Cassava productivity is hampered by pests and diseases including cassava<span style="font-family:;" "=""><span style="font-family:Verdana;"> mosaic disease (CMD) and cass...Cassava productivity is hampered by pests and diseases including cassava<span style="font-family:;" "=""><span style="font-family:Verdana;"> mosaic disease (CMD) and cassava brown streak disease (CBSD).</span><b> </b><span style="font-family:Verdana;">The main ob</span><span style="font-family:Verdana;">jective of this study was to identify stable superior genotypes that combine</span><span style="font-family:Verdana;"> dis</span><span style="font-family:Verdana;">ease resistance and high yield. Sixteen cassava genotypes were planted in a</span> <span style="font-family:Verdana;">randomized complete block design with three replications for six planting </span><span style="font-family:Verdana;">seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (</span></span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;">< 0.001) effects of genotype, environment, and genotype-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">by-environment (</span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;">) interactions were observed for all traits studied. Per</span><span style="font-family:Verdana;">cent sum of squares (SS) due to environment (12.66% - 85.23%) was the</span><span style="font-family:Verdana;"> highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) </span><span><span style="font-family:Verdana;">was highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (26.14% - 35.91%) for CBSD foliar and root</span></span><span style="font-family:Verdana;"> symptoms indicating that the environment and </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.</span></span>展开更多
Tomato(Solanum lycopersicum L.)belonging to the family Solanaceae is the second most consumed and cultivated vegetable globally.Since the ancient time of its domestication,thousands of cultivated tomato varieties have...Tomato(Solanum lycopersicum L.)belonging to the family Solanaceae is the second most consumed and cultivated vegetable globally.Since the ancient time of its domestication,thousands of cultivated tomato varieties have been developed targeting an array of aspects.Among which breeding for yield and yield-related traits are mostly focused.Cultivated tomato is extremely genetically poor and hence it is a victim for several biotic and abiotic stresses.Among the biotic stresses,the impact of viral diseases is critical all over tomato cultivating areas.Improvement of tomato still largely rely on conventional methods worldwide while molecular approaches,particularly Marker Assisted Selection(MAS)has become popular across the globe as a fast,low cost and precise tool which is essential in present day plant breeding.In this review paper,breeding tomato for high yield and viral disease resistance,particularly to tomato yellow leaf curl virus disease(TYLCVD)using conventional and molecular approaches will be discussed.Lining up of this set of information will be useful to those who are interested in tomato variety development with high yielding and TYLCVD resistance.展开更多
[Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth ...[Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth area were identified by wheat stripe rust under high temperature; then the wheat cultivars showing stripe rust at seedling stage were further used to identify the same resistance in field. [Results] 13 cultivars were proved to be stripe rust resistant under high temperature, and the expression stages of stripe rust in the 13 cultivars were revealed. The field identification results confirmed the identification results at seedling stage via inoculation of mixed stripe rust of physiological races. The stripe resistances of wheat cultivars were also proved to be non-race-specific. [Conclusion] Wheat resources in Huanghuai growth area are abundant in wheat cultivars with high temperature resistance to stripe rust.展开更多
Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it in...Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.展开更多
Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have
