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 DN...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
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.
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.
