维普中文期刊产品整合服务
212篇 您的检索式:关键字=FERTILITY
    题名 作者 年代 出处 被引量
1Development of japonica Photo-Sensitive Genic Male Sterile Rice Lines by Editing Carbon Starved Anther Using CRISPR/Cas9显示文摘Rice is one of the most important crops as it supports over25%of total caloric intake for humans(Kusano et al.,2015).The world population reached 7.3 billion in 2015 and is projected to reach 8.5 billion in 2030(Word Population Prospects:2015 Revision).To meet the food demands for the everincreasing population with limited arable land,scarceQuanlin Li Dabing Zhang Mingjiao Chen Wanqi Liang Jiaojun Wei Yiping Qi Zheng Yuan 2016Journal of Genetics and Genomics2016,43,6:26
2Evaluation of soil fertility of the shelter-forest land along the Tarim Desert Highway显示文摘To study the changes of soil fertility of the shelter-forest land along the Tarim Desert Highway, soils from the forest land were collected at the layers of 0―10 cm, 10―20 cm, 20―30 cm. Different soil fertility parameters were measured, and quantitative evaluation of soil fertility was performed by the soil integrated fertility index (IFI). The main results show that the construction of the shelter forest along the Tarim Desert Highway improved the soil physical structure, increased soil porosity and enhanced wa- ter-holding capacity. With the increase of plantation time of the shelter forest, soil microbial biomass C, N, P and the activities of six types of enzyme were enhanced, which promoted the accumulation and transformation of soil nutrients of the forest land. Consequently, the soil nutrients in 12-year-old forest land were much higher than in the newer ones and drifting sand. However, soil salt content of the older forest land was higher owing to the drip-irrigation with salt water. Through the comprehensive evalua- tion, we found that soil fertility index in the forest land was enhanced with the forest age, and it had close correlations with the growth indices of the forest trees. In summary, construction of the shelterforest along the Tarim Desert Highway accelerated the improvement of aeolian soil in the forest land, and the soil fertility improved year by year. We conclude that the forest trees grow normally under the stress of the present drip-irrigation with salt water.JIN ZhengZhong LEI JiaQiang XU XinWen LI ShengYu ZHAO SiFeng QIU YongZhi XU Bo 2008Chinese Science Bulletin2008,53,S2:18
3Responses of Soil Enzyme Activities and Microbial Community Composition to Moisture Regimes in Paddy Soils Under Long-Term Fertilization Practices显示文摘The effects of fertilization on activity and composition of soil microbial community depend on nutrient and water availability;however,the combination of these factors on the response of microorganisms was seldom studied.This study investigated the responses of soil microbial community and enzyme activities to changes in moisture along a gradient of soil fertility formed within a long-term(24 years)field experiment.Soils(0–20 cm)were sampled from the plots under four fertilizer treatments:i)unfertilized control(CK),ii)organic manure(M),iii)nitrogen,phosphorus,and potassium fertilizers(NPK),and iv)NPK plus M(NPK+M).The soils were incubated at three moisture levels:constant submergence,five submerging-draining cycles(S-D cycles),and constant moisture content at 40%water-holding capacity(low moisture).Compared with CK,fertilization increased soil organic carbon(SOC) by 30.1%–36.3%,total N by 27.3%–38.4%,available N by 35.9%–56.4%,available P by 61.4%–440.9%,and total P by 28.6%–102.9%.Soil fertility buffered the negative effects of moisture on enzyme activities and microbial community composition.Enzyme activities decreased in response to submergence and S-D cycles versus low moisture.Compared with low moisture,S-D cycles increased total phospholipid fatty acids(PLFAs)and actinomycete,fungal,and bacterial PLFAs.The increased level of PLFAs in the unfertilized soil after five S-D cycles was greater than that in the fertilized soil.Variations in soil microbial properties responding to moisture separated CK from the long-term fertilization treatments.The coefficients of variation of microbial properties were negatively correlated with SOC,total P,and available N.Soils with higher fertility maintained the original microbial properties more stable in response to changes in moisture compared to low-fertility soil.LI Weitao WU Meng LIU Ming JIANG Chunyu CHEN Xiaofen Yakov KUZYAKOV Jorg RINKLEBE LI Zhongpei 2018Pedosphere2018,28,2:16
