Final answer:
Shuttle breeding is a technique involving growing crops in different environments to select for desirable traits quickly, differing from off-season nurseries which accelerate breeding by altering seasons in one location. Shuttle breeding focuses on environmental stress selection while off-season nurseries aim to increase generation turnover.
Step-by-step explanation:
Shuttle breeding is a technique used in plant breeding programs where crops are grown in two geographically distinct locations with different environmental conditions within the same growing season. This method allows breeders to quickly produce several generations of plants and select those with desirable traits more efficiently. In contrast, an off-season nursery is used to grow plants in a different season than usual to speed up the breeding process, often by taking advantage of different climate conditions that allow for multiple crop cycles in a year.
Two differences between shuttle breeding and off-season nursery are:
- Shuttle breeding utilizes two different locations with distinct environmental conditions to expose plants to varied stresses, while off-season nurseries typically occur in one location where the season is artificially manipulated to suit the growing cycle.
- Shuttle breeding can expedite the selection for traits like disease resistance and stress tolerance due to the exposure to different environmental challenges, whereas off-season nurseries focus mainly on increasing the speed of generation turnover without specific environmental stresses.
Breeding systems, asexual and sexual reproduction, including hybrid seeds and the creation of novel plants, are central to traditional breeding practices as well as modern genetic engineering. Both techniques aim at generating genetic changes to introduce new traits in organisms, but they differ in specificity and methodology.