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In order to prevent soil and water loss and improve the soil properties in Three Gorges Reservoir Region, the effects of different biological measures on soil physicochemical properties under different soil and water conservation biological measures were comprehensively evaluated by grey correlation coefficient analysis to select better measures. The result showed that all different biological measures improved soil physicochemical property compared with control——bare land although the effects varied with measures. Under different biological measures, the tested indices including soil bulk density, total porosity, soil organic matter, total nitrogen, total phosphorus, total potassium and soil C/N were the significantly different (P<0.05) or extremely significantly different (P<0.01). The soil total porosity, organic matter, total nitrogen, total phosphorus, total potassium, alkaline hydrolysis nitrogen, available potassium and soil C/N were the highest under treatment with Koelreuteria bipinnata+Sophora xanthantha. The improved effects of soil physicochemical properties decreased in the following order: K. bipinnata+S. xanthantha>hedgerows>closed forest>natural restoration>economic forest>traditional planting>bare land. The measure with K. bipinnata+S. xanthantha had great effects for preventing soil and water loss which could be applied further. These results had an important significance for ecological civilization construction and the management of soil and water loss in Three Gorges Reservoir Region
In order to explore the response of soil organic carbon components to enclosure in rangeland, the soil particulate organic carbon (POC), particulate organic nitrogen (PON), light fraction organic carbon (LFOC), light fraction organic nitrogen (LFON), microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) of Seriphidium transiliense desert after different enclosure years(including 0 year, 1 years, 6 years and 9 years)were studied. The results showed that the POC, PON, LFOC and LFON contents in soil layer of 0-5 and 5-10 cm in S. transiliense desert firstly decreased then increased with the increase of enclosure years which reached minimum after 6-year enclosure. Only POC, PON, LFOC and LFON contents in 0-5 cm soil layer after 6-year enclosure were significantly lower than those of the control (0 year) and after 9 year enclosure. Except with that LFOC contents in 10-20 cm, 30-50 cm soil layers and LFON content in 30-50 cm soil layer after 6-year enclosure were significantly lower than those after 1 year enclosure, there was no significantly difference between different enclosure years for POC, PON, LFOC, LFON contents in 10-50 cm soil. The MBC and MBN contents in 0-30 cm soil firstly decreased then increased with the increase of enclosure years which reached minimum after 1 year enclosure. Except with MBC content in 5-10 cm soil layers, all other indices were significantly lower than those after 9 years enclosure. There was significantly positive correlation among POC, PON, LFOC, LFON, MBC and MBN, especially PON could more accurately reflect the soil quality changes. In conclusion, carbon and nitrogen content of soil organic carbon components in 0-5 cm soil were more sensitive to enclosure and the soil microbial biomass carbon and nitrogen response more quickly.
The present study measured soil physicochemical and grassland spectrum of Seriphidium transiliense desert grassland to discuss their response to enclosure. The results showed that soil water content decreased during the growth period and increased with the enclosure period extending in May and September. The model of the relationship between community spectrum and soil water content was simulated with R2 of 0.633. The difference of soil organic matter between inside and outside of fence in May increased with the enclosure period extending. Difference of soil organic matter decreased linearly in grassland enclosed 7 and 10 years. The models simulated with both indoor soil spectra and the field bare land spectra were optimal with R2 of 0.64 and 0.38, respectively. These results showed that soil moisture and organic matter were sensitive to grassland restoration which can be used to monitor S. transiliense desert grassland.
Three rhizobial strains were used to study the nodulation effects of three Vicia sativa cultivars growed in low nitrogen nutrient solution under greenhouse conditions. The results showed that the plant average height, the root length, the amount of nodules, fresh weight of nodules, total nitrogen content and nitrogenase activity of the inoculated V. sativa were significantely increased (P<0.05) compared with controls and strain CCBAU01069 had the best effects.
