Molecular Characterization Of Four Geminiviruses In Fujian Province

Members of the genus Begomovirus in the family Geminiviridae have circularsingle-stranded DNA genome encapsidated in twinned icosahedral particles.Begomoviruses have caused significant yield loss to many crops and are becoming aserious threat to crops in south China since 1990s. The current study was carried outto identify begomoviruses in several crops and weeds in Fujian province.Thirteen begomovirus samples were collected from Ageratum conyzoides,Eclipta prostrate, Delonix regia, Artemisia indica Willd, Phyllanthus urinaria andCapsicum frutescens. PCR detection using universal primer pair PA/PB forbegomoviruses indicated that these samples were infected by begomoviruses. Basedon the nucleotide sequences of the 500 bp fragments amplified by PA and PB, the 13isolates consist offour main types: FY1, FY2, FY3, FY4, FY5, FY6 and F26 areisolates of Pepper yellow vein Mali virus (PYVM1V); F09 and F21 are isolates ofMalvastrum yellow mosaic virus (MaYMV-[Hn38] ); F25 is isolate of Papaya leafcurl China virus (PLCCNV); F22, F23 and F24 are isolates of Alternanthera yellowvein virus (A1YVV).The virus isolate F09 was collected from Ageratum conyzoides showing yellow vein symptoms in Fujian Province. The complete nucleotide sequence of the DNA A like molecule of F09 is determined to be 2753 nucleotides. F09 DNA A is most closely related to isolates of AYVV with 89．1%～98．4% nucleotide sequence identities, while less than 79．6 nucleotide sequence identities are found in comparisons with other begomoviruses. Therefore, F09 is taxonomically considered as an isolate of AYVV. Further studies show that F09 is associated with a DNAβmolecule. The DNAβof F09 contains 1350 nucleotides having the highest nucleotide sequence identity (93．1 %) with DNAβassociated with TLCV, while less than 55．4% nucleotide sequence identities are found in comparisons with other DNAβmolecules. This is the first report of new isolate of AYVV in Fujian, and the first report of TLCV-associated DNAβmolecule infecting Ageratum conyzoides.The virus isolates F21, F22, F25 and F26 were obtained from Eclipta prostrate. Complete DNA A sequences of F21 and F22 has 92．0% nucleotide sequence identity and have high nucleotide sequence identities (92．0% and 97．0%) with A1YVV. F25 DNA A has the highest sequence identity (99．1%) with PLCCNV-[G4] and shares only 66．5% nucleotide sequence identities with other DNA A sequences . F26 DNA A has the highest sequence identity (95．4%) with PYVMIV and shares only 66．8% nucleotide sequence identities with other DNA A sequences . It reveals that F21 and F22 are isolates of A1YVV, and F25 is isolate of PLCCNV-[G4] , F26 is isolate of PYVMIV. It is the first report of mixed infection in weeds in Fujian province.Eclipta prostrate with severer yellow vein symptoms was used to infect Eclipta prostrata, Nicotiana tabacum, Nicotiana benthamiana, Nicotiana glutinosa, Capsicum frutescens, tomato, cotton, Phyllanthus urinaria by Bemisia tabaci. There are the most severer yellow vein symptom in Eclipta prostrate than in other plants, and more severer yellow vein symptom in Capsicum frutescens, Nicotiana tabacum and Phyllanthus urinaria. They didn't produce obvious symptoms in Nicotiana benthamiana and N. glutinosa. It reveals that: There are mixed infection in Eclipta prostrate, three viruses are all used to infect healthy plants by B. tabaci, the virus infected Eclipta prostrate may infect healthy tomato, Nicotiana tabacum, Nicotiana benthamiana,Nicotiana glutinosa,cotton,Capsicum frutescens,Phyllanthus urinaria.The virus isolates FY1 obtained from Bougainvillea spectabilis Willd and FY5 obtained from Artemisia indica Willd showing yellow vein symptoms in Fujian Province. The complete nucleotide sequence of the DNA A like molecule of FY1 and FY5 are determined to be 2786 nucleotides and 2786 nucleotides, respectively. Complete DNA A sequences of FY1 and FY5 has 98．8% nucleotide sequence identity and share high nucleotide sequence identities 95．5% with PYVMIV, while less than 78．8% nucleotide sequence identities are found in comparisons with other begomoviruses. It is the first report that PYVMIV could infect Bougainvillea spectabilis Willd and Artemisia indica Willd.