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The investigation on the species and composition characteristics of Phragmites communis and Typha angustata communities distributed mostly in Heihe River was carried out. The results showed that P. communis and Echinochloa crusgalli were the dominant species, with the total important value of 56.4% of P. communis community. T. angustata was the dominant species of T. angustata community,with the important value of 35.09%. Species diversity analysis of the ShannonWiener (H) indices, Margalef abundancedegree (F)、Pielou evenness (J) and dominant index (D) of the two communities suggested that there were significant positive correlation between H and M, and H and J. Significant negative correlation existed between H and D. T. angustata community species diversity was higher than P.communis community and the former one is more stable. The similarity index of the two communities was 52.94%, indicating that there is some relation between them.
The desertification area of Xinjiang Uigur Autonomous Region is the largest in China. The grassland ecosystem is the main ecosystem in Xinjiang. The occurrence and development of grassland desertification is related to ecological security and environmental quality of Xinjiang. The laws of distribution, characteristics and utilization in grassland ecosystem of Xinjiang were analyzed. The influence of natural factors and human factors on grassland desertification was discussed by analyzing the process of grassland desertification and the relationship of grassland ecosystem between other ecosystems. The result showed: (1) the type of desertification process was divided into 2 types. Ⅰ type was the process of desertification, salinization and degradation of desert grassland in the zone of plain and low hill, and Ⅱ type was the process of degradation in mountain grassland. (2) under the combined effect of human activities and the changes of hydrological environment on desertification, the grassland could transform into farmland, woodland, wetland, desert and community in the process of desertification. (3) the background of grassland desertification was the special topography, geomorphology, soil and climate. The natural factors provide the substance of desertification. The climate change was one of the main factors of desertification in the grassland of Southern Xinjiang and Eastern Xinjiang. (4) the unreasonable use of water resources was the main factor of desertification in the grassland of midstream and downstream. The reclamation and excavation grassland were the direct factors of desertification in the grassland around oasis. The longterm overgrazing and disorder grazing, low input of grassland management were the main factors of desertification in the pasture and mowing grassland. The driving force of grassland desertification has the characteristics of regionalism, multifactor and the desertification was the results of combined effect of natural factors and human activities.
As a case of the Naqu region in northern Tibet, this study analyzed the current situation and development trend of alpine rangeland ecosystem from alpine rangeland, population, livestock and social economy of Naqu region in northern Tibet from 1955 to 2005. During the 50 years, the annual average temperature increased 0.8-2.0 ℃, with an average annual precipitation increased by 100-240 mm. Animal husbandry population increased by 5 times or so, and livestock numbers increased by 2.9 times. Per capita net income of the herds increased by 94.1%, and the per capita consumption expenditure increased by 93.1%. The degradation area of alpine rangeland accounted for 64.3% of the total rangeland area in the Naqu region in northern Tibet. These results showed that main reasons of alpine rangeland degradation were increasing in population of herdsman and overgrazing, but not climatic change due to development of weather varied from dry to moist from 1955 to 2005. These reasons make positive contribution to slow down trend of rangeland degradation. Therefore, rational using rangeland resources through correctly managing relation between ecological safety shelter zone and animal husbandry economy is an issue that needs to be resolved to maintain the alpine rangeland ecosystem in northern Tibet.
It is important to comprehensively evaluate the benefit of the conversion from cropland to forest and grassland, which will help to determine whether the conversion from cropland to forest and grassland continues. At present, the benefit evaluation of the conversion from cropland to forest and grassland has been conducted in the region scale, however, the evaluation in a county scale is fewer. This study established the index system of the conversion from cropland to forest and grassland for county scale by taking the Yuzhong County as an example, and this index system was used to evaluate the comprehensive benefit of conversion from cropland to forest and grassland of the Weiying Township of Yuzhong County. The evaluation result showed the score of comprehensive benefit of this township was 70.85 points, which was at good level. The score of ecological benefits was 74.8 points and it was at good level. The score of economic benefit was 55.5 points, which was at medium level. The score of social benefit was 78.2 points and it was at good level.
