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Plant stoichiometric homoeostasis is correlated with dominance and stability in natural community. However, there is considerable limited work dealing with this relationship at species-level or function group-level. Study was made on the response of 10 dominant speicies from four function groups to N, P addition and N-P co-addition on a sub-alpine meadow in Tibetan Plateau. Results showed N and N-P addition promoted community biomass while P addition inhibited, indicating the N-limited type for grassland. Graminoid biomass increased, while legume and forb biomass decreased after either addition, and sedge biomass increased after N addition. The strong leaf P homeostasis of graminoid species may play a role in competition in the community. However, a regular rule on the leaf N homeostasis needs to be found out, and further study should be conducted to test the role of species homeostasis in the construction of community.
Soil nutrient is the basis for maintaining alpine grassland ecosystem health. The distribution characteristics of soil nutrient for swamp meadows, typical meadow, steppe meadow and sandy grassland were studied to provide theoretical basis for reasonable management of alpine grassland. The results demonstrated that (1)obvious difference was detected for soil organic matter and total nitrogen content between different type alpine grassland ecosystems, and swamp meadows＞typical meadow＞steppe meadow＞sandy grassland. Moreover, soil organic matter and total nitrogen content showed a significant decrease trend with the increase of soil depth in all the studied alpine grassland ecosystems. (2) The soil available nitrogen content in steppe meadow was as high as 65.5 mg·kg-1, which was greater than those of the other three grassland ecosystems. In contrast, the soil available nitrogen content in sandy grassland was as low as 11.5 mg·kg-1, which was the least one. The soil available nitrogen content in typical meadow was greater than that in swamp meadow. Furthermore, the maximum value of soil available nitrogen among different alpine grassland ecosystems appeared in 10―20 cm soil layer except for the sandy grassland. (3) No significant difference for soil total phosphorus and available phosphorus were detected between different degradation periods of alpine grassland ecosystems as well as different soil layers of the same alpine grassland ecosystems. (4) Different soil nutrients could influence each other in the degradation process of alpine grassland ecosystem. A significant positive correlation was found between soil organic content and soil total total nitrogen, total phosphorus, available nitrogen and available phosphorus, as well as between soil available nitrogen and total nitrogen. In addition, a significant positive correlation was detected between soil available phosphorus and total phosphorus. However, no significant correlation could be found for soil pH and soil nutrients.
The supply of available soil microelement will affect the normal growth and development of plant. The present study was conducted to analyze the distribution characteristics of available soil microelement Fe, Cu, Mn, Zn, and B and its response to disturbance in the meadow soil of Wugong Mountain. The results showed that the average contents of available Fe, Cu, Mn, Zn, and B were 169.15, 0.94, 3.73, 1.60, and 0.28 mgkg-1, respectively, and available Fe, Cu, Zn, and B did not significantly change with the increase of altitude, and available Mn at 0―20 cm soil layer had a significant (P 0.05) decreasing trend with the increase of altitude. Available Fe, Mn, Zn had spatial heterogeneity. Available Cu was sensitive response to human disturbance at both 0-20 cm and 20-40 cm soil layer, and the enrichment of available Cu was positively associated with the increase of the degree of human disturbance with the biggest enrichment 139.5% and 181.8%, respectively.
Artificial revegetation is a vital method of ecological recovery for damaged ecosystems. However, the assessment on the recovery effects of various vegetation patterns is still rare to date. In this study, the recovery situation of recliamed soil nutrients in Heidaigou opencast coal mine recovered for nearly 20-years was evaluated using various artificial vegetation patterns. The results showed that soil nutrients content was significantly affected by vegetation patterns. The contents of SOM, TN and NO3--N were significantly different in various soil depth while there was no significant difference for soil TP, TK and NH4+-N. Although SOM, TN and NO3--N assembled in the surface soil, artificial vegetation changed their vertical distribution properties compared with natural vegetation. Herbage vegetation with fabaceous plants was better than other vegetation patterns for soil nutrients recovery. Average SOM, TN and NO3--N within 50 cm soil depth had recovered to 63.9%, 57.8% and 184.8% of natural vegetation site after nearly 20 years recovery, the average level of SOM, TN and NO3--N within 30-50 cm soil depth even exceeded abandoned field. The results indicated that artificial revegetation was an effective measure to improve soil nutrients recovery, and herbage vegetation with fabaceous plants was the first choice to implement soil ecological recovery in the mine reclaimed land. Furthermore, SOM, TN and NO3--N could be used as an index to evaluate the effects of soil recovery in this mine region.
