Apple Breeding - From the Origin to Genetic Engineering

摘要

Apple is the most important temperate fruit crop and ranks fourth in world production of fruits after citrus, grapes and bananas. Although more than 10,000 cultivars are documented, only a few dozen are grown on a commercial scale worldwide. Despite the abundant number of cultivars there is a demand for new cultivars better adapted to climatic conditions/changes and sustainable production. Yet, the challenge for apple breeding is the establishment of improved, multiple disease resistant cultivars with high and regularly yield suited for modern production systems. Due to the fast development of molecular techniques an increasing knowledge on the genome of apple is available, e.g. the whole genome sequence of 'Golden Delicious' (Velasco et al. 2010).Molecular markers for a lot of major traits, mostly resistance genes, and QTLs facilitate marker assisted selection, especially the pyramiding of resistance genes to achieve more durable resistance. Mainly the breakdown of the Rvi6 (Vf) scab resistance enhanced the breeding for pyramided resistance genes. But nevertheless, until now there is a gap between the existing molecular knowledge and its application in apple breeding. This paper will focus on the origin and domestication of apple, breeding objectives and classical as well as molecular approaches to achieve breeding aims. Besides this an update on molecular knowledge and the current state and progresses in genetic engineering will be presented.