Paper published in the IPGRI Newsletter for Europe, No 33 – November 2006
Europe has been at the forefront of the development of new plant varieties with pioneers like the Svalöf Institute in Sweden and the Vilmorin family in France at the end of the 19th century. European plant breeders have also been among the first to preserve landraces with the initiative of Vavilov in the 1920s and the work of EUCARPIA in the 1960s. The work of the breeders has been encouraged by the development of a sui generis protection system of new plant variety, the UPOV Convention, since 1961.
There is an ongoing debate on the impact of modern varieties, including GMO, on sustainability. Four main areas need further consideration.
1. Modern varieties have decreased the diversity within crops
This is true if we measure the diversity by the number landraces at a country level. However it is doubtful that this criterion is the most relevant one. Indeed, if, to characterize diversity, social scientists use numbers of cultivars, the proportion of area planted to cultivars and the rate at which farmers are switching from one cultivar to another, biological scientists use rather genealogical indicators, analyses of morphological characteristics and indices of gene frequencies from analysis of bio-chemical or molecular markers. Not only do these indicators measure different phenomena, but also the empirical relationship between them is sometimes weaki. The example of the German Variety Catalogue provides an interesting example: in 1935, the number of wheat varieties, mainly landraces, dropped from 454 to 17 accepted cultivars and 54 accepted with reservation. The same situation occurred at the same period in Franceiii. This drop was mainly caused by name redundancy and phenotypical similarity. In addition, in the French situation, in the early 1960s, lines derived from exotic germplasm represented less than one third of the parents used in breeding programs but represented almost 50% in the 1980s3.
More recent studies, using DNA markers, give similar results: the comparison of the main varieties cultivated in the United Kingdom of barley, wheat, maize and potato and oilseed rape over the past 50 to 60 years shows that: barley genetic diversity was quantitatively unchanged with more diversity among varieties presently actively in commerce; similarly in wheat an overall increase in diversity over time was noted; in maize in Germany an increase was first noted with a subsequent decrease whilst in France no overall reduction was found; in potato a slight increase was found; in oilseed rape also an overall maintenance was showniv, v.
At an even more detailed level of analysis, the locus, the comparison of old and new collection of wheat from Albania, Austria, Nepal and North India shows that no significant differences were detected both in the number of alleles per locus and in the mean PIC values in all four regions. In other words, the genetic diversity has been maintained within hexaploid wheat since genebank activities started in the first half of last centuryvi. More recently, a CIMMYT study concluded: “The successful incorporation and re-mixing of genetic diversity from wheat relatives has created wheats containing more variation than has ever been available to farmers...
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