Genetic diversity and classification of safflower (Carthamus tinctorius L.) germplasm by isozyme techniques

Zongwen Zhang

Abstract  

Genetic diversity of 89 accessions of safflower originating from 17 countries was assessed using isozyme markers. Four isozymes, esterase (EST), alcohol dehydrogenase (ADH), acid phosphatase (ACP) and shikimate dehydrogenase (SKDH), were analysed. Among 8 loci identified, 7 were polymorphic (87.5%) and among the 25 alleles identified, 15 were polymorphic (60%). The materials from East Asia had the highest value for both the mean allele frequency (0.014) and the mean gene diversity (0.54). For different loci, the gene diversity ranged from 0.16 for ACP1 to 0.87 for ACP3. The 89 accessions were classified into 4 groups by cluster analysis with isozyme data. The results of the classification showed that accessions from India possessed high diversity, accessions from Turkey were closely related to those from the other Middle East countries, and the accessions with unknown origin were more closely associated with India, Turkey and the Middle East than Europe and the USA.  The results showed isozymes are useful for characterization of safflower genetic resources.

Key words: Safflower; Germplasm; Isozyme; Genetic diversity; Classification