Objective To examine insulin resistance and high sensitivity C-reactive protein (hsCRP) association with clinical and angiographic severity of coronary artery disease (CAD) in patients with normal glucose toleranc...Objective To examine insulin resistance and high sensitivity C-reactive protein (hsCRP) association with clinical and angiographic severity of coronary artery disease (CAD) in patients with normal glucose tolerance. Methods In 638 consecutive patients with normal glucose tolerance, 221 had atypical chest pain and normal coronary artery (control group), 279 had stable angina and CAD (SAP group ), and 138 suffered acute myocardial infarction ( MI group). The degree of CAD was further divided into borderline lesion ( lumen diameter narrowing 50% - 69% ), significant 1-, 2- or 3-vessel disease ( luminal diameter narrowing 〉I 70% ). Fasting serum glucose, insulin and hsCRP levels and lipid profiles were measured, and homeostasis model assessment for insulin resistance ( HOMA-IR ) was calculated. Multivariate analysis was performed to assess risk factors for 3-vessel disease or acute MI. Results Serum hsCRP, lipoprotein (a) levels, and insulin resistance index (IRI) were higher in AMI group than those in SAP and control groups. Serum hsCRP level and IRI were also higher in 3-vessel disease than those in other groups. Multivariate regression analysis revealed that insulin resistance, cigarette smoking, serum hsCRP, and lipoprotein (a) levels were independent risk factors for acute MI. Lipoprotein ( a ) elevation was an independent risk factor for 3-vessel disease. Conclusion Insulin resistance and high serum hsCRP level were associated with occurrence of acute MI and angiographic severity of coronary disease in patients with normal glucose tolerance.展开更多
As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or...As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or QTL from the AA genome wild rice O. longistaminata, which is characterized by tall and robust habit and long tassels and anthers and shows high potential for use in cultivated rice improvement. We constructed a stable BC_(2)F_(20) backcross inbred line(BIL) population of 152 lines from the cross of 9311 × O.longistaminat. Some BILs showed large panicles, large seeds, and strong resistance to rice false smut, bacterial leaf blight, rice blast spot, and brown planthopper. Genomic resequencing showed that the 152 BILs covered about 99.6% of the O. longistaminata genome. QTL mapping with 2432 bin markers revealed 13QTL associated with seven yield traits and eight with resistance to brown planthopper and to four diseases. Of these QTL, 12 for grain yield and 11 for pest and disease resistance are novel in Oryza species.A large-panicle NIL1880 line containing QTL qPB8.1 showed a nearly 50% increase in spikelet number and27.5% in grain yield compared to the recurrent parent 9311. These findings support the potential value of O. longistaminata for cultivated rice improvement.展开更多
Objective The aim of this study is by observing the number change of islets beta cells in gestational rats exposed to high fat diet, tofurther reveal the mechanism of gestational diabetes mellitus. Methods Female Wist...Objective The aim of this study is by observing the number change of islets beta cells in gestational rats exposed to high fat diet, tofurther reveal the mechanism of gestational diabetes mellitus. Methods Female Wistar rats were exposed to high fat diet for five weeks, and then became pregnant. During pregnancy dynamically detected indicators of glucose and fat. Until the third trimester of pregnancy evaluated the sensitivity of insulin and glucose tolerance. After executed rats, selected pancreatic tail tissue and fixed, further slides were stained with insulin antibody by immunohistochemistry to confirm the location of beta cells. Image analysis system determined mean area stained positive cells in each islet, which stood for total number of beta cells. The apoptotic beta cells in islet were detected and quantified by the Tunel technology to calculate apoptosis ratio. Results The level of free fatty acids in rats exposed to high fat diet was significantly higher than the control groups, and insulin resistance was more serious. Compared mean