4Research Progress on Heat Stress of Rice at Flowering Stage显示文摘Global warming has caused frequent occurrence of heat stress at the flowering stage of single-season rice in the Yangtze River region of China, which results in declines of spikelet fertility and yield in rice. Rice flowering stage is the most sensitive period to high temperatures, and therefore, the key for heat stress happening is the flowering stage coinciding with high temperature, which causes spikelet fertility decreasing in heat-sensitive varieties, and is the major factor for heat injury differences among various rice planting regions. With the development of rice breeding, temperature indexes for heat stress has been converted from daily maximum temperature of 35 oC to 38 oC with the stress duration of more than 3 d. During the flowering stage, anther dehiscence inhibition and low pollen shedding onto the stigma are two main reasons for spikelet fertility reduction under high temperatures. At panicle initiation stage, high temperatures aggravate spikelet degeneration, and destroy floral organ development. Various types of rice varieties coexist in production, and indica-japonica hybrid rice demonstrates the highest heat resistance in general, followed by indica and japonica rice varieties. In production, avoiding high temperature is the main strategy of preventing heat stress, and planting suitable cultivars and adjustment of sowing date are the most effective measures. Irrigation is an effective real-time cultivation measure to decline the canopy temperature during the rice flowering stage. We suggested that further study should be focused on exploring heat injury differences among different rice variety types, and innovating rice-planting methods according to planting system changes in rice planting regions with extreme heat stress. Meanwhile, high temperature monitor and warning systems should be improved to achieve optimal heat stress management efficiencies.WANG Yaliang WANG Lei ZHOU Jianxia HU Shengbo CHEN Huizhe XIANG Jing ZHANG Yikai ZENG Yongjun SHI Qinghua ZHU Defeng ZHANG Yuping 2019Rice science2019,26,1:13
5Regulation of anti-Mullerian hormone(AMH)in males and the associations of serum AMH with the disorders of male fertility显示文摘Anti-Mullerian hormone(AMH)is a functional marker of fetal Sertoli cells.The germ cell number in adults depends on the number of Sertoli cells produced duri ng peri natal development.Rece ntly,AMH has received increasi ng attenti on in research of disorders related to male fertility.This paper reviews and summarizes the articles on the regulation of AMH in males and the serum levels of AMH in male fertility-related disorders.We have determined that follicle-stimulating hormone(FSH)promotes AMH transcription in the absenee of androgen signaling.Testosterone inhibits the transcriptional activation of AMH.The undetectable levels of serum AMH and testosterone levels indicate a lack of functional testicular tissue,for example,that in patients with anorchia or severe Klinefelter syndrome suffering from impaired spermatogenesis.The normal serum testosterone level and undetectable AMH are highly suggestive of persistent Mullerian duct syndrome(PMDS),combined with clinical manifestations.The levels of both AMH and testosterone are always subnormal in patients with mixed disorders of sex development(DSD).Mixed DSD is an early-onset complete type of disorder with fetal hypogonadism resulting from the dysfunction of both Leydig and Sertoli cells.Serum AMH levels are varying in patients with male fertility-related disorders,in cludi ng pubertal delay,severe con genital hypog on adotropic hypogonadism,nonobstructive azoospermia,Klinefelter syndrome,varicocele,McCune-Albright syndrome,and male senescence.Hui-Yu Xu Hong-Xian Zhang Zhen Xiao Jie Qiao Rong Li 2019Asian Journal of Andrology2019,21,2:13
6湖南永顺烟区土壤养分状况的综合评价显示文摘对湖南省永顺县烟区的239个土壤样品、19项土壤养分指标进行了测定,确定了各指标所属的隶属度函数类型及其阈值,采用主成分分析法求得各指标的权重,用加乘法算出各土样的土壤肥力综合指标值(IFI),进而对永顺县植烟土壤适宜性进行了综合评价。结果表明:永顺县烟区土壤肥力存在较大的差异,其IFI值平均为0.541,变幅为0.341~0.730,变异系数5.14%。采用聚类分析法将土壤肥力分为高、较高、中等、较低4类,各类土样所占比例依次为15.86%、21.61%、44.17%、18.36%。朱续熹 宋文峰 刘国顺 杨永锋 周琳 2010江西农业学报2010,22,8:9
7A Control Problem for Nonstationary Population SystemsWANG Hui(Department of Mathematics.Harbin Normal University,Harbin 150080)HOU Xuezhang(Deparfment of Mathematics,Northeast Normal University,Changchun 130024) 1994Systems Science and Systems Engineering1994,4,1:7