The components and stability of pigment from Anemone obtusiloba with two different flower colors were analyzed by the specific color reactions and UV-visible spectrum. Results showed that the two different colored petals of A. obtusiloba consisted of chlorophyll and carotenoid, the main petal pigments belonged to flavonoid, definitely including flavone, anthocyanins, flavonols, flavanonols, excluding flavanonols and aurones. These flavonoid had phenolic hydroxyl,4-keto, 3-hydroxy or 4-keto, 5-hydroxy. The stability of anthocyanins was affected by different values of pH, the anthocyanins under dark condition were more stable than that under light. The stability of petal pigments was mainly influenced by Fe3+ and Cu2+.
Meta analysis was performed to quantify the effect of AM fungi inoculation on plant biomass and nutrient uptake of Trifolium plant. In this research, 525 independent observations were extracted from 30 published scientific papers through database search of Web of Science. The results indicated that total biomass, shoot biomass and root biomass of Trifolium were significantly increased by AM fungi inoculum. Plant uptake of nitrogen and phosphorus was also promoted. Both AM fungi species and Trifolium species showed influence on the effect of inoculation. Gigaspora margarita inoculation showed the largest amount of biomass enhancement in Trifolium, while the shoot and root biomass of T. alexandrinum strongly responded to AM fungi inoculation. The stress treatment significantly reduced the effect size of plant shoot and root biomass. The effect size of plant N, K and Zn uptake was significantly positively correlated with incubation time.
Pennisetum purpureum is a perennial resource plant and widely cultivated in tropical and sub-tropical regions. High lignin, however, to some extent, restricts the full use of it. In order to investigate the effect on the lignin synthesis by the cinnamoyl-CoA reductase (CCR) gene, P. purpureum cv. Huanan was selected to construct sense and antisense expression vector and transformed into tobacco by Agrobacterium infection method. The transgenic plants were histochemically stained by Wiesner and Maule reagents. Results showed that the composition of lignin did not change significantly, however, PpCCR overexpressing tobacco transgenic lines increased lignified cells while antisense expression lines with cells arranged loosely. Furthermore, the red-brown was found on the base of stem of the transgenic line with lignin content reduced sharply in tobaccos of the CCR antisense expression. The results emphasized the importance of CCR on the lignin synthesis and a foundation was laid for the genetic improvement of elephantgrass.
To investigate genetic relationships among Stylosanthes species, a total of 33 accessions from 14 Stylosanthes species were studied using 23 simple sequence rpeats (SSR) markers. All 23 SSR markers were polymorphic among 33 Stylosanthes accessions. A total of 138 alleles were generated by 23 SSR markers among different Stylosanthes accessions. The number of alleles per SSR marker ranged from 4 to 10 with an average of 6 alleles. The polymorphic information content per SSR marker varied from 0.501 to 0.830, with an average of 0.700. Based on the results of analysis of cluster and principal components, the 33 Stylosanthes accessions were divided into 5 separate clusters, which were named to be cluster AB, cluster AC, cluster J, cluster DE and cluster G based on genome contained. The highest and lowest genetic relations were presented between S. subsericea and S. hamata (I), S. hamata (I) and S. capitata, respectively.
Polygalacturonase-inhibiting proteins(PGIP)are one of the most important defensive proteins, and the understanding of the nucleotide sequences of PGIP genes is the premise and basis of the molecular genetics and molecular biology. This study aimed to isolate the genomic coding sequences of PGIP genes in alfalfa(Medicago sativa)by a homology-based method. Consequently, the part genomic coding sequences of 7 PGIP genes were cloned, and each of these 7 alfalfa PGIP genes had a corresponding homologous PGIP gene from M. truncatula, and they were named as MsPGIP5, MsPGIP6, MsPGIP7, MsPGIP8, MsPGIP9, MsPGIP10 and MsPGIP11. Of the found 7 alfalfa PGIP genes, MsPGIP5, MsPGIP6, MsPGIP8, MsPGIP9 and MsPGIP11 possessed a divergent average inter-SNP distance with a value of 20, 74, 34, 423 and 21 bp, respectively. FPCR-SSCP analysis was performed for MsPGIP5, MsPGIP6, MsPGIP8 and MsPGIP11, and the results showed that a trend of the ratios between their SSCP allele numbers and their PCR fragment sizes, with a value of 20, 56, 22 and 19 bp, respectively, and they were basically consistent with those of their average inter-SNP distances. In contrast, of the found 7 alfalfa PGIP genes, the sequence of MsPGIP9 was highly conserved while MsPGIP5 and MsPGIP11 displayed a large sequence variation, and MsPGIP6 and MsPGIP8 had a median sequence variation.