In order to reveal the relationship between succulent xerophyte Zygophyllum xanthoxylum and other plants and to provide evidences for the biologically evolution，total DNA was extracted from leaves of Z. xanthoxylum seedlings, and the 18S rRNA gene was cloned by PCR using general primers and cloned into pGEMT vector．The positive clone identified by PCR was sequenced．The sequencing result revealed that the 18S rRNA gene fragment from Z. xanthoxylum contains 1808 bp．Homology comparison with other plants 18S rRNA gene sequences in the GenBank showed that it shared over 96% nucleotide sequence homology, so it is concluded that 18S rRNA is very conservative gene in plants. However，Homology matrix and Blast showed that Z. xanthoxylum shared high similarity (98%) with the identified 18S rRNA in Galearia filiformis, Cnidoscolus aconitifolius and Hevea brasiliensis. Phylogenetic tree analysis indicated that Z. xanthoxylum and Panax notoginseng were most consanguineously grouped.
In the present study，the transcriptional factor gene CBF1 was successfully cloned by PCR from the leaves of Arabidopsis. The sequence was preliminarily analyzed and plant expression vector was constructed. Then through agrobacteriummediated transgene technique, CBF1 gene was introduced into maize SAUMZ1. PCR assay revealed that the CBF1 gene was integrated in the maize grass SAUMZ1 genome. Under different low temperature treatments，the relative electrolyte leakage percentage of transgenic plant was lower than Control．The results showed that the coldresistance of maize grass SAUMZ1 was enhanced after CBF1 gene transformation.
The HKT transporters from higher plants function as relatively K+-Na+ transporters, playing vital roles in salt tolerance. We analyzed the expression pattern of PutHKT2;1 from Puccinellia tenuiflora by RTPCR method. The results showed that the expression of PutHKT2;1 was induced dramatically in roots under K+starvation stress for 24 h, but its expression was only slightly regulated by all stresses in shoots, therefore, the expression of PutHKT2;1had tissue specificity. Under 1 mmolL-1 K+ or K+ starvation stress, PutHKT2;1 expression gradually decreased with salt concentration increase. PutHKT2;1 may play an important role in roots, which may control Na+ uptake, strengthen the selectivity of K+ over Na+ and enhance salt tolerance.
Seed storage proteins of three Lespedeza hedysaroides were analyzed by SDSPAGE technique. Results indicated that SDSPAGE of saltsoluble proteins and seed storage proteins were practical and reliable methods for determining relationships among three L.hedysaroides. Saltsoluble protein and seed storage protein in the commontype and deep greentype L.hedysaroides were significantly different from those in the talltype. The protein molecular weight ranged from 10.375 KDa to 155.53 KDa. 6 bands were shared and 13 bands were polymorphism (68.42%) of total 19 saltsoluble protein bands. 19 bands were shared and 9 bands were polymorphism (32.14%) of total 28 seed storage protein bands. Clustering showed that three L.hedysaroides were divided into two groups. The commontype and the deep greentype were classified as the first group and the talltype one was second group. Therefore, SDSPAGE technology is an important method to study intraspecies variation among Lespedeza species.
Plantlets of thyme were cultured on the 1/2 MS medium that containing surcose with different concentrations, NO3-/NH4+, phenylalanine, glutamic acid and pyruvic acid. The LOX activity of thyme was tested after 30 d. Furthermore, the plantlets were induced for 0～120 h by MeJA, SA and chitosan at different culture for 20 d, 30 d and 40 d, and LOX activity was tested. The results showed that the highest LOX activity was obtained when the plantlets of thyme were cultured on the 1/2 MS medium with 4% sugar and 2∶1 NO3-/NH4+ ratio for 30 d. The LOX activities were increased respectively when adding 0.6 mmolL-1 precursor regulation Lphenylalanine, 0.4 mmolL-1 glutamic acid. The LOX activities of plantlets cultured for 20 d were 655.4％, 503.8％ and 429.1％ more than control by adding 1.0 mmolL-1 MeJA,150 mgL-1 SA, and 200 mgL-1 chitosan. The LOX activities of plantlets cultured for 30 d were increased to 688.1％, 383.8％ and 383.3％ when adding 0.5 mmolL-1 MeJA, 150 mgL-1 SA, and 200 mgL-1 chitosan, respectively. The LOX activities of plantlets cultured for 40 d did not change. Therefore, the LOX activity was affected by adding different inducer at different time.
