Chapter 19 - Hybrid varieties

Abstract

Hybrid cultivars are one of the most important types of cultivars, particularly for crops that have majority breeding efforts happening in the private seed sector. A hybrid cultivar is the F1 offspring of a planned cross between inbred lines, cultivars, clones, or populations. Hybrid may be the product of a single cross, a three-way cross, or a double cross. Absolute requirements for a hybrid cultivar are superior performance over the parents (heterosis) and an ability to economically generate seed for commercial seed sale. This chapter contains: steps in the development of hybrid varieties, hybrid seed production, production of hybrids, including through the use of cytoplasmic male sterility. We also include information on hybrid varieties in horticultural crops and in self-pollinated crops, including mechanisms that promote the development of hybrids, such as male sterility and self-incompatibility. Approaches to overcome self-incompatibility are described, along with its implications in plant breeding.