First report of citrus bacterial canker caused by Xanthomonas axonopodis pv. citri in iraq

Firas Al-Dulaimi,Mahl Abdulwadood,Laith Al-Rubaye,Asmaa A Al-Kaisse

doi:10.24126/jobrc.2018.12.2.534

Abstract

Collected citrus leaves, with erumpent, callus – like lesions with a water-soaked margin of Tangerine (Citrus reticulate Blance), Mexican lemon (Citrus limon), and Sweet orang (Citrus sinensis Osbec) from different orchards in Diyala, Baghdad and Babylon Governorate of Iraq. Pathogenicity of different isolates was confirmed along with symptoms under laboratory condition on detached leaf using pin prick method, observed that 21 (60 %) isolate Xac. was highly virulent to initiate water soaked lesion and fully developed symptoms within 10 to15 days, 14 (40 %) isolate Xac. were less virulent. The results of morphological (shape, colony and color) and biochemical characteristic (gram reaction, starch hydrolysis, gelatein liquefaction, KOH test, Indole production, oxidase reaction, acid and gas production, catalase reaction, fluorescent pigmentation test and NaCl tolerant). Molecular identification was performed by PCR using specific primer J-pth1̸ J-pth2 amplicon 198 bp indicated the occurrence of CBC in Iraq. All isolates 35(100%) were harbor pthA gene. These represent the first report of CBC in Iraq.

Highlights

Canker is a disease affecting citrus species caused by the bacterium Xanthomonas axonopodis pv. citri
Citrus bacterial canker typically occurs on seedlings and on young and adult trees of susceptible hosts in which there is a flush of actively growing shoots and leaves from late summer through to autumn in most citrus growing areas
Severe infections can cause a range of symptoms from defoliation, blemished fruit, premature fruit drop, and twig dieback, to general tree decline [3,4], reported that the pathogen originated in the tropical areas of Asia, such as China, Indonesia and India, where citrus species are presumed to have originated

Summary

Introduction

Canker is a disease affecting citrus species caused by the bacterium Xanthomonas axonopodis pv. citri. Introduction Canker is a disease affecting citrus species caused by the bacterium Xanthomonas axonopodis pv. Citri from the canker infected part of citrus seedlings and identified by studies on morphological, biochemical and cultural features of the bacteria.

Results

Conclusion