Study on the Nutrition Characteristics of Different K Use Efficiency Cotton Genotypes to K Deficiency Stress

To study the mechanism of plant K use efficiency, both K high and low use efficiency cotton genotypes, 103 and 122, respectively, were selected from 86 cotton cultivars （Gossypium hirsutum L.）. The research was conducted using pot experiment for planting cotton on without K （0.0 g kg-1 soil） and with K （0.4 g kg-1 soil） treatments in 2005. Experimental result showed that, with K deficiency stress, genotype 103 grew much better than genotype 122 except that its lower leaves showed the symptoms of K deficiency, whereas all the leaves of genotype 122 showed the symptoms of K deficiency. Root dry matter weights of treatments for genotype 103 with and without K application were 1.07 and 1.25 times of genotype 122. It indicated that the root system of genotype 103 was well developed and has better nutrition uptake capability than that of genotype 122. The result also showed that the cotton shoots of genotype 103 were 1.07 and 1.13 times over genotype 122 on treatments of with and without K application. It indicated that genotype 103 has stronger transport organs. In genotype 103, plants, dry matter, and potassium were mainly transported to cotton bolls. The boll dry weight of genotype 103 was 2.58 times in without K treatment and 1.90 times in with K treatment over genotype 122. The potassium accumulation in bolls of genotype 122 was only 49.3% of that in genotype 103. Potassium accumulation in the other organs of genotype 103 was relatively low compared with in bolls. This indicated that the distribution of K and organic matter in genotype 103 was more efficient than genotype 122. The main differences between high K efficiency cotton genotype 103 and low K efficiency genotype 122 lie in their potassium nutrition and organic matter using efficiency on uptake, transportation, accumulation, distribution, and utilization.     

Assessment on Phosphorus Efficiency Characteristics of Soybean Genotypes in Phosphorus-Deficient Soils

A glasshouse study compared the growth and phosphorus （P） efficiency of 96 genotypes of soybean [Glycine max （L.） Merrill] in a P-deficient soil. The soybean genotypes differed greatly in growth, nodulation and P uptake after growing in the soil for 45 days, with shoot biomass ranging from 0.91 to 1.75 g per plant. The application of P improved biomass production, nodulation and P uptake and decreased root to shoot ratio, root length and surface area and P utilization efficiency. The 96 soybean genotypes were divided into 3 categories in P efficiency using the principal component analysis and cluster analysis, and 4 categories according to F values in combination with growth potentials. The Pefficient genotypes were associated with high biomass production, root to shoot ratio, root length and surface area and P uptake but low shoot to root P concentration ratio under P deficiency. The results indicate that there is a substantial genotypic variation in P efficiency in existing germplasm, and that P efficiency was correlated positively with dry weights of shoots and roots, ratio of root to shoot dry weight, root length and surface area, root P content and total P uptake. The shoot dry weight under P deficiency and relative shoot dry weight （deficient P/adequate P supply） are effective and simple indicators for screening P-efficient genotypes at the seedling stage.     

Characteristics of Potassium-Enriched, Flue-Cured Tobacco Genotype in Potassium Absorption, Accumulation, and In-Ward Potassium Currents of Root Cortex

This study was to investigate the main traits of potassium-enriched,flue-cured tobacco genotypes related to potassium absorption,accumulation,and in-ward potassium currents of the root cortex.Hydroponic methods,K -depletion methods,and patch-clamp,whole-cell recordings were conducted to study the accumulation of dry matter and potassium in different organs,and to measure potassium absorption and dynamic and in-ward potassium currents in potassium-enriched,fluecured tobacco genotypes.The average dry weights of leaves and whole plant of potassium-enriched,flue-cured tobacco genotype ND202 were 10.20,and 14.85g,respectively,higher than JYH(8.50 and 13.11g,respectively)and NC2326(8.39 and 12.72g,respectively),when potassium concentration in the solution ranged from 0.1 to 50mmol L-1.Potassium accumulation in the leaves of ND202 was 18.6% higher than JYH and 34% higher than NC2326 when potassium concentration in the solution was superior to 0.5mmol L-1.The Vmax(the maximum velocity)of ND202 was 118.11μmol FW g-1h-1,obviously higher than that of JYH(58.87 μmol FW g-1 h-1)and NC2326(64.40μmol FW g-1 h-1).In the in-ward potassium currents,the absolute value of current density(pA/pF)of ND202 was 60,higher than that of JYH(50)and NC2326(40).Potassium concentration in leaves,Vmax and in-ward potassium currents,could be used to screen potassium-enriched,flue-cured tobacco genotypes.     

