USE OF DISEASE RESISTANCE'S TESTS IN OFFICIAL TRIALS OF DISTINCTNESS UNIFORMITY STABILITY (DUS) OF VEGETABLE SPECIES IN FRANCE

• First, using standard protocols as practiced by breeders and official services it allows the exchange of data along one basis of comparison in the same way as the morphologic and physiologic characters are currently used. These data allow the running of the test of Distinctness, Uniformity and Stability (DUS) to be more pertinent since they permit the grouping of varieties according to their type of resistance at a given disease considering a varietal group.
• Second, levels of varieties' resistance to various diseases and pests that cause serious damages to crops are then made official and become a major resource for farmers when choosing the varieties suitable for their growing conditions :

As early as 1981, G.E.V.E.S.* (the official body in France for studying and checking varieties and seeds) published. The first inventory of tests of resistance to diseases and pests of vegetable species which had been conducted for studying DUS on behalf of Technical Committee for Plant Breeding (C.T.P.S.*), the Committee for the Plant Breeders' Rights (C.P.O.V.*), along with bilateral agreements between countries.

On up to date inventory was accomplished by G.E.V.E.S. (sites of Angers, Brion and Cavaillon), The National Institute for Agronomic Researches (I.N.R.A.*), sites of Avignon, Bordeaux and Versailles, along with private firms for selection of vegetable species, resulted in 1995 document¹ published under the responsibility of C.T.P.S. entitled, "Tests of diseases resistance - vegetable species".

This document includes, among other things, an inventory of diseases of the vegetables species studied in France by GEVES, and all the standardized protocols of the tests which are run in official laboratories for DUS trials.

Four classes of tests had been defined according to the economic importance of the disease in France, the existence of an artificial and reliable tests, the costs of performing rontine tests and the possibility of using of the results of the test for distinctness and/or uniformity purposes. The four classes are defined as follows:

Class 1: test of susceptible and resistant varieties in an official laboratory (characteristic used for grouping of varieties and compulsory declaration for each variety);

Class 2: varieties declared resistant by their breeder are tested in an official laboratory;

Class 3: varieties declared resistant by their breeder are tested at the breeder's (coded test of distinctness)

Download Adobe Acrobat Reader (free software to read PDF files)