EAPSI: Identifying Fungi Associated with the Ancient Conifer Agathis Australis and Testing their Potential as Biological Control Agents against Harmful Pathogen

贝壳杉（Agathis australis）是一种具有重要经济和文化意义的树木，原产于新西兰，目前正受到一种破坏性土壤病原体的威胁，这种病原体会导致一种被称为贝壳杉枯死病的疾病。与新西兰奥克兰Landcare Research的Maj Padamsee博士合作，他在研究贝壳杉枯梢和与贝壳杉相关的真菌方面具有专业知识，这项工作旨在(1)识别与贝壳杉根部相关的有益真菌；(2)评估其抑制感染或减缓病原体进展的潜力。为完成这项工作而形成的网络将有利于专业发展和未来的国际合作。这项研究的发现有可能改善杉木枯梢病和由类似病原体引起的疾病的控制方法，如橡树猝死病、大豆根腐病和可可黑豆荚病，这些疾病威胁着全球其他地区经济和文化上重要的树木。澳洲杉木，通常被称为贝壳杉，是一种古老的、长寿的、经济上重要的和文化上重要的针叶树，是新西兰特有的。自欧洲人到来以来，贝壳杉的种植面积从160万公顷减少到只有约7500公顷，而剩下的树木目前受到了疫霉的威胁，这是一种卵菌病原体，会导致破坏性的贝壳杉枯病。Padamsee和他的同事们将菌根与贝壳杉的根联系起来，并通过显微镜分析发现了与根相关的暗隔内生菌（DSEs）的证据。目前的工作范围是：(1)通过对其内部转录间隔区（ITS）区域进行测序，在物种水平上鉴定杉木相关的DSE真菌；(2)通过两项体外抑制试验，评估DSE真菌对agathicida真菌营养生长和孢子萌发率的抑制潜力。该研究结果可作为生物防治方法的基础，应用于杉木枯死病和其他由疫霉引起的重要疾病。该奖项由美国国家科学基金会和新西兰皇家学会共同资助，由东亚和太平洋暑期研究所项目资助一名美国研究生进行暑期研究。

Kauri (Agathis australis) are economically and culturally important trees that are native to New Zealand and are currently threatened by a devastating soil pathogen that causes a disease known as kauri dieback. In collaboration with Dr. Maj Padamsee of Landcare Research in Auckland, New Zealand, who has expertise working with kauri dieback and fungi that associate with kauri, this work aims to (1) identify beneficial fungi that associate with the roots of kauri; and (2) evaluate their potential to inhibit infection or slow the progression of the pathogen. The network formed to complete this work will be beneficial for professional development and future international collaborations. Findings from this research have the potential to improve control methods for kauri dieback and diseases caused by similar pathogens such as sudden oak death, soybean root rot and cocoa black pod disease that threaten economically and culturally important trees in other regions around the globe.Agathis australis (Araucariaceae), commonly referred to as kauri, is an ancient, long-lived, economically important and culturally significant conifer that is endemic to New Zealand. Kauri have been reduced from 1.6 million hectares to only ca. 7500 hectares since European arrival and the remaining trees are currently threatened by Phytophthora agathicida, an oomycete pathogen that causes a devastating collar rot known as kauri dieback. Padamsee and colleagues characterized mycorrhizal associations with kauri roots and found evidence of dark septate endophytes (DSEs) also being present in association with the roots via microscopic analyses. The scope of the present work is to (1) identify kauri-associated DSE fungi at the species level by sequencing their internal transcribed spacer (ITS) regions; and (2) evaluate the potential of DSE fungi to inhibit vegetative growth and spore germination rates of P. agathicida via two in vitro inhibition assays. Results from this investigation may serve as the basis for biocontrol methods that can be applied to kauri dieback and other important diseases that are caused by Phytophthora spp.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Royal Society of New Zealand.