Genetic and environmental control of fruit maturation, dry matter and firmness in apple (Malus × domestica Borkh.)

Abstract

For any given genotype, the environment in which an apple is grown can influence the properties of the fruit considerably. While there has been extensive research on the mechanism of the genetic control of fruit quality traits, less effort has been made to investigate the way that these genetic mechanisms interact with the environment. To address this issue, we employed a large ‘Royal Gala’ × ‘Braeburn’ population of 572 seedlings replicated over sites in three climatically diverse apple-growing regions in New Zealand. Phenotyping for traits including fruit maturation timing, firmness and dry matter content was performed at each of these three sites for a single growing season (2011), and at two sites (Motueka and Hawke's Bay) for two seasons (2009 and 2010). The phenotype data collected over 2 years at two sites enabled the detection of 190 quantitative trait loci (QTL) that controlled these traits regardless of year or growing location, as well as some chromosomal loci that influenced the traits in a single given environment or year. For those loci that were environmentally stable over three sites, there was an interdependency of fruit maturation date, dry matter content and storage potential within this population, with two regions on Linkage Groups (LGs) 10 and 16 strongly contributing. If these loci were used in a marker-assisted selection programme to select for progeny bearing firmer fruit, this would have the unintentional consequence of selecting, high dry matter content, later maturing apples. In addition, a further 113 new QTLs with a smaller effect were identified, some of which were exhibited only in a single growing environment, demonstrating the underlying complexity of control of traits determining fruit quality, in addition to the need for being aware of environmental effects when developing new apple varieties.

Combining Genome-Wide Information with a Functional Structural Plant Model to Simulate 1-Year-Old Apple Tree Architecture

“…This could result from differences in the climatic conditions in the plantation years, from the variability in the plant material obtained after grafting and from the existence of large GxE interactions. This GxE interaction has been previously observed in clonally propagated plants (Alspach and Oraguzie, 2002; Chagné et al, 2014). Nevertheless, having re-multiplied the same progeny several times is quite unique for a perennial crop in which a single orchard and a low number of replicates per genotype are often considered.…”

Identification of QTLs for Flesh Mealiness in Apple (<i>Malus</i> × <i>domestica</i> Borkh.)

“…A new strategy for detecting QTLs (e.g., metaQTL analysis) could also be beneficial. Several QTLs for fruit texture and storability traits have been identified on this chromosome (Ben Sadok et al, 2015;Bink et al, 2014;Chagné et al, 2014;Costa et al, 2010;Kenis et al, 2008;King et al, 2000;Kumar et al, 2013;Kunihisa et al, 2014;Longhi et al, 2013b). Our findings confirm the importance of chr 10 for elucidating the regulatory mechanisms of fruit texture and storability.…”

A dense SNP genetic map constructed using restriction site-associated DNA sequencing enables detection of QTLs controlling apple fruit quality

“…On one hand, functional genes related to a specific trait could be transformed as DNA markers using in QTL analysis and MAS. For example, PG1 and ACO1 were tightly linked to QTLs mapped on LG10 for fruit firmness in apple [ 32 , 33 , 67 ]; LAR1 was associated with QTL cluster located on LG16 for polyphenolic composition in apple fruit [ 69 ]. A mutation, transition G to A, at base 1455 in the open reading frame of an ALMT (Aluminum-activated malate transporter) gene leads to a premature stop codon is responsible for the low acidity of apple fruit [ 68 ], which could be used in earlier stage selection of breeding process.…”