Wetland soil bacterial community structure under the simulation nitrogen depositions was studied using 16S rDNA gene sequencing. The soil samples were collected from three different nitrogen depositions in the Sanjiang Plain Field Experiment Station of the Institute of Nature & Ecology, Heilongjiang Academy Sciences. Total microbial DNA was directly extracted from soil samples and 16S rDNA genes were sequenced and analyzed by Miseq molecular technology. The results showed that both low N and high N treatment increased the bacterial diversity compared with control treatment and low N treatment had the highest diversity. The wetland bacterial community structures significantly changed under simulation N depositions. In low N treatment, high N treatment and control treatment, Acidobacteria were predominated followed by Proteobacteria. The richness of Acidobacteria decreased and the richness of Proteobacteria increased first then decreased along the deposition. Soil pH decreased with deposition, which showing acidic property and increasing the Acidobacteria distribution. Soil physicochemical properties changed by input N which resulted in the soil bacterial community composition and abundant changed. The heatmap tree based on the 16S rDNA sequences showed that different bacterial community structure differently responded on Nitrogen deposition. This research provided basic data and theory consultation for predicting the influence of future atmospheric nitrogen deposition on soil microorganism in Sanjiang Plain wetlands.
The present study explored the effects of fungal endophytes on host growth with endophyte-infected (E+), endophyte-free (E-) and mixture of E+ and E-(M) populations of L. perenne under two different growth environmental conditions including greenhouse and field. In green house, four different water treatments including 15%(FWC15), 30%(FWC30), 45%(FWC45) and 60%(FWC60) of field water content (FWC) were simulated in pots. The results showed that the plant height and tiller numbers, growth rates of plant height and tiller, blade width and length, aboveground water content and aboveground biomass of E+, E- and M gradually increased with the increase of soil moisture content in greenhouse which reached maximum under FWC45 treatment. However, the growth indices of plants under FWC60 moisture condition were less than those of plants under FWC45 treatment which suggested that FWC60 treatment inhibited plants growth. All these results suggested that FWC45 was optimal condition for perennial ryegrass. The tiller numbers, growth rate of plant height and tiller, blade width, aboveground water content of E+ populations were significantly higher (P<0.05) than those of E- and M populations and the blade length of E + populations were significantly higher (P<0.05) than that of E- populations under each moisture condition in pot experiment. There were no significant difference between E+ and M population for aboveground biomass with FWC60 treatment, while E+ populations were significantly higher (P<0.05) than that of M populations (P<0.05) under other treatments. With FWC15, FWC30 and FWC45 treatment, aboveground biomass of E+ population were significantly higher (P<0.05) than those of E- and M populations although there were no significant difference between E- and M populations, however, aboveground biomass of E+ and M population were significantly higher (P<0.05) than that of E- populations. Under natural field conditions, the plant height and tiller numbers, growth rates of plant height and tiller, blade width and aboveground biomass of E+ populations were significantly higher (P<0.05) than those of E- and M populations, while the blade length and aboveground water content had no significant difference with M population. The growth indices of E- were significantly (P<0.05) less than those of E+ population. These results suggested that the fungal endophytes could promote the growth and enhance the drought resistance of L. perenne in the greenhouse and field conditions.
Axonopus compressus is perennial herbaceous plants and used in south China. Genetic diversity of 64 carpetgrass accessions (cultivar) was analyzed using the ISSR markers. The results showed that 25 ISSR primers generated 208 distinct bands (300~1 500 bp), 196 (94.23%) of which were polymorphic bands. The number of observed bands ranged from 4 to 15, with average of 8.3. The genetic similarity coefficient is between 0.46~0.99. Unweighted pair-group method with arithmetic means (UPGMA) clustered 64 accessions (cultivar) into three groups, and not all samples from the same region belonged to the same group. ISSR markers has potential in marker-assisted breeding and the assessment of genetic diversity in wild germplasm resources of carpetgrass.
