关键词：
Ramie;Gas exchange;Chlorophyll fluorescence;Pigments;Antioxidant enzymes;Yield;Salinity stress;A;net photosynthesis;CAT;catalase;Chl a;chlorophyll a;Chl b;chlorophyll b;Chl a + b;total chlorophyll;Ci;intercellular CO2;E;transpiration rate;ETR;electron transport rate of PSII;Fv/Fm;maximum quantum efficiency of PSII photochemistry;Fvʹ/Fmʹ;quantum efficiency of open PSII reaction centers;gs;stomatal conductance;MDA;malondialdehyde;NPQ;non-photochemical quenching;POD;peroxidase;PSII;photosystem II;φPSII;quantum yield of PSII;qP;photochemical quenching;RWC;relative water content;SOD;superoxide dismutase;WUE;water use efficiency;WUEi;intrinsic water use efficiency
摘要：
Ramie (Boehmeria nivea L) is one of the oldest and most important fiber crops in China due to the comfortable textile of its fine fiber. Increased ramie fiber demand brings ramie cultivation to salt-affected regions. The aim of this research was to determine morphological, physiological and biochemical responses of ramie by subjecting plants to varying concentrations of NaCl (0, 2, 4, 6 and 8 g NaCl/kg dry soil) at vigorous growth stage for 10 and 20 days. Results indicated that salinity stress substantially inhibited the growth of hybrid ramie plants and led to remarkable decline in fiber yield. However, when grown at 2 g NaCl/kg growth and fiber yield were similar to non-saline control. In addition, chlorophyll fluorescence and gas exchange parameters were correlated with growth and yield response. Salt treatments promoted a subsequent decrease in maximum quantum efficiency of PSII photochemistry (Fv/Fm), quantum efficiency of open PSII reaction centers (Fv'/Fm') and quantum yield of PSII ((phi PSII)) while non-photochemical quenching (NPQ) changed conversely. Photochemical quenching (qP) and electron transport rate of PSII (ETR) increased at 2 and 4 g NaCl/kg then decreased at 6 and 8 g NaCl/kg. Substantial decline in the PSII activity at high salinity was associated with the loss of chlorophyll contents. Moreover, marked decrease in net photosynthetic rate (A), transpiration rate (E), stomatal conductance (g(s)) was also recorded. Nonetheless, intercellular CO2 (Ci) decreased at low salt stress, subsequently increased at high salt stress while water use efficiency (WUE) and instantaneous water use efficiency (WUEi) altered in opposite direction. Substantial decrease of photosynthesis at high salinity was due to non-stomatal factors. Furthermore, salinity stress led to decrease of proteins and accumulation of proline and malondialdehyde (MDA), as well as enhanced activities of superoxide dismutase (SOD, EC 1.15.1.1) and peroxidase (POD, EC 1.11.1.6), whereas, catalase (CAT, EC 1.11.1.7) enhanced at low salinity, decreased at high salinity. Nonetheless, these changes were closely related with the severity and duration of the salinity stress and their interaction. The results suggested a certain tolerance to salinity stress for hybrid ramie. This meets the essential condition for utilization in salinity-prone environments. (C) 2014 Elsevier Masson SAS. All rights reserved.
通讯机构：
[Yan, Mingli] Hunan Univ Sci & Technol, Sch Life Sci, Xiangtan 411201, Hunan, Peoples R China.
