Regional differences in performance of Canadian-bred apple cultivars and implications for breeding

Abstract

K. 2009. Regional differences in performance of Canadian-bred apple cultivars and implications for breeding. Can. J. Plant Sci. 89: 81Á91. To evaluate their commercial potential in several major production regions of Canada, 10 Canadian breeding selections and two standard cultivars of apple (Malus )domestica Borkh.) were planted at four locations: one in British Columbia, two in Ontario and one in Nova Scotia. Subsidiary objectives of the trial were to determine whether wider testing of promising apple selections was warranted, and to accumulate information to help guide breeders in selecting apples for widespread adaptation. At each site the planting was arranged in a randomized complete block design with eight replicates. Individual trees were the unit of replication. Data were collected for 7 yr (5 cropping years). The measures of orchard performance recorded were: tree survival, trunk-cross sectional area, final tree height and canopy spread, precocity, times of bloom and harvest, yield, yield efficiency, and average fruit size. The effects of location, genotype and genotype )location interaction were statistically significant for all response variables. The two standard cultivars, Royal Gala and Summerland McIntosh, were intermediate to high in precocity, tree vigour, yield and fruit size. No single cultivar was superior in these characteristics at all locations. Among the test selections, S23-06-153 and 8S-27-43 had the most consistently good performance with regard to tree survival, tree vigour, yield, yield efficiency, pre-harvest fruit drop and fruit size. 8S6923 (Aurora Golden Gala TM ) and Silken also performed well, except that fruit size was smaller in eastern Canada. Many of the selections took fewer days to reach maturity in Nova Scotia and Ontario than they did in British Columbia. The results obtained suggest that regional testing is highly desirable for characteristics such as tree survival, yield, pre-harvest drop and climatic suitability (e.g. dates of bloom and harvest), all of which profoundly affect the commercial desirability of the cultivar. If the present results can be generalized, breeding and selection of new genotypes at one location are probably adequate for tree vigour, relative order of bloom and harvest, and precocity, despite the genotype )environment interaction demonstated. For these characteristics, the modest changes in rank among cultivars from location to location do not have great practical or economic consequences. Selection at one location may also be effective for fruit size and percentage of over colour, if the breeder takes location effects into account (smaller fruit in Ontario and Nova Scotia, less colour on early-harvest apples in British Columbia).

Towards genomic selection in apple (Malus × domestica Borkh.) breeding programmes: Prospects, challenges and strategies

“…Hampson et al (2009) also showed that the effect of G × E on growth and yield traits of 11 advanced apple selections was minimal. Although the BV estimates, which are the sum of effects across a number of loci, might be relatively similar across different environments, it does not necessarily mean that the effects at an individual locus will also be similar.…”

Quantifying apple diversity: A phenomic characterization of Canada’s Apple Biodiversity Collection

“…There are numerous apple germplasm collections that have been established worldwide (e.g., USA (Gross et al, 2013), China (Gao et al, 2015), New Zealand (Kumar et al, 2010), and Europe (Jung et al, 2020)). Within Canada, there are apple collections located across the country, for example, in Ontario and British Columbia (Hampson et al, 2009;Ward, 1978). Most recently, Canada's Apple Biodiversity Collection (ABC) was established in Nova Scotia, Canada, with over 1,000 accessions that includes trees primarily belonging to the domesticated apple, M. domestica, and its primary wild ancestor, M. sieversii.…”

Study of Apple Varieties in High-Density Plantation under Cold Dry Temperate Conditions of Kinnaur

“…The variation could also be the result of phenotypic characteristics of the varieties, management practices and the site of the plantation (Bhat et al, 2006 andHampson et al (2009). This variation could be due to the phenotypic characteristics of the cultivars, management practices.…”