Evaluation of somatic hibrids and transgenic plants of Citrus spp. for disease resistance

• Grant number: 12/01109-3
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2012
• Effective date (End): July 27, 2014
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal researcher: Beatriz Madalena Januzzi Mendes
• Grantee: Fabiana Rezende Muniz
• Home Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Citrus fruits are the first in fruit production volume in Brazil, especially the production of sweet oranges. Nevertheless, the productivity of citrus in the country is still low compared to the one obtained in other producing countries. This low productivity is due, among other factors, to the occurrence of diseases in the culture. Among the major diseases are citrus tristeza caused by Citrus tristeza virus, citrus variegated chlorosis caused by Xylella fastidiosa, citrus canker caused by Xanthomonas axonopodis pv. citri and huanglongbing (HLB) caused by Candidatus Liberibacter spp.. These diseases are widespread in commercial orchards and are known for their devastating power. Biotechnology techniques, like genetic transformation and somatic hybridization, are good alternatives to overcome some of the characteristics of the citrus complex reproductive biology, which make it difficult to obtain disease-resistant plants by conventional breeding. The aim of this work is to evaluate citrus transgenic plants and somatic hybrids, obtained in previous works by the citrus biotechnology research group from CENA/USP and ESALQ/USP, for resistance to the diseases citrus tristeza, citrus variegated chlorosis, citrus canker and HLB. Resistance to disease will be evaluated in clones of the somatic hybrids and transgenic plants, after inoculation with the specific pathogen, according to the genetic construct inserted, by evaluation of symptoms and pathogen quantification by Real-time PCR. The evaluation of these plants behavior against the diseases will allow the selection of promising plants which can be incorporated into plant breeding programs. (AU)