8Utilization of Ogura CMS germplasm with the clubroot resistance gene by fertility restoration and cytoplasm replacement in Brassica oleracea L显示文摘Clubroot disease,a major plant root disease caused by Plasmodiophora brassicae,has become one of the most destructive diseases among cultivated cruciferous vegetables.However,clubroot-resistant Brassica oleracea materials are rare.A few clubroot-resistant cabbage varieties are available on the market,but all are Ogura cytoplasmic male sterile(CMS)types.Therefore,in this study,to reutilize the clubroot-resistant Ogura CMS germplasm of cabbage,a new fertility-restored Ogura CMS material,16Q2-11,was used as a bridge to transfer the clubroot resistance(CR)gene from the Ogura CMS cytoplasm to the normal cytoplasm by a two-step method(a fertility restoration and cytoplasm replacement method).In the first cross for fertility restoration of Ogura CMS clubroot-resistant cabbage(FRCRC),16Q2-11 was used as a restorer to cross with Ogura CMS materials containing the CR gene CRb2.Eleven Rfo-positive progenies were generated,of which four contained CRb2:F8-514,F8-620,F8-732 and F8-839.After inoculation with race 4 of P.brassicae,these four CRb2-positive individuals showed resistance.Furthermore,F8-514 and F8-839 were then used as male parents in the second cross of FRCRC to cross with cabbage inbred lines,resulting in the successful introgression of the CRb2 gene into the inbred lines.All offspring produced from this step of cross,which had a normal cytoplasm,showed a high resistance to race 4 of P.brassicae and could be utilized for the breeding of clubrootresistant cabbage varieties in the future.This is the first time that the Ogura CMS restorer has been used to restore the fertility of Ogura CMS clubroot-resistant cabbages,which could improve germplasm diversity in cabbage and provide a reference method for using CMS germplasm in Brassica crops.Wenjing Ren Zhiyuan Li Fengqing Han Bin Zhang Xing Li Zhiyuan Fang Limei Yang Mu Zhuang Honghao Lv Yumei Liu Yong Wang Hailong Yu Yangyong Zhang 2020Horticulture Research2020,7,1:7
9Responses of Soil Microbial Community Structure and Activity to Incorporation of Straws and Straw Biochars and Their Effects on Soil Respiration and Soil Organic Carbon Turnover显示文摘Like straw, biochar incorporation can influence soil microorganisms and enzyme activities and soil carbon(C) responses;however,few studies have compared the various effects of straw and biochar and the underlying mechanisms. An experiment was performed to study the changes in soil respiration(SR) and soil organic C(SOC) fluxes in response to the incorporation of three kinds of straw(reed, smooth cordgrass, and rice) and their pyrolyzed products(biochars) at Chongming Island, China. In addition, the microbial activity and community structure of some amended soils were also analyzed to clarify the mechanisms of these responses. The results showed that all biochar incorporation(BC) induced lower SR than the corresponding unpyrolyzed straw incorporation(ST), and the average SR in the soils following BC and ST during the experimental periods was 21.69 and 65.32 μmol CO2 m^-2s^-1, respectively.Furthermore, the average SOC content was 16.97 g kg-1 following BC, which was higher than that(13.71 g kg-1) following ST,indicating that compared to ST, BC was a low-C strategy, even after accounting for the C loss during biochar production. Among the BC treatments, reed-BC induced the lowest SR(17.04 μmol CO2 m^-2s^-1), whereas smooth cordgrass-BC induced the highest SR(27.02 μmol CO2 m^-2s^-1). Furthermore, in contrast with ST, BC significantly increased the abundance of some bacteria with poorer mineralization or better humification ability, which led to lower SR. The lower easily oxidizable C(EOC) and higher total C contents of biochars induced lower SR and higher SOC in the soil following BC compared to that following ST. Among the BC treatments,the higher total nitrogen content of rice biochar led to significantly higher soil microbial biomass, and the lower EOC content of reed biochar led to lower soil microbial activity and SR.TIAN Xiaoping WANG Lei HOU Yahong WANG Han TSANG Yiu Fai WU Jihua 2019Pedosphere2019,29,4:7
10女性生育力保存与肿瘤生殖学显示文摘生育力保存(fertility preservation)是指使用手术、药物或实验室技术对存在不育风险的成人或儿童提供帮助,保护和保存其产生遗传学后代的能力。众多肿瘤患者需要接受化疗或放疗,而治疗可导致卵巢功能低下乃至卵巢衰竭。如何有效保护和保存生育力,提高女性肿瘤患者的生殖健康水平,已经成为肿瘤治疗中必须面对的问题。潘宁宁 马彩虹 2015中国妇产科临床杂志2015,16,6:6