关键词：
Microbial community;Molecular ecological networks;Heavy metal contamination;Microbial interactions
摘要：
Due to the persistence of metals in the ecosystem and their threat to all living organisms, effects of heavy metal on soil microbial communities were widely studied. However, little was known about the interactions among microorganisms in heavy metal-contaminated soils. In the present study, microbial communities in Non (CON), moderately (CL) and severely (CH) contaminated soils were investigated through high-throughput Illumina sequencing of 16s rRNA gene amplicons, and networks were constructed to show the interactions among microbes. Results showed that the microbial community composition was significantly, while the microbial diversity was not significantly affected by heavy metal contamination. Bacteria showed various response to heavy metals. Bacteria that positively correlated with Cd, e.g. Acidobacteria_Gp and Proteobacteria_thiobacillus, had more links between nodes and more positive interactions among microbes in CL- and CH-networks, while bacteria that negatively correlated with Cd, e.g. Longilinea, Gp2 and Gp4 had fewer network links and more negative interactions in CL and CH-networks. Unlike bacteria, members of the archaeal domain, i.e. phyla Crenarchaeota and Euryarchaeota, class Thermoprotei and order Thermoplasmatales showed only positive correlation with Cd and had more network interactions in CH-networks. The present study indicated that (i) the microbial community composition, as well as network interactions was shift to strengthen adaptability of microorganisms to heavy metal contamination, (ii) archaea were resistant to heavy metal contamination and may contribute to the adaption to heavy metals. It was proposed that the contribution might be achieved either by improving environment conditions or by cooperative interactions. (C) 2017 Elsevier Ltd. All rights reserved.
摘要：
No-tillage (NT) is an alternative cropping system for saving costs and conserving soils relative to conventional tillage (CT). However, NT effects on paddy soil and rice growth are still controversial or not fully understood. A fixed field experiment was conducted to compare soil and crop properties between NT and CT wet-seeded flooded super hybrid rice in Changsha, Hunan Province, China. After 6 years of continuous cropping, NT had higher contents of active organic carbon, NaOH hydrolysable N and NH4OAc extractable K and higher activities of invertase, urease and acid phosphatase at 0–5 cm soil depth, higher bulk density at 5–10 cm soil depth, and higher contents of double acid P at 5–10 cm and 10–20 cm soil depths. NT or associated soil compaction caused an adverse root environment for NT rice at early growth stage, which resulted in a lower capacity of photosynthetic carbon metabolism and consequent reductions in number of tillers and aboveground biomass accumulation before heading. However, no reductions were observed in total aboveground biomass and grain yield in NT rice, because the negative effects of NT or associated soil compaction on aboveground biomass production before heading were compensated for by its positive effects on aboveground biomass accumulation after heading. On one hand, the reduction in growth before heading of NT rice made its population density lower but more suitable during heading to 20 days after heading, which led to a more appropriate leaf area index, a lower leaf senescence and a consequent increase in net assimilation rate. On the other hand, N uptake was delayed in NT rice, which was another critical factor in determining its low leaf senescence. Our study suggests that the negative effects of NT or associated soil compaction on crop growth at early growth stage do not necessarily become concerns in NT wet-seeded flooded rice production.
摘要：
The study was undertaken to assess the genetic effect of quantitative trait loci (QTLs) conferring heat tolerance at flowering stage in rice. A population consisting of 279 F-2 individuals from the cross between 996, a heat tolerant cultivar and 4628, a heat-sensitive cultivar, was analyzed for their segregation pattern of the difference of seed set rate under optimal temperature condition and high temperature condition. The difference of seed set rate under optimal temperature condition and high temperature condition showed normal distribution, indicating the polygenic control over the trait. To identify main effect of QTL for heat tolerance, the parents were surveyed with 200 primer pairs of simple sequence repeats (SSR). The parental survey revealed 30% polymorphism between parents. In order to detect the main QTL association with heat tolerance, a strategy of combining the DNA pooling from selected segregants and genotyping was adopted. The association of putative markers identified based on DNA pooling from selected segregants was established by single marker analysis (SMA). The results of SMA revealed that SSR markers, RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively, accounted for 17 and 3% of the total variation respectively. The heat tolerance during flowering stage in rice was controlled by multiple gene. The SSR markers, RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively, accounted for 17 and 3% of the total variation respectively. The two genetic loci, especially for RM3735 on chromosome 4, can be used in marker-assistant-selected method in heat tolerance breeding in rice.