In order to reveal phenotypic variation and variation patterns in different districts across Xinjiang province, 13 populations of wild Medicago falcata were taken as experimental materials and pod length, pod width, seeds number per pod, seed length, seed width and 1 000seedweight were measured. Phenotypic variations among and within populations were analyzed using variance analysis and correlation analysis. The results showed that, various characters of Medicago Falcata groups had significant differences. Pod length, pod width, seeds number per pod, seed length and seed width all have a significant positive correlation with 1 000seed weight. Hierarchical cluster analysis revealed these 13 populations were divided into three groups: 1) Altai; 2) BeiTun, TaCheng and FuYun; and 3) BuErJin, YuMin, EMin, HaBahe, Tekesi, JiMunai, Urumqi of Nanshan, FuHai and ChaBuchaer. These findings can offer basic data for further study of conservation biology and genetic breeding of this species.
A pot experiment was conducted to study the morphological and physiological changes of maize inbred lines including droughttolerant lines Langhuang，Chang72 and droughtsensitive line TS141 under natural drought stress, in order to probe the mechanism of drought tolerance and provide the meterials for improving droughttolerant germplasm resources and finding the loci of droughttolerant gene. The results showed that, in three maize inbred lines under drought stress, survival rates and leaves relative water content decreased significantly. Leaves relative conductivity increased significantly. The proline content increased while SOD and POD activities increased. Droughttolerant lines Langhuang and Chang72 had higher survival rates，relative water content，proline concent，SOD，POD activity and lower relative conductivity with a small change，compared with droughtsensitive line TS141.
High temperature induces a series of responses in physiology and morphology. In order to study this changes, 22 alfalfa (Medicago sativa) varieties were used to measure the contents of relative water content, soluble protein, relative electrical conductivity, and the activity of superoxide dismutase and peroxidase under different natural temperature in the summer. A randomized complete block design was conducted with three replicates. Using the method of cluster analysis, the heat resistance of these varieties were preliminarily evaluated. The results showed that, 1) the four indicators except the relative electrical conductivity, increased as the temperature progressed from 25 May to 21 June, and then dropped as the temperature dropped. However, the relative electrical conductivity increased by 3.36 times gradually; 2) in this study, 22 alfalfa varieties were divided into three types by hierarchical clustering, which are strong heatresistance type, weak heatresistance varieties and intermediate type, respectively. The varieties of heatresistant type included Sitel, followed Derby, Phabulous, Empress 2000, 8925MF, Gold Empress and WL414, while the intermediate heatresistant varieties were Sardi 7, Alfasuper, Powerplant, WL525HQ, Algonquin, Hunter River, Alfking, AmeriGraze401 and Siriver. The other varieties were weak heatresistant varieties; 3) there was very significant negatively correlation (P0.01) between FD class and relative water content. There were significant negatively correlations (P0.05) between FD class and soluble protein content, and FD class and POD activity. The relationships between FD class and the conductivity or FD class and SOD activity were not significant (P0.05). The correlation coefficient were 0.138 and -0.405. There were significant correlations among different indicators (P0.01).
