Reaction of Different Vaccinium Species to the Blueberry Leaf Rust Pathogen Thekopsora minima

Abstract

<jats:p>Blueberry leaf rust caused by <jats:italic>Thekopsora minima</jats:italic> is a serious threat to blueberry production. To investigate the host range and characterize new sources of resistance, 15 southern highbush accessions (<jats:italic>Vaccinium corymbosum</jats:italic>), two interspecific hybrids (<jats:italic>V. elliottii</jats:italic> × <jats:italic>V. pallidum</jats:italic> and <jats:italic>V. corymbosum</jats:italic> × <jats:italic>V. pallidum</jats:italic>), and accessions from five diploid <jats:italic>Vaccinium</jats:italic> species were inoculated with an isolate of <jats:italic>T. minima</jats:italic>. Of 15, only two southern highbush accessions displayed resistance, whereas both accessions of <jats:italic>V. arboreum</jats:italic> displayed immunity against <jats:italic>T. minima</jats:italic>. Accessions of <jats:italic>V. darrowii</jats:italic> exhibited necrosis but with limited sporulation, indicating a high level of resistance. Sporulating lesions and brown spots were observed in accessions of <jats:italic>V. elliottii</jats:italic> and <jats:italic>V. tenellum</jats:italic>. Brown lesions, large pustules, and abundant sporulation were observed on <jats:italic>V. pallidum</jats:italic> accessions and their interspecific hybrids. As the lesions expanded, defoliation was observed in <jats:italic>V. pallidum</jats:italic> accessions. When tested against rabbiteye (<jats:italic>V. virgatum</jats:italic>) and southern highbush blueberries, urediniospores of <jats:italic>T. minima</jats:italic> from overwintering leaves of <jats:italic>V. pallidum</jats:italic> were found to be virulent, suggesting that <jats:italic>T. minima</jats:italic> overwinters on <jats:italic>V. pallidum</jats:italic>. Based on symptoms and scanning electron microscopy (SEM) of urediniospores, we hypothesize that <jats:italic>V. elliottii</jats:italic>, <jats:italic>V. tenellum</jats:italic>, <jats:italic>V. pallidum</jats:italic>, and <jats:italic>V. corymbosum</jats:italic> exhibit no host specificity to <jats:italic>T. minima</jats:italic>.</jats:p>

High-quality reference genome and annotation aids understanding of berry development for evergreen blueberry (Vaccinium darrowii)

“…There is a continual need to broaden the genetic base of SHB cultivars and enrich them with alleles from other species to enhance fruit quality and improve the level of tolerance to biotic and abiotic stresses 4 . V. darrowii continues to be an important source of traits; SHB cultivars lack resistance to the blueberry leaf rust pathogen Thekopsora minima while V. darrowii exhibits a high level of resistance 10 . Growing interest to continue to utilize diverse V. darrowii accessions for breeding could be bolstered by new genomic resources 11 , 12 .…”

Cinco Tipos de Poda en Arándano (Vaccinium Corymbosum L. Cv. Biloxi) y su Influencia en Determinados Parámetros Productivos

“…Los cultivares SH fueron creados mediante la "hibridación interespecífica" de variedades NH y especies nativas de Vaccinium del sur de Estados Unidos con un bajo requerimiento de frío (Babiker et al, 2023).…”