Study On The Tissue Culture And Anatome Plantarum Of Rhododendron Chrysanthum Pall.

The tube seedlings were cultivated through germinating under aseptic conditions with the seeds of Rhododendron chrysanthum Pall.(RCP) on the basis of the previous tissue culture about the azaleas in this study,and the reproduction of RCP were performed by using the shoots and leaves from the seedlings as explants. The best media formula for the in vitro culture of RCP were screened by the statistical methods of orthogonal experiment design,variance analysis and multiple comparisons,as well as the influence of basic media,ZT and AC on the regeneration of RCP were discussed.The results are as follows:(1) It was found that the germination rate of RCP seeds was low,and adding 2.00mg/L GA₃ to media not only shortened germination time but also enhanced germination rate and promoted seedling growth through the investigating of seed germination rate and growth in the germination trial.(2) The best medium compounding for tube-seedling leaf initial induction was WPM(medium)+ZT 10mg/L+IBA 3mg/L in the tube-seedling leaf initial culture for investigating induction-differentiation rate.(3) The best medium compounding for tube-seedling shoot initial induction was WPM(medium)+ZT 10mg/L+IBA 1mg/L in the tube-seedling shoot initial culture for investigating induction-differentiation rate.(4) To increase concentration of ZT was helpful for increasing of branches, but it increased slight branches well as;to decrease the concentration caused the branches sturdy and leaves greener in the subculture multiplication.For that, to add 1-3 mg/L ZT to medium was more reasonable in the subculture multiplication process of RCP.(5) The best medium formula was WPM(medium)+IBA 0.5mg/L+NAA 2.0mg/L+AC 1.0g/L in the rooting in-tuber for comprehensive survey of rooting rate and root number.(6) Peaty soil was the best medium in the acclimatization and transplant of RCP,the survival rate was up to 78%.The observation on histological anatomical structure of the root,stem,leaf, flower,fruit and seed of wild RCP showed that:(1) The most of roots about RCP were secondary structure,they were consisted of secondary vascular tissue and periderm.(2) The stems of RCP were consisted of epidermis,cortex and vascular cylinder, there were a large number of special cells stained deep color in cortex.The thickness of epidermal,cortical,phloem and vascular cambium gradually became smaller with the increasing of altitude.(3) RCP had bifacial leaf that their mesophyll differentiation were obvious, the structure was consisted of epidermis,mesophyll and vein,the palisade tissue was well developed.The diameter of main vein became lower,however the average thickness of leaf and the palisade/sponge tissue(P/S) became bigger with increasing of altitude.(4) The flowers of RCP were bisexual flower,consisted of pedicel,receptade, calyx,corolla,androecium and gynoecia.There were 5 limbs of calyx and petal; 10 androeciums consisted of filament and anther;the pollen grains were tetrad, arranged in tetrahedron,the dehiscence of anther was poricidal;the ovaries were superior,5 carpel were connate;the styles on the carpel were open type,and had slit style groove;the ovary had axile placenta and quinquelocular cells,the number of ovule in cell were different.(5) The fruits of RCP were capsule,had 5 cells and axile placenta:the seeds grew around the placenta,the number of seeds in every cell were different;the fruits would dehiscence from the midst of the wells when they riped.(6) The longitudinal section of RCP seeds were long rotund,consisted of testa, embryo and endosperm.The testa was tawny,had crispate corrugations,narrow membranaceous wings at both ends of the seed;the embryo was erect type,holding two fine cotyledons;the endosperm cells contained very rich starch grains.