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2012 Vol.29(6)

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Estimation of consistency about permafrost distribution and steppe classification in the QinghaiTibetan Plateau
2012, 6(6): 851-856.
[Abstract](1265) [PDF 972KB](741)
Abstract:
Correlations between various types of frozen ground and steppes may provide useful insights for the regularity of permafrost distribution and steppe classification, and a better understanding of mutual feedback mechanism between frozen ground and steppes. The frozen ground on the QinghaiTibetan Plateau (QTP) is characteristic by permafrost, seasonal frost and others, which occupies 49.64%, 46.68% and 3.68% of total areas of QTP, respectively. In contrast, the steppe is divided into dominant grassland, transition grassland and others, which occupies 57.51%, 41.08% and 1.41% of total areas of QTP, respectively. Through image merging and analyzing the error matrix of image classification, we found that consistency precision of permafrost distribution and steppe classification is 65.95%, which suggested that conspicuous consistency presents among them.
Dynamic analysis for vegetation coverage change in Hoboksar based on dimidiate pixel model
2012, 6(6): 857-862.
[Abstract](1069) [PDF 857KB](629)
Abstract:
In this study, we monitored the changes of vegetation coverage based on the normalized difference vegetation index and the dimidiate pixel model, using of MODIS remote sensing data of Hoboksar from 2003 to 2010 in August of each year. We focused on the spatial distribution of vegetation coverage of the different levels and the change of vegetation coverage in this area. The results showed that the vegetation fraction decreased gradually from north to south in Hoboskar. Over the past eight years, the vegetation coverage in Hoboskar was increasing slightly, and the highest coverage had reached 91.18% in 2005. In some years, the vegetation coverage decreased slightly compared with those in the previous years. These results indicate improved ecological environment in Hoboskar County.
Responses of soil microbial prosperities to different management modes in typical steppe, Ningxia
2012, 6(6): 863-868.
[Abstract](1368) [PDF 848KB](484)
Abstract:
Soil microorganism community of grassland is a driver of soil nutrient cycle, which can sensitively reflect changes of ecological environment of grassland, and is always looked as an indicator for soil quality. Present study was conducted on the typical steppe grassland in Ningxia to investigate soil microorganism properties and the relationship between microorganism properties and soil organic content under different management modes including enclosure, grazing and horizontal ditch. The results showed bacteria amountactinomyces amountfungus amount in 0-40 cm soil depth of research area. Bacteria and actinomyces number increased with enclosure time increasing. Fungus amount in grassland enclosed for 5 years was the highest in all treatments. The total amount of microorganism, microbial biomass carbon, and nitrogen increased with the increasing of enclosure time, and were the lowest in grazing grassland. There was no advantage of microorganism properties in horizontal ditch grassland. In different soil layers, the highest microorganism amount was observed in 5-15 cm soil depth, and the lowest amount was found in 25-40 cm soil depth. There was a significantly positive relationship between microorganism amount and soil organic content.
Seasonal changes and sufficiency or lack analysis of trace elements in grazing system in Stipa breviflora desert steppe
2012, 6(6): 869-875.
[Abstract](1180) [PDF 432KB](433)
Abstract:
In order to provide scientific basis for preventing diseases of trace elements metabolism of livestock, the contents of trace elements were investigated and analyzed in grazing system in Stipa breviflora desert steppe in Siziwang area of Inner Mongolia.The detection of trace minerals in soilforagesheep ecosystem was performed using the methods of sampling in the field and lab analysis. The results showed that the soil is lack of Cu and Se critically. The pasture is rich in Fe and Mn, however, it is lack of Se. The indicators were also compared between local sheep and health sheep, and we found that the content of Fe was higher than the normal value in summer and autumn, and the content of Mn was higher than normal value in the whole year in the plasma. In contrast, the content of Se was lower than the normal value in autumn and the content of Cu was lower than the normal value in winter in the plasma. Furthermore, the contents of Fe and Mn were higher than the normal values in the whole year, and the content of Cu was lower than the critical values in the winter in the liver. Meanwhile, the content of Se in the liver was lower than the normal value in autumn and winter. The content of Fe was higher than the normal value and the contents of Cu and Se were lower than the normal values in the whole year in the wool. Using the comprehensive analyses of intake, digestibility of minerals, the results revealed that in this area the contents of Fe and Mn are high, and the contents of Se is low. The contents of Cu and Zn are low seasonally.
