[Correlation analysis and breeding application of agronomic traits and quality indexes in Dendrobium nobile].

The present study aimed to explore the correlation between agronomic traits and quality indexes of Dendrobium nobile and its application value in agricultural breeding. The cultivated strains of D. nobile in Hejiang-Chishui producing areas were extensively collected,and the main agronomic traits and quality indexes were measured. The agronomic traits with significant correlation with quality indexes were screened out by the correlation analysis,and then the parental lines and self-bred F_1 generation plants were furtherverified. Among 96 lines of D. nobile,the content of soluble polysaccharides showed a significant negative correlation with dendrobine( P < 0. 01),and no significant correlation with agronomic traits in stems and leaves. The content of dendrobine exhibited a significant positive correlation with the stem width-thickness ratio( at the largest cross section; P < 0. 01),and no significant correlation with other agronomic traits. Regression analysis further verified the positive correlation between dendrobine content and stem width-thickness ratio( R2> 0. 9). Two lines,JC-10 and JC-35,with significant differences in stem width-thickness ratio were screened out( P <0. 05). The corresponding F1 generation plants by self-pollination both showed that the dendrobine content was higher with greater stem width-thickness ratio( P < 0. 01). The experimental results suggested that within a certain range,the dendrobine content was higher in D. nobile with flatter stem. Therefore,in the breeding of D. nobile,this specific trait could be used for screening plants with high content of quality indexes such as dendrobine.

[Quantitative proteomics of inhibitory mechanism of Dendrobium denneanum ether extract on lung cancer cells].

Dendrobium denneanum have been used for a long time as rare medicinal herbs in traditional Chinese medicine. Our previous works found that ether extract of D. denneanum had higher anticancer activities than alcohol or water extract,thus with better development prospects. Quantitative proteomics based on SILAC technique was used to investigate the anticancer mechanism of D. denneanum on lung tumor cell line A549,and 4 855 proteins were detected in A549 cells. Quantitative proteomics experiments found that 193 proteins of A549 cells were up-regulated,and 44 proteins were down-regulated by ether extract of D. denneanum. Those proteins are associated with synthesis,transport and metabolism of biological macromolecules,chaperone,DNA repair,oxidoreductase,cell adhesion,cell cycle,apoptosis and autophagy. Through the function analysis of differentially expressed proteins,it was inferred that ether extract of D. denneanum caused cell protein metabolism disorder,endoplasmic reticulum stress response,abnormal self-repair mechanism of cells,damage of cell adhesion and proliferation; besides,it caused a dramatic increase in ROS level in A549 cells,and upset the balance of intracellular oxidation reduction system. Affected by the above factors,lung cancer cells initiated apoptosis and autophagy,which accelerated cell death. This research explains the anticancer mechanism of D. denneanum from the perspective of quantitative proteomics,and lays a foundation for future research and development of new anticancer drugs based on ether extract of D. denneanum.

Genome-wide researches and applications on Dendrobium.

MAIN CONCLUSION: This review summarizes current knowledge of chromosome characterization, genetic mapping, genomic sequencing, quality formation, floral transition, propagation, and identification in Dendrobium. The widely distributed Dendrobium has been studied for a long history, due to its important economic values in both medicine and ornamental. In recent years, some species of Dendrobium and other orchids had been reported on genomic sequences, using the next-generation sequencing technology. And the chloroplast genomes of many Dendrobium species were also revealed. The chromosomes of most Dendrobium species belong to mini-chromosomes, and showed 2n = 38. Only a few of genetic studies were reported in Dendrobium. After revealing of genomic sequences, the techniques of transcriptomics, proteomics and metabolomics could be employed on Dendrobium easily. Some other molecular biological techniques, such as gene cloning, gene editing, genetic transformation and molecular marker developing, had also been applied on the basic research of Dendrobium, successively. As medicinal plants, insights into the biosynthesis of some medicinal components were the most important. As ornamental plants, regulation of flower related characteristics was the most important. More, knowledge of growth and development, environmental interaction, evolutionary analysis, breeding of new cultivars, propagation, and identification of species and herbs were also required for commercial usage. All of these studies were improved using genomic sequences and related technologies. To answer some key scientific issues in Dendrobium, quality formation, flowering, self-incompatibility and seed germination would be the focus of future research. And genome related technologies and studies would be helpful.