Sooty canker,a destructive disease of banyan (Ficus benghalensis L.) trees in landscapes of Kish Island (Iran)

Ficus benghalensis L (banyan tree) has been planted as ornamental tree in parks, landscapes as well as along roads and streets in many southern cities of Iran. During field surveys conducted in Kish Island (Hormozgān province) an unusual decline was noticed on F. benghalensis. Affected trees exhibited bark necrosis, peeled off bark and cankers on branches and aerial roots, yellowing and defoliation, branch dieback and eventually death. A black sooty mass of fungal spores under the bark as well as wood discoloration in cross sections were also observed on infected parts of trees and pruning wood debris. Samples were collected from all affected parts of trees showing disease symptoms, pruning wood debris as well as rove arthropods in close proximity to the trees for the presence of fungal inoculum. In this study 239 Botryosphaeriaceae-like isolates were obtained from discoloured wood tissues, pruning wood debris and from the bodies of collected arthropods. Based on morphological characteristics and DNA sequence data of ITS and tef-1α gene regions, isolates were identified as Lasiodiplodia theobromae and Neoscytalidium dimidiatum. Pathogenicity of both species was performed on the branches of banyan trees and L. theobromae was more virulent, based on the length of necrotic lesions in the wood, than those of N. dimidiatum. This study is the first report of N. dimidiatum associated with sooty canker and dieback of F. benghalensis worldwide. Our study showed for the first time that L. theobromae and N. dimidiatum can also be associated with some arthropods. Our outcomes can improve the management strategies of trunk diseases caused by Botryosphaeriaceae species on ornamental trees in landscapes.     

观赏草的观赏特性与养护技术研究进展

观赏革种类繁多，是一个相当大的族群。其特点是：分孽性强，单株多丛生，群体成片分布；茎秆姿态优美，叶片色泽丰富，花序多姿多彩，具有较高的观赏价值。观赏草大多对环境要求粗放，管护成本低，抗性强，繁殖力强，适应面广，符合当前建设节约型园林的要求。其独特的景观效果，不仅是公路、河流、山坡等处绿化美化的优良材料，而且可以广泛应用于各种园林景观的营造中。本文就观赏草的观赏特性，栽培养护及其应用等几个方面进行了综述。