Physiological responses and accumulation of Bromus inermis to Cd and Zn stress
2012, 6(6): 876-882.
[Abstract](1146) [PDF 888KB](482)
Abstract:
In order to explore the phytoremediation potential of Bromus inermis to Cd and Zn stress, the physiological response of B.inermis at the different concentrations of Cd and Zn (five concentrations of Cd: 0, 200, 400, 600 and 800 mgkg-1; Zn: 0, 400, 800, 1 200 and 1 600 mgkg-1) and accumulation features were studied by a greenhouse pot experiment. The results showed that the chlorophyll content increased slightly, MDA accumulation was a little, SOD and POD activities were higher under the low concentration stress compared with control. With the increase of Cd and Zn concentration, the chlorophyll content decreased, MDA accumulation increased, SOD and POD activities decreased and plantlets suffered persecution significantly. Moreover, the results also showed that the optimum concentration of accumulation to Cd was 400 mgkg-1; and the Cd accumulations of aboveground and underground of the single plantlet were 183.533 and 661.128 mgkg-1 respectively. It demonstrated that B.inermis is a Cd enrichedtype plant. Meanwhile, the Zn accumulations of aboveground and underground of the single plantlet were 11.839 and 6.844 mgkg-1 respectively; and B.inermis is also a Zn avoidedtype plant.
Effects of tillage on surface moisture and temperature of alpine meadow
2012, 6(6): 883-888.
[Abstract](1248) [PDF 694KB](444)
Abstract:
Effects of tillage on the degraded alpine meadow in a semiarid basin on the northeast ridge of the QinghaiTibetan Plateau were studied by investigating the relationships among soil moisture, surface temperature and fractional vegetation cover. The results showed that 1) areas with higher vegetation cover had higher soil moisture; 2) after rainfall, the surface temperature of areas with lower vegetation cover was lower; 3) after drying of several days, the surface temperature of areas with higher vegetation cover was lower. Our results indicated that changes of vegetation cover and belowground soil structure by tillage would cause quick loss of soil moisture in this area, which makes it harder for the degraded alpine meadow to recover. Measures, e.g. irrigation and notill sowing, might be suitable alternatives for vegetation recovering of this region.
Effects of Bacillus mucilaginosus agents on the quantity of microorganism in ryegrass rhizosphere
2012, 6(6): 889-893.
[Abstract](1450) [PDF 455KB](677)
Abstract:
This experiment was aimed to investigate the effect of 5 strains of Bacillus mucilaginosus, isolated from rhizospheres of Zea mays (K02), Poa pratensis (K05), Elymus dahuricus (K09), Lolium perenne (K11) and Agrostis palustris (K12) resipectively, on the quantity of microorganism in ryegrass (L.perenne) rhizosphere by using a dilution coating flat method. The result showed that after fertilizing with the agents, the quantities of bacteria and actinomycetes of three different sampling periods in ryegrass rhizosphere were significantly higher than those in control. The fungi quantity of three different sampling periods in ryegrass rhizosphere tended to decrease compared with control. It indicated that the effect of B.mucilaginosus agents on fungus quantity was negative, but they were beneficial to increase the quantities of bacteria and actinomycetes in ryegrass rhizosphere.
Allelopathic effects of different concentration root exudates of Kochia scoparia on oil flax seed germination
2012, 6(6): 894-897.