11Review of the impact of heat stress on reproductive performance of sheep显示文摘Heat stress significantly impairs reproduction of sheep,and under current climatic conditions is a significant risk to the efficiency of the meat and wool production,with the impact increasing as global temperatures rise.Evidence from field studies and studies conducted using environmental chambers demonstrate the effects of hot temperatures(≥32℃)on components of ewe fertility(oestrus,fertilisation,embryo survival and lambing)are most destructive when experienced from 5 d before until 5 d after oestrus.Temperature controlled studies also demonstrate that ram fertility,as measured by rates of fertilisation and embryo survival,is reduced when mating occurs during the period 14 to 50 d post-heating.However,the contribution of the ram to heat induced reductions in flock fertility is difficult to determine accurately.Based primarily on temperature controlled studies,it is clear that sustained exposure to high temperatures(≥32℃)during pregnancy reduces lamb birthweight and will,therefore,decrease lamb survival under field conditions.It is concluded that both ewe and ram reproduction is affected by relatively modest levels of heat stress(≥32℃)and this is a concern given that a significant proportion of the global sheep population experiences heat stress of this magnitude around mating and during pregnancy.Despite this,strategies to limit the impacts of the climate on the homeothermy,behaviour,resource use and reproduction of extensively grazed sheep are limited,and there is an urgency to improve knowledge and to develop husbandry practices to limit these impacts.William H.E.J.van Wettere Karen L.Kind Kathryn L.Gatford Alyce M.Swinbourne Stephan T.Leu Peter T.Hayman Jennifer M.Kelly Alice C.Weaver David O.Kleemann Simon K.Walker 2021Journal of Animal Science and Biotechnology2021,12,3:6
12Benefits of Biochars and NPK Fertilizers for Soil Quality and Growth of Cowpea (Vigna unguiculata L. Walp.) in an Acid Arenosol显示文摘Fertilization is required for optimum plant growth, particularly in unfertile soils, while optimizing nutrient use effciency is an alternative to reduce inorganic fertilizer needs and reduce environmental problems caused by nutrient leaching. This study investigated soil properties and cowpea yield responses to biochars(BCs) made from different feedstocks, baby corn peel biochar(BC1), branches of mango tree biochar(BC2), and rice husk biochar(BC3), applied in combination with nitrogen-phosphorus-potassium(NPK) fertilizers.The experiment was conducted in a greenhouse, using an acid sandy soil(Arenosol) that was submitted for 70 d to the following eight treatments: i) control;ii) full dose of NPK(a commercial compound fertilizer(12-24-12 of N-P2O5-K2O)+ urea(46% N));iii) BC1+ half dose of NPK;iv) BC1 + full dose of NPK;v) BC2 + half dose of NPK;vi) BC2 + full dose of NPK;vii) BC3 + half dose of NPK;and viii) BC3 + full dose of NPK. All biochars were applied at a rate of 0.9%(weight/weight), and each type of biochar was combined with half and full doses of NPK fertilizers. Soil pH increased significantly(P < 0.05) in treatments with BC1 and BC2,while cation exchange capacity(CEC) and available P were higher in the treatments with BC1;BC1 and BC2 also induced higher activity of enzymes related to the P cycle and higher cowpea yield. Similar soil properties and cowpea yield parameters were obtained with the full and half doses of NPK fertilizers for each type of biochar used. In conclusion, biochars in the combination with NPK fertilizers improved soil chemistry and enzymatic activities, allowing reduced fertilizer application and food production costs in the acid soil studied.Rogerio Borguete Alves RAFAEL Maria Luisa FERNANDEZ-MARCOS Stefania COCCO Maria Letizia RUELLO Flavio FORNASIER Giuseppe CORTI 2019Pedosphere2019,29,3:6
13Inflammatory bowel diseases and human reproduction:A comprehensive evidence-based review显示文摘To evaluate the effects of inflammatory bowel diseases(IBDs)on human reproduction,we reviewed the current literature using a systematic search for published studies(articles and/or abstracts)without limits for English language.We searched on Medline(through PubMed),the Institute for Scientific Information,the Web of Science and the websites for the registration of controlled trials(http://gffzz872f90091fd340c7hqf090kokff5n6566.ffgz.tsg.suse.edu.cn/).Bibliographies of retrieved articles,books,expert opinion review articles and reviewed bibliographies from subject experts were manually searched.Titles and abstracts were screened initially,and potential relevant articles were identified and reviewed.Whenever possible,data were analyzed by comparing IBD patients vs healthy controls,and patients with active IBDs vs those with disease in remission.The effects of IBDs on female fertility,fertility in infertile couples,pregnancy and male infertility were examined separately.Patients with IBDs in remission have normal fertility.At the moment,there is no established guideline for the