Neopestalotiopsis Species Associated with Flower Diseases of Macadamia integrifolia in Australia.

Kandeeparoopan Prasannath,Victor J Galea,Roger G Shivas,Olufemi A Akinsanmi

doi:10.3390/jof7090771

Abstract

Macadamia (Macadamia integrifolia) is native to eastern Australia and produces an edible nut that is extensively cultivated in commercial orchards in several countries. Little is known about the diversity of fungi associated with diseases of macadamia inflorescences. A survey of fungi associated with the dry flower disease of macadamia detected several isolates of Neopestalotiopsis (Pestalotiopsidaceae, Sordariomycetes). Five new species of Neopestalotiopsis were identified based on molecular phylogenetic analyses of concatenated gene sequences of the internal transcribed spacer (ITS), β-tubulin (TUB), and the translation elongation factor 1-alpha (TEF1α). The new species are named Neopestalotiopsis drenthii, N. maddoxii, N. olumideae, N. vheenae, and N. zakeelii, and are described by molecular, morphological, and cultural characteristics. The ecology of the isolates and their pathogenic, saprophytic, or commensal ability were not determined.

Highlights

Macadamia (Macadamia integrifolia) is a tree nut crop that is cultivated for its highvalue kernel in tropical and subtropical regions in Australia, Asia, Africa, South America, and the U.S.A
Phylogenetic trees were generated from Maximum Likelihood (ML), Bayesian Inference (BI), and Maximum Parsimony (MP) analyses
The phylogenetic tree inferred from the concatenated alignment resolved the 13 Neopestalotiopsis isolates from symptomatic macadamia inflorescences into five well-supported monophyletic clades that represent novel species of Neopestalotiopsis (Figure 2)

Summary

Introduction

Macadamia (Macadamia integrifolia) is a tree nut crop that is cultivated for its highvalue kernel in tropical and subtropical regions in Australia, Asia, Africa, South America, and the U.S.A. Diseases of flowers and fruit result in significant yield losses and poor-quality kernels [6,7,8]. A mature macadamia tree may produce over 10,000 racemes (inflorescences) at peak anthesis, with each raceme typically having 100–300 flowers (Figure 1a) [9,10]. Macadamia racemes may be affected by fungal pathogens at different developmental stages. Most of the diseases that affect macadamia inflorescences are flower blights [12]. A diversity of fungi has been associated with flower blights of macadamia in Australia [13], including species of Botrytis [14], Cladosporium [15], Neopestalotiopsis, and Pestalotiopsis [8]. ((aa)) PPeennddaanntt rraacceemmeess iinn ttrreeee ccaannooppyy,, aanndd ((bb)) ddrryy flfloowweerr ddiisseeaassee. Living cultures of the isolates were deposited in the Queensland Plant Pathology Herbarium (BRIP), Brisbane, Australia

Cultural and Morphological Studies

Phylogenetic Analyses

Taxonomy

Conclusions