Lycium ruthenicum seedlings were treated with 0.5, 1.0 and 2.0 mmolL-1 betaine by root irrigation under 300 mmolL-1 NaCl stress to study physiological responses of L.ruthenicum to exogenous betaine under salt stress. Changes of main physiological indices of the seedlings were analyzed after 7 and 14 days of the treatments. The results showed that total chlorophyll, membrane permeability, malondialdehyde (MDA), proline and soluble sugar contents of L.ruthenicum leaves markedly increased in comparison with the control under salt stress condition. In the case of equal salt stress, MDA content and the damage rate of membrane permeability of the seedlings treated with betaine reduced markedly; while contents of chlorophyll, proline and soluble sugar increased significantly. Betaine had effective effects on inhibition of MDA generation and on alleviating damage of cell membrane, and also increased contents of total chlorophyll, proline and soluble sugar after root irrigation on L. ruthenicum seedlings. Applying the optimum concentration of betaine under salt stress can improve salt resistance of L.ruthencium seedlings and increase adaptabilities of salt stress condition.
Feed source shortage is the main problem that limits livestock production in Longdong loess plateau of China. The object of this experiment was to compare the dry matter yield of forage crops under different rotation sequences to meet livestock demand. The experiments were carried out in 2008 and 2009. Eight forage crops, forage maize (Zea mays), sudan grass (Sorghum sudanense), proso millet (Echinochloa crusgalli var. frumentacea), oats (Avena sativa)，foxtail millet (Setaria italica), common vetch (Vicia sativa), lucerne (Medicago sativa), and one mixed crop (maize, foxtail millet and sorghum sown together, a traditional livestock feed source) were trialed. The forage crops were grown in four rotation treatments: maizevetchoats rotation (MVO), sudan grassvetchoats rotation (SVO), prosovetchoats rotation (PVO) and milletvetchmixed crop rotation (MVM), and the other treatment was perennial lucerne field (Lucerne). The dry matter yield over 2 experimental years averaged 9.5 tha-1a-1 for maize, 5.8 tha-1a-1 for sudan grass, 5.4 tha-1a-1 for oats, and 4.0 tha-1a-1 for proso. The mixed crop had the lowest average yield (2.1 tha-1a-1). The MVO rotation had the highest DM yield (average 7.4 tha-1a-1). Compared to the PVO rotation, the SVO rotation had a higher DM yield (5.6 tha-1a-1). The results showed that maize, proso and oats were productive forage options, especially oats are good summer forage in the region. Introducing annual forage crops into current farming system could reduce feed deficits for livestock producers.
Field trails in Hainan Granitic Laterite with four treatments (biochar/soil=0, 0.1%, 0.5%, 1.0%), were conducted to analyze the effects of biochar on yield and nutrition of King grass. Results showed that biochar treatments had an indistinctive decreasing trend on the yield of King grass. Biochar decreased the whole nutrient qualities of King grass. Compared to the control, the treatment of 0.1% significantly decreased the content of nitrogenfree extract by 13.95% in the third mowing. The treatments of 0.5% and 1.0% significantly increased the content of crude ash by 22.15% and 17.69% in the sixth mowing, respectively. The treatment of 0.1% significantly increased the content of acid detergent fiber in the sixth mowing. Through the analyzing the data of yield and nutrient by grey relational grade analysis, we found that control had the largest average grey relational grade in all treatments. Specifically, the average grey relational grade of 0.5% treatment was significantly smaller than control. The results also indicated that the treatment of 0.5% decreased the yield and nutrient qualities of King Grass.
In this paper, plant growth and photosynthetic characteristics in leaves of fluecured tobacco grown in continuous cropping soil for 2 and 5 years were investigated. The results showed that 2years continuous cropping did not affect plant growth and photosynthetic characteristics in the leaves of fluecured tobacco, but 5years continuous cropping limited plant growth and photosynthetic capacity. The chlorophyll content in leaves of fluecured tobacco grown in 5years continuous cropping soil significantly reduced. The net photosynthetic rates (Pn), transpiration rate (Tr) and stomatal conductance (Gs) in leaves of fluecured tobacco for 5years continuous cropping decreased, but intercellular CO2 concentration (Ci) changed little. The apparent quantum yield (AQY), light saturation point (LSP), photosynthetic rate saturated light (Pmax), carbolyation efficiency (CE), CO2 saturation point (CSP) and photosynthetic rate at saturated CO2 (Jmax) in leaves of tobacco decreased, and CO2 compensation point(CCP) and light compensation points (LCP) increased significantly for 5years continuous cropping. It suggested that continuous cropping significantly decreased light and CO2 utilization in leaves of tobacco, and the decrease of photosynthetic capacity under 5years continuous cropping was not only caused by stomatal factors, but also utilization ability of CO2 in mesophyll tissue.