[Abstract](1430) [PDF 376KB](460)
Abstract:
Allelopathic effects of different concentration root exudates of Kochia scoparia on oil flax seed germination were studied by using methods of bioassay. The results showed that: 1) different concentrations of K.scoparia root exudates had different degrees of inhibition (or promotion ) on germination energy, germination rate, germination index and vigor index of oil flax seeds, while the inhibition rate increased with the treatment concentration rising. 2) Different concentrations of K.scoparia root exudates showed to promote the root length of oil flax seedlings and inhibit the shoot height, root fresh weight and shoot fresh weight. However, whether it is promotion or inhibition, the effects trended to be increased with the increase of concentration; but there was no significant difference between the treatments and the control. All these results showed that the root system secretion was one of the way in which K.scoparia could release allelochemicals and affect plant growth around them.3) The reason of K.scoparia root exudates affecting flax seed germination was mainly due to inhibit the seed vigor index; and affecting flax seedling growth was largely due to made roots becoming thin and long.
Allelopathic effects of Parthenium argentatum on seed germination and seedling growth of three plant species
2012, 6(6): 898-903.
[Abstract](1203) [PDF 448KB](561)
Abstract:
Allelopathic effects of aqueous extracts and powder of different parts of Parthenium hysterophorus on seed germination and seedling growth of Abutilon theophrasti, Digitaria sanguinalis, and Raphanus sativus were evaluated either in petri dishes or a greenhouse. The results showed that the aqueous extracts of roots, stems, leaves and fruits all had negative effects on the seed germination and seedling growth of three tested plants, while the aqueous extracts from leaves and fruits had higher inhibiting on the seed germination and seedling growth of all tested plants than those from roots and stems. A. theophrasti and R. sativus were more sensitive to the extracts than D. sanguinalis. This conclusion was also confirmed by testing seed germination and seedling growth of the three plants in the mixture of 25 g powder (from different parts of P. argentatum) with 1 kg soil in a greenhouse.
Comparison of drought resistance of Sedum plants
2012, 6(6): 904-908.
[Abstract](1474) [PDF 850KB](502)
Abstract:
Comparative study was carried out on drought resistance of 14 varieties of Sedum under continuous drought stress in field conditions. The measurement included superficial morphology, leaf relative water content, MDA content, chlorophyll content, and soluble carbohydrate content. The results of the study revealed that drought resistance of Sedum were shown to decrease in the order of Sedum spectabile cv.Mossback, S.spectaile Boreau, S.telephium cv.Herbstfreude, S.spectabile cv.Iceberg and S.spectabile cv.RosentellerS.spectabile cv.Jameson, S.matrona, S.spectabile cv.Rosebloom, S.spectabile cv.Brilliant, S.hybridum and S.engleriS.reflexum,S.spurium cv.Coccineum and S.aizoon.
2012, 6(6): 909-910.
[Abstract](860) [PDF 328KB](1343)
Abstract:
Construction and identification of a cold and droughtinduced cDNA library from zoysiagrass using Gateway technology
2012, 6(6): 911-917.
[Abstract](1312) [PDF 578KB](596)
Abstract:
The first cDNA library was constructed using Gateway technology from zoysiagrass (Zoysia japonica) subjected to coldand droughtstress treatments. Quality assessment showed that the titer of unamplified library was 1.76106 pfumL-1 and the capacity was 7.04106 pfu. The average insert size was larger than 1 kb with the recombination efficiency of 90%. It was suggested that the cDNA library was successfully generated in high quality; most likely containing lots of novel genes. The library may provide an essential resource for future functional genomic analysis of zoysiagrass and could be an effective tool for further studies on highthroughput EST sequencing, for example, new stressresponsive genes screening, gene chips preparing.
Cloning and sequence analysis of a plasma membrane Na╋/H╋ antiporter fragment from halophyte Suaeda salsa
2012, 6(6): 918-923.
