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Zhu X.-F.,Nanjing Agricultural University | Xu Y.,Nanjing Agricultural University | Xu Y.,Shanghai Landscape Gardening Research Institute | Peng D.,Nanjing Agricultural University | And 4 more authors.
Crop Protection | Year: 2013

The resistance to bismerthiazol in the Xanthomonas oryzae pv. oryzae population in China has not been clearly determined. Three bismerthiazol-resistant mutants (1-1-1, 2-1-1, 4-1-1) of X. oryzae pv. oryzae were induced on rice plants and the characteristics were compared with their parental strain ZJ173. After 10 subcultures on fresh bismerthiazol-free nutrient agar plates and after being inoculation onto and re-isolation from untreated rice plants two times, the mutants remained pathogenicity on rice plants treated with 300 μg/ml bismerthiazol, indicating that the in vivo-induced bismerthiazol resistance was stable in vivo. The in vitro characteristics of the bismerthiazol-resistant mutants and a wild-type bismerthiazol-sensitive strain (ZJ173) were also compared. The three mutants grew faster than ZJ173 during the logarithmic growth phase but at the same rate during the decline phase. Bismerthiazol had protective and curative activity against strain ZJ173 but not against the three mutants. To evaluate the current degree of bismerthiazol resistance in field populations of X. oryzae pv. oryzae in China, 781 isolates of X. oryzae pv. oryzae were obtained from 1419 leaf samples collected from Yunnan, Sichuan, Jiangsu, Anhui, Hubei, Guangdong, Hainan, and Hunan Provinces in China from 2007 to 2009. The in vivo sensitivity of 505 of the 781 isolates to bismerthiazol was determined by applying them to rice plants treated with 300 μg/ml bismerthiazol and evaluating blast severity. The tested strains were considered resistant, if they showed <70% inhibition relative to strain ZJ173. Of the 505 isolates, 62 were resistant to bismerthiazol. The resistance frequencies among field population ranged from 0 to 21.1%, differed among the provinces, and was 11.2, 20.0 and 10.4% in 2007, 2008 and 2009, respectively. Resistance determined i. n vivo was not related to resistance determined in vitro. The in vivo-induced bismerthiazol resistance identified in this study will serve as a base line for further studying bismerthiazol resistance in fields, and the current degree of bismerthiazol resistance in field populations of X. oryzae pv. oryzae in China determined would be useful for the rice growers for control of rice bacterial blight. © 2013 Elsevier Ltd.

Chen X.-B.,Beijing Forestry University | Chen X.-B.,Shanghai Landscape Gardening Research Institute | Ye W.-G.,Zhejiang University of Science and Technology | Tian Q.,Chenshan Botanical Garden | Zhang Q.-X.,Beijing Forestry University
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2010

In order to show the phenotypic variation of eight natural populations of Sinocalycanthus chinensis, 22 phenotypic traits including flowers, leaves, fruits and seeds were investigated. Significant variations among and within populations were found (P < 0.01). The average coefficient of variation (CVs) was 12.15% (ranging from 6.40% to 45.87%), while the average phenotypic differentiation coefficient (Vst) was 41.87% (ranging from 1.14%-85.07%). The variation within eight populations (58.13%) was larger than that among populations (41.87%). The outer-perianth color of S. chinensis varied from white, baby pink, pink to dark pink and the proportion of outer-perianth color varied among different populations. Among the 22 phenotypic traits, eight showed a significant relation with ecological factors. According to a UPGMA cluster analysis, the eight populations were divided into four groups. The differentiation of phenotypic traits was consistent with the geological distribution of S. chinensis populations.

