A Bipartite Geminivirus Infecting Tomatoes in Cuba

Area of Science:

• Plant Virology
• Molecular Biology
• Agricultural Entomology

Background:

• Whitefly-transmitted geminiviruses are a growing threat to agriculture, with increased distribution linked to the vector Bemisia tabaci.
• Gemini virus disease symptoms have been observed in Cuban tomato plants since the early 1990s, impacting commercial varieties.

Purpose of the Study:

• To investigate and identify the geminivirus causing severe disease symptoms in tomato plants in La Habana, Cuba.
• To characterize the genetic makeup of the newly identified geminivirus.

Main Methods:

• Field surveys of tomato plants exhibiting geminivirus disease symptoms.
• Molecular techniques including hybridization, polymerase chain reaction (PCR) amplification, DNA sequencing, and sequence alignment (CLUSTAL W).
• Comparative analysis of the obtained viral DNA sequence against existing geminivirus sequences in GenBank.

Main Results:

• Detection of both Tomato Yellow Leaf Curl Geminivirus (TYLCV) and a distinct bipartite geminivirus in affected tomato plants.
• Successful amplification and sequencing of a 1.1-kb fragment (Component A) of the bipartite geminivirus.
• Sequence analysis revealed the new virus is most closely related to Tomato Mottle Virus (78% similarity).

Conclusions:

• Identification of a novel bipartite geminivirus in Cuban tomatoes, proposed to be named Havana tomato virus.
• The new virus is genetically related to Tomato Mottle Virus.
• Further studies are underway to determine the distribution frequency of this virus and its relationship with whitefly populations.