Morphological structure and trichome density of leaves at different age and position in Dendranthema indicum and D. indicum var. aromaticum, were compared by analyzing the type and content of the excretion through GC-MS. The results showed that there were two types of glandular trichomes. One was T-shaped non-glandular hairs without the secretion function, and the other was capitate trichomes with the secretion function. There were little difference between upper and lower epidermis on the density of T-shaped non-glandular hairs, while the capitate trichomes were mainly concentrated in the lower epidermis. There were 73 compounds found in the leaf secretion of the two plants, which included mostly terpenoids and their derivatives, and 18 compounds were shared by the two plants. There were 48 and 43 compounds identified from D. indicum and D. indicum var. aromaticum, respectively, and these compounds constituted 90.96% and 84.33% respectively of the total content of leaves surface exudates.
The present study analyzed the relationship between photosynthetic characteristics in different growth stages and environmental factors and discussed plant adaption characteristics and mechanism in wetlands based on natural plants of Lythrum salicaria, Phragmites australis, Scirpus triqueter and Acorus calamus’s growing in Yintan wetland of Lanzhou section of Yellow River. In May 11, the two peaks curve of net photosynthetic rate (Pn) of L. salicaria and P. australis was not obvious and the Pn of S. triqueter and A. calamus were relatively stable, the average of Pn decreased in the following order: P. australis>L. salicaria>S. triqueter>A. calamus. In August 19, the curves of Pn of L. salicaria, P. australis and S. triqueter showed two peaks with significant photosynthetic “midday depression” and the curves of Pn of A. calamus was one peak, the average of Pn decreased in the following order: P. australis>A. calamus>L. salicaria>S. triqueter. In May 11, photosynthetically active radiation (PAR), atmospheric temperature (Ta), atmospheric CO2 concentration (Ca), relative humidity (RH), transpiration rate (Tr), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and water use efficiency (WUE) had positive correlation or significant correlation with the diurnal variation of Pn. In August 19, only PAR, Ca, Tr, Gs, WUE and soil moisture had positive correlation or significant correlation with the diurnal variation of Pn. In May 11, PAR and WUE had the greatest effects on Pn of 4 studied plants, which were the major environmental and physiological factors. In August 19, PAR and Tr had the greatest effect on Pn of L. salicaria and S. triqueter’s and PAR and WUE had the greatest effect on Pn of P. australis and A. calamus which were the major environmental and physiological factors. Although each factors had different effects, PAR was the main cause of plant photosynthetic physiological characteristics.
MODIS data in 2002-2012 was used to build the spatial logistic fire risk model based on the spatial distribution of fire and fire influencing factor by using geographic information system technology in Shanxi Province. Fire risk zoning study was conducted in a long temporal scale and provincial spatial scale. Logistic model of fire risk was built by spatial samples in fires region, and the simulated model fit well with the fire influencing factors (P<0.05), and the relative operating characteristic (ROC) was 0.757. The probability distribution map of fire events was made by map algebra. Fire area of Shanxi Province was zoned five classes, include none, low, moderate, high, and extremely high fire risk zones. The factors influence the fire event occur include altitude (GC), land use type (LT), land surface temperature (LST), Normalized Difference Vegetation Index (NDVI) and global vegetation moisture index (GVMI), whereas the influences of slope (PD) and distance to the nearest path (DL) exhibit insignificant in Shanxi Province. The NDVI and LST are significant factors in Shanxi Province globally, whereas the GC, LT and GVMI are only significant factors locally. Seven fire prevention regions are delimitated according to the fire influencing factors. Different fire prevention policies and emphases should be taken into consideration for each of the seven fire prevention regions.
Precipitation plays a major role in maintaining the water supply in Mountainous area, which directly impacts the development of ecology environment and economic society in the mid and down streams of arid regions. Due to the technical and geographical limitations, one difficult problem in precipitation study is to accurately observe the meteorological factors. The entropy is used in this study to investigate the spatio-temporal variations of precipitation in annual, seasonal and monthly time series from 31 stations located in the Tianshan Mountain during 1960-2008. The results showed that there was an obvious spatial-temporal variability of precipitation in the Tianshan Mountain. The variability of precipitation of annual entropy was less than that of the seasonal, which is in turn less than the monthly. The decreasing trend of annual entropy was significant. In seasons, the variability of entropy was very significant in winter, but not in summer. The variability of entropy exhibited difference between precipitation and elevation for seasons. There was an increasing trend in the precipitation in northern slope with the elevation increase, while decreasing in southern slope of Tianshan Mountain in spring, summer and fall. The precipitation increased from April to September, and decrease from October to March of next year. The variability of monthly entropy and precipitation were antithetical. The spatial variability of entropy was more radical in southern and eastern slope than northern and western slope. The variability of entropy was minimal in Ili River valley. Obviously, the spatio-temporal variations of precipitation can be depicted by entropy, and supply a scientific basis to the rational development of water resources in Mountain area.
