Changes of morphological, physiological, and biochemical indices during seed development of Notopterygium incisum Ting ex H.T.Chang

Abstract [Objective] The study aims to explore the changes of morphological, physiological, and biochemical indexes during the development of Notopterygium incisum seeds, and to provide theoretical basis for the introduction and domestication of N . incisum and the cultivation of high-quality germplasm resources. [Methods] The morphological, physiological, and biochemical indexes of N . incisum seeds at different developmental stages were determined by observation samplings and the frozen section method. [Results] During the development of N . incisum seeds, seed size and wing thickness were first increased and then decreased, while wing width was increased. The color of the outer seed coat was changed from bright blue-green to yellow-brown. The contents of starch, soluble sugar, and soluble protein were increased. Amylase activity was fluctuated in a small range; succinate dehydrogenase activity was increased; glucose-6-phosphate dehydrogenase activity was increased and decreased alternately; pyruvate kinase activity showed “M”-shape changes. POD activity was decreased while SOD activity was decreased. GA3, IAA, and ZR contents were decreased, while ABA contents were increased. The morphological indexes of the seeds were negatively correlated with the activity of SOD. The content of the storage materials was negatively correlated with the seed thickness, but positively correlated with the width of the fruit wings. [Conclusion] When N . incisum embryo is developed to pre-cardioid embryo, the outer seed coat is changed from blue-green to yellow-brown, the content of storage material is increased, and the activity of key enzymes is fluctuated and decreased. The content of growth-promoting hormones is fluctuated and decreased, while the content of stress hormones is increased.