: Phylogenetic relationships of the different species in the genus Dendranthema (DC.) Des Moul. were estimated based on chromosome fluorescent in situ hybridization (FISH) with 18S-26S rDNA of Arabidopsis and genomic ...: Phylogenetic relationships of the different species in the genus Dendranthema (DC.) Des Moul. were estimated based on chromosome fluorescent in situ hybridization (FISH) with 18S-26S rDNA of Arabidopsis and genomic DNA of Dendranthema as probes. The results revealed that there was no positive correlation between the number of nuclear organization region (NOR) loci and the ploidy of Dendranthema. The exact cytogenetic information of NORs about 14 operational taxonomic units (OTUs) indicated that D. vestitum (Hemsl.) Ling et Shih was closer to the cultivars than other putative species, whereas D. zawadskii (Herb.) Tzvel. was the most distinct. The ambiguously distributed signals of genomic in situ hybridization (GISH) with genomic DNA of lower ploidy species as probes suggested that different genomes among Dendranthema were mixed. The result also indicated the limitation of GISH in studies on the phylogenetic relationships of the different species in this genus Dendranthema and on the origin of cultivated chrysanthemums. Based on these results and previous research, the origin of Chinese cultivated chrysanthemum is discussed.展开更多
Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer,...Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. However, these plants are all near-extinction species due to over-collection and their own biological characteristics. The chemical synthesis of podophyllotoxin is so complicated that its price is unbelievably high. This paper discusses the current status of the biosynthetic pathway of podophyllotoxin and that of the podophyllotoxin production using several biotechnological approaches such as plant organ cultures, plant cell cultures with both flasks and bioreactors, hairy root cultures, bioconversions and metabolic regulations.展开更多
Fluorescent in situ hybridization (FISH) was applied to investigate the phylogenetic relationship among Dendranthema spp. Genomic DNA of wild species which was used as probe did not give specific signals, while 18S-26...Fluorescent in situ hybridization (FISH) was applied to investigate the phylogenetic relationship among Dendranthema spp. Genomic DNA of wild species which was used as probe did not give specific signals, while 18S-26S rDNA from Arabidopsis, which was used as control probe, showed the loci on the target chromosomes clearly. Satisfied results of FISH were gotten when denaturing digoxingenen-labeled probe and chromosome together in oven at 80℃ for 1015min. There is little influence on the result by the stringency of washing when rDNA was used as probe. The result also indicates the limitation of genomic in situ hybridization (GISH) when used as an approach to analyze the phylogenetic relationship among Dendranthema spp. and the origin of cultivated chrysanthemum.展开更多
The effects of culture media and light intensity on in vitro growth of Oncidium 慉loha Iwanga were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and...The effects of culture media and light intensity on in vitro growth of Oncidium 慉loha Iwanga were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and the leaf number per plant, shoot number per plant, leaf width and leaf chlorophyll content were also investigated. The results were as follows: 1) The seedling height, fresh and dry weight, leaf number per plant, leaf width and leaf chlorophyll content of the shoots growing on MS complete culture medium were higher than those on 1/2MS, VW and 1/2VW media. The root number per plant and ratio of dry matter of the seedlings cultured on 1/2MS and 1/2VW media were higher than those on MS and VW; 2) The seedling height, fresh weight, dry weight, dry matter ratio and leaf chlorophyll content, leaf length, leaf width, root length, leaf number per plant, root number per plant of seedlings of Oncidium growing under 4 500 lx and 1 700 lx were higher than those under 750 lx. However, there was no significant difference in those growth parameters mentioned above while dealing with 4 500 lx and 1 700 lx except for the seedling height. Nevertheless, the leaf color of plants under 4 500 lx was lighter and the leaves of the lower parts became yellowish in comparison with those growing under 1 700 lx.展开更多
Abstract: Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescen...Abstract: Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescence and the post-harvest quality of ornamentals, fruits, and vegetables. In the present paper, PCD in relation to petal senescence in ornamental plants is reviewed. Morphological, anatomical, physiological, and biochemical changes that are related to PCD in petals, such as water content, sink-source relationships, hormones, genes, and signal transduction pathways, are discussed. Several approaches to improving the quality of post-harvest ornamentals are reviewed and some prospects for future research are given.展开更多