In order to clarify genetic characteristics of seed coat color in spotted colored pea, three pea cultivars were used as experimental materials, i.e. Mawan1 (spotted seed coat, purple flower and semi-leafless), Zhongwan 6 (no dots on seed coat, white flower and common leaf) and 90-PE-10 (no dots on seed coat, white flower and semi-leafless). Reciprocal cross combinations, i.e. Mawan 1 and Zhongwan 6, Mawan1 and 90-PE-10 were set. Progenies of parents, F1 and F2 were observed under field condition and statistical analyses were undertaken to the obtained data. The results showed that F1 displayed spotted seed coat in the two reciprocal cross combinations, and the F2 progenies segregated in a 3∶1 ratio indicating monogenic inheritance. Spotted seed coat is dominant over the no dots on seed coat. In two pairs of relative characters experiments, two kinds of recombinants (spotted seed coat and white flower, no dots on seed coat and purple flower) were not found in F2 progenies in the two reciprocal cross combinations. The gene of spotted seed coat is tightly linked to the gene of purple flower. It is convenient to select for seed color or flower color using the genetic marker. The gene of spotted seed coat located on chromosome 1 in pea, is different from F and Fs, spotted genes, located on chromosome 3 and chromosome 5 respectively.
To understand tripping phenomenon and reproductive characteristics of Xinjiang Trifolium, flowering habit, pollen spreading time and the influence of different mating pattern on reproductive characteristic were studied. The results as followed: 1) flower from budding to wilting maintained 50~52 h, pollen display belongs to keel valvular insufficiency; 2) the pistil stigma crazed when wing petal grow to 1/2 of flag petal; 3) the podding rate of Trifolium from Changji desert steppe in the autonomous selfing was highest (98.61%); the podding rate of Trifolium from Urumqi Nanshan mountain meadow under homologous strain cross-pollination was the highest (100%) ; the podding rate of Hutubi Trifolium under forest belt with free pollination was the lowest (96.30%). The results of this study can provide some references for further study on breeding system and reproductive biology of Trifolium repens.
Failure of seedling establishment is one of the main reason limiting cultivation of Medicago sativa in arid rain-fed region of Loess Plateau. Seed priming has been proven to be an effective method for enhancing stress tolerance of seeds at the germination stage; and consequently increased seedling establishment. This study determined the optimal conditions for hydropriming of M. sativa cv. “Longdong” by manipulating priming temperature (10, 15, 20 ℃), duration (12, 24, 36, 48 h) and water addition (90%, 120%, 150% seed weight). The results showed that most priming treatments could significantly increased germination rate and seedling growth, but showed no effect on final germination percentage. The optimal response to hydropriming was achieved at 10 ℃ for 36 h with 90% water of original seed weight.
In order to investigate the effects of exogenous betaine on seed germination, activities of antioxidase enzymes of Lycium ruthenium under NaCl stress. The L. ruthenium seed germination and seedling growth were studied in middle reaches of Heihe River of Hexi Corridor. Several physiological indexes, such as the germination percentage (GP), germination vigor (GV), germination index (GI), vigor index (VI), and relative salt damage rate, antioxidant enzymes (SOD, POD and CAT) were measured. The results indicated that, low NaCl concentration (25 mmol·L-1) could promote the seed germination but high NaCl concentration (50~300 mmol·L-1) could inhibit the seed germination. The NaCl concentration threshold for seed germination in L. ruthenium was 50 mmol·L-1, the maximum was 300 mmol·L-1; The SOD, POD and CAT activity showed a trend of first rising and then falling along with the salt concentration increasing. After the treatment by exogenous betaine, SOD, POD and CAT activity increased to some extent, but they had less decrease range under NaCl stress. Exogenous betaine could significantly alleviate the damages to the seeds and seedlings of L. ruthenium under NaCl stress and promote the salt resistance of the seeds and seedlings.
