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Shijiazhuang, China

An P.,Tottori University | Li X.,Hebei Academy of Forestry Science | Zheng Y.,CAS Institute of Botany | Eneji A.E.,University of Calabar | And 3 more authors.
Journal of Geographical Sciences

The distribution of plant species and relationships between species and soil factors in the east central part of Gurbantunggut Desert was studied to provide more insight into the flora and determine differences in vegetation across various parts of the desert. Two-way Cluster Analysis showed that the vegetation in the area could be divided into three groups, the first group was dominated by the shrub species, Ephedra przewalskii and the grass species, Carex physodes mainly in areas of flat grounds and gentle slopes; the second group was dominated by C. physodes, Artemisia songorica and A. xerophytica mainly on the slope of sand dunes and the third group was dominated by the shrub species, Haloxylon persicum mainly on the top of sand dunes. There was no difference in plant density between Groups 1 and 2 but there was a significant decrease in Group 3. Soil water under vegetation Group 3 was much lower than that in the other two groups at all soil depths. The EC, organic matter, total P and soluble Na, Ca and Mg varied very similarly with soil water. Canonical correspondence analysis (CCA) satisfactorily assessed the species-soil relations in the area. The distribution of plant species was strongly correlated with the soil factors of water content, organic matter, EC and nutrients. The variations in species occurrence explained by the three CCA axes were about 70%, indicating that some explanatory site variables may exist outside our studied parameters. Soil texture is suggested to be included in future studies to improve the explanation of CCA. © 2014, Science in China Press and Springer-Verlag Berlin Heidelberg. Source

Sun F.,Qufu Normal University | Jia Z.,Hebei Academy of Forestry Science
Sensor Letters

Centering on the nondestructive measurement of field crop-stem lodging resistance, with stem's tilt angle and the corresponding resilience under external force as the research objects and tilt-angle sensor and pressure sensor as the measuring elements, this paper designs a portable nondestructive crop lodging resistance measurement system which can rapidly and nondestructively acquire stem tilt angle and the corresponding resilience in the field and can communicate the signal acquired to the upper computer through wireless bluetooth or wired mode, and meanwhile the upper computer software carries out data processing, such as real-time display and storage. The test result demonstrates that the system is able to promptly acquire field stems' tilt-angle and corresponding resilience, which serve as an indicator to study crop-stem lodging resistance provide relevant researchers with scientific data reference and decision support. Copyright © 2014 American Scientific Publishers. Source

Gao S.,China Agricultural University | Gao S.,Institute of Forensic Science | Guo W.,China Agricultural University | Guo W.,Hebei Academy of Forestry Science | And 9 more authors.
Molecular Plant Pathology

Several plant lipid transfer proteins (LTPs) act positively in plant disease resistance. Here, we show that LTP3 (At5g59320), a pathogen and abscisic acid (ABA)-induced gene, negatively regulates plant immunity in Arabidopsis. The overexpression of LTP3 (LTP3-OX) led to an enhanced susceptibility to virulent bacteria and compromised resistance to avirulent bacteria. On infection of LTP3-OX plants with Pseudomonas syringae pv. tomato, genes involved in ABA biosynthesis, NCED3 and AAO3, were highly induced, whereas salicylic acid (SA)-related genes, ICS1 and PR1, were down-regulated. Accordingly, in LTP3-OX plants, we observed increased ABA levels and decreased SA levels relative to the wild-type. We also showed that the LTP3 overexpression-mediated enhanced susceptibility was partially dependent on AAO3. Interestingly, loss of function of LTP3 (ltp3-1) did not affect ABA pathways, but resulted in PR1 gene induction and elevated SA levels, suggesting that LTP3 can negatively regulate SA in an ABA-independent manner. However, a double mutant consisting of ltp3-1 and silent LTP4 (ltp3/ltp4) showed reduced susceptibility to Pseudomonas and down-regulation of ABA biosynthesis genes, suggesting that LTP3 acts in a redundant manner with its closest homologue LTP4 by modulating the ABA pathway. Taken together, our data show that LTP3 is a novel negative regulator of plant immunity which acts through the manipulation of the ABA-SA balance. © 2016 BSPP and John Wiley & Sons Ltd. Source

Zhao W.,CAS Institute of Botany | Zhao W.,University of Chinese Academy of Sciences | Meng J.,Beijing Forestry University | Wang B.,Umea University | And 6 more authors.

Determining how a new hybrid lineage can achieve reproductive isolation is a key to understanding the process and mechanisms of homoploid hybrid speciation. Here, we evaluated the degree and nature of reproductive isolation between the ecologically successful hybrid species Pinus densata and its parental species P. tabuliformis and P. yunnanensis. We performed interspecific crosses among the three species to assess their crossability. We then conducted reciprocal transplantation experiments to evaluate their fitness differentiation, and to examine how natural populations representing different directions of introgression differ in adaptation. The crossing experiments revealed weak genetic barriers among the species. The transplantation trials showed manifest evidence of local adaptation as the three species all performed best in their native habitats. Pinus densata populations from the western edge of its distribution have evolved a strong local adaptation to the specific habitat in that range; populations representing different directions of introgressants with the two parental species all showed fitness disadvantages in this P. densata habitat. These observations illustrate that premating isolation through selection against immigrants from other habitat types or postzygotic isolation through selection against backcrosses between the three species is strong. Thus, ecological selection in combination with endogenous components and geographic isolation has likely played a significant role in the speciation of P. densata. © 2014 The Society for the Study of Evolution. Source

An P.,Tottori University | Li X.,Hebei Academy of Forestry Science | Zheng Y.,CAS Institute of Botany | Egrinya Eneji A.,University of Calabar | And 2 more authors.
Canadian Journal of Plant Science

It has been widely suggested that calcium (Ca) application ameliorates salt stress, but characteristic changes in root cell wall due to Ca application under saline conditions are poorly documented. Our objectives were: (1) to determine the effect of Ca on root cell wall composition, using two soybean cultivars differing in sensitivity to salt stress and (2) to understand the relationship between the internal effects of sodium-calcium interaction on the root cell wall. Uniform seedlings were transplanted into mixed solutions of NaCl (0, 40 mM,) and CaCl2 (0, 0.5, 2 mM). Root lengths were measured after an exposure of 14, 24 and 40 h to the treatments and cell wall analysis performed for total sugars, uronic acid and ion contents. Without salinity stress, Ca application caused no significant changes in root growth and cell wall constituents in both cultivars. However, it did ameliorate the decrease in the amount of cell wall under stress, especially the pectin fraction. Both cell wall and cellular Ca2+ and K+ contents were significantly increased by additional Ca2+ under saline condition. Therefore, by applying Ca2+, the maintenance of pectin level and increase in cell wall Ca2+ may contribute to the restoration of root growth under salinity. Calcium application significantly increased the pectin level under salinity and soybean root growth also showed notable restoration. One way Ca ameliorates salt toxicity may be by maintaining the composition of the cell wall. This ameliorative effect was more conspicuous in the salt-tolerant cultivar, Dare, than the salt-sensitive cultivar, Touzan 69. Source

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