Conventional breeding programme and expected progress
Progress in breeding
Progress in breeding is often slow due to:
- the genetic set-up of the potato
- the numerous known properties of the potato
- the low frequency in which desired genotypes are present in populations resulting from crossings
Varietal properties
Numerous different properties are desired in a potato cultivar.
and the genetic set-up of the plant is complex.
GENETIC SYSTEM AND RESULTS
The introduction of many new characteristics at a time does not lead to good results in most cases.This is especially the case when the new characteristics are derived from wild and primitive species.
Example breeding programme
In the given example from 40 000 seedlings in 8 years 2 promising genotypes are selected.
Breeding programme
Only a few of these selected promising genotypes finally will find a place in the market.
Geert Veenhuizen 1857-1930
Priorities
"The ideal variety does not exist and will not exist" is the guideline for the breeder and in breeding programmes it is needed to set priorities.
BREEDING CRITERIA----- SELECTION PROCEDURES
Selection Index
The 'estimated' selection index is a tool to demonstrate the efforts which are needed in order to introduce new characteristics.Selection index
Example selection index
To select a potato with the characteristics: high yield (0.1), good shape (0.1), good culinary qualities (0.1), resistance to second growth (0.1), resistance to common scab (0.1), field resistance to late blight (0.1), large tubers (0.2), high dry matter content (0.2) and resistance to PVY (0.5) a programme of at least:
would be needed