stained positive area among each group, the largest was gestational rats fed high fat diet, and gestational rats was larger than virgin rats, but the difference had no statistical significance. About apoptoticratio of beta cells was higher in diet intervened rats, gestational rats were higher than virgin rats. The same trend happened in the number of positive cells, but discrepancy was not remarkable. Conclusion Based on insulin resistance, apoptosis of pancreatic beta cellsincreased in gestational ratstaking high fat diet, through changing the number of beta cells to down regulate the pancreas endocrine function. That may be the mechanism of gestational mellitus.展开更多
The equiatomic TiNbZrTaHf alloy was successfully rolled at room temperature with the reduction of ~ 85%. The microstructure and tensile properties were investigated after cold working and annealing. It was determined ...The equiatomic TiNbZrTaHf alloy was successfully rolled at room temperature with the reduction of ~ 85%. The microstructure and tensile properties were investigated after cold working and annealing. It was determined that the recrystallization temperature of the TiNbZrTaHf alloy between 850 and 900 ℃. Complete recrystallization and normal grain growth occurred, the high stability of single phase was maintained after annealing at 1000, 1200, and 1400 ℃. But the precipitated phase appeared after long term annealing, as seen after 500 h at 1000 ℃. After cold working, the tensile strength and the elongation of TiNbZrTaHf were 1137 MPa and 25.1%, respectively. The annealed alloy has a high tensile strength (σ_(b )= 863 MPa) and ductility (ε_(e )= 28.5%). Moreover, the oxidation of TiNbZrTaHf alloy at elevated temperatures has a significant impact on its mechanical properties. The poor oxidation resistance of TiNbZrTaHf can accelerate tensile failure by inducing fractures at grain boundaries.展开更多
According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and exis...According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and existing problems concerning high-quality inbred rice va- riety in Guangxi: the rice quality has been greatly improved,but the amylose content is still low; a series of scented rice varieties with high quality and high yield have been bred,such as Zhongguangxiang No. 1,Sanxiang 628,Guixiang No. 1,Liufengxiangzhan,Jiafuxiang No. 1, Zhaoxiang No. 1; the production of high-quality inbred rice during the period 2009-2011 was significantly enhanced,annually more than 66 00 kg / ha,but the disease resistance of rice variety bred was generally poor,and disease-resistant breeding stuck in the mud. Henceforth it is necessary to be oriented by the rice market,and take the rice type with long grain,high adhesive strength,medium-low amylose content and low chalkiness degree as the breeding objectives; introduce the existing high-quality variety resources with medium amylose content at home and abroad,then directly use them or innovate upon them as hybrid strain; take the thick-and-long-grain rice type as breeding objectives,and further improve the yield per unit area of high-quality inbred rice by improving the thousand-grain weight; increase capital investment,improve breeding techniques,strengthen disease-resistant and degeneration-resistant breeding,and improve the application of modern biotechnology in the breeding of high-quality inbred rice.展开更多
[目的]气候变化新形势下,进一步筛选适宜西北地区抗寒、抗抽干葡萄砧木品种,可为葡萄免埋土栽培推广提供理论依据和技术支撑。[方法]本文以41Bmgt、Riparia、420Bmgt、101-14、196-17、44-53ma、110R、Rupestris du Lot、SO4、161-490、...[目的]气候变化新形势下,进一步筛选适宜西北地区抗寒、抗抽干葡萄砧木品种,可为葡萄免埋土栽培推广提供理论依据和技术支撑。[方法]本文以41Bmgt、Riparia、420Bmgt、101-14、196-17、44-53ma、110R、Rupestris du Lot、SO4、161-490、1103P、5BB、3309、Leon Millt共14种13年生葡萄砧木为试材,通过测定离体一年生枝条累计失水速率,结合田间调查葡萄砧木存活率和离体一年生枝条抽干率,以此来评价不同葡萄砧木品种抗抽干能力;结合前人研究及砧木品种特性,采用高低温交变试验箱模拟低温的方法,设置4(对照)、-15、-20、-25和-30℃一系列温度梯度水平,测定不同葡萄砧木一年生枝条相对电导率、丙二醛、游离脯氨酸、可溶性糖及可溶性蛋白5个生理生化指标,利用隶属函数法进行综合评价不同葡萄砧木的抗寒性。[结果]不同葡萄砧木的抗抽干能力由强到弱依次为:3309>161-490>196-17>Leon Millt>420Bmgt>44-53ma>Riparia>110R>1103P>SO4>101-14>41Bmgt>5BB>Rupestris du Lot;随着处理温度的降低,不同葡萄砧木枝条的抗寒指标总体呈现上升趋势,但不同品种之间存在差异。根据隶属函数的综合分析,结果显示各葡萄砧木的抗寒性由强到弱依次为:SO4>196-17>Leon Millt>5BB>Riparia>44-53ma>420Bmgt>1103P>3309>110R>Rupestris du Lot>101-14>41Bmgt>161-490。[结论]Riparia、196-17、44-53ma和Leon Millt具有较强的抗抽干能力和抗寒性,可作为我国西北地区免埋土葡萄砧木使用。展开更多