Screening of diverse cassava genotypes based on nitrogen uptake efficiency and yield

As one of the top three tuber crops of the world, cassava is a staple food and feed crop for tropical and subtropical regions. Because of its high drought resistance and tolerance to nutrient deficiency, cassava is usually cultivated on hilly areas that are nutrient-poor. Nitrogen(N) is one of the significant factors affecting cassava yield. A double factorial(N level×genotypes) split-plot field experiment was conducted to analyze differences in yield and N accumulation of 25 cassava genotypes under low-N conditions to screen for cassava genotypes with high-N efficiency. The two-year field experiment showed that cassava yield and N accumulation are determined by specific genotypes, soil N levels, and year. Among these factors, soil N levels are the main factors that are responsible for differences in cassava yield. When yield and relative N accumulation under low-N conditions were used as screening markers, we identified an efficient and responsive genotype(SC10), and two inefficient and non-responsive genotypes(SC205 and GR5). The efficient and responsive genotype and the inefficient and non-responsive genotype can be used as study materials to further reveal the mechanisms for high-N efficiency in cassava.     

The Difference in Growth and Four Microelement Concentrations Between Two Rice Genotypes Differing in Grain Cadmium-Accumulating Capacity

A pot experiment was conducted with two rice genotypes having different Cd concentrations in their grains to study the effect of soil Cd level on biomass, Cd and Fe, Zn, Cr and Pb accumulation in different plant parts. Cd was added into soil to form 4 levels, i.e.,0, 0.5, 2.5 and 12.5 mg kg^-1, respectively. The results showed that the Cd-induced reduction in biomass accumulation varied in both genotypes and growth stages. The Cd-induced reduction in biomass became less with the progress of growth, and Xiushui63, a genotype with relatively higher grain Cd concentration, was more severely inhibited than Xiushui217,a relatively lower Cd concentration. Both Cd concentration and accumulation in the various plant parts increased substantially with the increase of Cd levels. The difference between two genotypes in Cd concentration and accumulation became more pronounced with increased Cd level as well as prolonged duration of exposure. Xuishui63 had much greater Cd accumulation than Xiushui217, in particular at late growth stage. Xuishui63 had a remarkably higher Cd translocation of roots to shoots than Xiushui217 in all Cd levels.The effect of Cd addition on four microelement concentrations in straw and milled riceal so varied in genotypes and Cd levels. Without Cd addition, Xiushui63 was significantly lower than Xiushui217 in the concentrations of all four elements in straw, while the case was just opposite in milled rice. Zn, Fe and Pb concentrations decreased in milled rice with the increase of Cd level, although the reduction extent differed in two genotypes.The results indicated that Cd concentration in rice grain is primarily dependent on the shoot Cd concentration, which is in turn mainly determined by Cd translocation from roots to shoots.     

Nucleic Acid Metabolism,Proline Concentration and Antioxidants Enzyme Activity in Canola （Brassica nupus L.） Under Salinity Stress

Seedling of five canola genotypes, Hyola 308, Hyola 401, Hyola 60, Option 50 and RGS003, were grown in Hoagland nutrient solution containing S1 = 0, S2 = 100, S3 = 200 and S4 = 300 mmol L-1 NaCl in controlled environment. Proline, antioxidant activities like catalase （CAT）, ascobrate peroxidase （APX） and guaiacol peroxidase （GPX） and some enzyme activities of nucleic acid metabolism were determined in shoot and root 20 days after induction of salinity stress. Results showed application of stress significantly affected plant growth components such as fresh （FW） and dry weight （DW） of canola genotypes. Among the genotypes, RGS003 had the highest reduction of FW and DW in S3 treatment. By increasing NaCl levels from 0 to 300 mmol L-1, the activity of two antioxidant enzymes （APX and CAT） in shoot and root increased but GPX in all of genotypes decreased. The increase in salinity stress, increased proline concentration in both root and shoot tissues of canola genotypes. Hyola 401 genotype had the maximum concentration of proline in root and shoot in S3 treatment. Along with increased salinity stress in all of the studied plants, salinity significantly increased the level of the total nucleic acid and the activity of DNase I in all of salinity treatments and at the S3 level, RGS003 had the maximum concentration of nucleolytic enzyme.     

