Advanced Flowering of Juvenile Citrus Induced by a Viral Vector

The long juvenile period of citrus trees, which is often more than 6 years, has hindered genetic improvement by traditional breeding methods. Karelia Velázquez and scientists from Instituto Valenciano de Investigaciones Agrarias in Spain, have developed a tool to promote transition from the vegetative to reproductive phase in juvenile citrus plants. This was done by expressing the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus-based vector (clbvINpr-AtFT and clbvINpr-CiFT, respectively).

Citrus plants of different genotypes inoculated with either of these vectors started flowering within 4–6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology compared to non-inoculated adult plants. The vector also did not integrate in with the plant genome or was pollen or vector transmissible. However, seed transmission at low rate was detected.

Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up citrus genetic studies and breeding programs.

For more information, read the full article on Plant Biotechnology Journal.