Genetic diversity in Chilean strawberry (Fragaria chiloensis): differential response to Botrytis cinerea infection

Abstract

Botrytis cinerea Pers. is a necrotrophic and polyphageous pathogen economically important on soft fruits and crops producing severe agricultural losses. The Chilean strawberry, Fragaria chiloensis (L.) P. Mill. is one of the wild parents of commercial strawberry and has the capacity to tolerate the infection from the pathogenic fungus. A study was performed to make a genetic analysis of wild and cultivated individuals collected from three different regions of Central South Chile and compare the Botrytis infection performance. The dominant ISSR markers were used to generate the genetic fingerprinting and the native samples were contrasted against the commercial Fragaria × ananassa Duch. The samples from Contulmo presented the lowest diversity within population and the highest diversity between populations, but at the same time showed the highest tolerance to Botrytis infection. Infected leaves and fruits from F. × ananassa showed 3.6% of the area covered by the fungus, three days after inoculation, while the plants from Contulmo showed 3.3% of the area covered by the pathogen, five days after inoculation. The plants from Contulmo were classified as highly tolerant (HT), tolerant (T), moderately tolerant (MT), and susceptible (S) where 50% of plants belonged to the group of tolerant. The results, highly significant (p ≤ 0.01), indicate that the samples of F. chiloensis from Contulmo are more genetically homogeneous and can be classified as tolerant to the infection by Botrytis cinerea.Additional key words: grey mould, native strawberry, resistance. ResumenDiversidad genética en frutilla chilena (Fragaria chiloensis): respuesta diferencial a la infección con Botrytis cinerea Botrytis cinerea Pers. es un patógeno necrótrofo y polífago de importancia económica en cultivos y frutales, ocasionando importantes pérdidas en agricultura. La frutilla chilena, Fragaria chiloensis (L.) P. Mill., antecesor silvestre de la frutilla comercial, tiene la capacidad de tolerar la infección de una serie de hongos patogénicos. En este estudio se efectuó un análisis genético de plantas de frutilla chilena silvestres y cultivadas, recolectadas en tres diferentes regiones de la zona centro sur de Chile, en cuanto a su comportamiento frente a la infección de Botrytis. Los marcadores dominantes ISSR fueron utilizados para generar el patrón genética y las muestras de frutilla chilena fueron comparadas con las de Fragaria × ananassa Duch. Las muestras de Contulmo mostraron la más baja diversidad dentro de la población y la mayor entre poblaciones. Al mismo tiempo presentaron la mayor tolerancia a la infección con Botrytis. Las hojas y frutos de F. × ananassa, mostraron, tres días después de la inoculación, un 3,6% de su área cubierta por el patógeno. Por el contrario en las plantas recolectadas en Contulmo la infección fue más lenta, observándose un 3,3% del área cubierta por el patógeno, cinco días después de la inoculación. Las plantas de Contulmo fueron clasificadas como altamente tolerantes, tolerantes, moderadamente tolerantes y...

Grey mould of strawberry, a devastating disease caused by the ubiquitous necrotrophic fungal pathogen Botrytis cinerea

“…In this study, two wild ecotypes of F. virginiana showed high resistance to B. cinerea infections and slow disease progression. Such high tolerance in wild species was also reported in B. cinerea ‐inoculated leaves and fruit of F. chiloensis accessions from Chile (González et al , ). In these wild accessions, B. cinerea grew much slower.…”

Isolation of genes differentially expressed during development and ripening of Fragaria chiloensis fruit by suppression subtractive hybridization

“…. It has been grown for centuries by the indigenous Mapuches in south-central Chile and it has been characterized for having intense aroma (González et al, 2009a) and a remarkable pest-and diseaseresistance spectrum (González et al, 2009b), and the potential to become a new exotic berry for Chile. Strawberries are highly perishable fruits.…”

Independent Preharvest Applications of Methyl Jasmonate and Chitosan Elicit Differential Upregulation of Defense-Related Genes with Reduced Incidence of Gray Mold Decay during Postharvest Storage of Fragaria chiloensis Fruit

“…Fr, a causal agent of gray mold disease, is a widely distributed necrotrophic fungus, and is one of the most destructive strawberry diseases worldwide. It can cause yield losses of up to 25% for non-protected strawberries [ 5 ] in spite of a certain degree of tolerance to fungal infection found in Chilean populations of F. chiloensis [ 6 ]. Traditionally, the control of postharvest gray mold decay relies mainly on the use of synthetic fungicides; however, long term monitoring of the fungicide resistance of B. cinerea initiated in French wine-growing regions has revealed the appearance of strains with cross resistance to chemically unrelated fungicides [ 7 ].…”