Welcome to Balsgård Department of Plant Breeding, Swedish University of Agricultural Sciences (SLU) www.slu.se/balsgard Here, apple breeding has been carried out since the late 1940s. Present breeder: Hilde Nybom
Chemistry laboratory Processing facility Fields and greenhouses At Balsgård, many different facilities are being used to produce new cultivars, research and information Plant breeding Publications Genebanks DNA-laboratory Information
Apple: production and consumtion Commercial orchards: 20-25.000 tonnes/year Home gardens: 35.000 tonnes/year Imported table fruit: > 100.000 tonnes/year + juice etc. Obviously there is room for a strongly increased domestic production! This is difficult to achieve without new cultivars, that are better suited to our weather conditions and more suitable for environmental-friendly production methods.
Plant breeding at Balsgård: crosses are made Suitable parents with complementary traits (adaptation, yield, resistence, quality) are chosen. Obtained seeds are sown, and the resulting seedlings are potted and then transferred into seedling fields. Field-planted apple seedlings at Balsgård: 600 plants from crosses 1999 2000, 400 plants from 2005, 100 plants from 2007, 800 plants from 2010. 1500 plants from 2011, 450 plants from 2012, and 523 plants from crosses 2013.
New seedlings are planted close to an international apple scab trial, Vinquest Seedlings, Monitoring of breakdown of race-specific resistence all over Europe Vinquest planting Malus floribunda, donor of Vf-resistance selection for field resistance against scab!
Observation trials Selected seedlings are grafted on rootstocks and planted in observation trials. Tree and fruit traits are carefully evaluated. Presently, we are still evaluating about 20 of the most promising selections planted in observation trials during 2004 2008. In 2013, 7 promising new selections were planted in the field.
Selections are evaluated in close co-operation with commercial fruit growers and plant nurseries (selling trees mostly to home gardens) about choice of selections for further test-growing in different orchards all over Sweden, and possible marketing in the future. Several selections and newly released cultivars are also being tested at numerous orchards in other countries.
DNA analyses are used in the apple breeding: for cultivar identification and analyses of relatedness for identification of S-alleles (compatibility between cultivars much appreciated by home gardeners) for identification of genes that affect disease resistence (apple scab, fire blight) and other important traits like fruit quality (firmness, storability)
The good old varieties are they not a bit soft and mealy, if truth be told? Improved fruit texture is now a major goal in all apple breeding programs around the world! Several genes have been identified that can affect fruit texture. At Balsgård, we screen for two genes that affect ethylene synthesis (Md-ACS1 and Md-ACO1) and two that affect cell wall degradation (PG1 and Expansin-7). The worst alleles are common in older cultivars whereas especially Md-ACS1 allele 2 and PG1 allele 2 are common in modern, crisp cultivars. White astrakan
A major breeding goal is increased storability Inoculation tests are carried out by injecting a spore solution into the fruit, mainly using Penicillium, and, to a lesser extent Colletotrichum and Neofabraea, to detect genetic variation in tolerance. Evaluation is conducted after 6 or 12 weeks of cold storage of the inoculated fruit, using induced lesion area as evidence of tolerance level. Part of this work is carried out within the Nordapp project, ppp-apples.nordgen.org
Another major breeding goal is increased tolerance to apple canker Estimating levels of tolerance in the field is not efficient Inoculations are instead made in a greenhouse, using young trees or detached shoots. The spore solution is applied on wounds obtained by cutting off a bud. Part of this work is carried out within the Nordapp project, ppp-apples.nordgen.org
Another potential threat is fire blight Inoculation tests have been performed in a greenhouse on young apple shoots, using a scissor dipped in spores of the bacterium Erwinia amylovora. Length of infected shoot tip is measured once a week for up to 6 weeks, to produce an estimate of level of tolerance. A correlation was found between inoculation-based evaluation of tolerance, and the application of DNA-markers for a QTL providing some tolerance to fire blight in the cv. Fiesta and its relatives.
A more recent breeding goal is apples with a higher level of health-related compounds At Balsgård, we estimate total phenol content (spectrophotometry), and content of single phenolic compounds (HPLC) in flesh and skin of apple fruits of different cultivars. Analyses are also carried out to quantify importance of cultivation and harvesting procedures, and to study the association between chemical compounds and tolerance to storage diseases.
The basis for all apple breeding and research is a large apple gene bank! We have approx. 600 apple cultivars at Balsgård.
Besides providing parents for the crosses, phenotyping and genotyping of gene bank material can produce information about trait inheritance. Presently, c. 180 Nordic/cold climate cultivars in the Balsgård genebank are being studied within the large international EU-funded Fruitbreedomics a project which aims to improve the efficiency of fruit breeding (apple and peach) by bridging the gap between scientific genetics research and application in breeding; www.fruitbreedomics.com SLU participates as an invited partner
Fruitbreedomics: Phenotyping Flowering time During May, scorings 2-3 days apart Harvest date During August to mid-october, scorings 2-5 days apart, correct date determined using starch conversion test Fruit characterization at harvest Ripeness, shape, proportions, regularity, mean diameter, mean weight, crown, cover colour, russetting, stalk length, firmness, sweetness, acidity, acidity/sweetness, juiciness, bitterness, texture, impression Fruit characterization after cold storage Sweetness, acidity, acidity/sweetness, juiciness, bitterness, texture, impression
Fruitbreedomics: Genotyping All sampled apple cultivars (in 6 gene banks) were checked in 2012 with SSR for inadvertent duplicates etc A 400 K SNP chip is being designed, for analyses in 2014 of c. 1200 different apple cultivars Genome-wide association studies will be conducted on SNP markers and phenotype data GWA markers for major (qualitative) genes and QTLs Genome-wide selection: instead of relying on individual loci significantly associated with a trait, GWS uses all marker data as predictors of performance and thus delivers more accurate predictions perhaps! Development of SNP-based tests for traits of interest: identification of superior crossing parents and marker-assisted selection of seedlings
Applied research projects: Centrum för innovativa drycker 80 cvs have been analysed chemically, and for their ability to produce good juice and cider old cultivars get a new job!