【目的】 研究‘凤丹’蓇葖果及种子发育过程中形态变化规律的同时,探讨种子发育过程中营养物质间的转化规律,以充分了解‘凤丹’种子的发育特性,并为其科学栽培和管理提供理论依据。【方法】 以‘凤丹’蓇葖果及种子为材料,对其发育过程中6个阶段进行生物学观察,同时测定种子中的含水率、种子发育过程中营养物质(可溶性糖、可溶性蛋白、粗淀粉和粗脂肪含量)以及相关酶活性[总淀粉酶、总蛋白酶、乙酰辅酶 A 羧化酶(ACCase)和植物磷脂酸磷酸酯酶(PPase)]。【结果】 ‘凤丹’种子的发育大致可分为两个阶段:绿熟阶段(花后45~85 d)和褐熟阶段(花后95~115 d)。在测定的各阶段,种子含水率持续显著下降,种皮颜色由黄色变为乳白色,最终表皮坚固,呈黑褐色。果皮颜色也从绿色转变为黄褐色,最终呈现灰褐色并伴随着果荚开裂。对营养物质及相关酶活性而言,‘凤丹’种子发育过程中,油脂积累旺盛期主要集中于花后45~85 d,中后期时油脂增长较为缓慢,于成熟时达至此次测定的最高值(33.1%)。可溶性糖的消耗趋势与可溶性蛋白积累的趋势类似;且可溶性糖含量的变化与淀粉含量的变化呈显著正相关关系,均呈现下降—上升—下降的变化趋势,并均于花后85 d时达到了此次测定的最低值。在此过程中,总淀粉酶活性和总蛋白酶活性变化趋势分别与粗淀粉和可溶性蛋白变化趋势相反,且当粗淀粉含量随着总淀粉酶活性的升高而减少时,可溶性蛋白含量则随着总蛋白酶活性的降低而升高。此外,乙酰辅酶A羧化酶和磷脂酸磷酸酯酶活性则随着油脂积累速度的增加而升高。【结论】 各营养物质含量以及相关生物学特性等变化趋势表明,‘凤丹’种子于花后115 d左右采收较为合适。同时,在栽植过程中的不同阶段需采用不同的管理方案,于花后45~65 d时需保证水分及磷肥的充分供应;花后65~85 d时,则应以浅浇灌为主,增施适量的氮肥及钾肥;而种子发育中后期,应进一步适量减少水分供应,并追施少量磷肥。

【Objective】 To understand the developmental characteristics of Paeonia ostii ‘Feng Dan’ seed and to provide theoretical basis for their scientific cultivation and management, we studied the morphological changes during P. ostii ‘Feng Dan’ follicle as well as seed development and discussed the transformation of nutrients during P. ostii ‘Feng Dan’ seed development. 【Method】 The P. ostii ‘Feng Dan’ follicles and seeds were stratified at six stages and used as materials for biological observation. Additionally, indexes such as water, soluble sugar, soluble protein, crude starch, crude lipid content, total amylase, total protease, acetyl-CoA carboxylase (ACCase), and phosphatidate phosphatase (PPase) activities in seeds were studied. Changes in nutrients and their related enzyme activities during seed development were analyzed. 【Result】 P. ostii ‘Feng Dan’ seed development was divided into two stages: green ripe stage (45-85 days after flowering) and brown ripe stage (95-115 days after flowering). During this process, the water content of P. ostii ‘Feng Dan’ seed decreased significantly, and the seed coat changed from yellow to white. Finally, the coat was hard and black brown. The pericarp also changed from green to yellowish brown and finally showed as grayish brown with dehiscent pods. Results of nutrient and related enzyme activity determination showed that during P. ostii ‘Feng Dan’ seed development, the oil accumulation flourished mainly at 45-85 days after flowering, increasing slowly at the middle and later stages, and reached the highest value of 33.1% at maturity. In addition to the consumption trend of soluble sugar corresponding to the accumulation trend of soluble protein, the change in soluble sugar content also showed a significant positive correlation with the change in crude starch content, showing downward-rising decreasing trends, and all reached the lowest value at 85 days after flowering. During the process, the trend of total amylase activity was opposite to that of crude starch, and the trends of total protease and soluble protein were the same. When the content of crude starch decreased with an increase in total amylase activity, the content of soluble protein increased with a decrease in total protease activity. ACCase and PPase activities also increased with an increase in lipid accumulation rate. 【Conclusion】 The changing trend of nutrient contents and related biological characteristics indicated that it is more appropriate to harvest P. ostii ‘Feng Dan’ seed at approximately 115 days after flowering. Additionally, distinct management schemes must be adopted at different stages of the planting process. A sufficient supply of water and phosphorus fertilizer should be ensured at 45-65 days after flowering. At 65-85 days after flowering, shallow irrigation should be used, and an appropriate amount of nitrogen and potassium fertilizer should be applied. However, in the middle and later stages of seed development, the water supply should be further reduced and a small amount of topdressing phosphorus should be reapplied.