In order to provide the scientific basis for alfalfa fertilization, a field experiment was conducted to investigate the forage yield of alfalfa under different fertilizer combinations of nitrogen, phosphorus and potassium in Qihe, Shandong province. Orthogonal experiment design was used with 2 replicates. The results showed that there was no significant effect of nitrogen and potassium fertilizer on forage yield of alfalfa, however, phosphorus fertilizer significantly increased the alfalfa forage yield. The interactive effects between phosphorus and nitrogen on forage yield under the first cut and second cut were significant, and phosphorus fertilizer mixed with low level of nitrogen fertilizer effectively improved alfalfa forage yield. According to the total forage yield of alfalfa, the proper combination of nitrogen, phosphorus and potassium applied for alfalfa in experiment field was 60 kgha-1 N， 90 kgha-1 P2O5 and 100 kgha-1 K2O.
Effects of different concentrations of foliar application with boron on the protective enzyme activity, yield and agronomic characteristics of winter rapeseed in cold and drought region of northwest China were studied. The results showed that proper concentrations of boron could improve the activities of protective enzyme SOD, POD, CAT, and APX. The activities of SOD, POD, CAT, and APX were highest when foliar application with 0.16% boron was carried out. The foliar application with boron treatments had significant effect on agronomic characteristics of winter rapeseed. Plant height, branch height, length of main florescence, silique of main florescence, total of plant, length of silique, seeds per silique, 1000seed weight and yield per plant were higher than the control. The yield and oil content were highest when foliar application with 0.16% boron was performed. Compared to control, yield and oil content was increased by 36.85% and 14.52% respectively. The optimized concentration of foliar application with boron is 0.16% for winter rapeseed in cold and drought region of northwest China.
The caloric values of 27 species from 10 families in alpine meadow with different degraded degrees of Guoluo prefecture ware measured and the change law of caloric value among four degradation levels was analyzed. The results show that: 1) the average caloric value of aboveground parts for alpine meadow common plants varied from 13.99 kJg-1 to 19.45 kJg-1 and the average caloric value of all species was 17.99 kJg-1, which is higher than global scale terrestrial plants. 2) The caloric value changing trends were different due to characteristics of plants' own biological proprieties. With the increased degradation degree, the caloric values of Gramineae, Compositae and Gentianaceae were increased firstly and reached highest point in moderately degraded meadow, then decreased, and that of Cyperaceae showed gradually increasing trend. 3) Caloric value was increased firstly and then decreased with the increased of degradation degree at the level of community, which reached highest point 18.16 kJg-1 in lightly degraded meadow, and lowest 16.29 kJg-1 in heavy degraded degree. Changes in species composition lead to the variance of community caloric value among different degradation degrees.
Roegneria Koch is the largest genus in the Triticeae Species groups. Within this genus there are many good resources, for example, the genes related to highyield, pestresistant and stress tolerance, and they are necessary for wheat and other grain crops. However, many issues are still in debate in Roegneria, such as the classification system, evolution status and evolutionary relationship with other related genera. This essay aimed to give better understanding of the phylogenetic profiles in Roegneria systematically. According to research data on the establishment of Roegneria, evolution status, genome composition and differentiation, an overview was given. With the development of the molecular marker techniques, the method for phylogenetic studies on Roegneria would become more effective, which combined with molecular systematics, cytology and traditional morphological techniques.