Effect of Indole Butyric Acid on the Transportation of Stored Calcium in Malus hupehensis Rhed. Seedling

Calcium （Ca） plays an important role in the metabolism of higher plants. Recently, research on Ca^2＋ in plants has been focused especially at the cellular and molecular levels. Uptake, transport, and distribution are also very important for Ca to accomplish its function at the whole-plant level. In this experiment, one-year-old apple seedlings （M. hupehensis Rehd.） were investigated to determine the distribution of stored Ca, the different forms of Ca, and Ca^2＋-ATPase activity after treatment with indole butyric acid （IBA）. The results showed that the total Ca measured in mature leaves and Ca^2＋- ATPase activity in tender leaves were higher compared with those in the control （CK）. Calcium nitrate and calcium chloride （ALe-Ca） and calcium phosphate and calcium carbonate （HAC-Ca） decreased in both mature leaves and shoots, whereas water-soluble calcium （H2O-Ca）, calcium pectate （NaCl-Ca）, and calcium oxalate （HCl-Ca） increased. The percentage of active calcium, calcium pectate, and water-soluble calcium increased, whereas the percentage of calcium phosphate and calcium carbonate decreased. When treated with IBA, calcium fractions and percentage of the different forms of Ca was enhanced in 40 part per million （ppm） IBA compared with 20 ppm IBA and water. The results indicated that IBA increased the percentage of both active calcium （NaCl-Ca and H2O-Ca） in tender shoots and boosted the transportation of stored Ca in plants. IBA promoted Ca^2＋-ATPase activity and Ca^2＋ uptake in tender shoots of M. hupehensis. It can improve the total Ca contents and the relative percentage of Ca.     

Effect of Partial Root-Zone Irrigating Deuterium Oxide on the Properties of Water Transportation and Distribution in Young Apple Trees

Partial root-zone irrigation （PRI） has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water （D2O） in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.     

Stability analysis of different cotton genotypes under normal and water-deficit conditions

Cotton plant observes significant reduction in seed cotton yield when subjected to water stress. To find out genotypes having better drought tolerance, seven genotypes of Gossypium hirsutum L. were tested under two moisture levels, i.e., normal and water deficit stress conditions at five locations of Punjab, Pakistan(Faisalabad, Sahiwal, Vehari, Rahim Yar Khan, and Bahawalpur) in 2013 and 2014. Genotype×environment interaction(GEI) was studied using the genotype main effects and genotype by environment interaction(GGE) biplot and additive main effect and multiplicative interaction analysis. The genotypes G3(7001/11) and G6(FH-942) were stable under normal condition, while under drought condition, the stable genotype was G5(FH-326) when analysed using additive main effects and multiplicative interaction(AMMI) biplot scheme. While GGE biplot analysis on the basis of best performance revealed that under normal condition the genotypes, G1(L-13/10) and G2(FH-2056/10), carrying the common position in biplot. Whereas, under water deficit stress condition, G5 was the best adaptive genotype at all five locations. In the same way, ranking of genotypes showed that the G5 was the ideal genotype under both conditions. So, it is concluded that the genotype G5(FH-326) was found best for water deficit stress condition and can be cultivated under water scarce areas of Punjab.     

Corelation Between Single Nucleotide Polymorphisms in Mu Opioid Receptor Exon 2 and Stereotypic Behaviour in Sows

Three breeds of sows were observed to investigate the relationship between Single Nucleotide Polymorphisms（SNPs） in Mu Opioid Receptor（MOR）and stereotypic behaviour,such as,sham-chewing,bar biting and standing still in order to better understand the mechanism of stereotypic development of the animals in restrained conditions.MOR exon 2 partial sequences were amplified to analyze single nucleotide polymorphisms by PCR-SSCP.One SNP,a silence mutant was found.A significant difference （P〈0.01）was found in the frequency of genotypes in these 3 breeds where only the BB genotype,which was identical to that published in GenBank,was found in the Duroc breed,while no AA genotype was found in Landrace,3 genotypes AA,BB and AB were found in Yorkshire.The result also indicated that the individuals with AA and AB genotypes tended to be more active in sham-chewing than those with the BB genotype（P〈0.05）.The overall results of this study suggested that sham-chewing of sows may be subjected to both genetic control and environmental conditions,but activity level was more likely to be affected by their environment.We can putatively draw the conclusion that MOR gene has effect on the sham-chewing behavioral traits of sow.     

