Description

Fruit trees have a long juvenile phase. For example, the juvenile phase of apple lasts for 6–12 years and is a serious constraint for creating new varieties by breeding based on crossing and selection. In this chapter, we report a novel technology using the apple latent spherical virus (ALSV) vector to accelerate flowering time and life cycle in apple and pear seedlings. Inoculation of apple and pear cotyledons immediately after germination with ALSV-AtFT/MdTFL1 concurrently expressing Arabidopsis FLOWERING LOCUS T (AtFT) gene and suppressing apple TERMINAL FLOWER 1-1 (MdTFL1-1) gene can shorten the period from seeding to flowering to 1.5–3 months after germination and generation times in order to obtain next-generation seeds in 1 year or less. Most next-generation seedlings obtained from ALSV vector–infected plants were free of the virus. We also developed a method for eliminating ALSV vectors from infected apple and pear plants by only high-temperature treatment. A method combining the promotion of flowering in apple and pear by ALSV vector with an ALSV elimination technique is expected to see future application as a new plant breeding technique that can significantly shorten the breeding periods of apple and pear.

Chapter