Physiological changes involved in the acquisition of seed vigor during maturation of sunflower seed

Abstract Maturity is an important factor in regulating seed vigor, while inappropriate harvest date affects vigor seriously. Here we reported that the was highest among 25–28 days after pollination, and these were best time for sunflower seeds. Seed moisture content increased first then decreased, dry weight continuously with advancement of development. Oil protein are main nutriments mature seeds changes both contents consistent weight. For antioxidases, activity ascorbate peroxidase (APX) decreased gradually before maturity. Compared to gibberellin (GA), whose abscisic acid (ABA) accumulated during Moreover, spermidine (Spd) continually, although no regularity variation found putrescine (Put) spermine (Spm). Further analysis showed activities GA3ox GA20ox, NCED ABA8ox, SAMDC SPDS corresponding genes expression resulted GA, ABA Spd accumulation, respectively. In addition, moisture, soluble sugar, APX significantly negatively correlated indexes, weight, oil, positively indexes. These metabolic processes may be closely related formation, can used predict vigor.