[Abstract](1088) [PDF 1538KB](496)
Abstract:
To investigate longdistance transport of Na+ in Suaeda salsa, degenerate primers were designed based on the conserved sequences of the SOS1 genes from other plants. Total RNA was extracted from the roots of S. salsa and the SOS1 gene fragment was obtained by reverse transcription polymerase chain reaction (RTPCR) aiming to provide the foundation for cloning fulllength SOS1 gene and expression regulation. The sequencing result showed that the SOS1 gene fragment (736 bp) from S. salsa encoded 224 amino acids. Homology comparison showed that the SOS1 gene fragment shared over 74% nucleotide and 61% amino acid similarity to SOS1 fragments from other plants.
Construction of fingerprinting map based on SSR for Medicago sativa Huaiyin
2012, 6(6): 924-930.
[Abstract](1241) [PDF 590KB](411)
Abstract:
In the present study, the genetic diversity of alfalfa was investigated using SSR molecular makers and optimum number of samples was determined using different sampling strategies. Based on the optimum number of samples with the screened SSR primers, the fingerprint of Huaiyin alfalfa was built and the varieties of Huaiyin alfalfa were identified. Genomic DNA from 320 strains of Huaiyin alfalfa was set to six treatments (alfalfa DNA samples randomly obtained from a mixture of equal amount of 10, 20, 30, 40, 50 and 60 plants , respectively). Each treatment has eight repeats. Genetic diversity analysis was conducted using four pairs of SSR primers. The results showed that the genetic diversity index of the treatment of andom DNA mixture from 40 individuals was stable and the fingerprint of Huaiyin alfalfa can represent the genetic diversity of Huaiyin alfalfa groups. Fifteen alfalfa materials were tested with the treatment mentioned above and the results showed that the SSR fingerprinting could be used for the identification of varieties in Huaiyin alfalfa groups.
Callus induction and plant regeneration of Androsace longifolia
2012, 6(6): 931-936.
[Abstract](1459) [PDF 519KB](510)
Abstract:
The hypocotyls and leaves from the sterile seedlings of Androsace longifolia were taken as explants to study the effects of different hormone compositions on callus induction, bud induction and rooting. The optimum medium for hypocotyls callus induction was MS + 0.3 mgL-1 6BA + 0.1 mgL-1 NAA, and the induction rate reached 85%. The medium MS + 0.02 mgL-1 NAA + 0.3 mgL-1 TDZ was better for leaf callus induction, and the induction rate reached 80%. The buds were induced in medium MS + 0.5 mgL-1 6BA + 0.2 mgL-1 NAA from hypocotyls callus, and the differentiation rate reached 92.5%. The medium MS + 1.0 mgL-1 6BA + 0.2 mgL-1 NAA was optimal for inducing buds from leaf callus, and the differentiation rate was the highest (82.5%). The best rooting medium was medium MS + 1.0 mgL-1 IBA. The rooting rate reached 100% and survival rate reached 95%.
Distinguishing Elymus nutans from Elymus sibiricus in QinghaiTibet Plateau using a SSR marker
2012, 6(6): 937-942.
[Abstract](1082) [PDF 525KB](440)
Abstract:
Elymus nutans and E.sibiricus, which belong to Elymus genus of the Triticeae, are perennial herbaceous plants. These two species are highquality forage grasses which wildly planted in China, especially in alpine zone of QinghaiTibet Plateau. Due to ecoadaptive variation, it was often confusing while identifying some wild germplasms between them. In order to distinguish E.nutans from E.sibiricus, materials collected from Sichuan, Gansu and Tibet and somewhere else were screened using 42 SSR primers, including 21 genomic SSR and 21 ESTSSR, which located on the 21 chromosomes of wheat. The results showed that a ESTSSR primer Xcwem38c could produce 3 bands in E.nutans and 1 band in E.sibiricus in PCR system. It indicated that the band with 100 bp presented in both E.nutans and E.sibiricus, while two contiguous bands with 150 bp were only existed in E.nutans. Thus, the two bands could be used to distinguish E.nutans from E.sibiricus. At the same time, the results obtained from further cytological identification study were consistent with the molecule marker, which supported the conclusion that the ESTSSR primer Xcwem38c could be used to distinguish E.nutans from E.sibiricus effectively.
