Daniela Soleri and Steven Smith, in the College of Agriculture at the University of Arizona, have been carrying out research to compare the genetic effect of community management versus ex situ conservation of genetic resources. The research involves comparing samples of one Hopi blue maize variety at three levels: (1) between original and subsequent growouts of the same variety held in cold storage by the USDA in Iowa over the past 45 years, (2) within populations of the same variety maintained in situ by farmers and collected at Hopi in January 1992; (3) between the most recent USDA seed regeneration (1985) and the 1992 Hopi populations. Analysis completed thus far on some of the morphological and phenological data shows significant differences between ex situ (USDA) maintained populations for agroeconomically important characteristics such as plant height, flag leaf dimensions and timing of reproduction. These same differences, as well as some related to tassel pigmentation, also appeared between USDA and Hopi maintained populations.
These findings suggest that, in this case, ex situ maintenance may not be achieving its goal of genetic conservation. What appears to be genetic shift should be cause for concern among breeders because it indicates a change in allele frequencies and, more importantly, a possible loss of rare alleles. Although many researchers involved with genetic conservation, including some at the USDA, have suspected such a problem, until now there has been no investigation of it. This shift may also represent a change in elements of a suite of traits that characterised the adaptation of this variety to the Hopi agricultural system.
If this is so, it raises a question about the utility of ex situ programmes for maintaining germplasm of use to the communities who developed it.