Divi U.K.,CSIRO | Zhou X.-R.,CSIRO | Wang P.,CSIRO | Wang P.,Murdoch University | And 10 more authors.
Plant and Cell Physiology | Year: 2016

Chinese tallow (Triadica sebifera) is a valuable oilseedproducing tree that can grow in a variety of conditions without competing for food production, and is a promising biofuel feedstock candidate. The fruits are unique in that they contain both saturated and unsaturated fat present in the tallow and seed layer, respectively. The tallow layer is poorly studied and is considered only as an external fatty deposition secreted from the seed. In this study we show that tallow is in fact a non-seed cellular tissue capable of triglyceride synthesis. Knowledge of lipid synthesis and storage mechanisms in tissues other than seed is limited but essential to generate oil-rich biomass crops. Here, we describe the annotated transcriptome assembly generated from the fruit coat, tallow and seed tissues of Chinese tallow. The final assembly was functionally annotated, allowing for the identification of candidate genes and reconstruction of lipid pathways. A tallow tissue-specific paralog for the transcription factor gene WRINKLED1 (WRI1) and lipid droplet-associated protein genes, distinct from those expressed in seed tissue, were found to be active in tallow, underpinning the mode of oil synthesis and packaging in this tissue. Our data have established an excellent knowledge base that can provide genetic and biochemical insights for engineering non-seed tissues to accumulate large amounts of oil. In addition to the large data set of annotated transcripts, the study also provides gene-based simple sequence repeat and single nucleotide polymorphism markers. © The Author 2015.

Xu Y.,Nanjing Agricultural University | Xu Y.,Shanghai Landscape Gardening Research Institute | Zhu X.-F.,Nanjing Agricultural University | Zhou M.-G.,Nanjing Agricultural University | And 4 more authors.
Journal of Phytopathology | Year: 2010

Rice leaves with bacterial blight or bacterial leaf streak symptoms were collected in southern China in 2007 and 2008. Five hundred and thirty-four single-colony isolates of Xanthomonas oryzae pv. oryzae and 827 single-colony isolates of Xanthomonas oryzae pv. oryzicola were obtained and tested on plates for sensitivity to streptomycin. Four strains (0.75%) of X. oryzae pv. oryzae isolated from the same county of Province Yunnan were resistant to streptomycin, and the resistance factor (the ratio of the mean median effective concentration inhibiting growth of resistant isolates to that of sensitive isolates) was approximately 226. The resistant isolate also showed streptomycin resistance in vivo. In addition to resistant isolates, isolates of less sensitivity were also present in the population of X. oryzae pv. oryzae from Province Yunnan. However, no isolates with decreased streptomycin-sensitivity were obtained from the population of X. oryzae pv. oryzicola. Mutations in the rpsL (encoding S12 protein) and rrs genes (encoding 16S rRNA) and the presence of the strA gene accounting for streptomycin resistance in other phytopathogens or animal and human pathogenic bacteria were examined on sensitive and resistant strains of X. oryzae pv. oryzae by polymerase chain reaction amplification and sequencing. Neither the presence of the strA gene nor mutations in the rpsL or rrs were found, suggesting that different resistance mechanisms are involved in the resistant isolates of X. oryzae pv. oryzae. © 2010 Blackwell Verlag GmbH.

Zhao X.,Chinese Academy of Agricultural Sciences | Zhang G.,Shanghai Landscape Gardening Research Institute | Wang Y.,ShenYang Agricultural University | Zhang F.,Chinese Academy of Agricultural Sciences | And 5 more authors.
PLoS ONE | Year: 2015

A rice introgression line, NIL-SS1, and its recurrent parent, Teqing, were used to investigate the influence of the introgression segment on plant growth. The current research showed NIL-SS1 had an increased flag leaf width, total leaf area, spikelet number per panicle and grain yield, but a decreased photosynthetic rate. The metabolite differences in NIL-SS1 and Teqing at different developmental stages were assessed using gas chromatography - mass spectrometry technology. Significant metabolite differences were observed across the different stages. NIL-SS1 increased the plant leaf nitrogen content, and the greatest differences between NIL-SS1 and Teqing occurred at the booting stage. Compared to Teqing, the metabolic phenotype of NIL-SS1 at the booting stage has closer association with those at the flowering stage. The introgression segment induced more active competition for sugars and organic acids (OAs) from leaves to the growing young spikes, which resulted in more spikelet number per plant (SNP). The results indicated the introgression segment could improve rice grain yield by increasing the SNP and total leaf area per plant, which resulted from the higher plant nitrogen content across growth stages and stronger competition for sugars and OAs of young spikes at the booting stage. © 2015 Zhao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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