、黑色和黄色芥菜）的种子胚胎感染和幼苗传播。芥菜基因型中 TuMV 的种子传播对芥菜种子的种子交换计划具有重要意义。
