Silverleaf (Chondrostereum purpureum) Effects on Japanese Plum (Prunus salicina).

Daina Grinbergs,Carla Hahn,Andrés France,Mariana Isla,Jorunn Børve,Marisol Reyes,Javier Chilian

doi:10.3390/plants10122777

Daina Grinbergs, Carla Hahn + Show 5 more

Open Access

https://doi.org/10.3390/plants10122777

Copy DOI

Abstract

Silverleaf is an important fungal trunk disease of fruit crops, such as Japanese plum (Prunus salicina). It is known that infection by Chondrostereum purpureum results in discolored wood, “silvered” foliage, and tree decline. However, effects on fruit yield and quality have not been assessed. Therefore, the objectives of this study were to determine C. purpureum pathogenicity on P. salicina and the effects on physiology, fruit yield, and quality, in Chile, in 2019 and 2020. Wood samples from affected plum trees were collected in the Chilean plum productive area. Fungi were isolated by plating wood sections from the necrosis margin on culture media. Morphological and molecular characteristics of the isolates corresponded to C. purpureum (98%). Representative isolates were inoculated from healthy plum plants and after 65-d incubation, wood necrotic lesions and silver leaves were visible. Fungi were reisolated, fulfilling Koch’s postulates. To determine Silverleaf effects, xylem water potential and fruit yield and quality were measured in healthy and Silverleaf-diseased plum trees ‘Angeleno’. Water potential was altered in diseased trees, and fruit yield was reduced by 51% (2019) and by 41% (2020) compared to fruit from healthy trees. Moreover, cover-colour, equatorial-diameter, and weight were reduced, and fruit were softer, failing to meet the criteria to be properly commercialized and exported to demanding markets.

Highlights

White-cottony mycelia (Figure 1C) with clamp connections grew from wood sections from the necrosis progress area, which were surface disinfected and plated on Petri plates containing acidified potato dextrose agar (APDA) (25% PDA, acidified with 0.2% v/v 85% lactic acid) and water agar (WA)
C. purpureum was successfully isolated from the necrotic margin of stained wood of Japanese plums trees showing Silverleaf foliar symptoms
Chondrostereum purpureum is a primary invader of woody angiosperms and enters its host through a fresh wound, followed by the infection of aggressive saprobic fungi such as Trametes versicolor and Schizophyllum commune [15,16]

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The Japanese plum (P. salicina L.) is a deciduous stone fruit tree native to China. It is grown globally, and Chile cultivates 4520 ha, mainly ‘Angeleno’, ‘Black-Amber’, and ‘Friar’. Chilean production volume is ~400,000 t (2019–2020), and Chile is the major fresh plum exporter worldwide [1]

Objectives

Methods

Results

Conclusion