文摘: Phylogenetic relationships of the different species in the genus Dendranthema (DC.) Des Moul. were estimated based on chromosome fluorescent in situ hybridization (FISH) with 18S-26S rDNA of Arabidopsis and genomic DNA of Dendranthema as probes. The results revealed that there was no positive correlation between the number of nuclear organization region (NOR) loci and the ploidy of Dendranthema. The exact cytogenetic information of NORs about 14 operational taxonomic units (OTUs) indicated that D. vestitum (Hemsl.) Ling et Shih was closer to the cultivars than other putative species, whereas D. zawadskii (Herb.) Tzvel. was the most distinct. The ambiguously distributed signals of genomic in situ hybridization (GISH) with genomic DNA of lower ploidy species as probes suggested that different genomes among Dendranthema were mixed. The result also indicated the limitation of GISH in studies on the phylogenetic relationships of the different species in this genus Dendranthema and on the origin of cultivated chrysanthemums. Based on these results and previous research, the origin of Chinese cultivated chrysanthemum is discussed.
基金Supported by the Natural Science Foundation of Tibet (Grant No. 2002-66)
文摘Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. However, these plants are all near-extinction species due to over-collection and their own biological characteristics. The chemical synthesis of podophyllotoxin is so complicated that its price is unbelievably high. This paper discusses the current status of the biosynthetic pathway of podophyllotoxin and that of the podophyllotoxin production using several biotechnological approaches such as plant organ cultures, plant cell cultures with both flasks and bioreactors, hairy root cultures, bioconversions and metabolic regulations.
基金National Natural Science Foundation of China (Grant No. 39600119)
文摘Fluorescent in situ hybridization (FISH) was applied to investigate the phylogenetic relationship among Dendranthema spp. Genomic DNA of wild species which was used as probe did not give specific signals, while 18S-26S rDNA from Arabidopsis, which was used as control probe, showed the loci on the target chromosomes clearly. Satisfied results of FISH were gotten when denaturing digoxingenen-labeled probe and chromosome together in oven at 80℃ for 1015min. There is little influence on the result by the stringency of washing when rDNA was used as probe. The result also indicates the limitation of genomic in situ hybridization (GISH) when used as an approach to analyze the phylogenetic relationship among Dendranthema spp. and the origin of cultivated chrysanthemum.
文摘The effects of culture media and light intensity on in vitro growth of Oncidium 慉loha Iwanga were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and the leaf number per plant, shoot number per plant, leaf width and leaf chlorophyll content were also investigated. The results were as follows: 1) The seedling height, fresh and dry weight, leaf number per plant, leaf width and leaf chlorophyll content of the shoots growing on MS complete culture medium were higher than those on 1/2MS, VW and 1/2VW media. The root number per plant and ratio of dry matter of the seedlings cultured on 1/2MS and 1/2VW media were higher than those on MS and VW; 2) The seedling height, fresh weight, dry weight, dry matter ratio and leaf chlorophyll content, leaf length, leaf width, root length, leaf number per plant, root number per plant of seedlings of Oncidium growing under 4 500 lx and 1 700 lx were higher than those under 750 lx. However, there was no significant difference in those growth parameters mentioned above while dealing with 4 500 lx and 1 700 lx except for the seedling height. Nevertheless, the leaf color of plants under 4 500 lx was lighter and the leaves of the lower parts became yellowish in comparison with those growing under 1 700 lx.
文摘Abstract: Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescence and the post-harvest quality of ornamentals, fruits, and vegetables. In the present paper, PCD in relation to petal senescence in ornamental plants is reviewed. Morphological, anatomical, physiological, and biochemical changes that are related to PCD in petals, such as water content, sink-source relationships, hormones, genes, and signal transduction pathways, are discussed. Several approaches to improving the quality of post-harvest ornamentals are reviewed and some prospects for future research are given.
