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A SURVEY OF THIRTY YEARS APPLE, PEAR AND BLACK CURRANT BREEDING AT THE FRUIT RESEARCH STATION OF ANGERS (INRA) – OBJECTIVES FOR THE FUTURE
In such long term programs, the output of research is not commercial varieties, but it is also improved genitors, methods and know-how.
The main results obtained at Angers are presented and discussed.
They concern apple (dessert and cider or juice), pear (varieties and rootstocks), and black currant. They come from hybridation and from mutagenesis. 20 cultivars have been released for these 4 species (including quince rootstocks). Genitors have been bred, with accumulated genes coding for important agronomical characters, especially for disease resistances.
Lastly we have greatly increased knowledge concerning genetic variability and its management for short and long term genetic improvement.
Fruit breeding needs time and continuity for objectives to be achieved, unless nature generates new situations.
In France, Fire blight is a good example of a new situation.
Already, and for the near future, we must add new tools offered by biotechnologies to conventional plant breeding methods. The recent contributions of the Angers Station include electrophoresis of isozymes as genetic markers and neoformations in vitro mainly with apple (somatic bud like neoformations, androgenesis and gynogenesis).
Thirty years is not a long time for a breeder, particularly for apple and pear.
In a process of hybridization, if we assume the probability of one recombination per chromosome and per meiosis, we can not hope for great genetic improvement during these thirty years.
Nevertheless, every breeder is helped at the beginning of hid work by the material and the know-how for former breeders.
This was the case with our Station in the sixties.
This paper is a synthesis of the results and the prospects for breeding of Apple, Pear (varieties and rootstocks) and Black currant.
For the survey of breeding programs we can use three criteria (Table 1). The more conspicious is the number of released varieties. It is the more important result for the fruit industry.
It is also the visible face of the iceberg.
However, in a so long a process, the genetic variability, knowledge and know-how determine the vital capacity for genetic improvement in the future.
Genetic variability offers two distinct aspects : the free genetic variability which can be evaluated on the basis of the actual best progenies and hybirds, and the cryptic genetic variability which is the potential value of parents to give improved progenies and hybirds in the future.