摘要：
Leaf-color is an effective marker to identify the hybridization of rice. Leaf-color related genes function in chloroplast development and the photosynthetic pigment biosynthesis of higher plants. The ygl7 (yellow-green leaf 7) is a mutant with spontaneous yellow-green leaf phenotype across the whole lifespan but with no change to its yield traits. We cloned gene Ygl7 (Os03g59640) which encodes a magnesium-chelatase ChlD protein. Expression of ygl7 turns green-leaves to yellow, whereas RNAi-mediated silence of Ygl7 causes a lethal phenotype of the transgenic plants. This indicates the importance of the gene for rice plant. On the other hand, it corroborates that ygl7 is a non-null mutants. The content of photosynthetic pigment is lower in Ygl7 than the wild type, but its light efficiency was comparatively high. All these results indicated that the mutational YGL7 protein does not cause a complete loss of original function but instead acts as a new protein performing a new function. This new function partially includes its preceding function and possesses an additional feature to promote photosynthesis. Chl1, Ygl98, and Ygl3 are three alleles of the OsChlD gene that have been documented previously. However, mutational sites of OsChlD mutant gene and their encoded protein products were different in the three mutants. The three mutants have suppressed grain output. In our experiment, plant materials of three mutants (ygl7, chl1, and ygl98) all exhibited mutational leaf-color during the whole growth period. This result was somewhat different from previous studies. We used ygl7 as female crossed with chl1 and ygl98, respectively. Both the F-1 and F-2 generation display yellow-green leaf phenotype with their chlorophyll and carotenoid content falling between the values of their parents. Moreover, we noted an important phenomenon: ygl7-NIL's leaf-color is yellow, not yellowy-green, and this is also true of all back-crossed offspring with ygl7.
关键词：
No-tillage and direct seeding;Super hybrid rice;Rice–oilseed rape cropping system;Yield formation;Economics
摘要：
No-tillage and direct seeding (NTDS) is an effective crop production method for reducing production costs and soil conservation. In order to understand performance of super hybrid rice under NTDS in rice-oilseed rape cropping system, a researcher-managed trail (2004-2010) and an on-farm research (2002-2005) were conducted to compare different tillage (conventional tillage or no-tillage) and rice establishment methods (transplanting or direct seeding) in super hybrid rice-oilseed rape cropping system. Under researcher-managed condition, grain yields of super hybrid rice under NTDS and conventional tillage and transplanting (CTTP) were equal. Compared with under CTTP, super hybrid rice under NTDS was characterized by more panicle number per m(2) but less spikelet number per panicle, and lower aboveground biomass production before heading but higher aboveground biomass accumulated during heading to maturity. Higher maximum tiller number per m(2) and lower spikelet production efficiency were responsible for the more panicle number per m(2) and less spikelet number per panicle under NTDS, respectively. Under farmer-managed condition, super hybrid rice under NTDS had more panicle number m(2) than under CTTP, which resulted in higher grain yield. Labor input under NTDS was lower than that under CTTP. Moreover, adoption of NTDS for super hybrid rice production had no significant impacts on seed yield and yield components of oilseed rape in rice-oilseed rape cropping system. Our study showed that MP could be replaced with NTDS to maintain yield and save labor for super hybrid rice production in rice-oilseed rape cropping system. Published by Elsevier B.V.
作者机构：
[Shu, W. S.; Lan, C. Y.; Zhou, M.; Ye, Z. H.; Yang, B.] Sun Yat Sen Zhongshan Univ, State Key Lab Biocontrol, Guangzhou 510275, Guangdong, Peoples R China.;[Shu, W. S.; Lan, C. Y.; Zhou, M.; Ye, Z. H.; Yang, B.] Sun Yat Sen Zhongshan Univ, Sch Life Sci, Guangzhou 510275, Guangdong, Peoples R China.;[Qiu, R. L.] Sun Yat Sen Zhongshan Univ, Sch Sci & Engn, Guangzhou 510275, Guangdong, Peoples R China.;[Qiu, R. L.] Sun Yat Sen Zhongshan Univ, Guangdong Prov Key Lab Environm Pollut Control &, Guangzhou 510275, Guangdong, Peoples R China.;[Jie, Y. C.] Chinese Acad Agr Sci, Inst Bast Fiber Crops, Changsha 410205, Hunan, Peoples R China.
