Indian Journal of Agricultural Biochemistry

Percent germination and vigour index of sunflower seeds decreased with storage period of 180 days. However, the seeds obtained from different whorls of mature sunflower head showed higher values for percent germination and vigour index for peripheral and middle positions as compared to those located at central whorls. The dry matter and oil content of cotyledons and embryonic axis was higher at 180 days as compared to ‘zero’ day. The amount of starch decreased and total soluble sugars and reducing sugars increased in cotyledons of germinating seeds collected from different positions of sunflower head. The starch and reducing sugars content was higher in embryonic axis of seeds from peripheral whorls as compared to seeds from central whorls. However, in embryonic axis, the values for these parameters were less with increased activity of invertase and decreased activity of amylases at 180 days of storage as compared to ‘zero’ day. Data suggested that seeds from peripheral positions seem to be more vigorous as compared to those from middle and central positions on sunflower head.