preservation of fertility in women with IBD undergoing surgery.Further data are needed regarding guidelines for the management of these patients.Data regarding IBDs and infertility are currently completely lacking.Considering the prevalence of intestinal pathology in young adults of childbearing age,this field is of great scientific and clinical interest,opening up important future perspectives.Another important and as yet unexplored point is the response to treatments for infertility in patients with IBDs.In particular,the question is whether the reproductive outcomes(clinical and biological)can be influenced by the IBD of one of the partners.The goals for successful reproductive outcomes in IBD population are correct counseling and disease remission.IBDs significantly affect several reproductive aspects of human(female,male,couple)reproduction.Further data are needed to develop guidelines for the clinical management of subjects of reproductive age with IBDs.Stefano Palomba Giuliana Sereni Angela Falbo Marina Beltrami Silvia Lombardini Maria Chiara Boni Giovanni Fornaciari Romano Sassatelli Giovanni Battista La Sala 2014World Journal of Gastroenterology2014,20,23:6
14In vitro testicular organogenesis from human fetal gonads produces fertilization-competent spermatids显示文摘Unlike most organs that mature during the fetal period,the male reproductive system reaches maturity only at puberty with the commencement of spermatogenesis.Robust modelling of human testicular organogenesis in vitro would facilitate research into mechanisms of and factors affecting human spermatogenic failure and male fertility preservation in prepubertal tumor patients.Here,we report successful recapitulation of human testicular organogenesis in vitro from fetal gonadal ridge.Our model displayed the formation of mature seminiferous epithelium and self-renewing spermatogonia.Remarkably,in vitro-derived haploid spermatids have undergone meiotic recombination,and showed increased genetic diversity as indicated by genetic analysis.Moreover,these spermatids were able to fertilize oocytes and support subsequent blastocyst formation.The in vitro testicular organogenesis system described here will play an important role in elucidating the regulation of human testis development and maintaining male fertility in prepubertal cancer patients.Yan Yuan Laihua Li Qing Cheng Feiyang Diao Qiao Zeng Xiaoyu Yang Yibo Wu Hao Zhang Mingqian Huang Junqing Chen Quan Zhou Yunfei Zhu Rong Hua Jianyu Tian Xin Wang Zuomin Zhou Jie Hao Jinjin Yu Dong Hua Jiayin Liu Xuejiang Guo Qi Zhou Jiahao Sha 2020Cell Research2020,30,3:6
15Influence of Exogenous Lanthanum on Fertility Parameters of Red Soil and Paddy Soil显示文摘The effects of exogenous La on the fertility parameters such as cation exchange capacity (CEC), exchangeable basic cations, and exchangeable acidity in red soil and paddy soil were studied with soil column simulation. The results show that with increasing amount of the added La, the proportion of exchangeable La in soils increases and there is more exchangeable La in red soil than in paddy soil. When the concentration of La is more than 600 mg·kg -1 , the proportion of exchangeable La almost remains constant. When the concentration of La is less than 1200 mg·kg -1 , there is no significant effect on CEC in red soil. But when the concentration of La is more than 1200 mg·kg -1 , it has significant effect on CEC in paddy soil. The application of La resulted in increasing exchangeable aluminum, Ca and Mg in soil solution, and decreasing exchangeable Ca and Mg retained in soils. But when the concentration of La is less than 150 mg·kg -1 , it has no significant influence on CEC, exchangeable Ca and Mg, and exchangeable acidity in red soil and paddy soil.谢祖彬 朱建国 褚海燕 曾青 张雅丽 曹志洪 2001Journal of Rare Earths2001,19,3:6
16Variance components and correlations of female fertility traits in Chinese Holstein population显示文摘Background: The objective of the present study was to estimate(co)variance components of female fertility traits in Chinese Holsteins, considering fertility traits in different parities as different traits. Data on 88,647 females with 215,632 records(parities) were collected during 2000 to 2014 from 32 herds in the Sanyuan Lvhe Dairy Cattle Center, Beijing, China. The analyzed female fertility traits included interval from calving to first insemination, interval from first to last insemination, days open, conception rate at first insemination, number of inseminations per conception and non-return rates within 56 days after first insemination.Results: The descriptive statistics