Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 183

For each crop, there is a number of characters, which considered together, define the overall desirability of the cultivar from the combined perspectives of the producer and the consumer. These characters may range between about a dozen to several dozens, depending on the crop, and constitute the primary pool of characters that the breeder may target for improvement. These characters differ in importance (economic and agronomic) as well as ease with which they can be manipulated through breeding. Plant breeders typically target one or few of these traits for direct improvement in a breeding program. That is, the breeder draws up a working list of characters to address the needs embodied in the stated objectives. Yield of the economic product is almost universally the top priority in a plant breeding program. Disease resistance is more of a local issue, since what may be economically important in one region may not be important in another area. Even though a plant breeder may focus on one or a few traits at a time, the ultimate objective is the improvement of the totality of the key traits that impact the overall desirability or general worth of the crop. In other words, breeders ultimately have a holistic approach to selection in a breeding program. The final judgments are made on a balanced view of the essential trait of the crop.