A Postharvest Fruit Rot of Apple Caused by Lambertella corni-maris in Washington State

Abstract

Wiseman, M. S., Dugan, F. M., Kim, Y. K., and Xiao, C. L. 2015. A postharvest fruit rot of apple caused by Lambertella corni-maris in Washington State. Plant Dis. 99:201-206.During surveys for postharvest diseases of apple conducted in Wash ington State, an unknown fruit rot was observed on stored apple fruit collected from commercial fruit packinghouses. This disease was pre sent in 66 of the 179 grower lots sampled, accounting for an average 1 to 3% of the total decayed fruit sampled. The disease appeared to origi nate from infection of wounds on the fruit skin. Lesions were brown and decayed tissues were spongy. A Lambertella sp. was consistently isolated from the decayed fruit. Sequences of the fungus and those of Lambertella corni-maris in GenBank differed by 0 to 4 bp across the combined small ribosomal subunit + internal transcribed spacer + large ribosomal subunit regions with a maximum identity ranging from 99 to 100%. The fungus grew at 0 to 20°C and formed apothecia on artificial media after 8 to 24 weeks. On potato dextrose agar under a 12-h photoperiod, apothecial dimensions were variable, ranging from 1 to 6 mm in diameter with stipes of 1 to 4 by 0.5 mm. Asci were 76 to 125 by 3.5 to 5.5 pm, inoperculate, eight-spored, clavate, and narrowed at the base. Ascospores were aseptate, 7 to 10 by 2.5 to 4.5 pm, uniseriate to biseriate, and orange-brown at maturity in the ascus. Colony char acteristics included little or no aerial mycelium, dark-yellow to grayblack mycelium, gray-black pseudosclerotia, and yellow pigmentation in the agar. Morphological characteristics of the fungus overlapped with the description of L. corni-maris. 'Fuji' apple fruit that were wounded, inoculated with representative isolates, and incubated at 0°C yielded the same symptoms as seen in packinghouses, and the fungus was reisolated from the diseased fruit. This is the first report of a fruit rot in stored apple caused by L. corni-maris in the United States. We propose Lambertella rot as the name of this disease.

Lambertella (Rutstroemiaceae, Helotiales) from Northern Thailand

“…Previous studies have reported Lambertella on various substrates, such as rotten or mummi ed fruits (Wiseman et al, 2015), and dead twigs and leaves (Tewari & Pant, 1967). Geographically, Lambertella has been found in various regions in the tropics, northern and southern hemispheres (Whetzel, 1943;Cash, 1958;Tewari, 1963;Dumont, 1971;Dumont, 1974 2016), even though phylogenetic positions for some species, such as L. pruni that showed slight differences in our phylogram based on ITS and LSU sequence data and with more Lambertella species and other representative genera in Rutstroemiaceae (Fig.…”

“…The family was characterized by brownish and greenish, stipitate to substipitate apothecia or sometimes cleistothecia with inoperculate, cylindric-clavate asci, and hyaline to brown, fusiform to ellipsoid ascospores. It mainly includes saprobes and a few parasites (Holst-Jensen et al, 1997; Galán et al, 2015;Wiseman et al, 2015;Zhao et al, 2016;Baral, 2017;Johnston et al, 2019). With several taxonomic revisions camera for photographs while Tarosoft (R) Image Frame Work software was used for the measurement (Senanayake et al 2020).…”