In the experiment, dormancy release of Leymus chinensis seed and plant regeneration is studied using plant growth regulator TDZ with different concentrations, and ultramicro observations are conducted on callus. The results showed that 0.02 mg·L-1 TDZ cold soaking has the best effect on dormancy release of L. chinensis seed and embryonic callus induction. The germination rate and the healing rate are 11% and 15.5%, respectively, the best media component formula for L. chinensis callus differentiation is MS+TDZ 0.5 mg·L-1+CH 2.0 g·L-1, the differentiation rate and green shoot differentiation rate are 56.7% and 423.3%, respectively. Otherwise, transmission electron microscope (TEM) observations found that the embryonic callus induced by TDZ cold soaking, L. chinensis seeds contain more rich contents and are more conductive to body embryo formation than that of non-embryonic callus cell plasmid. After acclimatization and transplanting, the survival rate of the multiple shoots through 3 times of subculture with 1/2 MS rooting media is 100%.
Low seed quality of western wheatgrass in China was caused by lodging and harvesting dates. The trials were conducted with 3-year western wheatgrass to study the change of seed quality after PP333 spraying in Jiuquan area of Gansu Province. The results showed thatspraying PP333 in three-leaf stage reduced western wheatgrass seed moisture decreasing rate during late seed development period. Seed moisture decreasing from 45% to 35% needs 3 d in CK but 6～9 d after spraying PP333, which made the seed maturation tend to be consistent and reduced grain losses effectively. When the PP333 spraying rate was 2.40 kg·ha-1,the most suitable harvest date western wheatgrass was the 42nd day after full-bloom stage because the seed dry-weight and standard germination percentage was the maximum value at that time.
This study was carried out to select appropriate plastic tray for C.breviculmis, C. giraldiana, C. lanceolata, C. humilis var. nana and C. pediformi seedlings growing. Six important indexes including germination initial time, germination duration time, germination rate, plant height, leaf number and fresh weight of five Carex spices were compared and analyzed. The result was as follows: the plastic trays of 128 cells and 105 cells were more appropriate for C. breviculmis, C. giraldiana; the trays of 105 cells were appropriate for C. lanceolata; the trays of 288 cells were appropriate for C. humilis var. nana and C. pediformis.
In the study, the vermiculite was used as substrate and the modified 1/2 Hoagland nutrient solution containing K2SiO3 (KCl as control) was irrigated to study the physiological effects of silicon (Si) on the growth and drought resistance of the succulent xerophyte Haloxylon ammodendron. Results showed that the low concentration of K2SiO3 (KCl as control) stimulated the growth and 15 mmol·L-1 K2SiO3 (30 mmol·L-1 KCl as control) was the optimum concentration, while ≥50 mmol·L-1 K2SiO3 significantly inhibited the growth of H. ammodendron. Compared with the control and 30 mmol·L-1 KCl, 15 mmol·L-1 K2SiO3 significantly increased plant height by 20.2% and 11.4%, branching numbers by 41.4% and 21.6%, fresh weight by 39.1% and 14.5%, and water content by 35.2% and 13.8%, respectively(P0.05). Under different osmotic stress (-0.5,-1.0 and -1.5 MPa), 15 mmol·L-1 K2SiO3 (30 mmol·L-1 KCl as control) significantly improved the drought resistance and alleviated the harmful effects of H. ammodendron by decreasing the content of MDA and relative conductivity in assimilating shoots. Compared with the control and 30 mmol·L-1 KCl, 15mmol·L-1 K2SiO3 significantly increased plant height by 24.7% and 10.1%, 26.4% and 13.8%, 24.2% and 12.9%, respectively, and fresh weight by 43.6% and 15.7%, 52.7% and 15.0%, 59.3% and 20.1%, respectively, while the MDA concentration in assimilating shoots significantly decreased by 26% and 12%, 32.8% and 17.2%, 31.3% and 17.2%, respectively, and relative conductivity by 26.7% and 13.3%, 41.2% and 23.5%, 47.5% and 25% in the mild (-0.5 MPa), moderate (-1.0 MPa) and severe osmotic stress (-1.5 MPa), respectively(P0.05). The results showed that a certain amount of K2SiO3 (KCl as control) could promote growth and improve the drought resistance of H. ammodendron by decreasing the relative conductivity and MDA content in assimilating shoots.