A major quantitative trait locus controlling phosphorus utilization efficiency under different phytate-P conditions at vegetative stage in barley

Organic phosphorus(P) is an important component of the soil P pool, and it has been proven to be a potential source of P for plants. The phosphorus utilization efficiency(PUE) and PUE related traits(tiller number(TN), shoot dry weight(DW), and root dry weight) under different phytate-P conditions(low phytate-P, 0.05 mmol L~(–1) and normal phytate-P, 0.5 mmol L~(–1)) were investigated using a population consisting of 128 recombinant inbred lines(RILs) at the vegetative stage in barley. The population was derived from a cross between a P-inefficient genotype(Baudin) and a P-efficient genotype(CN4027, a Hordeum spontaneum accession). A major locus(designated Qpue.sau-3 H) conferring PUE was detected in shoots and roots from the RIL population. The quantitative trait locus(QTL) was mapped on chromosome 3 H and the allele from CN4027 confers high PUE. This locus explained up to 30.3 and 28.4% of the phenotypic variance in shoots under low and normal phytate-P conditions, respectively. It also explains 28.3 and 30.7% of the phenotypic variation in root under the low and normal phytate-P conditions, respectively. Results from this study also showed that TN was not correlated with PUE, and a QTL controlling TN was detected on chromosome 5 H. However, dry weight(DW) was significantly and positively correlated with PUE, and a QTL controlling DW was detected near the Qpue.sau-3 H locus. Based on a covariance analysis, existing data indicated that, although DW may affect PUE, different genes at this locus are likely involved in controlling these two traits.     

Efficiency of potassium-solubilizing Paenibacillus mucilaginosus for the growth of apple seedling

Chemical potassium(K) fertilizer is commonly used in apple(Malus domestica L. Borkh) production but K is easily fixed by soil, resulting in reduced K fertilizer utilization and wasted resources. K-solubilizing bacteria(KSB) can cost-effectively increase the soluble K content in rhizosphere soil. Therefore, the objectives were to select high-efficiency KSB from apple orchards under various soil management models and evaluate their effects on apple seedling growth. Maize(Zea mays L.) straw mulching(MSM) increased the total carbon(TC), total nitrogen(TN) and available potassium(AK) in the rhizosphere and improved fruit quality. The number of KSB in the rhizosphere soil of MSM was 9.5×104 CFU g–1 soil, which was considerably higher than that in the other mulching models. Fourteen KSB strains were isolated with relative K solubilizing ability ranging from 17 to 30%, and five strains increased the dry weight per apple seedling. The most efficient strain was identified as Paenibacillus mucilaginosus through morphological observation and sequence analysis of 16 S rDNA, named JGK. After inoculation, the colonization of JGK in soil decreased from 4.0 to 1.5×10~9 CFU g~(–1) soil within 28 d. The growth of the apple seedlings and the K accumulation in apple plants were promoted by irrigation with 50 mL JGK bacterial solution(1×10~9 CFU mL~(–1)), but there was no significant increase in the AK content of rhizosphere soil. High-performance liquid phase analysis(HPLC) data showed that the JGK metabolites contained phytohormones and organic acids. Hence, the JGK strain promoted the growth of two-month-old apple seedlings by stimulating function of the produced phytohormones and enhanced K solubility by acidification for apple seedling uptake. This study enriches the understanding of KSB and provides an effective means to increase the K utilization efficiency of apple production.     

