Genetic diversity of Safflower (Carthamus tinctorius L.) genotypes at Wollo, Ethiopia using agro-morphological traits

Safflower (Carthamus tinctorius) is an annual oilseed crop of the Compositae or Asteraceae family commercially grown in Ethiopia and other countries. To study the genetic variation and relationships among twelve Safflower genotypes an experiment was carried out under field conditions in randomized complete block design with 3 replications in Wollo University, Dessie campus using the agro-morphological traits that includes plant height, days to flowering, Days to maturity, number of primary branches, number of secondary branches, number of capitula per plant, number of seed per capitulum, thousand seed weight, yield per plant, and yield per plot. Results of the analysis of variance showed significant differences among accessions for traits like days to flowering, days to maturity at p ≤0.01, and for number of primary branches and number of secondary branches at p ≤0.05. Seed yield per plant had significant correlations with number of capitula per plant, number of seeds per capitulum, number of primary and secondary branches. Cluster analysis grouped the 12 genotypes in 2 clusters and one of the accessions remains ungrouped, according to their similarity in various traits studied. The first three principal component analyses were found to explain 85% of the total variation that exists among accessions. The results revealed the presence of a high level of genetic diversity that deserves conservation attention and could be utilized in breeding program to improve Safflower varieties with a high seed yield.