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Alligatorweed (Alternanthera philoxeroides) has been recently investigated for its potential capability of phytoremediation of water eutrophication, especially for the accumulation of ammonium (NH4+) nutrient pollutes. However, molecular studies towards NH4+ uptake is largely unclear in this plant. In this study, we successfully isolated an NH4+ transporter cDNA, named ApAMT1;3, using degenerated primers and rapid amplification of cDNA end（RACE）techniques. Quantitative realtime PCR（qRTPCR）showed that ApAMT1;3 was majorly expressed in shoots, and the transcript levels were significantly enhanced in all tested organs, including roots, stems and leaves by NH4+ starvation of ApAMT1;3. Functional complementation of yeast mutant showed that ApAMT1;3 can mediate external NH4+ uptake. This study directly provide new gene resource to reveal NH4+ uptake and utilization of alligatorweed, and favorably help to investigate the mechanisms underlying NH4+ uptake and transport in aquatic plants.
The effects of the volatile oils from drunken horse grass infected (E+) and noninfected (E-) by Neotyphodium gansuense on germination and antioxidative enzyme activity involving superoxide dismutase (SOD) and peroxidase (POD) of perennial ryegrass (Lolium perenne) were determined. The germination experiment showed that the seed germination and POD activities of the perennial ryegrass under E- treatment were significantly (P0.05) higher than those under E+ treatment when the volatile oils concentration was greater than or equal to 300 mgmL-1. The inhibition effects increased with the concentration increase of volatile oils. However, the SOD activities of the perennial ryegrass under E- treatment were significantly (P0.05) lower than those under E+ treatment. In conclusion, endophyte infection can strengthen the allelopathic effect of the volatile oils.
Using photographic observation data of grassland phenology over the entire growing season and different satellite remote sensing data in Xilinguole of Inner Mongolia, we analyzed statistical relationships between the two datasets. The results showed that MODIS reflectance in visible light band positively correlated (P0.05) with the ground photographic digital number, in which the most significant correlation appeared between MODIS reflectance in 500 m spatial resolution and the ground photographic digital number. Nevertheless, TM/ETM+ reflectance did not significantly correlate (P0.05) with the ground photographic digital number. The positive correlation between MODIS Normalized Difference Vegetation Index (NDVI) and relative greenness index from ground photography (G%) was obviously higher than those between other vegetation indices and greenness indices. Errors between phenological occurrence dates derived from remote sensing and ground photography data were mostly within 7 days. In conclusion, the reliability of remote sensing phenology monitoring by means of ground photography was of crucial for selecting appropriate remote sensing data source and phenological monitoring index.
The monitoring of grassland vegetation based on remote sensing technology is an import branch and hotspot in regional vegetation change research. In order to precisely monitor grassland vegetation dynamic in Gannan, the present study monitors the dynamic change of Gannan grassland over 12 years from 2001 to 2012 and also uses the Perpendicular Vegetation Index (PVI) to explore its applicability and accuracy in grassland monitoring of Gannan. These studies will provide references for livestock production and ecological protection in Gannan pastoral area. The results show that the Dimidiate pixel model based on normalized difference vegetation index(NDVI) can more accurately simulate the vegetation coverage change with a precision of 88.14%. The vegetation coverage results show that the vegetation coverage is maximum at 76.63% in 2010 and minimum at 73.21% in 2002 during the studied period. There is very little interannual variation in vegetation coverage with a variation coefficient of 1.25%. The average grassland area in these 12 years accounts for about 85.47% of the total land area in Gannan with little interannual variation. The Exponential function of PVI can more accurately simulate aboveground biomass in Gannan pastoral area with a mean precision of the monitoring models at 70.48%.
Badlands are extremely developed due to gully erosion in Yuanmou dryhot valley of Jinsha River. Grass growth characteristics and soil moisture conditions in different slope positions of gully badlands were surveyed and analyzed. The results showed that there were significant differences (P0.05) for grass performance in different slope positions of gully badlands, especially, there were highly significant differences (P0.01) between the upper position and the middle or lower positions in the same slope. Both the grass coverage and aboveground biomass increased in the order of Upper Middle Lower. Under the same precipitation conditions, soil moisture in different slope positions declined in exponential trend with different rates over time which resulted in different soil water contents. The declined rates of soil moisture decreased in the order of Upper Middle Lower which brought different soil water contents in the reverse order in the same monitoring period. There were significant correlations between soil water content including average (P0.05) and final (P0.01) and grass coverage and aboveground biomass during the monitoring periods which indicated that the different soil water content under different slope positions were key factors to determine the grass growth in gully badlands.
