Study on Tissue Culture and Karyotype of Several Orchid Filial Generation in Cymbidium
|School||Shandong Agricultural University|
|Course||Ornamental Plants and Horticulture|
|Keywords||Cymbidium Tissue culture Karyotype analysis|
This test is imported from South Korea in Taishan Academy of Forestry Science Cymbidium (Cymbidium hybridum) the fine varieties based on the varieties cultivated Cymbidium orchid garden and Taishan Yixiang carried out research work mainly in the following three aspects content. First non-symbiotic germination of immature embryos of hybrid combinations (immature seeds), from different developmental stages of the fruit, germination medium-pronged approach to the establishment of a complete non-symbiotic germination technology system; Second is the hybrid embryos Germination formation of protocorm Tissue Culture Technique, from the basic medium, a large number of elements, sucrose concentration, additives aspects screened offspring protocorm proliferation micropropagation optimal medium for scientific research and production practice system with reasonable reference; hybrids by karyotype analysis identified early, clear the genetic background of the hybrids, including its ploidy, chromosome morphology, karyotype parameters for crossbreeding offspring Breeding reference and basis. The main findings are as follows: 1. Cymbidium orchid hybrid embryos explants in primary culture, screening out the hybrid embryos asymbiotic germination the best harvest time and germination optimum basic medium. Embryo age to about 150 days for the best harvest time, the highest germination rate; optimal germination medium B11 sucrose 20 g / L agar 8.0 g / the L AC3.0g / L. Cymbidium Cymbidium hybrid protocorm the optimal medium explants subcultured protocorm proliferation and differentiation screened. The different progenies in different media proliferation multiples of the same optimal basic medium subculture are KC sucrose 20 g / L agar 8.0 g / L mashed banana 150g / L,. Exogenous hormones promote the proliferation and differentiation of auxin NAA best results, cytokinin 6-BA; NAA 0.2mg / L when hybridization protocorm proliferation was the best, 6-BA and NAA concentration ratio of 4 to 5:1, the divisive effects best; 1.0mg / L GA subculture promoted; summary, the best medium for subculture KC NAA0.2mg / L 6-BA0.8mg / L GA1.0mg / L sucrose 20 g / L agar 8.0 g / L mashed banana 150g / L, respectively. The hybrid orchid rooting culture, a large number of elements with sucrose concentration on rooting impact is extremely significant. The optimum inorganic salt concentration 1/4MS, 60 days after the plantlets rooting rate of 100%, the average root number up to 2.4, average root length up to 1.79cm; sucrose concentration of 30 g / L, most root growth situation , the average root number up to 3.43, the average root length up to 1.34 cm. Hybrid orchid optimum rooting medium 1/4MS NAA0.2mg / L agar 8.0 g / L sucrose 30 g / L mashed banana 150g / L. Hybrid orchid plantlets transplanted roots root pruning treatment can stimulate the generation of new roots, improve the survival rate of seedlings, transplanting to 100 days after the matrix sphagnum survival rate of 81%, the average height is 11.89cm compared to non-root pruning treatment, the seedlings were growing significantly mend. 5. By four kinds Cymbidium paternal hybrids nuclear type analysis, early identification of hybrids. The results show that: the pattern paternal 'Emerald' and 'Angel' somatic chromosome number are 2n = 4x = 80, tetraploid with diploid the spring sword and Cymbidium hybrids somatic chromosome number are 2n = 3x = 60, can be identified hybrids is true hybrids; the flowers type paternal 'Summer Green', 'Sheng Leifen' somatic chromosome number 2n = 2x = 40, are diploid, with spring sword hybrids karyotype analysis, relative chromosome length, average arm ratio, and asymmetry coefficient indicators descendants have tended to be the parents of this intermediate value, hybrids chromosome morphology has characteristics of both parents, can also be identified as a true hybrid. 6 progenies karyotype theoretical karyotype are there are some differences, break the parental genome between the long-term evolution of the formation of a total fitness system that artificial hybridization. Parental and offspring chromosome structure composed mainly by the central and nearly metacentric chromosome, the longest chromosomes with the shortest chromosome ratio between 2.01 to 4.2, the arm than the percentage of greater than 2 chromosome is not high, no more than 35%. Karyotype classification criteria by Stebbins (1971), all the parents and their hybrids in addition to the 'Summer Green' 2C and the rest are of type 2B. This shows that the the orchid species chromosome number is relatively conservative, the variation is not, but also the karyotype higher symmetry.