Growth, leaf tissue water content, Na+, K+ accumulation in plant tissues were studied under -0.5 MPa osmotic stress, 50 mmol·L-1 NaCl and salt-osmotic intercross stress in Bianguo and Ningqi0702, two cultivars of Lycium barbarum. The results showed that both the growth of Bianguo and Ningqi0702 was inhibited under -0.5 MPa osmotic stress. Compared with the control, fresh weigh (FW) and root height of Bianguo and Ningqi0702 decreased by 34%, 38%, 32% and 17%, respectively. The addition of 50 mmol·L-1 NaCl significantly increased FW of Bianguo by 38%, and no effect on dry weight (DW), plant height and root height of Bianguo. However, FW, DW, plant height and root height of Ningqi0702 significantly decreased by 27%, 34%, 44% and 14% under 50 mmol·L-1 NaCl conditions, respectively. The growth of Bianguo remained unaffected when plants were exposed to salt-osmotic intercross stress, whereas FW, DW, plant height and root height of Ningqi0702 significantly decreased by 37%, 28%, 44% and 13% under salt-osmotic intercross stress, respectively. Compared with the control, leaf tissue water content of Bianguo remained unaffected under osmotic stress, whereas that of Ningqi0702 significantly decreased by 12%. Both the leaf tissue water content of Bianguo and Ningqi0702 increased by 25% and 18% under 50 mmol·L-1 NaCl conditions, meanwhile, and remained unaffected under salt-osmotic intercross stress. Moreover, FW and leaf tissue water content were positively correlated with Na+ concentration in leaves and stems of Bianguo. However, for Ningqi0702, FW was positively correlated with K+ concentration in leaves and negative relation with Na+ concentration in stems. Both Na+ and K+ concentration had no correlation with leaf tissue water content in Ningqi0702. Compared with the control, the net selective transport capacity for K+ over Na+ (ST value) of Bianguo increased by 84% and 43% under osmotic stress and 50 mmol·L-1 NaCl conditions, respectively, whereas that of Ningqi0702 decreased by 63% and 47%. These findings suggested that, Bianguo is able to accumulate a moderate concentration of Na+ in its leaves and have a strong ability to regulate Na+ and K+ homeostasis to improve water status, thus maintaining plant growth when subjected to drought and salinity. Bianguo possesses some characteristics of halophytes. Ningqi0702 haven’t these characteristics.
This study taken Cele oasis at the southern fringe of Taklimakan Desert as the research area, and studied the influence of clipping at different seasons (clipping in spring and clipping in fall) on the leaf functional traits of Alhagi sparsifolia.The results showed that the specific leaf area of A. sparsifolia increased obviously after clipping processing (P<0.01), and the increased degree was higher for clipping in spring compared with clipping in fall. The dry matter content of leaf decreased significantly (P<0.01), while no evident difference between clipping in spring and fall(P>0.05). Each treatment had a little influence on the carbon content and chlorophyll a/b. Compared clipping in spring with control and clipping in fall, the indexes of total N content, N∶P, chlorophyll a, chlorophyll b and total chlorophyll content increased significantly (P<0.05). By taking the leaf functional traits as an indicator of plant adaption to the environment, we concluded that clipping may cause the declination of the ability to preserve nutrition and the resources use efficiency of A. sparsifolia. However, in terms of economic benefit, clipping in fall can produce a positive effect on the biomass of A. sparsifolia. Therefore, when minimum destruction and livestock forage supply of A. sparsifolia were considered together, we recommend that clipping in fall was recognized as a proper management and use strategy for A.sparsifolia.