According to the national standard of land use classification, based on the Landsat 8 OLI remote sensing data on July 23, 2013, combined with the ground observed data, digital elevation model, grassland resource type data and other auxiliary information, the visual interpretation signature of land use types were established in Anqu demonstration area in Hongyuan County of Sichuan Province. Regarding the results of the visual interpretation as the true values, we analyzed and compared the accuracy of unsupervised and supervised classifications and expert knowledge decision tree classification. The results show that, the supervised classification result has higher accuracy (85.02%) which is close to the actual situation comparing with other methods. The classification accuracy of the land use types of grassland, wetland, road and water, accounting for 99% of the entire study region, are 88.66%, 83.42%, 83.73% and 85.26%, respectively.
The spatialtemporal dynamic change of vegetation was monitored based on the modeled longterm Normalized Difference Vegetation Index (NDVI) data in Xinjiang. The results showed that vegetation increased overall in the last 32 years, while there was stages difference and spatial heterogeneity. The NDVI values in growing season were high in the west and northwest and low in the south and southeast. The area with increased NDVI values was much larger than the area with decreased NDVI values during the study period in Xinjiang. The values of NDVI in the cropland area significantly increased whereas the values of NDVI in the grassland area significantly decreased. The center of vegetation moved from north to south in the whole study area, moved from southwestnortheast in the north to the Tianshan mountain and moved from west to east in the south to the Tianshan mountain
Fluorescent protein labeled strains of rhizobia play an important role in the research about the progress of strain infecting plant and forming nodules, as well as determining strain competitive capability. In the present study, assistant bacteria strain Escherichia coli pRK2073, recipient bacteria strains Sinorhizobium meliloti 12531 and Rhizobium meliloti GN5, and donor bacteria strain E. coli pMP45179 which provided cyan fluorescent protein were transformed based on triparental hybridization technology. The genetic stability of fluorescence expression and nitrogen fixation of these successful transgenic strains were evaluated on Nfree and TY medium. Then, the preliminarily screened stains were inoculated to alfalfa cv. Gannong No.5 to study their effects. The results indicated that triparental hybridization method was feasible for construction of cfp labeled rhizobia stains which provided abundant cfp labeled strains of S. meliloti 12531 and R. meliloti GN5. The strains of S. meliloti 12531cfp6 and R. meliloti GNfcfp5 had the best genetic stability with more fluorescence expression and better nodulation effects. Nfree medium with antibiotics have higher screening efficiency than the current medium with antibiotics. The large variations existed among these labeled strains which suggested that it was necessary to confirm the genetic stability of fluorescence expression, Nfixation and the effects on growth for cfp labeled strains selection.
The yellow stunt and root rot of standing milkvetch disease caused by Embellisia astragali is one of the major factors in the pasture degradation. Calmodulin is significant protein in Ca2+ dependent signaling pathway. The present study was aimed to clone calmodulin gene from E. astragali genomic DNA. The homologous DNA fragment of 539 bp was amplified from genomic DNA with primers CAL228F and CAL737R. Then, the 5 flanking sequence of 344 bp and 3 flanking sequence of 729 bp were amplified using HiTAIL PCR. Finally, the 1 290 bp fulllength DNA sequence was assembled and 840 bp fulllength cDNA sequence was amplified with primers CaMF and CaMR. There were 4 introns in DNA fulllength sequence which had the typical characteristics of ATAG. The polypeptide with 149 amino acid was translated from cDNA sequence.
Pennisetum sp. is monocotyledon plant and widely planted in China and Africa as it can be used as forage and culture substrates of edible fungi. However, the lack of cold tolerance limits its popularization. Genetic technology or somatic hybridization has potential to improve the cold tolerance or quality of Pennisetum sp. which require the establishment of Pennisetum sp. tissue culture system. In the present stydy, the effects of different disinfection ways and different growth hormone such as 2,4D, IAA, NAA and cytokinins (6BA and KT) on callus induction were studied using caulicle of Pennisetum sp. as explants. The results showed that the ideal disinfection method was soaking in 2% sodium hypochlorite solution for 10 min after wiping stripping leaf sheath with 75% alcohol. All of the medium with the different concentrations of 2,4D ranged from 1.0 mgL-1 to 4.0 mgL-1 can induce callus without significant difference. The medium with 0.2 mgL-1 IAA can induce more callus. The medium with different cytokinins can not induce more callus. Based on these observation, the optimal callus induction medium of Pennisetum sp. was MS + 2,4D (3.0 mgL-1) + IAA (0.2 mgL-1).
In order to determine the effects of polyethylene glycol (PEG) priming on the germination and seedlings growth of ultradried oat seeds, the present study measured the indices including germination percentage, lengths of roots and shoots, weights of roots and shoots of ultradried (4% moisture content) oat (Avena sativa) seeds which were accelerated ageing for 48 d at 45 ℃ and primed with different concentrations of polyethylene glycol (PEG) solutions (0, -0.3, -0.6, -0.9 and -1.2 MPa) for 0, 3, 6 and 12 h. The results showed that the germination percentage of aged oat seeds significantly decreased (P0.05) after priming at high osmotic potential of PEG (0 and -0.3 MPa) whereas significantly increased (P0.05) after priming at low osmotic potential (-0.9 and -1.2 MPa). The length of roots increased significantly (P0.05) but the length of shoots, and the fresh weights of roots and shoots significantly decreased (P0.05) after PEG priming. These results indicated that the effects of PEG priming on the germination and seedlings growth of ultradried oat seeds were closely related with its osmotic potential, priming time and their interactions which suggests the further research about how to prime ultradried oat seeds after ageing with PEG in agricultural production need to be conducted.
The superior tetraploid hybrid wheatgrass variety SZB02 was selected from colchicine induced chromosome doubling F1 hybrids after widely crossing of Agropyron cristatum cv. Fairway and Agropyron mongolicum. And then, the new variety of tetraploid hybrid wheatgrassMengza No.1 was obtained after a series of tests including varieties comparison, regional and production which lasted 13 years. Mengza No.1 is a perennial gramineous herb with fibrous root system, regular plant growth, lanceolate leaf length, and wide panicle type. The fresh grass yield, dry grass yield and seed yield of Mengza No.1 with twice mowing per year was 25 938.35 kghm-2, 9 552.33 kghm-2 and 802.37 kghm-2, respectively, which suggest that this variety has relatively high grass yield. Mengza No.1 has crude protein content of 16.13 % in anthesis, and is rich in nutritional composition such as crude fat, nitrogen free extract, calcium and phosphorus. It also has characteristics of soft texture, high leaf yield and good palatability which can be used for green fodder, graze and hay. It has strong resistance to low temperature in earlier development stage and wide ecological adaptability, which is suitable to be applied in the areas with the effective accumulated temperature more than 2 200 ℃d (10 ℃).
Using the chlorophyll fluorescence kinetics, the effects of application of chemical fertilizer and organic fertilizer on photoinhibition of PSⅡ at photosynthetic noonbreak in mulberry leaves grew in salinesodic soils were investigated. The results showed that maximal photochemical efficiency of PSⅡ (Fv/Fm) and photosynthetic performance index (PIABS) based on light absorption were only 0.69 and 0.19, respectively. Meanwhile, photoinhibition was significant in leaves of mulberry in salt and alkali soil at photosynthetic noonbreak. Both chemical fertilizer and organic fertilizer increased the Fv/Fm and PIABS although organic fertilizer were superior than chemical fertilizer. With standardization of OJIP curve, the electronic transmission ability of QA to QB in PSⅡelectronic receptor side increased at photosynthetic noonbreak. The application of chemical fertilizer and organic fertilizer alleviated photo inhibition of PSⅡ photosynthetic noonbreak by increasing electronaccepting ability of QB and PQ electronic library, especially, organic fertilizer application also increased electronaccepting ability of QB and decreased QA- accumulation. The application of chemical fertilizer and organic fertilizer increased the activities of oxygen evolution complex (OEC) in PSⅡelectronic receptor side to maintain the normal water cracking function and supply of photosynthetic electron. In addition, the application of chemical fertilizer and organic fertilizer also decreased the dissociation degree of chloroplast thylakoid and increased its adhesion of PSⅡprotein complex to maintain photochemical activity of PSⅡ. The relieve of photo inhibition of PSⅡphotosynthetic noonbreak of organic fertilizer was better than that of chemical fertilizer because the electronic transmission in PSⅡelectronic receptor, while there was few difference between two fertilizers on the condition of OEC and thylakoid membrane.
In order to study the relationship between hydrothermal conditions and forage yield, correlation analysis and multiple regression analysis of precipitation, temperature and forage yield were conducted in 12 major pastoral counties in northwestern Sichuan during the period 2006-2013. The results showed that the monthly dry forage yield was significantly positive correlated with the precipitation for each period except with the period of March-May. The positive correlation decreased in the following order: June-September（=0.192,P0.05）, June-August（=0.187,P0.1）, March-September（=0.171,P0.1）. In March-May, temperatures significantly affected forage yield whereas precipitation did not significantly affect forage yield. The monthly dry forage yield increased 17.1 kgha-1 if precipitation increased 1 mm in JuneSeptember and increased 585.1 kgha-1 if temperature increased 1 ℃ in MarchMay.
The WOX transcription factor family is unique to plant, which contains a short stretch of amino acids (65 residues) that folds into a DNAbinding homeodomain. The phylogenetic tree of the plant WOX proteins can be categorized into three clades, including WUS, intermediate and ancient clade. The ancient clade represents the oldest clade which suggests the WOX family may originate from green algae. The analysis of WOX gene expression and function shows that WOX family plays important roles in plant development, such as embryonic patterning, stemcell maintenance and lateral organ development. These functions are related to the promotion of cell division activity and/or prevention of premature cell differentiation. The present paper reviews the recent progresses of the WOX family, which would be beneficial for future studies about plant development and stress response. Moreover, the function of WOX protein in regulating plant leaf morphogenesis can be implicated for crop's biomass improving breeding.
Agrobacterium rhizogenes induces the neoplastic growth of plant cells that differentiate to form hairy roots. Hairy roots are characterized with a high growth rate and genetic stability which are widely used as a transgenic tool for the production of secondary metabolites, detoxification of environmental pollutants and breeding of crop species. In the present paper, the induction of hairy roots by A. rhizogenes and the recent development of the plant hairy roots application were reviewed. Meanwhile, the associated potential problems and future development prospects were also discussed. These reviews will provide references for the application of hairy roots in the field of pratacultural science.
Tissuespecific promoters can regulate excellent gene expression in certain organs or tissues, with some structural elements relevant to genespecific expression. Many researches indicated that tissuespecific promoters play critical roles in regulating plant growth and development processes and improving plant resistance to biotic and abiotic stresses. In the present paper, the latest research advances on structural features and regulating functions of tissuespecific promoters were reviewed and the research direction regarding tissuespecific promoters were also prospected.
Activities of plateau pika(Ochotona curzoniae) affects reproductive characteristics of different plant in alpine meadow communities by excavating and feeding. A field survey was conducted to determine the effects of disturbance of plateau pika on reproductive characteristic of Gentiana dahurica. The present study showed that aboveground biomass, plant height, stemleaf ratio, number of reproductive shoot, number of vegetative shoot, number of inflorescence, inflorescence biomass and seed yield per plant all increased with the increase of disturbance levels of plateau pika. When the disturbance levels wereⅠ(11232) holeha-1 andⅡ（19248）holeha-1, more assimilate substances in G. dahurica have allocated in the leaves to guarantee the survive of the populations. When the disturbance levels were Ⅲ （35264）holeha-1 and Ⅳ （60848）holeha-1, more assimilate substances in G. dahurica have allocated in the reproductive organ to form more reproductive shoots, inflorescences and seed yield per plant. In conclusion, the excessive disturbance of plateau pika decreased grazing quality in alpine meadow by improving reproductive growth of G. dahurica.
By visual observing, qudrat measuring and food analyzing before and after foraging, the food niche differentiation between livestock (yak and Tibetan sheep) and rodents (plateau pika and plateau zokor) was investigated in Gannan alpine meadow. The results showed that food spectrum of rodents and domestic animals were different. Tibetan sheep and yaks mainly feed grasses and sedges, however, pika had broad food spectrum and zokor mainly feed the plants with taproots, rhizome, bulbs and earthnut. The food niche width, species diversity and evenness of livestock were significantly higher than those of rodents. The overlap of food niche between Tibetan sheep and yak was the highest, that between pika and tibetan sheep followed and that between zokor and Tibetan sheep was lowest. These results indicated that the food niche differentiation between rodents and livestock was larger because of the limited adverse effects of food competition on livestock.
The present study was designed to investigate the effects of alfalfa meal addition on production performance and meat quality of finishing pigs. One hundred and sixty healthy Duroc Landrace Big finishing pigs with similar parity and body weight around 60 kg, half male and half female were selected. There were totally 5 treatments including the control group without alfalfa and the treatments with 5%, 10%, 15% and 20% of alfalfa meal. Each treatment had 4 replicates with 8 pigs per replication. Experiment was designed using completely randomized with single factor. The results showed that 10% alfalfa meal significantly (P0.05) increased the final weight of the pigs, and 10% and 15% alfalfa meal also significantly (P0.05) increased the average daily gain of the pigs and significantly (P0.05) reduced the feed conversion ratio of the pigs. The meals with 10%, 15% and 20% alfalfa significantly (P0.05) increased the pork loin area of the pigs. The meals with 5%, 10% and 15% alfalfa significantly (P0.05) increased the intramuscluar fat. However, there was no significant effects of alfalfa meal on the pork pH, water rate index and cooked rate. These results suggested that the alfalfa meal diets can improve the performance and meat quality of finishing pigs and the 10% alfalfa meal was optimal.
Plateau pika (Ochotona curzoniae) and plateall zokor (Myospalax baileyi) are the important members of the ecosystem and have significant effects on energy cycles in alpine meadow. The present paper analysis the benefits and harms of these two rodents on pasture grassland, plant community and soil and their response to these variations on grasslands which will improve the understanding on rodents. The key issue of conversion of rodents activities from harms to benefits is to determine the population density associated with disaster and the number and grazing method of livestock in alpine meadow ecosystem.
No.1 document for 2015 of central government explicitly proposed accelerating development of grasslands and animal husbandry. The development of grasslands and animal husbandry is an important content of agricultural structure adjustment, is the important component of transformation and development of agricultural modernization, also is an important guarantee of quality and safety of grassland and livestock products and ecological security. The concept of grasslands and animal husbandry was innovative elucidated in this paper, and proposed that the concept of grasslands and animal husbandry is industry coupling relationship of three in one with grassland, herbivorous animal husbandry and extended industry, based on grasslands basic industries theory, ecological animal byproducts supplydemand equilibrium theory, industrial technology and product quality upgrading to stimulate economic growth theory, industrial convergence and coupling theory, innovationdriven development theory, further interpreted grasslands and animal husbandry is a new kind of composite industries with integrated multiindustry, its development mainly on the theory of ecological economics and development economics. The developing of grasslands and animal husbandry in grassland areas, half agriculturehalf herding areas and farming and pastoral areas in China exist different bottleneck problems, the paper put forward the related breakthrough key technology and the optimization model, clarified key points on scientific and technological support of grasslands and animal husbandry at different regions, which will provide theoretical basis and technological support for accelerated the health sustainable development of grasslands and animal husbandry.
The present paper analyzes the importance and problems of the grassland ecosystem in karst area of Southwest China. The problems included soil erosion, water loss, poor soil, rocky desertification, reduced biodiversity and the unreasonable utilization which should be resolved by different methods such as increasing areas of artificial grassland, improving the public's awareness of environmental protection, adjusting rural industrial structure, conserving soil and water, preventing and controlling rocky desertification, establishing and improving the monitoring and evaluation system. Hopefully, these analysis could provide reference for the health, stable and sustainable development of grassland ecosystem in karst area.
In the present project, the qualities of the ground water in the nearby of the golf course located in Dongshan district in Haikou used for nearly 18 years were analyzed using different methods including experimental method, comparative analysis and single factor pollution index. The results showed that the color degree, turbidity, residual chlorine, total phosphorus and concentration of heavy metals of the sampled water from golf course were higher than the corresponding index of farmland ditches water from same composition during dry season. The contents of phosphorus, mercury, chromium and COD(Chemical Oxygen Demand) of water from the lake in golf course exceeded the standards of the national ground water quality class Ⅲ. The turf and the internal artificial lake in golf course can effectively prevent infiltration of rainwater and irrigation water into the perimeter of the stadium. The concentrations of residual chlorine, nitrite nitrogen, ammonia nitrogen and total phosphorus in the water from reservoir on the west side of the stadium decreased in the following order: upstreammidstreamdownstream. Except with the mercury content in the water from the upstream of the reservoir, the heavy metal contents in the water from other research areas were higher than the background level. The concentrations of COD and total phosphorus in water from upstream, total phosphorus and lead in water from midstream and all indices in water from downstream met the standards of the national ground water quality class Ⅱ. The pesticide residue of inner and outer water of the stadium did not exceed the standard level.