A Diversity Analysis of a World Collection of Barley¹

Abstract

Data on more than 17,000 accessions of the barley (Hordeum vulgare L.) world collection maintained by the USDA, SEA, were analyzed for variation of five morphological characters (growth habit, caryopsis type, awn type, kernel row number, and kernel color). Phenotypic frequencies within the accessions from each of 48 countries, grouped in 14 regions, were tabulated. Polymorphism was widespread in most countries for different sets of characters. Very weak east‐west clinal patterns were observed and this analysis only partially supported the earlier reported patterns of variation in the postulated centers of diversity. This result may be due to an inadequate sample of characters available for analysis and/or an inadequate number of geographic regions in the world collection.The H' diversity index was computed for each country and region, for individual characters, and after pooling all five characters. Analyses indicated the between‐regions component of diversity to be relatively smaller than the variation in H' among characters and among countries within regions. This analysis shows no distinct geographical patterns in these data, but its use with additional data is warranted.

Exotic barley germplasm: variation and effects on agronomic traits in complex crosses

“…Landrace and H. spontaneum accessions were collected from different ecogeographical areas (data not shown) and therefore probably retain a higher degree of genetic diversity than parents adapted locally by plant breeders . This phenomenon was also observed in a previous study on the diversity of the barley world collection (Tolbert et al ., 1979) . Furthermore, cluster analysis revealed that adapted parents, landraces and H. spontaneum were genetically divergent .…”

Quantitative variation within and between populations of the wild barley, Hordeum murinum

“…Of (a) and (b), (b) is the most difficult problem to address because the collection strategies recommended vary with the type of characters used to study the distribution of genetic variation in populations (Allard, 1970;Bennett, 1970;Qualset, 1975;Brown, 1975, 1981;Tolbert et a!., 1980;Witcombe and Gilani, 1979;Bogyo et a!., 1980;Brown and Munday, 1982). The results of this paper suggest that collection strategies will vary with the character of interest.…”

Assessment of glutenin and phenotypic diversity of Syrian durum wheat landraces in relation to their geographical origin

“…Sometimes agronomic and morphological data are used for this purpose (Ceccarelli et al, 1987;Konishi, 1987;Tolbert et al, 1979). They are relatively easy to collect, and often useful for other purposes as well.…”