Grouping of sunflower inbred lines under no use and consumption of phosphorus fertilizer conditions

Phosphorus (P) is the second most growth-limiting macronutrient after nitrogen which plays a critical role in many vital processes of plants including seed germination, flowering, and seed formation. The ability of genotypes in uptake and use of phosphorus is different and depends on their ability to absorb by root and also the use of phosphorus in the plant. Considering the importance of screening of genotypes with high phosphorus uptake efficiency, the present study aim was grouping the sunflower inbred lines under conditions of no use and consumption of phosphorus fertilizer. For this purpose, an experiment was conducted in research farm of Urmia University during 2017 growing season, using 100 sunflower lines collected from different parts of the world in two phosphorus fertilizer categories based on a completely randomized design with three replications in potted conditions. After soil analysis, soil with low phosphorus content (7.240 mg/kg) was selected, and the amount of 6 g triple superphosphate (TSP) as phosphorus fertilizer was added to each pot of 15 kg, under the condition of P fertilizer consumption, while no phosphorus fertilizer was given to another set of pots. Traits including seed yield per plant, 1000 seed weight, days to flowering, plant height, stem diameter, head diameter, leaf length, leaf width and petiole length were measured. Combined analysis of variance showed a significant difference between lines in terms of the effect of phosphorus fertilizer on all measured traits. There was also a high genetic variation between lines. Cluster analysis with Ward‟s method resulted in five groups in both no use and consumption of phosphorus fertilizer, but the distribution of lines in these groups was varied, indicating a different reaction of the studied lines in terms of the phosphorus uptake efficiency. It can be concluded that phosphorus application had an influence on agro-morphological traits and yield in sunflower, and there was a genetic variation among the studied lines for phosphorus uptake efficiency, which can be used to identify suitable parents for production of cultivars with high phosphorus uptake efficiency.

کلیدواژه ها:

Phosphorus uptake efficiency ، Sunflower ، Seed yield ، Cluster analysis