Potentilla reptans var. sericophylla has good ecological adaptability, can be wildly used as cover plant. But the current planting method can not meet the needs of field production, new planting method research is imminent. The research of suitable vegetative reproduction method for P. reptans var. sericophylla was accomplished in forestry college nursery of Shanxi agricultural university from July to October in 2014, this experiment with the P. reptans var. sericophylla which induced to nursery by predecessor as material, shearing the stem section, adopts the method of spreading stems and covering soil, the method of trenching and planting stem and the method of layering to plant, the results showed that in three different planting method, the method of spreading stems and covering soil worked best. The survival rate of this method which reproduce P. reptans var. sericophylla can reach 96%, its coverage reached 73% after 70 days, the number of ramets reached 289 per square meter and stolons reached 57 per square meter, higher biomass accumulation included biomass on the ground part 0.011 g·cm-2 and biomass under the ground part 0.004 2 g·cm-2, chlorophyll content was higher, it can reach 2.77 mg·g-1 and be widely used for field production.
In order to understand the adaptability of Lespedeza davurica on different forest light environmental, photosynthetic gas exchange and light response curve of chlorophyll fluorescence parameters were detected respectively. The results showed that Pn and AQY of L. davurica leaf growth in understory were significantly higher than that of the forest edge under low light intensity, which indicated that the ability of capture and utilization of weak light growth in understory were significantly higher than that in the edge of forest. On the contrary, the ability of capture and utilization of strong light growth in understory was significantly lower than that in the edge of forest, in which the value of LSP and Pmax were lower. The increased extent of GS and Tr of L. davurica leaves understory were lower than the edge of the forest with increasing the light intensity, but L. davurica grown in forest has relatively higher water use efficiency. Under low light intensity, the parameters of ФPSⅡ and ETR were both not different between understory and forest edge. But the parameters of ФPSⅡ and ETR for those grown in forest edge were higher than understory when the intensity was more than 400 μmol·m-2·s-1, ETR and LCP of L. davurica leaves were significantly higher than those understory. The heat dissipation capability of understory was higher than those grown in forest edge. In conclusion, the results of this study showed that the ability of L. davurica for adapting different light environments were strong.
In order to get the optimal harvest period of alfalfa, three varieties Guanzhong alfalfa, Algonquin and Gold Empress were harvested at budding stage, early blooming, full booming, pod setting stage and maturing stage, respectively. Their stems and leaves were separated and dried, yield, stem to leaf ratio, plant height, branches and nutritional characteristics were measured. The results showed that, along with the growth of alfalfa, yield increased then decreased, yield were highest at pod setting stage. Stem to leaf ratio was higher than other periods at budding stage, but plant height and branches were the highest at maturing stage. Along with the growth period delaying, crude protein, crude fat and relative feeding value gradually decreased, crude fiber, neutral detergent fiber and acid detergent fiber gradually increased. Crude protein and relative feeding value at budding stage were significantly(P<0.05) higher than that of early blooming, full booming, pod setting stage and maturing stage; In leaves and stems, compared with the latter, crude protein increased by 4.52%, 8.28%, 12.06%, 14.70% and 12.59%, 9.38%, 11.19%, 28.18%, respectively; compared with the latter, relative feeding value increased by 6.55%, 6.60%, 29.07%, 40.25% and 3.84%, 6.09%, 4.88%, 10.99%, respectively; compared with the latter, crude fiber decreased by 29.88%, 20.19%, 20.98%, 3.31% and 3.81%, 0.70%, 1.92%, 1.04%, respectively. Budding stage was the best stage of cutting.
In this study, 20 triticale lines were chosen as the experimental materials to study the development characteristics and forage quality sown in the spring and autumn. The grey correlation analysis was used to evaluate the responses of the hay yield, fresh dry ratio and forage quality to different sowing dates and determine the suitable sowing date for these lines. Results indicated that the other triticale lines, expect for J1, J3 and J20, could overwinter normally; lines J18, J19, J11, J2, J14 and J15 obtained high hay yield when they were sown in autumn and lines J3, J17, J8 ,J14, J13, J2 and J16 obtained high hay yield when they were sown in spring. Comprehensive analysis showed that lines J10 and J18 were suitable to be planted in autumn, lines J4, J5, J6, J8, J12, J13, J14, J15, J17 and J20 sown in spring had better performance, and five lines sown in spring and autumn: J2, J7, J9, J11 and J19 had similar performance, so they could be sown in these two seasons. The suitable sowing date for the lines J1, J3 and J16 needs to be studied further. This study will provide good basis for determining the wintering rate and suitable sowing date of these lines and lay foundation for increasing the hay yield and quality of triticale.
