The Study On Cell Morphology Of Nitella Papillata

Charophyta, the most evolutional species and most similar to higher plant in all algae, had been recognized as a kind of higher plant. The Systematic of Charophyta comprises one Charophyceae, three Characeaes. Nitella papillata is one species of Charales. It is the Chinese perticular specice, grayest green or dark green dioecious plant, growing in yunnan and guizhou provinces, and encrusted with calcium carbonate deposits and have nodes with whorled, filamentlike branches, compared with N. annandalei Pal and N. globulifera Pal which grow in Burma, Nitella papillata has central ray, gametangia in first ray of branchlet, but the other two species have none.In this paper, we have experimented on the karyotype of the gametophyte of Nitellapapillataby acidifing, enzyme bating, wiping off cellular and lower infiltration. After mang preparation experiments, we found the different influence on the Karyotype-made under different time and temperature of preparation, acidifing, enzyme bating, and Giemsa dyeing. At last, we know the best method to make the Karyotype and amitosis of the gametophyte of Nitella papillata, which has some differences with the traditional Research technocogy of plant chromosome.After chromosome experiments, wo confirmed that the number of chromosome of gametophyte of Nitella papillata is 9. the karyotype ofmale gametophyte is n=x=8m+T,and female is n=x=9. noteworthily, there are obviously differt NO. 9 chromosome between male and female gametophyte. Otherwise the rest 8 pair chromosomes are very similar to each homologous chromosome in relative length, arm ratio, Centromere site , Centromere index and position of centromeres,etc. as we know, Mtella papillata is a kind of dioecious plant, so there may be some important relation between the difference of NO. 9 chromosome and the sex of the species.We also study the amitosis of Nitella papillata. By modificating the method to gametophyte above mentioned, we research the conditions and positions of amitosis appearance of the plant. The changes of nuclear and nuclear-to-cytoplasmic ratio habe been recorded and analysed. Research result indicated that amitosis is a very common Cell division mode. The positions where the amitosis happens are centralized in second and third branch of Nitella papillata. Those positions are the activest growth area in the plant body. So we can conclude that amitosis is very important to the growth of the species.Above all, the best karyotype reaching method of the gametophyte of Nitella papillata and appropriate appearance conditions and positions of amitosis of the plant were obtained. There has a large number of Charophyta specises in China, and Nitella papillata is peculiar to our country, so the-study on Nitella papillata has great significance for Charophyta deeper research such as algae taxology, genetics and cell morphology in the world.