通讯机构：
[Ye, Z. H.] Sun Yat Sen Zhongshan Univ, State Key Lab Biocontrol, Guangzhou 510275, Guangdong, Peoples R China.
期刊：
Archives of Virology,2009年154(8):1303-1312 ISSN：0304-8608
通讯作者：
Nie, Xianzhou
作者机构：
[Hu, Xinxi; Nie, Xianzhou] Agr & Agri Food Canada, Potato Res Ctr, Fredericton, NB E3B 4Z7, Canada.;[Hu, Xinxi; Xiao, Ya; Xiong, Xingyao; He, Changzheng] Hunan Agr Univ, Coll Hort & Landscape, Hunan Prov Engn Res Ctr Potatoes, Changsha 410128, Hunan, Peoples R China.;[Nie, Xianzhou] Agr & Agri Food Canada, Potato Res Ctr, 850 Lincoln Rd,POB 20280, Fredericton, NB E3B 4Z7, Canada.
通讯机构：
[Nie, Xianzhou] Agr & Agri Food Canada, Potato Res Ctr, 850 Lincoln Rd,POB 20280, Fredericton, NB E3B 4Z7, Canada.
摘要：
Although potato virus Y (PVY) is one of the most economically important pathogens of potatoes in China, few studies have been carried out to characterize the virus in that country. Using reverse transcription-polymerase chain reaction (RT-PCR)-based genotyping developed previously, two types of recombinant PVY were identified in China for the first time. One resembled the European (Eu) type of potato tuber necrosis strain (Eu-PVY(NTN)), possessing three widely recognized recombinant joints (RJs 1-3) of the common strain (PVY(O)) and the Eu- type tobacco veinal necrosis strain (Eu-PVY(N)). The other, on the other hand, appeared to have only RJ1 and RJ2. The complete genome of a representative isolate, PVY-HN2, from the second type was subsequently sequenced. Comparison of the sequence of 'HN2' with those of PVY(O) and Eu-PVY(N) not only confirmed the recombinant nature of 'HN2' but also revealed the existence of three recombinant events in the isolate, similar to that in PVY(NTN)-Hun. However, the two isolates differed significantly at RJ1 (PVY(NTN)-Hun vs. HN2, nt 2419 vs. nt 2521) and RJ3 (PVY(NTN)-Hun vs. HN2, nt 9183 vs. nt 8572) and slightly at RJ2 (PVY(NTN)-Hun vs. HN2, nt 5844 vs. nt 5867). A primer pair was developed to facilitate the detection of the alternative RJ3. Using the newly and previously designed RJ primers, all targeted RJs were detected. Interestingly, tests of the available PVY samples indicated that two were doubly infected with both types of recombinant PVY, further confirming the effectiveness of the detection. Further analysis of these samples using enzyme-linked immunosorbent assay and bioassay revealed that 'HN2' possesses a PVY(O) serotype, a PVY(N) pathotype in tobacco and a PVY(NTN) pathotype in potato.
期刊：
Agricultural Water Management,2016年170:20-25 ISSN：0378-3774
通讯作者：
Huang, Huang;Zhang, Canming
作者机构：
[Zheng, Huabin; Li, Jingyi; Huang, Huang] Hunan Agr Univ, Coll Agron, Changsha 410128, Hunan, Peoples R China.;[Zheng, Huabin; Li, Jingyi; Huang, Huang] Collaborat Innovat Ctr Grain & Oil Crop Southern, Changsha 410128, Hunan, Peoples R China.;[Zhang, Canming] Asia Europe Meeting ASEM Water Resources Res & De, Changsha 410013, Hunan, Peoples R China.