The local alfalfa ‘Longdong’ was used as control, the comparative study of 14 introduced alfalfa cultivars were carried out in Eastern Gansu Province during 2010-2014. The results showed that introduced alfalfa cultivars had high seed value, the growth stage of introduced alfalfa cultivars was not significantly different in the spring sowing year. The tested cultivars could overwinter safely and perform the best in the third years. The grass yield of introduced alfalfa cultivars achived the highest in the third year and it decreased greatly from the fourth year. The Ladak+ and Defi had the highest production with the average hay grass yield of 11.2 t·ha-1 and 11.0 t·ha-1, increased by 9.8% and 7.8% than the local alfalfa ‘Longdong’, respectively. The stem to leaf ratio of Ladak+ and Defi was small, its grass quality was good. Among these studied cultivars, the Ladak+ and Defi had optimal performance and were suitable for promoting in Longdong Region as the preferred cultivars.
Aboveground biomass in different rangeland types or same type in different regions varied with time and space which reveals the dynamic relationship between vegetation biomass and environmental factors from different rangeland types and spatial and temporal scales. The results showed that aboveground biomass in Chinese northern steppe rangeland general declined in last 30 years although consistent increased in the recent 5 years. The decline was great in areas with better water conditions and was not significant in local scale. The interaction of annual temperature and precipitation did not have significant effects on aboveground biomass in time scale. The average annual temperature of temperate rangeland had significant effects on aboveground biomass in spatial scale. The precipitation is the main limiting factor of aboveground biomass in alpine rangeland.
In order to study the effects of grazing intensity on the branch number of Seriphidum transiliense and their response, the number and components of branch of S. transiliense were investigated every 30 days from 2012 to 2013 in desert grassland with four grazing intensities, including no grazing (CK), light grazing (LG), medium grazing (MG) and high grazing (HG) in Ashili Village, Changji City. The results showed that the branch numbers increased firstly and then decreased with the increase of grazing intensities which decreased in the following order: LG>CK>MG>HG. The vegetative branch numbers had the same variations which decreased in the following order: LG>CK>MG>HG. The vegetative branch numbers was the maximum in lighting grazing blocks which accounting for 20.5% of total branch number. The productive branch number in no grazing blocks was significant more(P<0.05)than that of the other three treatments. The reproductive branch numbers decreased with the increase of grazing intensities which decreased in the following order: CK>LG>MG>HG.
Altitude is the dominant factor that influenced vegetation habitat differences which has a profound influence on ecosystem structure and process. The present study analyzed plants diversity and primary productivity of community in altitude of 600-1 500 m range in the southern section of Motianling northern slope using the analysis of correlation, stepwise regression and the test of Pearson correlation coefficient. The results showed that the species abundance was significantly and positively correlated (R2=0.278 4) with the altitude gradient (P0.05), whereas plant coverage was significantly and negatively correlated (R2=0.43) with the altitude gradient and there was weak correlation between altitude gradient and vegetation height and density (P0.05). Furthermore, aboveground biomass firstly increased and then decreased with the increase of altitude, however, underground biomass changed more complicated which firstly increased, then decreased, and increased again with the increase of altitude. The variations of plant functional group of aboveground biomass and underground biomass were consistent with the variations of altitude gradient. All of the results showed that the characteristics of herbaceous communities had a significant change with attitude gradient in the southeast of Motianling northern slope. The difference of aboveground and underground biomass for each functional group was significant. There was highly significant positive correlation between biomass and the vegetation coverage of the herb layer (P0.01), and no correlation between biomass and plant height and density; between plant coverage, height and density.
