genomics-based selection approaches for brown rot disease ... · brown rot (br) br casual agents,...

Genomics-based selection approaches for Brown Rot disease resistance in Peach

Presented by:

Majid H. Mustafa MUSTAFA

Supervisor:

Prof. Daniele Bassi

Co-supervisor:

Dr. Marco Cirilli

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1° Year PhD candidate, XXXIV cycle,

Academic year 2019

http://www.MASPES.com/

Outlines

Introduction

Previous Studies

Research Challenges

Research Aims

Materials and Methods

Preliminary results

References

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Introduction

Peach (Prunus persica L. Batsch) is the most crop among

stone fruits.

Italy, with production 1.2 million tonnes/season, is one of

leading European producers (CSO, 2018) (Centro Servizi

Ortofrutticoli)

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Italian Peach production regions (SCO, 2019)

Brown Rot (BR)

BR casual agents, in Italy, are:

➢ Monilinia laxa

➢ Monilinia fructicola

➢ Monilinia fructigena (prevalent on pome fruits)

➢ Monilinia polystroma (Martini C, et al,. 2014)

▪ Damage

➢ Direct yield losses by blossom and twig blight, and fruit rot during pre &

postharvest.

➢ BR is considered one of the major causes of pesticide use on stone fruits

(Ritchie, 2000).

BR affects stone fruit crops in warm and humid climates worldwide

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Symptoms5

BR Symptoms on a Sensitive Cultivar

Monilinia spp. life cycle.

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Currently, commercial cultivars are more or less sensitive to BR.

To generate new cultivars resistance to BR the identification of

genes or loci associated with resistance to BR would allow

progress in breeding programs.

7 Previous studies

Previous studies

To date, two studies exploring genomic regions linked to BR

resistance have been published

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The study revealed three QTLs, two of

them in LG1 and one in the LG4 of

Prunus genome.

QTL analysis from F1 CxEL revealed

two QTL clusters, associated to skin

and flesh resistance to BR./in the LG2

and LG4 of Prunus genome

Research Challenges

BR phenotyping is often hindered by environmental

and seasonal conditions. Such as low temperatures, air

humidity, soil nutrient availability (nitrogen), and

orchard conditions, affecting significantly in BR

development.

Maturity date (MD) proven to significantly correlated

with disease impact.

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Research aims:

The main aim of this project is to identify

molecular markers associated with BR

resistance in peach.

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Specific Objectives

I. Phenotyping F2 segregating progenies from selfing

three F1 selections.

II. Genotyping the population by specific SSR and

SNP markers.

III. Studying plant defense biochemicals in flesh and

skin, that may have crucial role in tolerance and

sensitivity toward the BR.

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Material and Method

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293 offsprings available from MASPES breeding program (BO), Imola

BO07007

BO07008

BO 07009

BO92038071 , BO92038140, BO92038046

Contender (Resistant)

Elegant Lady(susceptible)

F1

F2

-Seedlings were grafted on the

GF305 rootstock-No fungicide

Plant material

Material and Method

Inoculum

Monilinia laxa was obtained from the same orchard.

Mass production of spores: the pure culture of the fungus was subjected to mass production conidia prior the inoculation trails by 7

days.

Inoculum concentration was measured on a Malassez counting

chamber and adjusted to 2x104 - 5x104 spores/ml with sterile aqueous

0.05 % Tween 20.

Material and Method

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IAD meter on 10 fruits/tree Spray 8 to 10 fruits/

seedling

Conidial suspension in1x Tween 20

Close them in paperbag (25*35 cm)

Counting Infection

Artificial Inoculation infection

Naturally infection

Control infection (water&Tween20)

After 7 days

10 fruits/seedling brought to lab

Infection procedure, phenotyping

1- Fruit weight, 2- IAD meter 3-Sugar

Preliminary results 15

• During the season (2019), 220 germplasms were phenotyped.

• Significant differences recorded for tolerant/susceptibility between the

genotypes.

References

Obi, V., Barriuso, J., & Gogorcena, Y. (2018). Peach brown rot: still in search of an ideal management option. Agriculture, 8(8), 125.

Monet, R. (1988, June). Peach genetics: past present and future. In II International Peach Symposium 254 (pp. 49-58).

Layne, D. R., & Bassi, D. (Eds.). (2008). The peach: botany, production and uses. CABI.

Pacheco, I., Bassi, D., Eduardo, I., Ciacciulli, A., Pirona, R., Rossini, L., & Vecchietti, A. (2014). QTL mapping for brown rot (Monilinia fructigena) resistance in an intraspecific peach (Prunus persica L. Batsch) F1 progeny. Tree genetics & genomes, 10(5), 1223-1242.

Hancock, J. F., Scorza, R., & Lobos, G. A. (2008). Peaches. In Temperate fruit crop breeding (pp. 265-298). Springer, Dordrecht.

Martini, C., Lantos, A., Di Francesco, A., Guidareli, M., D’Aquino, S., & Baraldi, E. (2014). First report of Asiatic brown rot caused by Monilinia polystroma on peach in Italy. Plant disease, 98(11), 1585.

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Thanks for your attention!

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