通讯机构：
[Huang, Huang] Hunan Agr Univ, Coll Agron, Changsha 410128, Hunan, Peoples R China.;[Zhang, Canming] Asia Europe Meeting ASEM Water Resources Res & De, Changsha 410013, Hunan, Peoples R China.
摘要：
As China requires more cultivated land to feed its increasing population, the sustainable development of cultivated land in its intensive agricultural production system has become a major issue for government and society. We firstly reviewed the progress of paddy-upland rotation (PUR) and conservation tillage, found that PUR was improve significantly soil properties, including redox potential of soil, the mineralization of soil organic matter, and the abundance of beneficial microorganisms, suggested that conservation tillage was an effective measurement for remedying the deficiency under the PUR. Meanwhile, we also systemically reviewed the statues of water resource infrastructure and policy level. Consequently, with current agriculture technology and the increasing capacity of adjusted artificial water resources, our results highlight the development of national-scale PUR as an effective adaptation strategy to protect and improve soil fertility and ensure agricultural security under climate change. In other words, from national strategy scale, national-scale PUR was a good choice in the major grain-producing areas of northern China in the coming 50-100 years. Lastly, further research in the few aspects was needed to better provide theoretical and technical support for promoting effectively the PUR. (C) 2016 Elsevier B.V. All rights reserved.
摘要：
Allotetraploid oilseed rape (Brassica napus L.) is an agriculturally important crop. Cultivation and breeding of B. napus by humans has resulted in numerous genetically diverse morphotypes with optimized agronomic traits and ecophysiological adaptation. To further understand the genetic basis of diversification and adaptation, we report a draft genome of an Asian semi-winter oilseed rape cultivar 'ZS11' and its comprehensive genomic comparison with the genomes of the winter-type cultivar 'Darmor-bzh' as well as two progenitors. The integrated BAC-to-BAC and whole-genome shotgun sequencing strategies were effective in the assembly of repetitive regions (especially young long terminal repeats) and resulted in a high-quality genome assembly of B. napus 'ZS11'. Within a short evolutionary period (similar to 6700years ago), semi-winter-type 'ZS11' and the winter-type 'Darmor-bzh' maintained highly genomic collinearity. Even so, certain genetic differences were also detected in two morphotypes. Relative to Darmor-bzh', both two subgenomes of 'ZS11' are closely related to its progenitors, and the 'ZS11' genome harbored several specific segmental homoeologous exchanges (HEs). Furthermore, the semi-winter-type 'ZS11' underwent potential genomic introgressions with B. rapa (A(r)). Some of these genetic differences were associated with key agronomic traits. A key gene of A03.FLC3 regulating vernalization-responsive flowering time in 'ZS11' was first experienced HE, and then underwent genomic introgression event with A(r), which potentially has led to genetic differences in controlling vernalization in the semi-winter types. Our observations improved our understanding of the genetic diversity of different B. napus morphotypes and the cultivation history of semi-winter oilseed rape in Asia. Significance Statement We generated a high-quality reference genome sequence of semi-winter Brassica napus. Our BAC-to-BAC strategy was effective in the assembly of repetitive regions. The main phenotypic difference between semi-winter and winter B. napus morphotypes is the vernalization requirement. Here, we found that a key gene controlling the vernalization-responsive flowering time was altered in the semi-winter type ZS11' through both homoeologous exchanges and genomic introgression with B. rapa.
