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Yan H.M.,Yunnan Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2012

To reveal the genetic variation of rice paddy landraces across 30 years, we compared the genetic variation of between 6 paddy rice landraces grown in Yuanyang Hani's terraced fields in Yuanyang County, Yunnan Province in the 1970s (past-grown landraces) and 6 paired ones that have been grown during the past decade (current-grown landraces) using 60 SSR markers. The results showed that one to four alleles were amplified in 60 loci and 159 alleles in all the landraces tested. The number of alleles from the current-grown landraces decreased by 7 alleles compared to the past-grown landraces. The average number of alleles (Na), effective number of alleles (Ne), locus polymorphism information content (PIC), and genotype diversity (H') of the past-grown landraces were higher than those of the current-grown landraces, with Na of 2.567>2.450, Ne of 2.052>1.968, PIC of 0.469>0.439, and H' of 0.768>0.722. The average genetic similarity coefficient (GS) of the past-grown landraces was 0.437 with a range from 0.200 to 0.700 based on the 60 SSR markers, and the average GS of the current-grown landraces was 0.473 with a range from 0.117 to 0.667. In conclusion, the genetic diversity in current-grown landraces was decreased compared to the past-grown landraces, and the degree of variation in some of the allele locus varied in different rice landraces as a result of 30 years' natural and artificial selection. Source

Lu M.,Shanghai JiaoTong University | Han Z.,Keyi Tech | Xu Y.,Yunnan Academy of Agricultural Sciences | Yao L.,Shanghai JiaoTong University
Flavour and Fragrance Journal | Year: 2013

Essential oils from Chinese indigenous aromatic plants were tested for antimicrobial activity and induction of morphological changes in the tobacco pathogens Alternaria alternata, Colletotrichum destructivum and Phytophthora parasitica. The results revealed that the extent of mycelial growth inhibition was widely dependent upon the composition and concentration of essential oils. Among the 29 essential oils tested, superior broad-spectrum antimicrobial activities were observed from cinnamon, geranium, cumin, thyme, basil and lemongrass essential oils. Concentration-dependent inhibition was also determined for these active essential oils. The essential oils from cinnamon and thyme exhibited the strongest antimicrobial activity against mycelial growth of A. alternata, C. destructivum and P. parasitica. The essential oils also had a strong detrimental effect on spore germination of all the plant pathogens tested in a dose-dependent manner. Compositions of the essential oils from cinnamon, geranium, cumin, thyme, basil and lemongrass were identified by gas chromatography and gas chromatography-mass spectrometry. The major components of these essential oils were cinnamaldehyde (80.4%), citronellol (41.6%), cuminaldehyde (46.9%), thymol (39.8%), linalool (50.0%) and citronellal (20.8%), respectively. Scanning electron microscopy revealed that these essential oils caused considerable morphological degeneration, including cytoplasmic coagulation, shrivelled hyphal aggregation, flattened empty hyphae, and swelling and lysis of hyphal wall in the three phytopathogens. © 2012 John Wiley & Sons, Ltd. Source

Zhou X.G.,Yunnan Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011

Based on the Phytophthora infestans genome sequence, we used bioinformatics and computer-based prediction algorithms to predict the secreted proteins of P infestans in detail, which would help us to elucidate the molecular mechanism underlying the interaction between the host plants and the P infestans. In this study, the signal peptide prediction algorithms SignalP v3.0 and PSORT, transmembrane helix prediction algorithms TMHMM-2.0 and THUMBUP, GPI-anchoring site prediction algorithm big-PI Predictor, and subcellular protein location distribution algorithm TargetP v1.01 were used to analyze the 22658 protein sequences of P infestans published. Our results suggested that there might be 671 secreted pro- teins, accounting for 3.0% of the total proteins. Among them, the functions of the 45 secreted proteins had been described previously. Their functions involved cellular metabolism and signal transduction etc. In addition, some of the secreted proteins were functionally similar to elicitin, which were likely to be associated with the virulence of P. infestans. Source

Liu Y.,CAS Kunming Institute of Botany | Yang S.-X.,CAS Kunming Institute of Botany | Ji P.-Z.,Yunnan Academy of Agricultural Sciences | Gao L.-Z.,CAS Kunming Institute of Botany
BMC Evolutionary Biology | Year: 2012

Background: As one of the most important but seriously endangered wild relatives of the cultivated tea, Camellia taliensis harbors valuable gene resources for tea tree improvement in the future. The knowledge of genetic variation and population structure may provide insights into evolutionary history and germplasm conservation of the species. Results: Here, we sampled 21 natural populations from the species' range in China and performed the phylogeography of C. taliensis by using the nuclear PAL gene fragment and chloroplast rpl32-trnL intergenic spacer. Levels of haplotype diversity and nucleotide diversity detected at rpl32-trnL (h=0.841; π=0.00314) were almost as high as at PAL (h=0.836; π=0.00417). Significant chloroplast DNA population subdivision was detected (GST=0.988; NST=0.989) , suggesting fairly high genetic differentiation and low levels of recurrent gene flow through seeds among populations. Nested clade phylogeographic analysis of chlorotypes suggests that population genetic structure in C. taliensis has been affected by habitat fragmentation in the past. However, the detection of a moderate nrDNA population subdivision (GST=0.222; N ST=0.301) provided the evidence of efficient pollen-mediated gene flow among populations and significant phylogeographical structure (N ST>GST; P<0.01). The analysis of PAL haplotypes indicates that phylogeographical pattern of nrDNA haplotypes might be caused by restricted gene flow with isolation by distance, which was also supported by Mantels test of nrDNA haplotypes (r=0.234, P<0.001). We found that chlorotype C1 was fixed in seven populations of Lancang River Region, implying that the Lancang River might have provided a corridor for the long-distance dispersal of the species. Conclusions: We found that C. taliensis showed fairly high genetic differentiation resulting from restricted gene flow and habitat fragmentation. This phylogeographical study gives us deep insights into population structure of the species and conservation strategies for germplasm sampling and developing in situ conservation of natural populations. © 2012 Liu et al. Source

Zhang Y.T.,Yunnan Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2013

It is utmost important to cultivate potato variety with drought resistance to reduce arid loss by research progress on potato drought resistance molecular mechanism. A comparative study with differences in protein group analysis of potato drought resistance variety in Ninglang 182 leaves was carried out by using two-dimensional gel electrophoresis during drought and normal processing conditions.There were 12 differentially expressed protein spots identified by Electro-phoresis and MALDI-TOF-TOF/MS analysis. The function classification of these proteins results that the potato varieties to drought tolerance could be improved through the protection of photosynthesis and mitochondria, regulation of the signal transduction induced under environmental stress and regulation of plant tissue N and C transport system, these proteins expression were increased under drought.The results showed that these proteins are the drought resistance associated proteins of potato variety in Ninglang 182.This study provided a theoretical basis of the molecular mechanism of improving drought tolerance in order to expound the potato drought resistance variety through multiple paths and the level regulation. Source

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