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TRANSCRIPT
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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