The present study was to explore the effects of different irrigation methods including subsurface drip irrigation(SDI), border irrigation(BI), sprinkler irrigation(SI), and CK on growth, quality and yield of alfalfa. The results showed that different irrigation methods had different effects on soil water content, and SDI treatment had the highest soil water content. In addition, this study found that different irrigation methods had greatly different effects on alfalfa quality, yield and water use efficiency. Dry yield of two cuttings alfalfa of SDI treatment was 4 815.87, 4 300.41 kg·ha-1, respectively. Compared with BI, SI and CK treatments, yield of two cuttings alfalfa of SDI increased by 10.56%, 14.92%, 95.26% and 13.64%, 23.60%, 120.85%, respectively (P＜0.05). Water use efficiency of two cuttings alfalfa of SDI treatment was 2.66, 2.50 kg·m-3, respectively. Compared with BI and SI treatments, water use efficiency of the two cuttings of SDI increased by 17.70%, 21.46% and 20.77%, 34.41%, respectively (P＜0.05).度SDI treatment had the lowest protein content and the highest fiber content, but crude protein yield of SDI treatment was significantly improved (P＜0.05). Crude protein yield of two cuttings alfalfa of SDI treatment was 816.13, 814.07 kg·ha-1, respectively. Compared with BI, SI,CK treatments, crude protein yield of two cuttings alfalfa of SDI increased by 2.38%, 5.84%, 61.90% and 10.90%, 18.83%,100.01%, respectively (P＜0.05). These results suggested SDI could improve the growth, crude protein yield, dry yield and water use efficiency of alfalfa. Therefore, SDI was more suitable for alfalfa planting in arid northwest China.
The effect of sowing rate and nitrogen fertilizing rate on productivity of Sudangrass (Sorghum sudanense ‘Xinsu No.2’) were studied in this research. The results showed that when the phosphate fertilizing rate was fixed, the highest plant height obtained at B1 (sowing rate 22.5 kg·ha-1) and N3 (nitrogen feritilizing rate 550 kg·ha-1), the biggest stem diameter and maximum tillers number obtained at B1 (sowing rate 22.5 kg·ha-1 ), the highest hay yield obtained at B2 (sowing rate 45 kg·ha-1) and N2 (nitrogen fertilizing rate 415 kg·ha-1), the total hay yield respectively reached 19 200.0 and 19 744.5 kg·ha-1, the highest crude protein yield obtained at B3 (sowing rate 67.5 kg·ha-1) and N2 (nitrogen fertilizing rate 415 kg·ha-1), the total crude protein yield respectively reached 1 607.03 kg·ha-1 and 1 572.00 kg·ha-1. Taking the hay and crude protein yield into consideration, the best treatment combination was B3 (sowing rate 67.5 kg·ha-1) + N2 (nitrogen fertilizing rate 415 kg·ha-1).
The field trial was conducted in Xiahe Region of Gansu Province. A randomized complete block design was applied to investigate the optimal cutting date of Lanjian No.1. Sampling was made during the periods of squaring, flowering, podding and mature to measure the content of crude protein (CP), water soluble carbohydrate (WSC), crude fat (CF), neutral detergent fiber (NDF), mineral elements and dry matter yield. The result showed that CP contents all reached the first level of the American forage standard. The content of CP was the highest while WSC, CF and NDF were of the medium level during the mature period. Mineral elements P, K, Na, Mg and Zn in Lanjian No.1 could satisfy the basic needs of livestock on alpine grassland. Grey relational analysis and weight assignment method were adopted for the comprehensive evaluation of dry matter yield, CP, WSC, CF, NDF and mineral elements levels. It was found that comprehensive evaluation index was the highest in the mature period. Thus, the optimal cutting date of Lanjian No.1 should be mature period.
In order to evaluate the carrying capacity of Kobresia tibetica grassland which was one of the main grassland types in Yushu Prefecture, three Datong yaks (five years old) were chosen to provide rumen solution, nutritional value of forage in K. tibetica grassland from Yushu prefecture belonged to Sanjiangyuan Region, and were evaluated in vitro with gas production method and conventional nutritional analysis method, and combined with forage yield, the carrying capacity of K. tibetica grassland was calculated. The results were as follows: 1) the yield of fresh forage, dry forage and edible forage of K. tibetica forageland were 1 272, 349.04, 341.29 g·m-2 respectively; 2) CP, EE, ADF, Ash, Ca, P were 10.16%, 2.26%, 34.07%, 4.76%, 0.31%, 0.11%, respectively; 3) the values of DOM, DE and ME were estimated according to the content of CP, EE and gas production of 120 h, which were 81.21%, 10.33 MJ·kg-1, 9.16 MJ·kg-1, respectively, and dry matter digestibility (DMD), ammonia nitrogen concentration(NH3-N), pH value were 62.67%, 7.72 mg·dL-1 and 6.65, respectively, and the curves of gas production rate showed the shape of single-peak (20―28 h); 4) the carrying capacity of production, ME and DCP for K. tibetica grassland in Yushu Tibetan Autonomous prefecture were 14.11(8.44 sheep units per hectare), 20.51(13.16 sheep units per hectare) and 22.02(12.26 sheep units per hectare) million sheep units approximately.
