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Geographical diversity for quantitative spike characters in a world collection of durum wheat

Journal Article · · Crop Sci.; (United States)
OSTI ID:6586817
Crop germplasm collections are formidable to plant breeders and others who wish to draw samples by virtue of their large number of entries and multiplicity of potentially interesting characters. They have examined discriminant and clustering methods for their utility in revealing germplasm groupings that are useful for selection of parental stocks and for revealing evolutionary patterns. More than 3000 entries of durum wheat (Triticum turgidum L., durum group) representing 26 countries of origin were obtained from the US National Small Grains Collection and grown in a common environment in northern California. Eight quantitative measurements on spike characters were made, including awn and spike length, awn/spike length ratio, spikelet number, rachis internode length, number and weight of kernels per spike, and mean single kernel weight. Five clusters were delineated among the 26 country origins: (i) 11 countries in Europe and North Africa; (ii) France, USSR, and USA; (iii) nine countries in the eastern Mediterranean are; (iv) Ethiopia and India; (v) Afghanistan. An east to west clinal pattern was detected that represents a gradient in unimproved to improved types. Some countries with contrasting agroecological conditions clustered together, probably because a high percentage of breeding lines and cultivars shared parents from among the clustered countries. These results revealed wide variation in numbers of entries from among countries. Certain areas should be sampled more extensively. Documentation data are less complete than desired to establish evolutionary and ecological relationships. The methods used here helped focus upon groups of materials for use in plant breeding and research.
Research Organization:
Univ. of California, Davis
OSTI ID:
6586817
Journal Information:
Crop Sci.; (United States), Journal Name: Crop Sci.; (United States) Vol. 27:2; ISSN CRPSA
Country of Publication:
United States
Language:
English