短柄五加种子结构、后熟作用及其细胞化学研究

STUDIES ON THE STRUCTURE, AFTERRIPENING AND CYTOCHEMISTRY OF SEEDS IN ELEUTHEROCOCCUS BRACHYPUS HARMS

短柄五加ＥｌｅｕｔｈｅｒｏｃｏｃｕｓｂｒａｃｈｙｐｕｓＨａｒｍｓ种子为扁肾形，种皮由一层细胞构成。种子脱落时，胚为心形胚期，胚周围的胚乳细胞解体形成液样囊腔，并包裹胚，胚细胞中存在较多蛋白质，胚乳细胞贮存大量蛋白质颗粒和脂类，但两者均未见多糖颗粒。有萌发潜能的种子只占全部种子的９．２７％。在试验地种植条件下饱满种子经１８～１９个月后萌发，出苗率为１．６７％，该过程细胞化学特点是胚细胞中蛋白质含量逐渐减少，并逐渐积累少量多糖颗粒。种子经变温层积处理６个月即可完成后熟过程，其细胞化学特点是胚细胞中蛋白质含量逐渐减少，但在心形胚后期即已积累大量多糖颗粒，并一直保持至胚完全发育成熟。经比较短柄五加与刺五加的种子结构、后熟作用及其细胞化学特点，认为短柄五加种子质量差、自然状态下后熟时间长和出苗率低是短柄五加致濒的重要生殖因素，并提出了相应保护方法。

Seeds of Eleutherococcus brachypus Harms were flat kidney shaped and their seed coats were only composed of one layer of cells. Embryos with abundant protein in their cells were just at the heart shaped stage and were capped by sacs formed from degenerating endosperm cells when seeds shed from their maternal plants. A large amount of stored protein grains and lipids existed in endosperm cells but no polysaccharide grains were present either in endosperm cells or in embryo cells. Viable seeds were only 9.27% of the total. The plump seeds germinated in the cultivated field after 18～19 months and their germinating rate was 1.67%. Besides, the content of protein decreased gradually and a few polysaccharide grains were stored in embryo cells during the process. The afterripening process of seeds stratified at different temperatures ended after 6 months and the cytochemistry features of the seeds were that the content of protein decreased gradually and numerous polysaccharide grains had been stored in embryo cells at the late heart shaped embryo stage and retained till the mature embryo stage. The structure, afterripening and cytochemistry of seeds were compared between Eleutherococcus brachypus and Eleutherococcus senticosus. The poor quality of the seeds, longer time of afterripening in a natural state and much lower germination rate of E. brachypus are considered to be important reasons for the endangerment of this species. Some measures are suggested for its conservation based on the above facts.