Animal fecal steroid level is an important indicator to detect physiological status of animals. The plasma determination method can make animals produce stress reaction during the collection of samples, and this method can affect the accuracy of determinable result. Compared with the plasma determination method, as a noninvasive method, the fecal steroid hormone detection technology has many advantages, including avoiding the anthropogenic interference to animals, easily to collect samples, and more accurate and reliable determination results. This paper summarized the domestic and foreign researches on determination of fecal steroid hormone in animals related to the samples collection and preservation, and analysis methods, and its important significance in the study of rodents, which could provide a reference for relevant research.
A 5-year research was conducted on the features of vegetation and topographic factors of habitats of two dominate small mammal species Eospalax bailyei and Ochotona curzoniae in alpine meadow of Xiahe, Gannan. Significant correlations were found between habitat utilization of these two species and vegetation, as well as geographic factors. Plateau pikas preferred sunny middle slope, while plateau zokors preferred flat and sunny lower slope. The coverage was an important factor predicting the presence of plateau pika. Areas with high or low biomass in flat area were more likely to be occupied by both species. Their coexistence last about 3 years. The abundance of four plant species Potentilla anserine, Melissilus ruthenicus, Radix bupleuri and Saussurea pulchra significantly affected habitat selection by both species.
This study was designed to compare silage quality and nutritional value of Sorghum bicolor×S. sudanense collecting from different parts of the container. The samples were taken from three parts of the 63 silage containers, and their quality, nutritional value were analyzed and relative feed value (RFV) was calculated. Results indicated that lactic acid content (LA) in silage increased with sampling sites deepened, and lactic acid content in the upper part was higher than that in the lower part significantly (P0.05).The nutritional value of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF) and the relative feeding value (RFV) were significantly affected (P0.05) by sampling positions. With the deepening of the sampling site, dry matter (DM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) decreased, while the relative feeding value (RFV) gradually increased.
Climatic factors and grassland property right system have an important effect on livestock husbandry production. However, the association effect between them has been largely overlooked with lack of causal linkage. Using meteorological data (1961-2007) and livestock production statistical data from Hongyuan County in eastern Qinghai-Tibet Plateau, a study was made on the characteristics of climate change and the institutional transition of grassland property rights and its impact on livestock numbers, structures, and survival rate of pups and livestock mortality. The results indicated that as a whole, the temperature showed a warming trend with a rising rate of 0.27 ℃·10a-1, and the most evident warming occurred in winter. Precipitation had been found decrease with the rate of -11.98 mm·10 a-1. Moreover, an obvious tendency of drying had also been found in the last 50 years. In general, the climatic characteristics will improve the survival rate of calves and it is obvious that the extreme weather have great negative effects on livestock death. Compared to the impacts of climate change, the institutional transition of grassland property right plays a strong and leading role in livestock husbandry.
Agriculture originated in the zonal native ecosystem, the agriculture type of one district showed the conversion of its native ecosystem. Ancient human remained in northwest Loess Plateau appeared earlier than southeastern part, and more extensive distribution as well. Hunting herbivore was the major food source for the human in the whole Loess Plateau. Livestock agriculture which characterized in domesticating animals and nomadism firstly initiated and farming agriculture which characterized in dry farming subsequent emergenced. At the beginning, livestock agriculture and farming agriculture both existed even mutual converting. Farming agriculture became the dominant agriculture type in northwest Loess Plateau while livestock agriculture became the dominant agriculture type in southeastern Loess Plateau after premier community historical stage, and their corresponding agricultural culture confronted each other. In summary, origin of the agriculture in Loess Plateau revealed conversion of grassland ecosystem and forest ecosystem, and grassland ecosystem was the major factor.
An analysis was made on moisture, crude protein, crude ash, crude fiber, fat, amino acids, heavy metals (Pb, Cd, Hg, As, Cr), pesticide residues and microorganisms in feeds collected from Shihezi of Xinjiang Province using the national standard method, and the determination and evaluation of the test results was analyzed with the relevant national standard. The results showed that the nutrition and pesticide residues, heavy metals and microbial indicators of all samples were in line with the relevant national standards except that crude ash of five samples was lower than the standard.