Genetic diversity analysis of 20 Dichondra repens germplasm by RAPD and SRAP
2012, 6(6): 943-949.
[Abstract](1158) [PDF 519KB](474)
Abstract:
Genetic diversity of 20 Dichondra repens wild germplasm collected from different location in southwest China, compared with an imported American variety (Common), were analyzed by RAPD and SRAP markers. The results showed that 20 RAPD primers produced 189 bands, including 130 polymorphic bands; the average percentage of polymorphic bands was 68.78%. 22 pairs of SRAP primers produced 242 bands, including 175 polymorphic bands; the average percentage of polymorphic bands was 72.31%. The 21 germplasm could be clustered into either two groups based on RAPD markers as well as SRAP markers. Moreover, the tested germplasm with same origin or similar morphology frequently clustered into the same group and showed a nice geographical distribution and relationships. There was significant positive correlation between RAPD and SRAP (r0.01=0.910), which indicated that the two methods were high consistant and reliable for detecting genetic diversity and genetic relationships in D.repens germplasms, though some germplasm were clustered into different groups between the two markers.
Nutritive value comparison among straw from different generations of hybrid offspring
2012, 6(6): 950-954.
[Abstract](1105) [PDF 390KB](398)
Abstract:
In the present study, we compared the nutrition values of straw from different generations of hybrid offspring of wild soybean (Glycine soja) and cultivated soybean (G.max), which may provide scientific basis for the forage soybean cross breeding technology. The results show that the contents of crude protein, crude ash and calcium in the reciprocal cross offspring of wild soybean and cultivated soybean are higher than those in the direct cross offspring, while the contents of crude fiber and crude fat in the reciprocal cross offspring are lower than those of direct cross offspring. From generation F1 to F4 of the hybrid offsprings through both direct and reciprocal crossing, the contents of the crude protein and crude ash in the plants increased, and the values increased from 5.66% and 4.74% to 16.34% and 6.59%, respectively. However, the contents of crude fiber, neutral detergent fiber and acid detergent fiber decreased, and the values decreased from 41.78%, 69.31% and 50.83% to 35.36%, 60.10% and 42.07%, respectively. Comprehensive comparison shows that the nutritive value of the RCF41 is the best in hybrid offspring, therefore it may be excellent forage potentially, and it could be used for breeding the forage soybean material.
Seed viability measwrement and breaking seed dormancy methods of Agriophllum squarrosum
2012, 6(6): 955-959.
[Abstract](1044) [PDF 380KB](580)
Abstract:
Eftects of pretreatments, including prechilling, preheating, scarification and concentrated sulfate acid, on breaking seed dormancy of Agriophyllum squarrosum were investigated in this study. The responses of seed viability to a pretreatment and concentrations of tetrazolium solution before staining were also explored. Results indicated that scarification before staining reduce staining time of tetrazolium solution significantly and the best performance was 1.0% of tetrazolium solution for 14-18 h staining. The scarification remarkbly broke seed dormancy of the five candidated seed lots. When seeds were pierced after 7 d of imbibition, all of seeds quickly germinated at 2 d of incubation and the average germination rate reached up to 92% at 7 d of incubation. The germination rate of scarified A.squarrosum seeds increased 47% comparing with the control treatment.
Effects of aqueous extracts from the stems and leaves of Trifolium pratense cv. Minshan ongermination and seedling growth of three crops
2012, 6(6): 960-963.