文摘Cassava productivity is hampered by pests and diseases including cassava<span style="font-family:;" "=""><span style="font-family:Verdana;"> mosaic disease (CMD) and cassava brown streak disease (CBSD).</span><b> </b><span style="font-family:Verdana;">The main ob</span><span style="font-family:Verdana;">jective of this study was to identify stable superior genotypes that combine</span><span style="font-family:Verdana;"> dis</span><span style="font-family:Verdana;">ease resistance and high yield. Sixteen cassava genotypes were planted in a</span> <span style="font-family:Verdana;">randomized complete block design with three replications for six planting </span><span style="font-family:Verdana;">seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (</span></span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;">< 0.001) effects of genotype, environment, and genotype-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">by-environment (</span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;">) interactions were observed for all traits studied. Per</span><span style="font-family:Verdana;">cent sum of squares (SS) due to environment (12.66% - 85.23%) was the</span><span style="font-family:Verdana;"> highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) </span><span><span style="font-family:Verdana;">was highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (26.14% - 35.91%) for CBSD foliar and root</span></span><span style="font-family:Verdana;"> symptoms indicating that the environment and </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.</span></span>
基金the Long-term Research Grant Scheme(LRGS),Ministry of Higher Education,Malaysia,Project No.LRGS/1/2019/UKM/5,Vote No.6300242 for the financial support to conduct activities on this research program.
文摘Tomato(Solanum lycopersicum L.)belonging to the family Solanaceae is the second most consumed and cultivated vegetable globally.Since the ancient time of its domestication,thousands of cultivated tomato varieties have been developed targeting an array of aspects.Among which breeding for yield and yield-related traits are mostly focused.Cultivated tomato is extremely genetically poor and hence it is a victim for several biotic and abiotic stresses.Among the biotic stresses,the impact of viral diseases is critical all over tomato cultivating areas.Improvement of tomato still largely rely on conventional methods worldwide while molecular approaches,particularly Marker Assisted Selection(MAS)has become popular across the globe as a fast,low cost and precise tool which is essential in present day plant breeding.In this review paper,breeding tomato for high yield and viral disease resistance,particularly to tomato yellow leaf curl virus disease(TYLCVD)using conventional and molecular approaches will be discussed.Lining up of this set of information will be useful to those who are interested in tomato variety development with high yielding and TYLCVD resistance.
文摘[Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth area were identified by wheat stripe rust under high temperature; then the wheat cultivars showing stripe rust at seedling stage were further used to identify the same resistance in field. [Results] 13 cultivars were proved to be stripe rust resistant under high temperature, and the expression stages of stripe rust in the 13 cultivars were revealed. The field identification results confirmed the identification results at seedling stage via inoculation of mixed stripe rust of physiological races. The stripe resistances of wheat cultivars were also proved to be non-race-specific. [Conclusion] Wheat resources in Huanghuai growth area are abundant in wheat cultivars with high temperature resistance to stripe rust.
基金sponsored by Department of Agriculture and Co-operation and Farmer Welfare(DAC&FW),Ministry of Agriculture,Government of India and Mars Wrigley,USAthe award of Junior/Senior Research Fellowship from Department of Biotechnology,Government of Indiapart of the CGIAR Research Program on Grain Legumes and Dryland Cereals(GLDC)
文摘Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.
