牡丹籽粒发育特性与营养成分动态变化的研究

Seeds Developmental Characteristics and Nutritional Components of Oil Tree Peony

通过对牡丹种子发育过程中主要形态指标和营养成分的分析,研究了牡丹种子生长与成熟期间营养物质与油脂转化的变化规律。结果表明,牡丹籽粒生长发育可以划分为4个时期,即受精与籽粒形成期（S1）、荚果与籽粒快速生长期（S2）、籽粒内含物充实转化期（S3）、果荚与种子脱水成熟期（S4）。在籽粒发育前期（S1～S2）,可溶性糖显著积累,中后期（S3～S4）持续下降;而淀粉呈连续降低趋势,种子成熟期（S4）有所升高;牡丹籽粒形成期（S1）蛋白质含量速下降,而后略有回升维持在相对稳定状态;牡丹籽粒粗脂肪含量呈现持续增长的趋势,在发育中前期（S1～S3）粗脂肪含量快速升高达到最大值,成熟末期（S4）含量略有下降。牡丹籽粒发育过程中,油脂积累与可溶性糖呈极显著负相关;油酸和亚油酸的含量呈上升趋势,而亚麻酸含量呈下降趋势,两者与亚麻酸含量均呈极显著负相关。花后第106天牡丹果荚和籽粒进入脱水转色期,花后114～121 d牡丹荚果快速脱水开裂前,种子含油量最高是牡丹荚果的最佳采收期。

Based on the analysis of the main morphologic indexes and nutrient contents of tree peony seeds,the changes of fat transformation and nutrients during seed growth and maturation of tree peony were studied. The four marked stages in the development of tree peony seed were observed at the early fertilization and grain formation stage（ S1）,the rapid growth stage of pod and seed（ S2）,the seed inclusion enrichment and conversion stage（ S3）,and the late dehydration and maturity stage of pod and seed（ S4）. The soluble sugar content of tree peony seed accumulated greatly during the early stage of seed development（ S1 ～ S2）,and then declined in the middle and later periods（ S3 ～ S4）. The starch content of seed fell first from grain formation stage to inclusion full and conversion stage,and then increased after seed maturation（ S4）. The protein content of seed dropped rapidly in the stage S1,and then increased slightly to maintain in a relatively stable state. The crude fat content of seed increased continuously and reached to the maximum value during the early and middle developmental stages（ S1 ～ S3）,but declined slightly after ripening. During the development process of tree peony seeds,the crude fat accumulation was negatively correlated with the soluble sugar. Meanwhile,the relative contents of oleic acid and linoleic acid were upward,the relative contents of linolenic acid were overall decreased during the tree peony seed growth and ripening process. Both the oleicacid and linoleic acid were much significantly negatively correlated with the linolenic acid contents. It was transformed into decoloration and dehydration stage of tree peony pods and seeds after flowering 106 d. The pods harvested in the early cracking stages after flowering 114 ～ 121 d,and seeds yielded the maximum oil with high linolenic acid content which could be suitable for edible oil production.