The Dunaliella salina is a kind of unicellular eukaryote without cell wall,which is mainly used for extracting natural β-carotene and polysaccharides. The D. salina powder, which derives from the drying process of D. salina, plays a vital role in anti-oxidation, anti-virus, anti-tumor, and promotion of immune function. Currently, the applications of D. salina powder focused on human beings and rodents, but very few studies paid attention on dairy cows. We reviewed the regulation of rumen fermentation, oxidative stress, immune response, nutrient utilization and lactation performance by D. salina powder in dairy cows, aiming at providing references for dairy production.
Body condition scoring is a method to evaluate fatness or thinness based on comprehensive score of various body parts of cows, and thus to manage nutrition and health of dairy herd. According to the body condition score of lactating cows in a typical dairy farm, the results showed that there were significantly positive correlations between the body condition of cows and milk protein percentage, estimated milk yield of 305 days (P<0.01). The body condition of cows at 3rd parity was the best, which was significantly better than other parities (P<0.01). The body condition of cows at late lactation stage was significantly better than other lactation stages (P<0.01). The parity had a significantly positive correlation with somatic cell score (P<0.05). In addition, the significantly positive correlations were observed between somatic cell score and estimated milk yield of 305 days, milk protein, as well as between milk protein and milk fat (P<0.05). The somatic cell score revealed a significantly positive correlation with milk protein and milk fat (P<0.01), which indicated it could be used to predict milk yield and quality. In summary, to produce more milk yield in high quality, the body condition of dairy cows should be in a reasonable range according to improving management of nutritional level and rising conditions.
The experiment with three fixed quadrates (50 m×20 m) was conducted to investigate the relationships between α diversity of plant community and the number of soil mound of Myospalax aspalax in the natural clipping ground in Baiyinkulun pasture, Xilinguole, Inner Mongolia. We investigated the plant community diversity and the population abundance of M. aspalax ranged from 2012 to 2014. The plant community diversity included Margalef index, Shannon-Wiener index and Pielou index. The population abundance was represented by the number of new soil mound of M. aspalax. The results showed that, 1) The movement of M. aspalax had no significant influence on plant community in the research area (P>0.05), and the influence of plant community diversity on M. aspalax was higher than that of M. aspalax on plant community diversity; 2) M. aspalax population abundance had the strongest effect on evenness index of plant community, while the plant species richness index had the strongest correlation with M. aspalax population abundance.
Alfalfa is a high quality forage grass widely cultivated in China. Insect pests have been becoming one of the most important factors that limited alfalfa’s yield and quality. In this study, research papers of alfalfa insect pests published since 1980 were obtained by searching the CNKI database, and the catalogue of alfalfa insect pests has been listed out by analyzing all these articles in detail. Results showed that a total of 297 species belonging to 48 families of 8 orders had been reported in China, among which the most extensively studied were Loxostege sticticalis, Acyrthosiphon pisum, Therioaphis trifolii, Heliothis dipsacea and Odontothrips loti. A total of 226 studies are related to alfalfa insect pests, including 2 PhD dissertations, 40 master dissertations and 184 journal articles. All these studies involved bioecology characteristics, control, species and diversity survey, population dynamics and community structure, as well as biochemistry and molecular biology. Among them, the first two were the most studied, whereas the last was the least. For the future prospects of alfalfa insect pest studies, the suggest that it is necessary: 1) to further investigate species diversity of alfalfa insect pests, and determine key pests occurred in each alfalfa planting region; 2) to enhance bioecology characteristics study; 3) to promote biochemistry and molecular biology study; 4) to establish integrated pest management system for alfalfa insect pests.
Gansu which is one of the largest alfalfa planting provinces in China, plays an important role in Chinese alfalfa industry. Improving the competitiveness of alfalfa industry in Gansu is a critical path to promote Chinese alfalfa and livestock industry. This study estimated the status of alfalfa industry competitiveness in Gansu Province using the index of market share based on understanding the current development situation of alfalfa industry, and analyzed the factors influencing the competitiveness of alfalfa industry applying Porter’s diamond model. Policy suggestions to enhance the competitiveness of alfalfa industry in Gansu are finally recommended.