文摘Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have
文摘Objective To examine insulin resistance and high sensitivity C-reactive protein (hsCRP) association with clinical and angiographic severity of coronary artery disease (CAD) in patients with normal glucose tolerance. Methods In 638 consecutive patients with normal glucose tolerance, 221 had atypical chest pain and normal coronary artery (control group), 279 had stable angina and CAD (SAP group ), and 138 suffered acute myocardial infarction ( MI group). The degree of CAD was further divided into borderline lesion ( lumen diameter narrowing 50% - 69% ), significant 1-, 2- or 3-vessel disease ( luminal diameter narrowing 〉I 70% ). Fasting serum glucose, insulin and hsCRP levels and lipid profiles were measured, and homeostasis model assessment for insulin resistance ( HOMA-IR ) was calculated. Multivariate analysis was performed to assess risk factors for 3-vessel disease or acute MI. Results Serum hsCRP, lipoprotein (a) levels, and insulin resistance index (IRI) were higher in AMI group than those in SAP and control groups. Serum hsCRP level and IRI were also higher in 3-vessel disease than those in other groups. Multivariate regression analysis revealed that insulin resistance, cigarette smoking, serum hsCRP, and lipoprotein (a) levels were independent risk factors for acute MI. Lipoprotein ( a ) elevation was an independent risk factor for 3-vessel disease. Conclusion Insulin resistance and high serum hsCRP level were associated with occurrence of acute MI and angiographic severity of coronary disease in patients with normal glucose tolerance.
基金partly granted from the National Natural Science Foundation of China(U20A2023, 31870322)the Creative Research Groups of the Natural Science Foundation of Hubei Province,China (2020CFA009)the Hubei Hongshan Laboratory (2021hszd010)。
文摘As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or QTL from the AA genome wild rice O. longistaminata, which is characterized by tall and robust habit and long tassels and anthers and shows high potential for use in cultivated rice improvement. We constructed a stable BC_(2)F_(20) backcross inbred line(BIL) population of 152 lines from the cross of 9311 × O.longistaminat. Some BILs showed large panicles, large seeds, and strong resistance to rice false smut, bacterial leaf blight, rice blast spot, and brown planthopper. Genomic resequencing showed that the 152 BILs covered about 99.6% of the O. longistaminata genome. QTL mapping with 2432 bin markers revealed 13QTL associated with seven yield traits and eight with resistance to brown planthopper and to four diseases. Of these QTL, 12 for grain yield and 11 for pest and disease resistance are novel in Oryza species.A large-panicle NIL1880 line containing QTL qPB8.1 showed a nearly 50% increase in spikelet number and27.5% in grain yield compared to the recurrent parent 9311. These findings support the potential value of O. longistaminata for cultivated rice improvement.
文摘Objective The aim of this study is by observing the number change of islets beta cells in gestational rats exposed to high fat diet, tofurther reveal the mechanism of gestational diabetes mellitus. Methods Female Wistar rats were exposed to high fat diet for five weeks, and then became pregnant. During pregnancy dynamically detected indicators of glucose and fat. Until the third trimester of pregnancy evaluated the sensitivity of insulin and glucose tolerance. After executed rats, selected pancreatic tail tissue and fixed, further slides were stained with insulin antibody by immunohistochemistry to confirm the location of beta cells. Image analysis system determined mean area stained positive cells in each islet, which stood for total number of beta cells. The apoptotic beta cells in islet were detected and quantified by the Tunel technology to calculate apoptosis ratio. Results The level of free fatty acids in rats exposed to high fat diet was significantly higher than the control groups, and insulin resistance was more serious. Compared mean stained positive area among each group, the largest was gestational rats fed high fat diet, and gestational rats was larger than virgin rats, but the difference had no statistical significance. About apoptoticratio of beta cells was higher in diet intervened rats, gestational rats were higher than virgin rats. The same trend happened in the number of positive cells, but discrepancy was not remarkable. Conclusion Based on insulin resistance, apoptosis of pancreatic beta cellsincreased in gestational ratstaking high fat diet, through changing the number of beta cells to down regulate the pancreas endocrine function. That may be the mechanism of gestational mellitus.
基金supported by the Key R&D Plan of Sichuan Province(23ZDYF0546 and SC2022A1C01J)China Nuclear Power Research and Design Institute-Sichuan University Joint Innovation Fund(HG2022173&JG2022311)the Natural Science Foundation of Zhejiang Province(LQ20E010003).
