[Morphological and biochemical characterization during seed development of Notopterygium incisum]

This study aimed to examine the morphological, physiological, and biochemical alterations occurring in Notopterygium incisum seeds throughout their developmental stages, with the objective of establishing a theoretical foundation for the cultivation of superior quality seeds. The experimental materials utilized in this study were the seeds of N. incisum at various stages of development following anthesis. Through the employment of morphological observation and plant physiology techniques, the external morphology, nutrients, enzyme activity, and endogenous hormones of the seeds were assessed. The results revealed a transition in seed coat color from light green to brown during the growth and development of N. incisum seeds. Additionally, as the seeds matured, a decrease in water content was observed. Conversely, starch content exhibited a progressive increase, while sucrose content displayed fluctuations. At 7 days after anthesis, the soluble sugar content attained its highest level of 4.52 mg·g~(-1), whereas the soluble protein content reached its maximum of 6.00 mg·g~(-1) at 14 days after anthesis and its minimum of 4.94 mg·g~(-1) at 42 days after anthesis. The activity of superoxide dismutase(SOD) exhibited an initial increase, followed by a decrease, and eventually reached a stable state. Conversely, the activities of catalase(CAT) and peroxidase(POD) demonstrated a decrease initially, followed by an increase, and then another decrease. The levels of the four endogenous hormones, namely gibberellin(GA_3), zeatin riboside(ZR), auxin(IAA), and abscisic acid(ABA), in the seeds displayed significant variations, with IAA and ABA exhibiting considerably higher levels compared to the other hormones. The levels of plant growth-promoting hormones, represented by IAA, generally displayed a pattern of initial increase followed by a subsequent decrease during seed development, while the plant growth-inhibiting hormone ABA showed the opposite trend. The findings indicate that the alterations in nutrient composition, antioxidant enzyme activity, and endogenous hormone levels vary throughout the maturation process of N. incisum seeds. These observations hold relevance for the cultivation of N. incisum seeds.