Phenotypic divergence between the cultivated apple (Malus domestica) and its primary wild progenitor (Malus sieversii)

Abstract

An understanding of the relationship between the cultivated apple (Malus domestica) and its primary wild progenitor species (M. sieversii) not only provides an understanding of how apples have been improved in the past, but may be useful for apple improvement in the future. We measured 10 phenotypes in over 1000 unique apple accessions belonging to M. domestica and M. sieversii from Canada’s Apple Biodiversity Collection. Using principal components analysis (PCA), we determined that M. domestica and M. sieversii differ significantly in phenotypic space and are nearly completely distinguishable as two separate groups. We found that M. domestica had a shorter juvenile phase than M. sieversii and that cultivated trees produced flowers and ripe fruit later than their wild progenitors. Cultivated apples were also 3.6 times heavier, 43% less acidic, and had 68% less phenolic content than wild apples. Using historical records, we found that apple breeding over the past 200 years has resulted in a trend towards apples that have higher soluble solids, are less bitter, and soften less during storage. Our results quantify the significant changes in phenotype that have taken place since apple domestication, and provide evidence that apple breeding has led to continued phenotypic divergence of the cultivated apple from its wild progenitor species.

Apple crown and collar canker and necrosis caused by Cytospora balanejica sp. nov. in Iran

“…The domesticated apple ( Malus × domestica Borkh.) is one of the oldest, most popular, and widely grown temperate fruit crops in the world 1 , 2 . It is one of the most economically important fruit crops and ranks as the 3rd most produced fruit crop worldwide 3 .…”

“…Apple trees have a long juvenile phase and often start bearing fruits after five years. For this reason, growers typically plant and grow a small number of well-assessed and historically successful apple varieties 2 . Two apple cultivars, ‘Red Delicious’ and ‘Golden Delicious’, are the main commercially grown apples in this region making up about 90% of apple cultivation.…”