Fluorescence images combined to statistic test for fingerprinting of citrus plants after bacterial infection

Author(s)

Verbi Pereira, Fabiola Manhas ^[1] ; Bastos Pereira Milori, Debora Marcondes ^[1] ; Pereira-Filho, Edenir Rodrigues ^[2] ; Venancio, Andre Leonardo ^{[1, 3]} ; Tavares Russo, Mariana de Sa ^[1] ; Martins, Polyana Kelly ^[4] ; Freitas-Astua, Juliana ^{[4, 5]}

Affiliation

^[1] Embrapa Instrumentacao Agr, BR-13561206 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Quim, Grp Anal Instrumental Aplicada, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Dept Fis & Matemat, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[4] Ctr APTA Citros Sylvio Moreira, BR-13490970 Cordeiropolis, SP - Brazil

^[5] Embrapa Mandioca & Fruticultura Trop, BR-44380000 Cruz Das Antis, BA - Brazil

• Document type: Journal article
• Source: ANALYTICAL METHODS; v. 3, n. 3, p. 552-556, MAR 2011.
• Web of Science Citations: 9

Abstract

The citrus greening (or huanglongbing) disease has caused serious problems in citrus crops around the world. An early diagnostic method to detect this malady is needed due to the rapid dissemination of Candidatus Liberibacter asiaticus (CLas) in the field. This analytical study investigated the fluorescence responses of leaves from healthy citrus plants and those inoculated with CLas by images from a stereomicroscope and also evaluated their potential for the early diagnosis of the infection caused by this bacterium. The plants were measured monthly, and the evolution of the bacteria on inoculated plants was monitored by real-time quantitative polymerase chain reaction (RT-qPCR) amplification of CLas sequences. A statistical method was used to analyse the data. The selection of variables from histograms of colours (colourgrams) of the images was optimized using a paired Student's t-test. The intensity of counts for green colours from images of fluorescence had clearly minor variations for healthy plants than diseased ones. The darker green colours were the indicators of healthy plants and the light colours for the diseased. The method of fluorescence images is novel for fingerprinting healthy and diseased plants and provides an alternative to the current method represented by PCR and visual inspection. A new, non-subjective pattern of analysis and a non-destructive method has been introduced that can minimize the time and costs of analyses. (AU)

• FAPESP's process: 07/08618-2 - Use of fluorescence images, laser-induced breakdown spectroscopy and chemometrics strategies to Greening disease study in citrus plantation
• Grantee: Fabiola Manhas Verbi Pereira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral