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In the present study,high temperature treatments (60, 70 and 75 ℃) was employed to construct Epichloё-free populations of Elymus dahuricus. The results indicated that high temperature treatments can kill Epichloё endophyte in the seeds. After 75 ℃ for 20 days treatment,the Epichloё endophyte infected rates significantly dropped from 93.17% to 0% (P<0.01), and the germination rate,germinating potential, germination index, vital index and seeding fresh weight of E. dahuricus increased by 36.37%, 73.94%, 50.38%, 63.38% and 7.79%, respectively(P<0.05). Meanwhile, high temperature improved hypocotyls and radical growth and the hypocotyls and radical length of the treated seedlings increased by 0.54% and 14.43%. Therefore, high temperature of 75 ℃ treatment was an effective way to construct Epichloё-free populations of E. dahuricus which provided some academic bases and references for establishing Epichloё-free populations of grass.
Biological and physiological characteristics of endophyte Epichloë bromicola strain WBE1 isolated from wild barley seeds were measured in a range of temperatures, pH, light, carbon source, nitrogen source and growth rate values. WBE1 was able to grow at temperate from 10 ℃ to 30 ℃ with the optimal temperature of 22~25 ℃ and stop growing at 4 ℃ and 35 ℃. The optimal pH for mycelial growth ranged 5.09 to 6.1. The ability of carbon source utilization decreased in the following order: maltose > D-sorbose > mannose > sucrose > lactose > starch > glucose. However, D-xylose inhibited the mycelial growth. The ability of nitrogen source utilization decreased in the following order: casein tryptone > beef extract > peptone > yeast > L-methionine > L-phenylalanine > leucine. However, potassium nitrate, praline and ammonium oxalate cannot be utilized by WBE1 and ammonium molybdate inhibited mycelial growth. Potato dextrose agar (PDA), oat meal agar (OMA), corn meal agar (CMA) and potato sugar agar (PSA) were optimal medium for WBE1. The mycelial growth rate on PDA reached maximum at the sixth week, then decreased gradually afterwards.
Lily bulb dormancy was broken during low temperature storage, Fluorescent difference gel electrophoresis, MALDI-TOF/TOF and bioinformatic technology were used in the experiment. A total of 31 differentially expressed proteins were separated by using fluorescent difference gel electrophoresis. Among these proteins, there were 15 proteins up-regulated and 16 proteins down-regulated in the dormancy breaking bulbs. These proteins were classified into 6 categories by function. Comprehensive analysis showed that these proteins were mainly stress protein,they may involved in metabolic process of the bulbs, and regulate the bulb dormancy breaking. According to the expression differences of the proteins in dormant and dormancy breaking bulbs, several proteins identified might be related to the process of bulb dormanc.Stress proteins had high expression in dormant bulbs, and proteolytic enzymes had high expression in dormancy breaking bulbs. This research had set the stage for further understanding of the bulb dormancy mechanisms in lily.
With the speeding up of humans activity and industrialization process, heavy metal pollution has caused serious harm to the environment. In the present study, the methylation-sensitive amplified polymorphism (MSAP) technique was employed to analyze the DNA methylation in Tagetes patula under different concentrations of cadmium(Cd) in pots experiment. The results showed that the genomic MSAP rate of T. patula was 24%, 30%, 35% and 41%, and the total methylation rate of T. patula was 20%, 23%, 25% and 27%, respectively, when treated with the different concetrations of Cd2+(0, 50, 250, 500 mgkg-1). The results indicated that the total methylation level of DNA increased with the increase of Cd2+ concentration. Moreover, in regards of the change pattern of DNA methylation, the denove methylation rates were 10%, 10% and 11%, respectively, under stress of 50, 250 and 500 mgkg-1 Cd2+, which indicated that the denove methylation was the main methylation pattern. In summay, the current study provides a theoretical reference for revealing the variation trend of heavy metal stress on plant DNA methylation and the mechanism of plant tolerance to heavy metal stress.
The effect of 20 d drought stress and rewatering on seedling morphological and physiological characteristics of Lysimachia davurica were studied. The results showed that growth and development of L. davurica were gradually inhibited as drought stress extended. The growth of above ground part of seedling was depressed first when drought stress lasted for less than 10 days and soil moisture content was higher than 14.52%. The leaf area and relative water content were reduced, while chlorophyll content, MDA content, soluble sugar, proline, POD and CAT activities of seedling were increased. The plant could quickly restored growth except the shoot tip when rewatering at this time. When drought stress lasted for 15 days, the seedling severely lost water and the upper part of the seedlings shriveled. 66.66% new sprout grew after rewatering. L. davurica would be dying and could not be revived after rewatering if drought stress lasted for 20 days. Therefore, L. davurica should be rewatered timely to rescue seedling when the drought stress was more than 10 days and the soil moisture content was less than 14.52%.
In order to establish the high efficient alfalfa-rhizobia symbiotia with competitive ability and genetic stability in saline soil, germination, rhizobia salt tolerance and inoculation experiments were conducted using 12 alfalfa cultivars. The results indicated that the seed salt tolerance varied greatly among cultivars. The highest of seed salt tolerant survival percent was Zhongmu No.1 and second highest of that was Xinjiangdaye and Gannong No.7 although there was no significant difference between these three research group. The highest of rhizobia salt tolerant was Ganonng.1 with the rich strains number of 2.49×106 . Zhongmu.1. of Xinjiangdaye symbiotic with rhizobia isolated from zhongmu.1 had highest salt resistance and nitrogenase activity of rhizobia and the highest efficiency with the highest aboveground biomass, stem and leaf crude protein content and nitrogenase activity.
In order to fully understand the distribution characteristics and geographical elements of fern flora and reveal their process of natural history in the Gansu Province grassland, the present study investigated the fern in this area and analysis the floristic composition and geographical distribution. The results show that there are 31 species which belong to 19 genera and 14 famlies in Gansu rangeland which accounts for 22.22% of the total family, 8.26% of the total genus, 1.99% of the total species of China ferns resources (63 families 230 genera and 2 600 species) , respectively. The dominant families are Dryopteridceae and Polypodiaceae; dominant genera are Selaginella and Woodsia. The family is mainly tropical distribution type and the genus is mainly tropical and temperate distribution without endemic genus. Vertical distribution is obvious containing old families and genera. The richness of fern in Gansu grassland is not high.
DNA barcoding is an emerging technology, which is used as a tool to indentify species accurately and quickly using the conservative DNA segments. Our research has established and optimized target fragments’ the amplification conditions for eleven samples (Sorghum bicolor×Sorghum sudanense, Zea mays, Stipa capillata, Lolium perenne ‘Plxie’, Lolium perenne ‘Caddieshack’, Festuca kansuensis, Festuca rubra ‘Bargena’, F. rubra ‘Maxima’, Poa pratensis ‘Barvictor’, P. pratensis ‘Diamond’, Achnatherum splendens) from seven major genera (Sorghum, Zea, Stipa, Lolium, Festuca, Poa, Achnatherum) and eight species according to nucleotide sequence of grass matK and rbcL genes in GenBank, and designed four universal primers. 5' end and 3' end conservative fragments in four marked fragments were selected by amplification products sequencing and analyzing. Single nucleotide polymorphism (SNP) haplotype analysis of conservative fragments nucleotide sequences of each maker loci showed there were 6 haplotypes(H1A, H1B, H1C, H1D, H1E and H1F), 7 haplotypes (H2A, H2B, H2C, H2D, H2E, H2F and H2G) and 3 (H3A, H3B and H3C) haplotypes among matK1, matK2, matK3 respectively, by the same token, rbcL gene has 5 haplotypes (H4A, H4B, H4C, H4D and H4E). According to the haplotypes about matK (matK1, matK2 and matK3) and rbcL, we have constructed the DNA barcoding for eight grass species. The research results provide a scientific basis for identification of mixed feed grasses including eight species of the seven generas.
The present study investigated the chromosome number and karyotype of Pennisetum purpureum×P. americanum cv. Reyan No.4 and P. purpureum cv. Gui minyin using the conventional compression method to provide theory basis of Pennisetum germplasm resources diversity protection and genetic breeding research. The results showed that their basic chromosome number was 7. Reyan No.4 was triploid and the chromosome number was 21, the karyotype formula was 2n=3x=21=21m (3SAT), the formula of chromosome relative length was I.R.L=9S+3M1+3M2+6L, three of chromosomes have trabant. Gui minyin was tetraploid and the chromosome number was 28, the karyotype formula was 2n=4x=28=18m (2SAT) +10sm (2SAT), the formula of chromosome relative length was I.R.L=10S+6M1+4M2+8L, four of chromosomes have trabant. For Reyan No.4 and Gui minyin, index of the karyotypic asymmetry was 60.15% and 62.19%, the karyotype was 1B type and 1C type, respectively. The results indicated that their karyotype belong to primitive types .
Based on 23 morphological traits and SSR markers, three cultivars (Chuancao No. 2, Aba and Kangba) and a new strain (Yajiang) of Elymus sibiricus widely utilized in Northwest Plateau of Sichuan were identified. There was obvious difference among varieties at phenotypic traits and genetic background. Morphological traits were measured, includingplant height, leaf length, leaf width, Culm diameter and so on, the new strain ‘Yajiang’ had betterperformance in major agronomictraits than that of other three varieties (P<0.05). Furthermore, 13 screened pairs of SSR primerwere amplified in four cultivars (strains) and generated 90 bands, of which 68 bands were polymorphic. According to the mean of percentage of polymorphic bands (PPB=76.32%), polymorphism information content (PIC=0.309) and Shannon diversity index (H=0.451), four cultivars (strains) presented high polymorphism. A positive correlation (r=0.696, P=0.08) existed between Euclidean distance and Dice genetic distance, indicating that the combination of morphological traits and genetic markers could be used for cultivar identification. Two UPGMA dendrogram based on morphological and SSR data were similar and there were differences among all cultivars (strains) for phenotypic and genetic background. Furthermore, four pairs of primers (Elw0669s043, Xgwm190, WMS169 and Xgwm311) were selected for DNA fingerprinting construction and cultivar identification. In general, the present study demonstrated that the new strain ‘Yajiang’ was significantly different from other three E. sibiricus cultivars, and provided important data for genetic relationship analysis and intellectual property rights protection for cultivars in the Northwest Plateau of Sichuan.
Germination and seedling growth of Medicago sativa seeds primed with H2O, PEG-6000(-0.6 MPa), KNO3 (2%), GA3 (100 mol·L-1) and CaCl2 (2%) were determined under different temperature, salt and water stress. The results showed that: 1) All priming treatments significantly increased germination percentage at low water potential but not under the other conditions except for a significant increase at severe salt stress condition by KNO3 priming. 2) Priming significantly decreased the average germination time except for at 10 and 15 ℃ after CaCl2 priming, or at high salt stress after PEG priming. 3) Effects of priming on seedling radicle and shoot growth varied with priming treatments, varieties and test conditions. For example, hydropriming significantly increased radicle growth at 10 ℃, but showed no effect under the other conditions. Hydropriming significantly increased shoot growth at 10 ℃ or under severe salt stress condition. In addition to hydropriming, all priming treatment significantly promoted alfalfa shoot growth under low water potential, among which KNO3 priming exhibited the optimal effect.
The aim of this study was to investigate the effect of spermidine (Spd) on seed germination and seedling drought resistance of Trifolium repens cv. Ladino under osmotic stress induced by different concentration of polyethylene glycol 6000 (PEG-26000). The results showed that 20 μmol·L-1 Spd soaking significantly enhanced seed germination percentage and germination index under 10% and 15% PEG solution, and increased radicle length and seedling fresh weight under 15% PEG solution, whereas had no effect on dry weight. Meanwhile, when exposed to 20% PEG, seedlings treated with 20 μmol·L-1 Spd showed a higher antioxidant enzymes activities including SOD, POD, CAT and APX, and leaf RWC, and decreased the electrolyte leakage and MDA content compared to control. In conclusion, these results indicated that Spd can effectively promote the ability of seed germination and environmental adaptability of whiter clover seedlings under osmotic stress, protect the structure of cell membrane, and alleviate the oxidative damage induced by osmotic stress resulting in the improved drought tolerance of white clover.
The seed germination percentage, germination index, radical length and seedling length of Lespedeza davurica cv. Longdong, L. hedysaroides cv. Keerqin and L. potanimii were measured under treatments with temperature, PEG and NaCl stress. The results showed that 20/30 ℃ was the most suitable temperature for the three Lespedeza species. PEG stress had great influence on seed germination index and seedling length. L. davurica cv. Longdong and L. potanimii had the better performance under drought tolerance stress. The germination index, radical length and seedling length of these three species seeds significantly decreasing under NaCl stress treatment. L. potanimii showed the best performance under NaCl stress treatment. L. potanimii Vass. was selected as the best accession with drought and salt stress tolerance by comprehensive evaluation, which will provide the insight for germplasm cultivation and genetic breeding for new varieties.
This study determined the allelopathy effects of Achnatherum inebrians growing in Tianshan Mountains at the returning green stage on seed germination of Onobrychis viciaefolia, Medicago sativa, Bromus inermis and A. inebrians by treating seeds with the aqueous extract of different parts of A. inebrians with four concentrations (0.2,0.1,0.05,0.025 g·mL-1). The results showed that the aqueous extract of A. inebrians had inhibitory effects on germination of four species, and the allelopathic sensitivity of four species ranked as: A. inebrians > B. inermis> O. viciaefolia> M. Sativa. Leaf showed a stronger allelopathy effect than root. Germination of M. sativa increased and then decreased as aqueous extract concentration increasing, whereas germination of B. inermis, O. viciaefolia and A. inebrians decreased to some extent at all testing concentration. Thus, M. sativa is recommended to use for restoring degraded grassland infested by A. inebrians.
In this study, seeds of caper (Capparis spinosa) separated from feces of Turpan wonder gecko (Teratoscincus roborowskii) were used as the treatment groups, and seeds separated from fresh fruit were used as the control groups. The treatment and control groups were both precooled at 4 ℃ for 60 days and then transferred to germination experiment in a constant temperature of 25 ℃ incubator for 30 days. The effects of passage through Turpan wonder gecko digestive tracts on caper seed’s water uptake ability and germination were determined. The results showed that seed through the digestive tract of Turpan wonder gecko had significant impacts (P<0.05) on water uptake ability and germination, the digestive function promoted the seed’s fast water uptake ability and improved seed germination percentage, but did not affect (P>0.05) germination rate and viability of caper seed.
Desert region salinization is being accelerated because of climate change and anthropogenic disturbance, resulting in major ecological problems. Studying the leaf traits response of desert species to salt stress is of great importance to understand its adaptation to salinization. A pot experiment were applied to study the effect of different salt concentrations (50, 100, 200, 400 mmol·L-1) on leaf traits of Alhagi sparsifolia in the first growing season. The results showed that: (1) Salt stress reduces the photosynthetic capacity of A. sparsifolia, the net photosynthetic rate and transpiration rate were significantly decreased, while water use efficiency is on the rise as salt stress increasing. The fluorescence parameters of Fv/F0 and Fv/Fm in the salt treatment were lower than the control. (2) With the increase of salt stress, the specific leaf area of A. sparsifolia gradually reduced, the leaf dry matter content reduced first and then increased, and all of them were lower than the control. (3) With the increase of salt stress, Nmass and Narea in leaves declined first and then ascended, and reduced again. Pmass decreased first and then increased. However, Parea showed less change first and increased later. These results showed that the A. sparsifolia could adapt to saline environment morphologically and physiologically.
In order to utilize Lotus corniculatus germplasm resources effectively for breeding, nine agronomictraits of 69 L. corniculatus germplasm resources introduced from Russia were evaluated and classified based on investigation results in field and indoor. The results showed the characteristics of 69 materials had obviously difference and varioustypes. The variation coefficient of the fresh weight per plant was the maximal(57.58%); While the growth period had the minimum variation coefficient of 6.92%. The nine agronomic characters were composed of 3 independent principal components, including grass yield factor, growth period (mature) factor, and thousand seed weight factor. The cumulative contribution of the 3 factors was 87.47%. Through cluster analysis based on the 3 principal components, the 69 Russian L. corniculatus germplasm resources in the present study were divided into 3 groups. Materialsin the first group had the trait of latematuring, half stolon and middle production; The second group was the precocious, procumbent and loweryield materials. The third groups belonged to middle maturity, upright and highyielding materials, and the third group had the best agronomic traits in the comprehensive yield.
In this study the test materials (HY2) from seed cultivation SP1 generations were used. By comparing with the agronomic characters of ‘Hangmu 1’ planting material on the earth, the mutagenic effects of alfalfa cultivar ‘Hangmu 1’ by re-onboard in space were studied. The preliminary results indicated that the average of plant height, branch number and multifoliate ratio were significantly higher than the control, ‘Hangmu 1’ by re-onboard in space showed strong growth vigor(P<0.05). The multifoliate plants were less than the control, the number of 7 leaflets plants significantly increased (P<0.05)and five plants had 7 leaflets ratio more than 60%. 5 leaflets plants were less than the control and 5 leaflets plants possessing 5 leaflets ratiomore than 60% significantly increased(P<0.05). The mutagenic effects were obvious and useful variation was rich. The research would provide an effective breeding approach and the excellent germplasm resources to the further improvement of alfalfa cultivar.
To select suitable perennial forages cultivating in alpine region of Diqing, the introduction adaptability of 12 perennial forage grasses was studied in this research, and the grey correlative degree analysis was used to evaluate the production performance of these 12 perennial forage grasses. The results showed that the order of production performance of 12 perennial forage grasses was Medicago sativa cv. Amerigraze401+Z > Cichorium intybus cv. Commander > Dactylis glomerata cv. Anmba > Lolium perenne cv.Yatsyn > Trifolium repens cv.Prop > Trifolium pratense > T. repens cv. Haifa > M. sativa cv. Eureka > M. sativa cv. WL-525 > Bromus willdenowii cv. Grasslands Matua > M. sativa cv. Hunterriver >Elymus sibiricus cv. Tongde. The production and adaptability of M. sativa cv.Amerigraze401+Z, Cichorium intybus cv. Commander, D. glomerata cv. Anmba, L. perenne cv. Yatsyn, T. repens cv. Prop, T. pretense and T. repens cv.Haifa were relatively better, which were preferred varieties used in establishing artificial grassland and modifying natural grassland in Diqing area. The results of this research play an important role in solving the forage shortage and promoting the sustainable development of local grassland animal husbandry.
The low temperature time is long in the northern part of Heilongjiang Province, and the land salinization in the western region is serious, which are two main factors that restrict the development of local agriculture and animal husbandry. In order to obtain forage adapting to the climate in Heilongjiang province and soil types, weevaluated agronomic characters and nutritional value for the new Rumex species “Щавель Чемпион” imported from Russia in five representative planting plotsrepresenting different accumulated temperature zone in Heilongjiang province such as Acheng, Zhaozhou, Xunke, Nenjiang and huma. The results showed that the growth status of the species in Zhaozhou was significantly lower than other regions, while it grownbetterin Nenjiang than other regions. The biomass was more than 150t/hm2 in Acheng, Xunke, Nenjiang, but slightly lower in Zhaozhou and huma, which were also above 120 t·hm-2. The nutritional data showed that the crude protein and crude fat content of samplesfrom Achengwere significantly higher than other regions (P<0.05), the crude protein was 18.41% and crude fat was 3.82%; The crude fiberof samples in Zhaozhou was significantly lower than other regions (P<0.05), and the content was 10.75%, while crude ash contentwas significantly higher than that of other planting areas (P<0.05), reaching 14.85%; calcium and water content in Nenjiang and huma respectively was higher than the other areas but did not reach significant level. The results showed that new variety ‘Щавель Чемпион’ has a good adaptability,which can grow in differenttypes of soil, and in different regions of Heilongjiang Province.
This study mainly measured the diurnal change of photosynthesis characteristics of Tamarix austromongolica, Platycladus orientalis and Caragana korshinskii in the Beishan Mountain of Lanzhou, as well as environmental factors. By using the relational grade analysis of grey system theory, the relational grade between Net photosynthetic rate (Pn),physiological and environmental factors were calculated. The results showed: The diurnal variation of Pn of three species showed asymmetric bimodal peak curve, with a remarkable photosynthetic “midday depressions”. It is caused by the midday high light intensity and temperature, rather than stomatal factors. The relation grades between Pn and physiological factors was Intercellular CO2 concentration (Ci) > Leaf temperature (Tl) > Transpiration rate Tr > Stomatal conductance (Gs) > Saturation vapor pressure difference foliage (VPD) > Stomatal limitating value (Ls) for T. austromongolica, Tr > Tl > VPD > Ci > Ls > Gs for P. orientalis and Tr > Tl > Ci > Gs > VPD > Ls for C. korshinskii. Among them, Ci has a obvious effect on Pn of T. austromongolica and it is Tr for P. orientalis and C. korshinskii. The relation grades between Pn an environmental factors was Photosynthetically active radiation (PAR)> Air relative humidity (RH) > Soil temperature (Ts) > Soil moisture (SM) > Air temperature (Ta) > Atmospheric CO2 concentration (Ca) for T. austromongolica, PAR > SM > Ta > Ts > RH > Ca for P. orientalis and RH > PAR > SM > Ta > Ca > Ts for C. korshinskii. Among them, PAR, has a deeply effect on Pn for P. orientalis and T. austromongolica, while itis RH for C. korshinskii.
Sorbaria kirilowii belongs to Rosaceae, with obvious ecological value such as resistant to diseases and insects, which is also a main shrub species in Xinglongshan Natural Reserve. Through two periods, 2004-2007 and 2012-2015, nine types phenologic phase of S. kirilowii in Xinglongshan National Natural Reserve were observed to analyze the change tendency of phenologic phase of S. kirilowii and explore the relationships of phenologic phase to monthly mean temperature and precipitation. The results indicated that most Spring phenologic phases for S. kirilowii showed a trend of delay but an advanced trend of Autumn phenologic phases, which caused the decrease of growth period, as much as 15.49 da-1. The trend of phenologic phases could be resulted from the phonologic phases of S. kirilowii correlated significantly with monthly mean temperature and precipitation. The blooming and fruit expansion periods are significantly negative correlated with mean temperature of April. There are significantly negative correlations between budding period and the precipitation of February, branching and the precipitation of May, fruit expansion period and the precipitation of July, while there is significantly positive correlation between fruit ripe period and the precipitation of October. Growth decrease caused by regional climate change influence not only propagation, but brush canopy density, which against animals living, such as Moschus sifanicus.
With the help of the time-series data of NOAA/AVHRR NDVI at 1-kilometer resolution from 1989 to 2008, and the vegetation chart of Xilingol League, this paper abstracted the NDVI time-series curves of eight types of vegetation after filtering the time-series images with the Savitzky-Golay method. After filtering the NDVI time-series curves with the S-G method, the paper estimated the annual beginning, end date and length of growing season of various vegetation using the improved dynamic threshold method, and performed the linear fitting. Finally, the accuracy of estimated phenophases and length of growing season of temperate needlegrass arid steppe was verified according to surveyed groud observations. The results indicated that there was significant difference among all vegetation types in beginning of growing season. Six vegetation types showed advanced trend of change in various degree, while temperate grass and forb holophytic meadow and temperate leaflet deciduous woodland showed delayed trend about 4 and 1 d·20 a-1, respectively. The end of growing season of all kinds of vegetation showed delayed trend in similar degree and the length of growing season of all kinds of vegetation extended. The end of growing season has greater impact on the length of growing season. Both surveyed and estimated values appeared similar trend of change which were 9 and 7 d·20 a-1 in advance, while end of growing season appeared converse. The RMSE between surveyed and estimated values was 16.59 d for the bginning of growing and 14.40 dfor wilting date, respectively.
Lycium ruthenicum is a kind of representative perennial shrub with cold, drought, and salinity tolerance, windbreak and sand-fixation, and it often grows in desert of China’s northwest. L. ruthenicum play important roles in healthcare such as fatigue resistance, anti-aging, prevention and treatment of diabetes, cardiovascular diseases, atherosclerosis and tumor because this shrub is rich in protein, amino acids, oligomeric proantho cyanidin (OPC), superoxide dismutase (SOD), and so on. However, L. ruthenicum growth suffered a serious threat due to long-term improper utilization, indicating natural distribution area becomes smaller. This study summarized recent advances in morphological characteristics, habitat and distributions, medical, economic and ecological values of L. ruthenicum. This study also reviewed the characteristics of adaptability to adverse and ecological and breeding methods (including tissue culture, seed germination, cutting seedlings and artificial cultivation) as well as exploitation and utilization. And then this study proposed the future directions in this field. Systematically understanding of advance in L. ruthenicum research would provide the basis of how to protect and comprehensive development and sustainable utilization of this plant resource.
Sweet sorghum (Sorghum bicolor) is an important forage and bioenergy crop. A rapidly growth of literatures on sweet sorghum has been shown in recent years. From the perspective of understanding the status of current researches, particularly focusing on the hot issues on this topic, the major purpose of this paper is to analyze the literatures on sweet sorghum published during 1985-2015 using bibliometric methods based on Scopus and CNKI database, with aspects of the issued amount, countries and institutions, highly cited papers, core authors, journals, and keyword, etc. The results indicated that the studies on sweet sorghum were very active, the amount of papers increased fast in the last decade. The study on bio-ethanol production using sweet sorghum as feedstock is a popular research topic in this area. Overall, research on sweet sorghum in China has been in the advanced level in the world, the number of research papers and institutions, as well as the core authors have been ranked as No. 1 in the world. The main domestic research institutions including Chinese Academy of Sciences, Shanghai Jiaotong University, and the Provincial Academy of Agricultural Sciences in Liaoning, Heilongjiang and Xinjiang, have been carried out fruitful work on variety breeding, the technology of bio-ethanol production, resistance traits, germplasm introduction, identification and evaluation. The research achievements have effectively promoted the development of sweet sorghum industry. The study results could provide reference for researchers and policy-makers on sweet sorghum industry.
The subterranean rodents are engineers of terrestrial ecosystem. However, it is very difficult to directly study the subterranean rodents because they live underground, which take some challenges for studying their behavior and bioecology. With the development of radio technology, the mini and light radio transmitter have made it possible for studying the subterranean rodents. Many foreigner scientists have successfully used the radio tracking on the borrowing systems, daily movement, home range dynamic and social structure of subterranean rodents. However, this technology was less used on the subterranean rodents in China. This paper summarized the research progress of radio tracking on some rodent species which lived underground. The purpose is to provide some references for studying the subterranean rodents in China in the future.
