Document Type : Original Article
Subjects
Preliminary Evaluation of Pistachio Leaf Chlorosis Etiology in Ardakan Planting Area
Mohammad Moradi (PhD)1*, Seyed Reza Fani (PhD)2, Hamid Alipour (PhD)1, Abbas Farajpour (BS)1, Hydar Masoumi (MSc)1
1 Pistachio Research Center, Horticultural Sciences Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Rafsanjan, Iran
2 Plant Protection Research Department, Yazd Agricultural and Natural Resources Research and Education Center (AREEO), Yazd, Iran
Received: 04.04.2024 Accepted: 11.06.2024
Abstract
Background: Over the past twenty years, yellow chlorosis has been appearing in various pistachio cultivars in the Ardakan region. In cases of severe infection, the trees may be completely destroyed. The development of leaf chlorosis can take several years before affecting the trees die.
Materials and Methods: Several experiments were carried out to assess the roles of fungi, nematodes, and phytoplasma as disease causes, along with the potential for pathogen transmission via grafting. Moreover, some trees displaying different levels of leaf chlorosis were trunk-injected with macro- and micro-elements.
Results: Based on evaluations of 500 bud grafts, the results indicated that less than 2% of the grafted sprouts exhibited symptoms of infection transmission after two years. All samples tested negative in PCR assays for the detection of plant phytoplasmas. Various isolates of fungal species, such as Fusarium, were identified from the roots of trees exhibiting chlorosis; however, Koch's postulates could not be confirmed. Additionally, several genera of nematodes, including Meloidogyne, Pratylenchus, Helicotylenchus, and Tylenchulus, were found in the rhizosphere of pistachio trees. Among these, the lesion nematode Pratylenchus neglectus was identified with a high frequency and was recognized as the most important and predominant species. Injections of macro and micro-elements into trees displaying different intensities of chlorosis alleviated the symptoms of the disease, with the effectiveness influenced by the timing of injection and the severity of the symptoms.
Conclusion: Pistachio chlorosis may be caused by a combination of biotic and abiotic factors, which require further investigations.
►Please cite this article as follows:
Moradi M, Fani SR, Alipour H, Farajpour A, Masoumi H. Preliminary Evaluation of Pistachio Leaf Chlorosis Etiology in Ardakan Planting Area. Pistachio and Health Journal. 2024;7(1-2):52-60.
