New Disease Reports (2005) 11, 45.

A distinct begomovirus causes Indian dolichos yellow mosaic disease

M.N. Maruthi 1*, A.R. Rekha 1, M.R. Govindappa 2, J. Colvin 1 and V. Muniyappa 2

*m.n.maruthi@gre.ac.uk

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Accepted: 27 Jun 2005

Dolichos (Lablab purpureus) is a popular leguminous vegetable in India. Since the 1950s, cultivation of this vegetable has been affected by dolichos yellow mosaic disease (DYMD; Capoor & Varma, 1950), which is associated with a begomovirus tentatively named Dolichos yellow mosaic virus (DoYMV). Characteristic symptoms of the disease are bright yellow mosaic patches on leaves, with significant yield reductions (Fig. 1). A sample from a DYMD-affected dolichos plant was collected from Mysore, Karnataka, southern India in February 2004. The putative virus was transmitted by the whitefly, Bemisia tabaci from dolichos to dolichos cv. Mani.

Total DNA was extracted from the symptomatic leaves and used to PCR-amplify a begomovirus DNA-A component using degenerate primers (Muniyappa et al., 2003). Sequence generated from this PCR product was used to design virus-specific primers to obtain full-length DNA-A clones. The sequence of one clone was determined to be 2760 nucleotides in length (Accession No. AJ968370) and to be most similar to the sequences of DoYMV-[Bangladesh] (AY271891) and a further clone of DoYMV originating from India (AY309241) at 95.2% and 93.4% nt sequence identities respectively. The number and arrangement of open reading frames on DNA-A were similar to viruses of the genus Begomovirus (family Geminiviridae) originating from the Old World. Attempts to identify DNA-B and -β components by PCR (Muniyappa et al., 2003; Briddon et al., 2002) were unsuccessful.

Phylogenetic analysis (Fig. 2) shows the three DoYMV isolates to form a sister clade to the mungbean-infecting begomoviruses which together cluster separately from begomoviruses infecting other host on the Indian sub-continent. DoYMV has only 62.9-63.8% nt identity with mungbean viruses and lower sequence identities with other begomoviruses (61.0-63.9%). These results show that, on the Indian sub-continent, dolichos is infected by a distinct species of begomovirus. Further experiments are being carried out to identify additional viral DNA components and also obtain infectious DoYMV clones.

