利用胚胎和幼孢子体进行蕨类细胞学研究

以蕨类植物胚胎和幼孢子体根为实验材料,以根尖和孢子母细胞为对照,进行细胞学观察方法的比较研究.结果显示:(1)野外材料的根尖仅在春季分裂期约1个月时间内存在分裂相,根尖个体数目较少(每植株根尖数目＜20条),根尖细胞内含有较坚硬的黏性物质,利用单株根尖进行压片,成功率低于40％；而从野外采回培养时根尖生长极为缓慢且较难成活,因而影响实验效果.(2)野外材料的孢子母细胞仅在孢子囊形成期约1周时间内存在分裂相,因此极大地限制了细胞学观察研究.(3)以胚胎和幼孢子体根为材料进行实验,单位面积(d=15cm培养皿)内幼孢子体根尖或胚胎的数量多于300个,分裂期细胞比例高,且细胞间基本不含黏性物质,进行细胞学研究时较少受到季节和实验时间的限制；利用单株根尖或胚胎进行压片,成功率高于80％.因此,利用蕨类植物的胚胎和幼孢子体根进行细胞学研究能有效地提高蕨类植物细胞学观察实验的成功率.

Cytological Methods in Fern by Using Embryo and Young Sporophyte

New cytological methods in ferns by using embryo and young sporophyte were provided with details.Cytological methods of using root-tip and spore mother cell were compared with the new ones.It was supported that:(1)Several aspects limited the success rate of cytological observation by using field root-tips,for the mitotic phase cells of field root-tips only existed in the spring season,about one month,less root-tips numbers (<20 per rhizome),more viscous materials in the field root-tips,and slowly growth and difficulties in manipulating root tips after their collection.Based on above reasons,a low success rate (<40%) existed in the cytological experiment by using field root-tips of one rhizome.(2)Meiosis phase cells of spore mother cells only existed in the formation period of sporangia,about one week,which restricted the success rate of cytological observation of ferns.(3)New cytological materials:embryo and young sporophyte have more than 300 root-tips or embryos in unit areas (d=15 cm dish),more mitotic cells and less viscous materials in root-tip or embryo cells,and few restrictions in experiment season and time.The success rate of cytological experiment is more than 80% by using embryo and young sporophyte.For these reasons,new cytological materials and methods could raise the success rate of the cytological experiment in ferns.