Canopy Temperature Depression as a Potential Selection Criterion for Drought Resistance in Wheat

Field studies were conducted at Bushland, Texas, USA, in 2004 to examine usefulness of canopy temperature depression （CTD）, the difference of air-canopy temperature, in screening wheat （Triticum aestivum L.） genotypes for yield under dryland and irrigated. Forty winter wheat genotypes were grown under irrigation and dryland. CTDs were recorded after heading between 1 330 and 1 530 h on 6 clear days for dryland and 9 days for irrigation. Drought susceptible index （DSI） for each genotype was calculated using mean yield under dryland and irrigated conditions. Genotypes exhibited great differences in CTD under each environment. The dryland CTDs averaged 1.33℃ ranging from -0.67 to 2.57℃, and the average irrigation CTD were 4.59℃ ranging from 3.21 to 5.62℃. A low yield reduction was observed under dryland conditions relative to irrigated conditions for high-CTD genotypes. CTD values were highly negatively correlated with DSI under dryland, and genotypes of CTDs = 1.3℃ in dryland condition were identified as drought resistant. For 21 genotypes classified as drought resistant by DSI, their CTDs were 1.68℃ for dryland and 4.35℃ for irrigation on average; for 19 genotypes classified as drought susceptible by DSI, average CTD was 0.94℃ in dryland and 4.85℃ in irrigation. The high-yield genotypes consistently had high CTD values, and the low-yield ones had low CTD values for all measurements in dryland. After heading, genotypes maintained consistent ranking for CTD. Regression results for CTD and yield suggested that the best time for taking CTD measurement was 3-4 weeks after heading in irrigation but any time before senescence in dryland. Crop water stress index （CWSI） calculated from CTD data was highly correlated with CWSI calculated from yield, which suggesting traditional costly CWSI measurement may be improved by using portable infrared thermometers. Most importantly, grain yield was highly correlated with CTD under dryland （R^2 = 0.79-0.86） and irrigation （R^2 = 0.46-0.58） conditions. These results clearly indicated grain yield and water stress can be predicted by taking CTD values in field, which can be used by breeding programs as a potential selection criterion for grain yield and drought resistance in wheat, but a second study year is needed to confirm further.     

不同苹果砧木的根际土壤微生物数量及酶活性

【目的】研究不同苹果砧木对土壤根际微生物数量和酶活性的影响。【方法】通过盆栽试验,采用微生物稀释平板培养法对平邑甜茶（Malus hupehensis Rehd.）、八棱海棠（M.micromalus Makino）、楸子（M.prunifolia(Willd) Borkh.）、新疆野苹果（M. sievesii(Ledeb.) Roemer）、东北山荆子（M.baccata Borkh.）等5种苹果砧木土壤根际微生物数量、土壤酶活性及其相关性进行研究。【结果】不同苹果砧木土壤根际微生物各生理类群数量差异显著,并且都以细菌占绝对优势,放线菌次之,真菌最少。土壤微生物多样性指数的变化趋势与土壤微生物数量的变化趋势不一致。不同苹果砧木土壤根际蔗糖酶、磷酸酶、脲酶和过氧化氢酶活性各异。皮尔逊相关分析得知,土壤微生物数量与土壤酶活性之间存在相关关系。【结论】选择合适的苹果砧木,有利于土壤微生物数量和酶活性的提高,从而为苹果树生长创造良好的微生态环境。     

Study on the Effect of ESR and FSH β Genes on Litter Size in Local Northeast Three Pig Breeds

The method of PCR-RFLP was used to analyze the effects of ESR and FSH β genotypes on the litter size, especially the corresponding changes with the difference of genotype distributions in the Min, Sanjiang and Junmu I pigs. The results show that the ESR and FSH β genes are the major genes of litter size ; the heterozygous genotype for ESR as well as for FSH β locus has a more litter size than others. However, the combined genotype ABDD means a more litter size than other genotypes,the frequencies of the heterozygous genotypes in Sanjlang and Junmu I are lower than in Min which maybe one of the most important reasons for the little litter sizes of those two breeds.     

Seasonal Variation of Major Elements in South Lake Cyohoha,Rwanda

The paper analyzed the seasonal variation of the concentrations of Cr,Mn,Al,N,P,As,Ba,Ca,Cu,Fe,Mg,and K in South Lake Cyohoha water using spectroscopic technique.Water samples were taken monthly at Ngenda,Karehe and Nyamabuye stations from January 2009 to December 2010.The results showed that the concentrations of aluminum,nitrogen,potassium,arsenic,phosphorous,manganese,chromium,barium and copper were high during the raining season and low during the dry season,while calcium,iron and magnesium varied independently with seasonal change.The results of conductivity and pH also confirmed the effects of seasonal change on the quality of water in the South Lake Cyohoha since the highest value of conductivity was found during the raining season,while the smallest was observed during the dry season,for pH the highest number was noticed during the dry season and the lowest during the raining season.     