[Abstract](1292) [PDF 413KB](581)
Abstract:
The allelopathy effects of aqueous extract from Trifolium pratense cv. Minshan on three receptor plants were investigated through bioassay of seed germination and seedling growth. Red clover stems and leaves were soaked in distilled water for 48 hours. Then distilled water was added to create four grades of concentrations (0.05, 0.10, 0.15 and 0.20 gmL-1). The results showed that different concentrations of aqueous extract from the stem and leaf of red clover had different allelopathy effects on germination and seedling development of the three receptor plants. There was no significant difference on germination rate for all three receptor plants among the four concentrations of aqueous extract. However, soaking solution (less than 0.20 gmL-1) did significantly inhibit the radicle and seedling growth of pakchoi (P0.05). Soaking solution at 0.2 gmL-1 concentration significantly reduced the radicle growth of oat, Dahurian wildrye, and pakchoi by 23.76%, 35.73% and 62.50% (P0.05), respectively. Soaking solution at 0.05 gmL-1, however, significantly promoted the growth of Dahurian wildrye (P0.05). Among the three receptors, pakchoi was the most sensitive to the aqueous extract.
Effects of KI on water absorption rate of seed and iodine, Vc content of red clover seedlings
2012, 6(6): 964-967.
[Abstract](948) [PDF 488KB](499)
Abstract:
In room temperature of 20 ℃, the dynamics of water absorption rate, vitamin C and iodine contents were studied when Rider red clover was disposed in different concentration of potassium iodine solution of 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 mgL-1, respectively. The results showed that with the rising concentration of potassium iodine solution, water absorption rate and iodine content of red clover seeds increased significantly. The highest iodine content was observed in the concentration of 3.0 mgL-1. Vitamin C content of seedling plants significantly reduced with the rising concentration of potassium iodine solution.
Effects of fertilizing rate on yield and its components of Qingyin No.1 oat
2012, 6(6): 968-972.
[Abstract](1063) [PDF 390KB](515)
Abstract:
In order to find out the limited nutrient factors for oat grass yield, straw yield, seed yield and find the fertilization formulas to achieve the maximum economic efficiency, Qingyin No.1 was used to study the effect of different fertilization formulas of N, P and K on oats yield and yield components in Qinghai Huangzhong in 2010. The results showed that N was the main nutrient limiting factor for increasing fresh forage yield of oat and inputting N can improve plant height and the oat fresh forage yield significantly. N337.5P105K60 treatment had the highest yield, with 66 194 kgha-1, increased by 44.9% compared with control. P was the main nutrient limiting factor for increasing seeds yield and inputting P can improve effective tiller number and spike lets. N225P157.5K60 treatment had the highest grain yield, with 6 678 kgha-1. Through analyzing economic benefits, it was found that N225P105K60 treatment had the largest comprehensive income. Forage grass field was 18 435.3 CNYha-1 and seed producing field was 22 877.5 CNYha-1. Compared with the control group, the income increased by 4 500.9 and 45 97.5 CNYha-1, respectively.
Characteristics of soil weed seed bank of alfalfa fields among different fore crops
2012, 6(6): 973-977.
[Abstract](1080) [PDF 406KB](511)
Abstract:
To study the effects of fore crops on the characteristics of soil weed seed bank of alfalfa fields at second growing years, three different fore crops, which were Zea Mays, Lespedeza hedysaroides and Astragalus adsurgens, were designed by the inducing germination method. The results showed that, when the fore crop was Z.mays, the mainly weed of alfalfa field were Portulaca oleracea and Amaranthus retroflexus; When the fore crop was L.hedysaroides, the mainly weed were P.olerecea, Chenopodium aristatum and A.retroflexus; When the fore crop was A.adsurgens, the mainly weed were C.aristatum and A.sretroflexus. Density of soil seed bank had significant difference between L.hedysaroides and the other two fore crops (P0.05); Weed seeds of the soil seed bank mainly concentrated in 0-5 cm soil layer and the distribution of deep level was very little.
Structures and growth analysis of Puccinellia tenuiflora clone at the vegetative stage after fruiting in the Songnen Plains of China
2012, 6(6): 978-982.