In the present study, the impact of grazing on the aboveground biomass of alpine grasslands and the gaining effect of sheep were investigated.Tuoyun pasture was selected as a study area. Three grazing plots were set as treatment plots and a natural growth grasslands was set as the control plot. The results showed that 1) Tuoyun pasture is an alpine meadow with Leucopoa albida, Fescue arioides, Androsace umbellata and Oxytropis falcatae as the dominant species; 2) aboveground biomass of alpine grassland was very low, even in the prohibited graze area in July, and the aboveground biomass (dry matter) was merely 830 kgha-1; 3) grazing activities have a great impact on the aboveground biomass of the pasture, and heavy grazing can significantly reduce the aboveground biomass; 4) using the effect of liveweight gain as an evaluation index, a better weight gain was obtained under the stocking rates of 1 sheep unit (i.e. an ewe and a lamb) per hectare in this alpine pasture.
The experiment was conducted to investigate the effects of adding propionic acid, lactic acid bacteria and mixture of the two additions on the fermentation quality of hybrid Pennisetum silage. There were treatments as following: the control (no addition), Lactic acid bacteria addition (LAB), Propionic acid addition at 0.2% (PA0.2), Propionic acid addition at 0.3% (PA0.3), Propionic acid addition at 0.4% (PA0.4）, Propionic acid addition at 0.5% (PA0.5), PA0.2+LAB, PA0.3+LAB, PA0.4+LAB and PA0.5+LAB (FM，%). After 45 days of ensiling, the ensiled forages were sampled and analyzed. The results showed that addition propionic acid could improve the fermentation quality of hybird P.silages, and adding Propionic acid at a rate of 0.3% is the optimum for fermentation quality of hybrid Pennisetum.
In order to explore the best way of storing alfalfa hay, the influence of natural compound mould inhibitor including dried tangerine peel, calcium oxide (CaO) and zeolite powder on Medicago varia cv. Caoyuan No. 2 was studied. The results showed that adding natural compound mould inhibitor NA to alfalfa hay bale has the obvious inhibition effect to the advantage fungi group, and the number of strains is declined, especially Alternaria, during Storage period. After storing ten days, the numbers of all strains reached the highest，and Alternaria is the most advantage fungi group. The next are Aspergillus, Fusarium, Penicillium, Trichoderma.
In the present study, we aimed to investigate the antioxidant activities of Prunella vulgaris in different extracts, which would provide theoretical basis for further research. The powder of P. vulgaris was extracted with 70% ethanol (in water, V/V) using ultrasonic extraction, and then the filtrate was extracted followed with ethyl acetate, nbutanol and water at equal volume. The antioxidant activities of different extracts were evaluated and BHT was used as a positive control. The results showed that the extracts of P. vulgaris have great antioxidant activity. Scavenging abilities on DPPH of the extracts and BHT were in descending order: ethyl acetatenbutanolBHTwater. Scavenging abilities on OH of the extracts and BHT were in descending order: BHTethyl acetatenbutanolwater. Scavenging abilities on O2- of the extracts and BHT were in descending order: ethyl acetatewaterBHT nbutanol. Reducing power of the extracts were in descending order: BHTethyl acetatenbutanolwater. The ethyl acetate extract of P. vulgaris had a strong antioxidant activity.
In order to find new ways to feed production, the screening test of silage cone in winter rapeseed stubble multiple cropping was carried out. The growth period, plant shape, grass yield, and nutrients were measured. The results indicated that Siliang No.2 and Wenyu No.5 were medium varieties. The stems of Siliang No.2 and Wenyu No.5 were the strongest with 1.91 and 1.82 cm, respectively. Siliang No.2 was the best with 79 303.7 kgha-1 fresh matter yield and Wenyu No.5 was the best with 20 127.6 kgha1 dry matter yield. These data suggest that Siliang No.2 and Wenyu No.5 were the most suitable silage corn in winter rapeseed stubble multiple cropping in the East of Gansu Province.