摘要：
Traits such as grain shape, panicle length and seed shattering, play important roles in grain yield and harvest. In this study, the cloning and functional analysis of PANICLE TRAITS 2 (PT_2), a novel gene from the Indica rice Chuandali (CDL), is reported. PT_2 is synonymous with Growth-Regulating Factor 4 (OsGRF4), which encodes a growth-regulating factor that positively regulates grain shape and panicle length and negatively regulates seed shattering. Higher expression of OsGRF4 is correlated with larger grain, longer panicle and lower seed shattering. A unique OsGRF4 mutation, which occurs at the OsmiRNA396 target site of OsGRF4, seems to be associated with high levels of OsGRF4 expression, and results in phenotypic difference. Further research showed that OsGRF4 regulated two cytokinin dehydrogenase precursor genes (CKX5 and CKX1) resulting in increased cytokinin levels, which might affect the panicle traits. High storage capacity and moderate seed shattering of OsGRF4 may be useful in high-yield breeding and mechanized harvesting of rice. Our findings provide additional insight into the molecular basis of panicle growth.
摘要：
To introgress the good fiber quality and yield from Gossypium barbadense into a commercial Upland cotton variety, a high-density simple sequence repeat (SSR) genetic linkage map was developed from a BC_1F_1 population of Gossypium hirsutum×Gossypium barbadense. The map comprised 2,292 loci and covered 5115.16 centiMorgan (cM) of the cotton AD genome, with an average marker interval of 2.23 cM. Of the marker order for 1,577 common loci on this new map, 90.36% agrees well with the marker order on the D genome sequence genetic map. Compared with five published high-density SSR genetic maps, 53.14% of marker loci were newly discovered in this map. Twenty-six quantitative trait loci (QTLs) for lint percentage (LP) were identified on nine chromosomes. Nine stable or common QTLs could be used for marker-assisted selection. Fifty percent of the QTLs were from G. barbadense and increased LP by 1.07%-2.41%. These results indicated that the map could be used for screening chromosome substitution segments from G. barbadense in the Upland cotton background, identifying QTLs or genes from G. barbadense, and further developing the gene pyramiding effect for improving fiber yield and quality.
通讯机构：
[Liu, Shengyi] Chinese Acad Sci, Oil Crops Res Inst, Key Lab Biol & Genet Improvement Oil Crops, Minist Agr, Wuhan 430062, Hubei, Peoples R China.
关键词：
Brassica napus;Allopolyploid;Resequencing;Genotyping;GoldenGate;Non-synonymous SNP
摘要：
Single nucleotide polymorphisms (SNPs) are the most common type of genetic variation. Identification of large numbers of SNPs is helpful for genetic diversity analysis, map-based cloning, genome-wide association analyses and marker-assisted breeding. Recently, identifying genome-wide SNPs in allopolyploid Brassica napus (rapeseed, canola) by resequencing many accessions has become feasible, due to the availability of reference genomes of Brassica rapa (2n = AA) and Brassica oleracea (2n = CC), which are the progenitor species of B. napus (2n = AACC). Although many SNPs in B. napus have been released, the objective in the present study was to produce a larger, more informative set of SNPs for large-scale and efficient genotypic screening. Hence, short-read genome sequencing was conducted on ten elite B. napus accessions for SNP discovery. A subset of these SNPs was randomly selected for sequence validation and for genotyping efficiency testing using the Illumina GoldenGate assay. A total of 892,536 bi-allelic SNPs were discovered throughout the B. napus genome. A total of 36,458 putative amino acid variants were located in 13,552 protein-coding genes, which were predicted to have enriched binding and catalytic activity as a result. Using the GoldenGate genotyping platform, 94 of 96 SNPs sampled could effectively distinguish genotypes of 130 lines from two mapping populations, with an average call rate of 92%. Despite the polyploid nature of B. napus, nearly 900,000 simple SNPs were identified by whole genome resequencing. These SNPs were predicted to be effective in high-throughput genotyping assays (51% polymorphic SNPs, 92% average call rate using the GoldenGate assay, leading to an estimated >450 000 useful SNPs). Hence, the development of a much larger genotyping array of informative SNPs is feasible. SNPs identified in this study to cause non-synonymous amino acid substitutions can also be utilized to directly identify causal genes in association studies.
