Prebreeding for future challenges - PowerPoint Presentation

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Prebreeding for future challenges in Nordic apples – the first two years

ABSTRACT

The Nordic Council of Ministers (NMR) has set up a Public Private Partnership (PPP) for pre-breeding of plant

crops, aiming to support the development of Nordic plant breeding and thus satisfy long-term needs of the agricultural and horticultural industries. In a PPP pre-breeding project on apple (2012-2014) we search for sources of resistance to Neonectria ditissima (causing European canker on trees), Penicillium expansum (causing blue mould on fruits) and Neofabraea spp. (causing bull’s eye rot on fruits). The obtained results will be used in further work towards genetic dissection of the complex resistance to these diseases. Within the project a network of Nordic and Baltic breeders of fruit and berries is developed, in order to define and develop projects that meet with the challenges for Nordic and Baltic fruit and berry production.

Figure 1. Left: Apple tree stem with fruit tree canker wound. Middle: Inoculation of wounded cut shoots. Right: Lesion developed after inoculation of cut shoot.

ACKNOWLEDGEMENTSAt SLU Balsgård, Jasna Sehic, Marian Ghasemkhani and Masoud Ahmadi-Afzadi assisted in the practical work, and at Graminor, experiment set-up, execution, and data recordings were done by Kurab Røen.

Dag Røen1, Larisa Garkava-Gustavsson2, Ibrahim Tahir2 , Saila Karhu3 and Hilde Nybom41Graminor - Njøs, Njøsavegen 5, NO-6863 Leikanger, Norway. E-mail: dag.roen@graminor.no2Swedish University of Agricultural Sciences, Department of Plant Breeding, Box 101, SE-230 53 Alnarp, Sweden3MTT Horticulture, Toivonlinnantie 518, SF-21500 Piikkiö, Finland4Swedish University of Agricultural Sciences, Department of Plant Breeding, Balsgård, Fjälkestadsvägen 459, SE-291 94 Kristianstad, Sweden. E-mail: hilde.nybom@slu.se

EXPERIMENTS ON FRUIT CANKER

INTRODUCTION

Apple canker caused by the fungus

Neonectria ditissima (syn. Nectria galligena) is a severe problem in apple orchards in Northern Europe. Different apple cultivars show continuous variation for partial resistance to the disease. Information on inheritance is limited, but two major QTL have been identified. Complete resistance is not known in apple. Identification of genotypes with high levels of resistance is an important step towards breeding of resistant cultivars. Several methods for artificial inoculation are developed to quantify resistance to apple canker, by inoculation on leaf scars on trees, wound inoculations on trees and wound inoculations on cut shoots.

PPP PROJECT ON APPLE: PREBREEDING FOR FUTURE CHALLENGES IN NORDIC APPLES (NORDAPP)Website: http://ppp-apples.nordgen.org Partners: Swedish University of Agricultural Sciences, Sweden; Graminor AS, Norway; MTT Agrifood Research, FinlandProject work packages: WP1. Nordic platform for fruit and berry breeding WP2. Information retrieval and networking WP3. Phenotyping of apple canker susceptibility in apple cultivars WP4. Phenotyping of storage rot susceptibility in apple cultivars WP5. DNA-based analysis WP6. Information dissemination

PUBLIC PRIVATE PARTNERSHIP ON PRE-BREEDINGThe Nordic Council of Ministers (NMR) decided to set up a Public Private Partnership (PPP) for Pre-breeding in 2011. The purpose of the PPP is to support the development of Nordic plant breeding, satisfying the long-term needs of the agricultural and horticultural industries, specifically regarding adaptation to climate change; targets for environmental policies; and demands from consumers, markets, etc.The Nordic PPP on pre-breeding has funded 3 projects in 2012-2014: barley, rye-grass and apple

Figure 2. Development of average lesion length on cut shoots wound inoculated with macrospores of Neonectria ditissima, recorded at 5 time points. Left: Results from experiment at SLU Balsgård 2013, three inoculation points per shoot, 6 replicates (shoots) per cultivar. Right: Results from experiment at Graminor Njøs 2013, one inoculation point per shoot, 6 replicates (shoots) per cultivar.

MATERIAL AND METHODS

Wound inoculations were made on cut shoots, with 1000 macroconidia of Neonectria ditissima per wound (100.000 per ml) on 20 cultivars at Alnarp, 30 cultivars at Balsgård and 20 cultivars at Njøs. On each shoot, three inoculation points were used in Sweden and one inoculation point in Norway. A total of six replicates were inoculated. As controls, two replicates were wounded and inoculated with water and two replicates were left unwounded. RESULTS

EXPERIMENTS ON BLUE MOULD

INTRODUCTION

Fruit rots cause large losses during storage and marketing of apples

. A

large number of fungi cause fruit rots, the most important in Nordic apple production being Neofabraea malicorticis and N. alba (bull’s eye rot), Glomerella acutata (bitter rot), Penicillium expansum (blue mould), Botrytis cinerea (grey mould) and Monilinia fructigena (monilia rot). Penicillium expansum is of special concern as it may produce the toxin patulin. This latter fungus is a weak parasite that normally attacks apple fruits through already existing wounds in fruit skin. Wound inoculation of fruits and recording of lesion development is then a good way of estimating susceptibility level of cultivars, and identify possible resistance sources.

Figure 3. Left: Apple fruit infected with blue mould. Middle: Wound inoculation of apple fruits. Right: Lesions developed after wound inoculation of apple fruits.

MATERIAL AND METHODS

Apples of 45 cultivars

in Sweden

and 45 cultivars in Norway were harvested at starch value 4-5 (iodine test) in 2012 and 2013, and wound inoculated on two inoculation points per apple, 15 apples per replicate. Three replicates were inoculated with Penicillium spores, one replicate inoculated with water and one replicate unwounded. Lesion diameter in two directions was measured after 6 weeks (early apples) and 12 weeks (later ripening apples) in cold store. RESULTS

Figure 4. Average lesion diameter on fruits wound inoculated with

P. expansum

; symptoms for early- and late-maturing cultivars. Early cultivars (stored for 6 weeks) with yellow colour and late cultivars (stored for 12 weeks) with blue colour. Cultivars are arranged according to ripening period. Top: Results from experiment at SLU Balsgård, Sweden, mean of two years. Bottom: Results from experiment at Graminor Njøs, Norway, mean of two years.