showed that the average fertility of heifers was superior to that of cows. Moreover,the genetic correlations between the performances of a trait in heifers and in cows were all moderate to high but far from one, which suggested that the performances of a trait in heifers and cows should be considered as different but genetically correlated traits in genetic evaluations. On the other hand, genetic correlations between performances of a trait in different parities of cows were greater than 0.87, with only a few exceptions, but variances were not homogeneous across parities for some traits. The estimated heritabilities of female fertility traits were low; all were below 0.049(except for interval from calving to first insemination). Additionally, the heritabilities of the heifer interval traits were lower than those of the corresponding cow interval traits. Moreover, the heritabilities of the interval traits were higher than those of the threshold traits when measuring similar fertility functions. In general, estimated genetic correlations between traits were highly consistent with the biological categories of the female fertility traits.Conclusions: Interval from calving to first insemination, interval from first to last insemination and non-return rates within 56 days after first insemination are recommended to be included in the selection index of the Chinese Holstein population. The parameters estimated in the present study will facilitate the development of a genetic evaluation system for female fertility traits to improve the reproduction efficiency of Chinese Holsteins.Aoxing Liu Mogens Sandø Lund Yachun Wang Gang Guo Ganghui Dong Per Madsen Guosheng Su 2017Journal of Animal Science and Biotechnology2017,8,4:6
17Heavy cigarette smoking and alcohol consumption are associated with impaired sperm parameters in primary infertile men显示文摘We assessed the concomitant impact of cigarette smoking and alcohol con sumption in men presenting for primary couple's infertility.Data from 189 in fertile men were an a lyzed.Semen analysis,serum hormones,and sperm DNA fragmentation(SDF)were obtained.Smoking status was categorized as follows:current nonsmoker(-S),moderate smoker(+MS),and heavy smoker(+HS).Alcohol consumption was categorized as follows:abstainer(-D),moderate drinker(+MD),and heavy drinker(+HD).Descriptive statistics and logistic regression models were applied.Among all the participants,132(69.8%),30(15.9%),and 27(14.3%)patients were-S,+MS,and+HS,respectively.In addition,67(35.4%),77(40.7%)and 45(23.8%)men were-D,+MD and+HD,respectively.Regarding concomitant habits,52(27.5%)patients were nonsmokers and abstainers(-S/-D:Group 1),91(48.1%)had at least one recreational habit(-S/+D or+S/-D:Group 2),and 46(24.3%)were both smokers and drinkers(+S/+D:Group 3).Sperm concentration and progressive motility were lower in+HS and+HD,compared with-S and-D(all P<0.05),respectively.Similarly,both parameters were significantly lower in Group 3 than Groups 1 and 2(all P<0.05).SDF values were higher in Group 3 than Groups 1 and 2(both P<0.05).In multivariate analysis,follicle-stimulating hormone(FSH)levels and concomitant+S/+D status were independent predictors of impaired sperm concentration and progressive motility(all P<0.05).Heavy smoking and heavy drinking were associated with worse seminal parameters than moderate smoking/drinking and nonsmoking/abstaining.When concomitant,+S/+D status has an even greater detrimental effect on semen parameters.Luca Boeri Paolo Capogrosso Eugenio Ventimiglia Filippo Pederzoli Walter Cazzaniga Francesco Chierigo Federico Deho Emanuele Montanari Francesco Montorsi Andrea Salonia 2019Asian Journal of Andrology2019,21,5:6
18Synthetic apomixis with normal hybrid rice seed production显示文摘Heterosis has long been exploited in the hybrid seed industry,which contributes to high and stable yields of modern agriculture(Huang et al.,2016).However,heterosis phenotypes of hybrid plants are segregated in its offspring.Apomixis allows instant fixation and propagation though seeds with heterozygous genotypes,showing great potential in plant breeding and agricultural practice(Ye and Cui,2019).Apomixis naturally occurs in hundreds of plant species,but it is absent in major crop species(Underwood and Mercier,2022).Recently,synthetic apomixis has been engineered in rice by combining Mitosis instead of Meiosis(MiMe)with a mutation of MATRILINEAL or ectopic expression of BABY BOOM1(BBM1),enabling clonal reproduction of F1 hybrids through seeds and stable transmission of heterotic phenotypes over generations(Khanday et al.,2019;Wang et al.,2019;Liu et al.,2022).However,the fertility of both two strategies was significantly reduced compared with that of the wild type,which hinders the application of both strategies in agriculture.In this study,we established synthetic apomixis with a high fertility that is almost comparable to normal hybrid rice.Xin Wei Chaolei Liu Xi Chen Hongwei Lu Jian Wang Shenlin Yang Kejian Wang 2023Molecular Plant2023,16,3:5