[Abstract](1298) [PDF 395KB](394)
Abstract:
Using a random sampling method, an entire tiller tuft was dug out of the soil at the vegetative stage after fruiting in a single dominant community, and the module structures and growth pattern of Puccinellia tenuiflora clones were quantitatively analyzed in the natural meadow in the Songnen Plains of China. The results showed that the total number of modules was 49.0729.74, in which the jointing tillers was 53.3% and young tillers was 46.7%. The total biomass of clone was 2.541.57 g, in which the jointing and the young tillers were 90.7% and 9.3%, respectively. With increase of tuft diameters, the number of jointing tillers and young tillers, the biomass of jointing tiller were all in a linear increase, while the total number of modules and the total biomass of clone were both increased by power function; and the biomass of young tillers was in a logarithmic function increase. In addition, the biomass of jointing tillers had a linear relationship with the number of jointing tillers, so was the total biomass of clone and the total number of modules. The relationship between the biomass and the number of young tillers was a power function. These correlation coefficients were all very significant (P0.01) each other.
Structure and dynamics of Picea crassifolia populations with graze disturbance in different seasons of enclosed forest
2012, 6(6): 983-988.
[Abstract](1113) [PDF 504KB](572)
Abstract:
In the present study, the structural features of Picea crassfolia populations in Haxi forest region of Qilian Mountain nature reserve in different grazing season were investigated. We surveyed the data with the method of contiguous grid quadrats in two sample plots and investigated the population age structure, population life tables and survival function of the P.crassifolia populations. The results showed that the survival rate of P.crassfolia population in Ⅰ ageclass to Ⅱ ageclass in winter grazing season was 67.5% and the highest mortality rate appeared in the Ⅳ ageclass. The population survivorship curve was close to the Deevey Ⅰ. The maximum death density function was 1.83%, which appeared in Ⅲ ageclass. The survival rate of P.crassfolia population in summer grazing season in Ⅰ ageclass to Ⅱ ageclass was only 16.5%. The maximum survival rate appeared in the Ⅲ ageclass and the highest mortality rate appeared in the Ⅰ and Ⅵ ageclass. The population survivorship curve was close to the Deevey type Ⅱ and the survival rate was relatively stable. The maximum death density function was 0.23%, which appear in Ⅴ ageclass. Our results indicated that the effect of grazing on the structure and dynamics of P.crassifolia population in winter was stronger than that in the summer. Grazing in winter has disturbed population structure seriously, leading to lack of seedlings and saplings reserves, and population structure disorders.
Effects of enclosure on plant diversity and community characteristics in pasture of Middle Tianshan Mountain
2012, 6(6): 989-992.
[Abstract](1085) [PDF 402KB](652)
Abstract:
Three types of artificial grasslands fenced for 25 years in Middle Tianshan Moutain were used to examine the effects of enclosure on vegetation characteristics and plant diversity. The results showed that after longterm enclosure, the coverage, height and above ground biomass were improved remarkably inside of fence than those of the outside in three types of grasslands. The above ground biomass and plant average height in the fenced meadow in three types of grasslands decreased in the following order: subalpine prairie meadowsubalpine meadow prairiesubalpine prairie. The differences of above ground biomass and plant coverage between the fenced meadow and the grazed meadow were significant (P0.01). In subalpine prairie meadow and subalpine meadow prairie, the plant average height showed significant difference between inside and outside of the fence (P0.01). After fencing for 25 years, the richness index and diversity index were higher outside of the fence than that of the inside in three types of grasslands; however, the evenness index had the opposite result.
Research advances on genetic diversity in wild Cynodon dactylon germplasm
2012, 6(6): 993-998.
