Phenotypic diversity of Jerusalem artichoke (Helianthus tuberosus L.) germplasm preserved by the Canadian genebank

Abstract

SUMMARY Jerusalem artichoke ( Helianthus tuberosus L.) originated from the eastern United States and Mexico. Although considerable breeding efforts were made in Europe, the former Soviet Union, and to some degree in Canada, the species remains a neglected crop. Comprehensive characterization data of the genetic resources preserved in different genebanks is rare. A total of 162 Jerusalem artichoke accessions were preserved by Plant Gene Resources of Canada (PGRC) in 2006. This material was agrobotanically characterized in the growing seasons of 2006 and 2008 at Saskatoon, Saskatchewan, Canada. The results of 158 accessions grown in both years were compared. The assessments of variability of 13 rated and 10 measured descriptors for leaf, stem, tuber and phenological characters documented a wide range of phenotypic variation. Repeatability of assessments between the years was generally low, indicating a strong environmental influence on phenotypic diversity. Earliness of flowering, tuber width, tuber weight, tuber shape, tuber epidermis coloration and below-ground growth habit (tubers clustered vs. spread) were the most informative characteristics for describing variation among Jerusalem artichoke accessions. Leaf dimensions and leaf margin serration could also be used to distinguish extreme genotypes. A suggestion for categorizing the PGRC collection into large-tuber and primitive material based on single tuber weight and tuber width is made. Six categories of tuber types based on tuber color and tuber shape are presented.