19Integrated Soil Fertility and Plant Nutrient Management inTropical Agro-Ecosystems:A Review显示文摘The greatest challenge for tropical agriculture is land degradation and reduction in soil fertility for sustainable crop and livestock production.Associated problems include soil erosion,nutrient mining,competition for biomass for multiple uses,limited application of inorganic fertilizers,and limited capacity of farmers to recognize the decline in soil quality and its consequences on productivity.Integrated soil fertility management(ISFM) is an approach to improve crop yields,while preserving sustainable and long-term soil fertility through the combined judicious use of fertilizers,recycled organic resources,responsive crop varieties,and improved agronomic practices,which minimize nutrient losses and improve the nutrient-use efficiency of crops.Soil fertility and nutrient management studies in Ethiopia under on-station and on-farm conditions showed that the combined application of inorganic and organic fertilizers significantly increased crop yields compared to either alone in tropical agro-ecosystems.Yield benefits were more apparent when fertilizer application was accompanied by crop rotation,green manuring,or crop residue management.The combination of manure and NP fertilizer could increase wheat and faba bean grain yields by 50%–100%,whereas crop rotation with grain legumes could increase cereal grain yields by up to 200%.Although organic residues are key inputs for soil fertility management,about 85% of these residues is used for livestock feed and energy;thus,there is a need for increasing crop biomass.The main incentive for farmers to adopt ISFM practices is economic benefits.The success of ISFM also depends on research and development institutions to provide technical support,technology adoption,information dissemination,and creation of market incentives for farmers in tropical agro-ecosystems.Getachew AGEGNEHU Tilahun AMEDE 2017Pedosphere2017,27,4:5
20Imaging in male-factor obstructive infertility显示文摘The main purpose of imaging evaluation in male infertility is to identify and treat correctable causes of infertility, such as obstruction of the seminal tract. Various imaging modalities are available to evaluate men with obstructive infertility including scrotal ultrasonography, transrectal ultrasound (TRUS), vasography, magnetic resonance imaging, seminal vesicle aspiration, seminal tract washout, and seminal vesiculography. To date the most reliable and accurate diagnostic technique for obstructive infertility is unclear. In this review article, we report the role of these modalities in diagnosis of obstructive infertility. Scrotal sonography is the initial modality, and if patient results indicate non obstructive azoospermia as varicocele or testicular pathology they will be treated according to standard protocols for management of these pathologies. If the patient findings indicate proximal obstructive azoospermia, they can be managed by vasoepididymostomy. If the scrotal ultrasound is normal, TRUS is the second imaging modality. Accordingly, they are classified into patients with criteria of obstructive infertility without urogenital cysts where TRUS-guided aspiration and seminal vesiculography can be performed and transurethral resection of the ejaculatory ducts (TURED) will be the management of choice. In patients with urogenital cyst, TRUS-guided cyst aspiration and opacification are performed. Ifthe cyst is communicating with the seminal tract, management will be transurethral incision of the cyst. If the cyst is not in communication, the obstruction may be relieved after cyst aspiration. If the obstruction is not relieved, TURED will be the management of choice. Sperm harvested during aspiration may be stored and used in assisted reproduction techniques. If the results of TRUS are inconclusive or doubtful, endorectal magnetic resonance imaging should be performed to serve as a 'detailed map' for guiding corrective operative interventions.Ragab H Donkol 2010World Journal of Radiology2010,2,5:5
返回顶部 每页显示:
共11页 首页 上一页 第1页 下一页 末页 /11 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费