Symbiotic And Asymbiotic Germination Of Cremastra Appendiculata Seeds

In this study,Cremastra appendiculata(D.Don)Makino,a medicinal source plant of the traditional Chinese medicine Pseudobulbus Cremastrae seu Pleiones,was used as the research object,and the asymbiotic germination and establishment of C.appendiculata were observed and compared through microscopic observation and paraffin sectioning.To explore the difference between asymbiotic germination and symbiotic germination of C.appendiculata seeds.The effects of medium types,addition of acid hydrolyzed casein,seed storage time at low temperature,different concentrations of 6-BA and NAA on the asymbiotic germination of C.appendiculata seeds were compared.The effects of temperature,light intensity,medium,container and other conditions on the symbiotic germination of C.appendiculata were explored.1.Observation and comparison of asymbiotic germination of C.appendiculata seedsThe protocorm of C.appendiculata first forms a rhizome,which only has limited branches.The rhizome can form dormant buds,the top of which differentiates into leaf buds,and the leaf base grows out of roots to develop into seedlings.difference.After the embryo of Bletilla striata swells into a protocorm,the upper end forms leaves,and then forms roots to directly form seedlings;Cymbidium ensifolium germinates and forms rhizomes and continues to proliferate.Observing the internal structure of Cremastra appendiculata and Cymbidium ensifolium rhizomes,there are obvious differences.2 Effects of different conditions on the asymbiotic germination of C.appendiculata seedsThere was no significant difference in the germination rate of different MS media.With the addition of acid hydrolyzed casein,the growth rate of 1/2 MS was significantly greater than that of 1/4 MS.Under the same culture time,the length and width of protocorm/rhizome in liquid medium were significantly larger than those in solid.The germination rate and growth rate of seeds stored at low temperature for 3 months were better than those of fresh seeds and seeds stored for 9 months.With 1/2 MS+2 g/L CH(liquid)as the basic medium,the combined addition of 0.1 mg/L 6-BA+1.0 mg/L NAA had the highest germination rate and the fastest growth rate.3 Research and comparison of symbiotic germination of C.appendiculataThe symbiotic germination bacteria of C.appendiculata seeds were isolated and identified.ITS sequencing showed that among the four strains,D1,D2,and D5 belonged to the Coprinus,and D3 might belong to the Coprinellus.There are differences between symbiotic germination and asymbiotic germination of C.appendiculata seeds.The temperature was 20 or 25 ?,dark or weak light(0 or 500-1100 lx),the seed germination rate was higher,and normal light(2500-3000 lx)inhibited the seed germination;there was no significant difference between the three container cultures.4 strains of germinated bacteria were inoculated on 3 kinds of medium,and the germination rate on OMA medium was the highest.Conclusion: The asymbiotic germination and establishment of orchid seeds can be divided into three modes.For the asymbiotic germination culture of C.appendiculata,1/2 MS+2 g/L CH liquid medium was used,and seeds stored at low temperature for 3 months and 0.1 mg/L6-BA+1.0 mg/L NAA were added,and the germination rate was cultured for 60 days.The largest,at 71.11%.Comparing the symbiotic and asymbiotic germination of C.appendiculata,it is found that the symbiotic germination time is shorter,the protocorm produces green slowly,does not form branches,and is not easy to differentiate into roots;asymbiotic germination takes longer time,produces green quickly,usually forms branches,and is easy to differentiate.differentiated into roots.When C.appendiculata seeds were symbiotically germinated,the OMA solid culture was used to culture in glass dishes,and the maximum germination rate was achieved in the dark or weak light at 20 or 25 °C.