The effects of different rations of fresh hybrid P. americanum × P. purpureum cv. Minmu 6 in Leymus chinensis hay on production performance and milk quality of dairy cows were studied using a randomized block experiment with 24 Holstein dairy cows which were first birth with similar milk production(15 kg). The experiment had 6 different ratios of fresh Minmu 6 forage (CK, 0; Group Ⅰ, 7.50 kg; Group Ⅱ, 15.00 kg; Group Ⅲ 22.50 kg; Group Ⅳ,30.00 kg; and Group Ⅴ, 37.50 kg) with 4 cows in each group and had 40 days treatment period including 10 days for pre-trial period and 30 days for regular trial period. In summer around 30~37 ℃, there was no differences (P>0.05) between treatments fresh Minmu 6 forage for dry matter intake and milk production. The milk production of the experimental group with fresh forage was more stable than that of the control group. The α-linolenic acid (ALA) content of milk in Group Ⅲ with 22.50 kg fresh Minmu 6 forage was 15.88 mg·100 g-1 which increased by 43.1% compared with CK (P<0.05). In conclusion, fresh Minmu 6 forage in hay was helpful to stable the milk production and can improve ALA content of milk.
The quality and safety of dairy products is the focus of society in recent years. Raw milk, as the upstream of the dairy supply chain, is the fundamental guarantee for sustainable development of dairy industry, which might be contaminated a variety of microorganisms, in which some of microorganisms are associated with human illness and milk spoilage. This paper stated the source and varieties of harmful microorganisms, and their refrigeration. And then this paper discussed the effect of pasteurization on harmful microorganisms, and the occurrence, hazards and current research of several milkborne pathogens. These would provide basis for dairy production.
In this study, the whole plant corn (Zea mays) silage nutritional quality at different compactions was analyzed to determine the appropriate compaction of silage. The treatments used Xinsiyu 10 for silage materials with five compaction degrees (350, 400, 500, 600 and 700 kg·m-3). Sampling and determination of the DM, CP, NDF, ADF, WSC and RFV of silages were done on the 1 st, 3rd, 5th, 7th, 9th, 15th, 30th and 50th day after ensiling. Dynamic monitoring of the temperature change of each silage treatment was also measured after opening silo. Results indicated that DM, CP, NDF, ADF, and WSC content and pH value from compaction degree of corn silage decreased significantly than before ensiling (P<0.05). Silage time had a significant effect on above indicators (P<0.01). After opening silo, 600 kg·m-3 had the lowest pH value, while the content of CP was the highest; DM, WSC and RFV of 700 kg·m-3 treatment was the highest, NDF and ADF was the lowest. The stable time after exposure to oxygen of treatment 600 kg·m-3 was significantly higher than other treatments (P<0.05), reaching 100 h. At the same time, there was a monotonic increasing trend of oxygen exposure time and temperature, and the correlation was significant (P<0.05). With the increasing of charge degree range (350~600 kg·m-3), the fermentation quality of the silage correspondingly increased. When compaction degree reaching to 600 kg·m-3, the quality did not change significantly, suggesting that 600 kg·m-3 is the best compaction.
The present paper analysis the present situation and problem of grassland ecological protection based on the research of major grassland ecological protection projects in China in recent years. The results shows that the grassland ecological protection in China has made certain achievements and the comprehensive grassland vegetation coverage rate increases. At the same time, grass yield increases in natural grassland and the number of illegal cases in grassland decreases. However, grassland ecological environment in some areas remains relatively fragile, as farmers and herdsmen have weak awareness of the grassland ecological protection. Besides, grassland rodents and pests are still relatively rampant, which is also one of the serious problems. Finally, it proposes to integrate existing projects and promote grassland ecological management, to strengthen grassland ecological protection publicity and grassland project supervision, and to enhance regulatory and investigation of grassland and other countermeasures.