Effects of Microbial Inoculants on Nutrient Availability and Rice Yield

Under fi eld conditions,an experiment was conducted to study the effects of ammonifi cation bacteria,potassium bacteria and phosphorus bacteria on nutrient availability in soil and yield of rice in the cold region of China and compared to the conventional fertilization.Results showed that DF1P2 treatment(ammonifi ers 1.5×10~8 cfu·m~(-2),phosphorus bacteria 1.5×10~8 cfu·m~(-2),and potassium bacteria 1.5×10~8 cfu·m~(-2))increased available nutrient concentrations in soil,increased the concentrations of N,P,and K in plant organs and increased the rice yield and was the most signifi cantly among all the treatments.This treatment could be recommended as the best suitable biological fertilizer application rate for the rice production in the cold region of China.     

Study of the Protective Effects in PEPC Transgenic Rice

The diurnal course of chlorophyll fluorescence parameter and active oxygen metabolism of flag leaves in PEPC transgenic and untransformed rice Kitaake were studied. The results showed that the photosynthetic rate under high light intensity has been increased by 50% and photoinhibition of photosynthesis in PEPC transgenic was alleviated after the introduction of PEPC gene from maize into rice. It was demonstrated that the increment of photosynthesis in PEPC transgenic was related to the introduction of PEPC gene using specific inhibitor of PEPC. Photoinhibition of photosynthesis in different genotypes exists at noon under natural condition. PEPC transgenic rice exhibited a less decrease in Fv/Fm, a less photoinhibition and a higher efficiency of light energy conversion to chemical energy and lower thermal energy dissipation.These results provided the physiological basis on the mechanism of tolerance to photoinhibition and rice breeding with high photosynthetic efficiency.     

Effects of Application of Nitrogen, Potassium and Glycinebetaine on Alleviation of Water Stress to Summer Maize

A pot experiment was conducted under water deficit and adequate water-supplied conditions with two maize genetypic varieties （Shaandan 9 and Shaandan 911） to study the effects of nitrogen, potassium and glycinebetaine （GlyBet） on the dry matter and grain yields as well as water use efficiency （WUE）. Determinations were made at different stages of the two varieties for revealing the function of these factors in increasing plant resistance to drought. Results showed that under a water-stressed condition, dry matter and grain yield were significantly reduced. However, the response of the two varieties to water stress was different： Shaandan 9 was significantly higher in dry matter and grain yields, and therefore could be regarded as a drought-resistant variety compared to Shaandan 911.Application of nitrogen, potassium and glycinebetaine raised dry matter and grain yield to different levels, and thereby alleviated the water stress and increased water use efficiency. These effects were higher for Shaandan 911 than for Shaandan 9. Under water-stressed conditions application of N fertilizer, either at low rate or at high rate, significantly increased dry matter, grain yield and water use efficiency. A significant different effect was found for Shaandan 911 between N rates, but not so for Shaandan 9. However, with supplemental water supply, effects of N fertilization were obviously decreased, showing that in addition to supplying nutrient, N fertilizer has a function in increasing drought-resistance of the crop. Potassium and glycinebetaine exhibited a remarkable function in increasing dry matter and grain yields as well as water use efficiency under water stress while such effects were obviously declined, even vanished, with supplemental water supply, indicating the important contribution of these factors in rise of drought-resistance ability of a crop.     

Apple Pectin Behavior Separated by Ultrafiltration

Separation conditions of ultrafiltration for apple pectin, weights and their structures and properties are studied and relations between apple pectin with different relative molecular Five kinds of ultrafiltration membranes with different molecular weight cut-offs are used to separate apple pectin. FT-IR and HPGC are used individually to determine the structures and monosaccharide composition of apple pectin with different relative molecular weights. In the case of transmembrane pressure difference of 0.08 MPa, material concentration of 1 g·L^-1, and temperature of 50℃, 6 kinds of apple pectins with different molecular weights have been obtained. Molecular weight of apple pectin is correspondingly related to its physicochemical properties. The galacturonic acid contents and esterification and gelatination degrees increase relatively with an increase in molecular weight, and the monosaccharide composition relatively increase much more. And at the same time, the ultrafiltration has a better role to play in decoloring apple pectin solution. Accordingly, this research can be used as a new method for in-depth exploration of apple pectin.