Figure1+
Figure 1: Symptoms of yellow mosaic on the leaves of dolichos cv. Mani infected by DoYMV-[Mysore]
Figure 1: Symptoms of yellow mosaic on the leaves of dolichos cv. Mani infected by DoYMV-[Mysore]
Figure2+
Figure 2: Most parsimonious tree showing the relationship of DoYMV isolates to other begomoviruses based on complete DNA-A component nucleotide sequences. Numbers at nodes indicate percentage bootstrap values out of 100 replicates. Virus sequences, with their accession numbers, used in the analyses are: Ageratum yellow vein Taiwan virus-[TaiwanPD] (AYVTV-[TwPD]; AF327902), Bean golden yellow mosaic virus-[Mexico] (BGYMV-[MX]; AF173555), Bhendi yellow vein mosaic virus-[Madurai] (BYVMV-[Mad]; AF241479), Cotton leaf curl Rajasthan virus (CLCuRV; AF363011), Dolichos yellow mosaic virus (DoYMV; AY309241), Dolichos yellow mosaic virus-[Bangladesh] (DoYMV-[BD]; AY271891), Dolichos yellow mosaic virus-[Mysore] (DoYMV-[Mys]; AJ968370), East African cassava mosaic Zanzibar virus (EACMZV; AF422174), Horsegram yellow mosaic virus (HYMV; AJ627904), Indian cassava mosaic virus-[Maharastra] (ICMV-[Mah]; AJ314740), Mungbean yellow mosaic virus (MYMV; D14703), Mungbean yellow mosaic virus-[Haryana] (MYMV-[Har]; AY271896), Mungbean yellow mosaic virus-[Thailand] (MYMV-[TH]; AB017341), Mungbean yellow mosaic virus-Vigna (MYMV-Vig; AJ132575); Mungbean yellow mosaic virus-Vigna[Maharastra] (MYMV-Vig[Mah]; AF314530), Mungbean yellow mosaic India virus-[106] (MYMIV-[106]; AJ512498), Mungbean yellow mosaic India virus-Cowpea (MYMIV-Cow; AF481865), Mungbean yellow mosaic India virus-[Madhya Pradesh] (MYMIV-[MP]; AJ416349), Mungbean yellow mosaic India virus-[Varanasi] (MYMIV-[Var]; AY547317), Stachytarpheta leaf curl virus-[Hn5.4] (StLCV-[Hn5.4]; AJ564743), Tomato leaf curl Bangalore virus (ToLCBV; Z48182), Tomato leaf curl Bangalore virus-[Bangalore4] (ToLCBV-[Ban4]; AF165098), Tomato leaf curl Bangladesh virus (ToLCBDV; AF188481), Tomato leaf curl Gujarat virus-[Vadodara] (ToLCGV-[Vad]; AF413671), Tomato leaf curl Karnataka virus (ToLCKV; U38239), Tomato leaf curl New Delhi virus-Mild (ToLCNDV-Mld; U15016) and Tomato leaf curl New Delhi virus-Severe (ToLCNDV-Svr; U15015).
Figure 2: Most parsimonious tree showing the relationship of DoYMV isolates to other begomoviruses based on complete DNA-A component nucleotide sequences. Numbers at nodes indicate percentage bootstrap values out of 100 replicates. Virus sequences, with their accession numbers, used in the analyses are: Ageratum yellow vein Taiwan virus-[TaiwanPD] (AYVTV-[TwPD]; AF327902), Bean golden yellow mosaic virus-[Mexico] (BGYMV-[MX]; AF173555), Bhendi yellow vein mosaic virus-[Madurai] (BYVMV-[Mad]; AF241479), Cotton leaf curl Rajasthan virus (CLCuRV; AF363011), Dolichos yellow mosaic virus (DoYMV; AY309241), Dolichos yellow mosaic virus-[Bangladesh] (DoYMV-[BD]; AY271891), Dolichos yellow mosaic virus-[Mysore] (DoYMV-[Mys]; AJ968370), East African cassava mosaic Zanzibar virus (EACMZV; AF422174), Horsegram yellow mosaic virus (HYMV; AJ627904), Indian cassava mosaic virus-[Maharastra] (ICMV-[Mah]; AJ314740), Mungbean yellow mosaic virus (MYMV; D14703), Mungbean yellow mosaic virus-[Haryana] (MYMV-[Har]; AY271896), Mungbean yellow mosaic virus-[Thailand] (MYMV-[TH]; AB017341), Mungbean yellow mosaic virus-Vigna (MYMV-Vig; AJ132575); Mungbean yellow mosaic virus-Vigna[Maharastra] (MYMV-Vig[Mah]; AF314530), Mungbean yellow mosaic India virus-[106] (MYMIV-[106]; AJ512498), Mungbean yellow mosaic India virus-Cowpea (MYMIV-Cow; AF481865), Mungbean yellow mosaic India virus-[Madhya Pradesh] (MYMIV-[MP]; AJ416349), Mungbean yellow mosaic India virus-[Varanasi] (MYMIV-[Var]; AY547317), Stachytarpheta leaf curl virus-[Hn5.4] (StLCV-[Hn5.4]; AJ564743), Tomato leaf curl Bangalore virus (ToLCBV; Z48182), Tomato leaf curl Bangalore virus-[Bangalore4] (ToLCBV-[Ban4]; AF165098), Tomato leaf curl Bangladesh virus (ToLCBDV; AF188481), Tomato leaf curl Gujarat virus-[Vadodara] (ToLCGV-[Vad]; AF413671), Tomato leaf curl Karnataka virus (ToLCKV; U38239), Tomato leaf curl New Delhi virus-Mild (ToLCNDV-Mld; U15016) and Tomato leaf curl New Delhi virus-Severe (ToLCNDV-Svr; U15015).

References

  1. Briddon RW, Bull SE, Mansoor S, Amin I, Markham PG, 2002. Universal primers for the PCR-mediated amplification of DNA-β: A molecule associated with monopartite begomoviruses. Molecular Biotechnology 20, 315-18.
  2. Capoor SP, Varma PM. (1950) New virus disease of Dolichos lablab. Current Science 19, 242-249.
  3. Muniyappa V, Maruthi MN, Babitha CR, Colvin J, Briddon RW, Rangaswamy KT, 2003. Characterisation of pumpkin yellow vein mosaic virus from India. Annals of Applied Biology 142, 323-31.

This report was formally published in Plant Pathology

©2005 The Authors