文摘The equiatomic TiNbZrTaHf alloy was successfully rolled at room temperature with the reduction of ~ 85%. The microstructure and tensile properties were investigated after cold working and annealing. It was determined that the recrystallization temperature of the TiNbZrTaHf alloy between 850 and 900 ℃. Complete recrystallization and normal grain growth occurred, the high stability of single phase was maintained after annealing at 1000, 1200, and 1400 ℃. But the precipitated phase appeared after long term annealing, as seen after 500 h at 1000 ℃. After cold working, the tensile strength and the elongation of TiNbZrTaHf were 1137 MPa and 25.1%, respectively. The annealed alloy has a high tensile strength (σ_(b )= 863 MPa) and ductility (ε_(e )= 28.5%). Moreover, the oxidation of TiNbZrTaHf alloy at elevated temperatures has a significant impact on its mechanical properties. The poor oxidation resistance of TiNbZrTaHf can accelerate tensile failure by inducing fractures at grain boundaries.
基金Supported by Guangxi Innovation Team Project,National Modern Agricultural Technology System(nycytxgxcxtd-01)Guangxi Scientific Research and Technological Development Project(10100004-1A)Guangxi Natural Science Foundation(2011GXNSFB018043)
文摘According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and existing problems concerning high-quality inbred rice va- riety in Guangxi: the rice quality has been greatly improved,but the amylose content is still low; a series of scented rice varieties with high quality and high yield have been bred,such as Zhongguangxiang No. 1,Sanxiang 628,Guixiang No. 1,Liufengxiangzhan,Jiafuxiang No. 1, Zhaoxiang No. 1; the production of high-quality inbred rice during the period 2009-2011 was significantly enhanced,annually more than 66 00 kg / ha,but the disease resistance of rice variety bred was generally poor,and disease-resistant breeding stuck in the mud. Henceforth it is necessary to be oriented by the rice market,and take the rice type with long grain,high adhesive strength,medium-low amylose content and low chalkiness degree as the breeding objectives; introduce the existing high-quality variety resources with medium amylose content at home and abroad,then directly use them or innovate upon them as hybrid strain; take the thick-and-long-grain rice type as breeding objectives,and further improve the yield per unit area of high-quality inbred rice by improving the thousand-grain weight; increase capital investment,improve breeding techniques,strengthen disease-resistant and degeneration-resistant breeding,and improve the application of modern biotechnology in the breeding of high-quality inbred rice.
文摘[目的]气候变化新形势下,进一步筛选适宜西北地区抗寒、抗抽干葡萄砧木品种,可为葡萄免埋土栽培推广提供理论依据和技术支撑。[方法]本文以41Bmgt、Riparia、420Bmgt、101-14、196-17、44-53ma、110R、Rupestris du Lot、SO4、161-490、1103P、5BB、3309、Leon Millt共14种13年生葡萄砧木为试材,通过测定离体一年生枝条累计失水速率,结合田间调查葡萄砧木存活率和离体一年生枝条抽干率,以此来评价不同葡萄砧木品种抗抽干能力;结合前人研究及砧木品种特性,采用高低温交变试验箱模拟低温的方法,设置4(对照)、-15、-20、-25和-30℃一系列温度梯度水平,测定不同葡萄砧木一年生枝条相对电导率、丙二醛、游离脯氨酸、可溶性糖及可溶性蛋白5个生理生化指标,利用隶属函数法进行综合评价不同葡萄砧木的抗寒性。[结果]不同葡萄砧木的抗抽干能力由强到弱依次为:3309>161-490>196-17>Leon Millt>420Bmgt>44-53ma>Riparia>110R>1103P>SO4>101-14>41Bmgt>5BB>Rupestris du Lot;随着处理温度的降低,不同葡萄砧木枝条的抗寒指标总体呈现上升趋势,但不同品种之间存在差异。根据隶属函数的综合分析,结果显示各葡萄砧木的抗寒性由强到弱依次为:SO4>196-17>Leon Millt>5BB>Riparia>44-53ma>420Bmgt>1103P>3309>110R>Rupestris du Lot>101-14>41Bmgt>161-490。[结论]Riparia、196-17、44-53ma和Leon Millt具有较强的抗抽干能力和抗寒性,可作为我国西北地区免埋土葡萄砧木使用。