بررسی تنوع ژنتیکی توده های آفتابگردان آجیلی بر اساس صفات آگرومورفولوژیک با استفاده از روش های آماری چند متغیره

     Confectionery sunflower (Helianthus annuus L.) is one of the valuable crops which less is known about its variability. Fifty sunflower populations have been gathered from different regions of Iran and evaluated for agro-morphological traits in completely randomized design with 10 repetitions under pot conditions. The twenty traits including days from planting to flowering, days from planting to physiological maturity, number of leaves, leaf length, petiole length, leaf width, plant height, stem diameter, head diameter, shoot dried weight, head dried weight, aerial part dried weight, harvest index, 100-seed weight, single seed weight, dehulled kernel weight, dehulled kernel weight to whole kernel, seed length, seed width, and seed dried weight per plant were evaluated. Analysis of variance showed that there is a meaningful difference between all traits except for single seed weight and stem diameter. The highest positive correlation (0.95) was observed between single seed weight and dehulled kernel weight and the highest negative one (-0.61) was observed between number of leaves and harvest index. Principal component analysis decreased the studied variables to six components with the cumulative variance of 81%. Cluster analysis with Ward method classified them into four different groups. The maximum distance was observed between genotypes of groups 1 and 4 as well as 3 and 4. The comparison of trait means in groups resulted from cluster analysis by Tukey’s test demonstrated that the populations in the first group have the maximum values for most of the studied traits and populations in the fourth group have the minimum values and therefore they can be used for choosing appropriate parents in crossing programs.