[Abstract](1347) [PDF 371KB](624)
Abstract:
The genetic diversity of germplasm is the basis of survival, adaptation, evolution and the improvement of species. Wild populations of Cynodon dactylon, with various botanical characteristics and diversity, are an important gene pool for improvement and innovation of C.dactylon. This paper reviewed literatures on genetic diversity of wild C.dactylon from different levels including morphology, cytopathology, protein level, molecular marker techniques and breeding. At the same time, suggestions for the further study were proposed, in order to provide reference to the study on the genetic diversity of germplasm of wild C.dactylon.
Animal demandingfeed availability balance control series (6) Animal number monthly change
2012, 6(6): 997-1001.
[Abstract](938) [PDF 428KB](487)
Abstract:
Based on the animal production data of Inner Mongolia Autonomous Region and Xilin Gol League in the past 60 years, patterns of monthly animal number change were simulated. Ratios of endyear animal number to midyear animal number were calculated and compared in every 10 years intervals. The results showed that the ratio decreased obviously in the recent 20 years, indicating the change of animal production pattern with a shrunken stocking rate in winter and an increasing selling rate in the autumn. Based on the endyear and midyear animal numbers, the pattern of animal number monthly change was deduced, and was compared with the pattern calculated from the actual observed figures. Representativeness and suitability of the monthly change pattern for animalfeed balance calculation in various situations were discussed.
A study on efficiency of napier grass and maize straw mixed silages
2012, 6(6): 1002-1006.
[Abstract](1289) [PDF 403KB](639)
Abstract:
In order to study the efficiency of mixed silages of napier grass (Pennisetum purpureum) and maize straw (Zea mays var. rugosa) with different moisture contents, the quality of mixed silages after 60 day fermentation in normal temperature was evaluated in which napier grass and maize straw with a same moisture content (71.20%) were brewed a mixed silage with 73.86%-73.10% moisture content (MC1 silage); and also napier grass with 59.30% and maize straw with 59.10% moisture content were brewed a mixed silage with 62.30%-60.91% moisture content (MC2 silage). Both MC1 and MC2 silages were mixed with 3 ratios at 80∶20, 70∶30 and 60∶40 of napier grass to maize straw by weight. Every treatment had 3 replicates. The results showed that the qualities of all the mixed silages were excellent. For both MC1 and MC2 silages, as the ratio of maize straw increased, the lactic acid content and dry matter recovery rate significantly increased (P0.01), while the pH value, the contents of moisture, acetic acid, ammoniaN, neutral and acid detergent fiber significantly decreased (P0.01 or P0.05). The quality of MC2 silage was better than that of MC1 silage.
Nutrition mechanism and application in animal feeds of amylase
2012, 6(6): 1007-1012.
[Abstract](918) [PDF 409KB](501)
Abstract:
Starch is one of the major nutrients in animal feeds and plays an important role in animal growth. Amylase, as a biocatalyzer to depredate starch, can improve utilization efficiency of grain starch and increase animal production. The research on applications of amylase in grain processing has great significance, but there was a lack of information in feed processing and animal nutrition. In this paper, the classification and current application of amylase were reviewed, and the development of amylase on animal production was also discussed.
Grassland industry and ecological security in the Hexi Corridor
2012, 6(6): 1013-1016.
[Abstract](965) [PDF 551KB](567)
Abstract:
Land desertification in the Hexi Corridor has accelerated due to changes in environments and intensification of human activities. This land desertification has threatened local economic development and ecological security of the Eurasian Continental Bridge. Based on the analysis of the Ecosecurity crisis for the Hexi Corridor, this paper indicated that ecological projects of grass industry should be built to prevent land desertification and improve Ecosecurity; and pointed out that the ecological engineering of grass industry mainly included three aspects: Firstly, windbreak and sand fixation ecological protection grass belts along the blown sand lines should be built to protect the existing grassland vegetation. Secondly, grass livestock transformation ecology industrial belts in oasis should be built to adjust planting structure. Finally, farming and animal husbandry complementary ecology displacement belts along the Qilian Mountains should be built to implement the balance between livestock numbers and forage resources.