Department of Plant Physiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar 263 145, Uttarakhand, India.
Plant Physiol Biochem. 2013 Aug;69:34-8. doi: 10.1016/j.plaphy.2013.04.019. Epub 2013 May 9.
Malformation is arguably the most crucial disease of mango (Mangifera indica L.). The etiology of the disease has not yet been successfully resolved. Here, we quantified the endogenous ethylene content in malformed and healthy vegetative and floral tissues of mango cultivars viz., Amrapali, Bombay green, Chausa, Dushehri and Mallika. Levels of ethylene were higher in malformed vegetative and floral tissues as compared with that of healthy tissues at both prior to full bloom and full bloom stages. The study also revealed that isolates of Fusarium dissected from mango exhibited most morphological similarities to the accepted standard features of Fusarium mangiferae. The growth dynamic of F. mangiferae were evaluated with varying temperatures ranging from 5 to 40 °C. Temperatures of 25 °C, 30 °C and 35 °C were better suited for growth of F. mangiferae than temperatures of 20 °C or 40 °C. Conidium germination of F. mangiferae was maximum at 30 °C and minimum at <15 °C. World-wide occurrence of mango malformation showed its most severity at 10-15 °C temperature range. Stress ethylene level is higher in diseased tissue at the same temperature range where growth of Fusaria is found to be completely restricted. The present study provides direct evidence that low temperature induced 'stress ethylene' is potentially responsible for the disease while on the other hand Fusarium role in the disease either through toxic principle or malformation inducing principle is not conclusive at <15 °C and is rather out of question.
畸形病可以说是芒果（Mangifera indica L.）最关键的病害。该疾病的病因尚未成功解决。在这里，我们量化了畸形和健康营养和生殖组织中芒果品种（Amrapali、Bombay green、Chausa、Dushehri 和 Mallika）的内源乙烯含量。在初花期和盛花期，畸形营养和生殖组织中的乙烯水平均高于健康组织。该研究还表明，从芒果中分离出的尖孢镰刀菌与公认的尖孢镰刀菌特征标准最为相似。评估了尖孢镰刀菌在 5 至 40°C 范围内的不同温度下的生长动态。25°C、30°C 和 35°C 比 20°C 或 40°C 更适合尖孢镰刀菌的生长。尖孢镰刀菌的分生孢子萌发在 30°C 时最高，在<15°C 时最低。芒果畸形病在全球范围内的发生表明，在 10-15°C 的温度范围内，其发病最为严重。在相同的温度范围内，患病组织中的应激乙烯水平较高，而尖孢镰刀菌的生长则完全受到限制。本研究提供了直接证据，表明低温诱导的“应激乙烯”可能是导致该疾病的原因，而另一方面，在<15°C 时，尖孢镰刀菌在疾病中的作用无论是通过毒性原理还是畸形诱导原理都不明确，而这一点是毋庸置疑的。
