岱海游乐场孔孢粉分析及其2500年来古气候演化   总被引：1，自引：0，他引：1  

乌云格日  刘清泗 《干旱区资源与环境》1998,12(3):21-27

本文通过对岱海游乐场钻孔剖面沉积物孢粉的定性、半定量分析,并结合岩性、岩相变化,初步恢复了该地区２５００年来古植被、古气候演化过程。研究结果表明,岱海湖盆自２５００年来植被类型有典型草原—灌丛草原—森林草原—灌丛草原的演化过程,古气候有较暖湿—较暖干—较冷干—较冷湿—较冷干的变化过程。  相似文献   

The phylogenetic status of typical Chinese native pigs: analyzed by Asian and European pig mitochondrial genome sequences   总被引：1，自引：0，他引：1  

Guanghui Yu  Hai Xiang  Jikun Wang  Xingbo Zhao 《畜牧与生物技术杂志(英文版)》2013,4(2):145-151

  相似文献   

云南省水稻稻瘟病菌无毒基因AVR-Pia变异及水稻抗性基因Pia的有效性     

王群  陆琳  何成兴  伏雪  许明辉  李进斌 《植物保护学报》2020,47(3):562-571

为进一步了解田间稻瘟病菌Magnaporthe oryzae群体中AVR-Pia基因的分布及变异,利用水稻单基因系IRBLa-C水稻品种对自云南省13个市(州)采集分离得到的471株稻瘟病菌菌株进行抗性基因Pia有效性测定;利用无毒基因AVR-Pia特异性标记对471株稻瘟病菌菌株进行PCR检测和测序,并分析稻瘟病菌群体中无毒基因AVR-Pia的分布及DNA结构变异;利用有效性结果和PCR检测结果对471株菌株进行反应型划分,筛选鉴定菌株;利用鉴定菌株对云南省112份地方稻种进行Pia基因鉴定。结果表明,在471株稻瘟病菌菌株中,对含有Pia基因的水稻单基因系IRBLa-C表现为抗病和感病的菌株数分别为139株和332株,所占比例分别为29.5%和70.5%;在471株稻瘟病菌菌株中,分别有244株和227株菌株含有无毒基因AVR-Pia和不含有无毒基因AVR-Pia,所占比例分别为51.8%和48.2%,无毒基因AVR-Pia主要为完全缺失变异;在471株稻瘟病菌菌株中,A-和V+反应型菌株数分别为56株和161株,共217株,占总菌株数的46.1%,在13个市(州)稻瘟病菌群体中,A-和V+反应型菌株所占比例差异较大,其中在普洱市、红河哈尼族彝族自治州、昭通市、玉溪市4个市(州)的比例较大,分别为77.8%、57.1%、52.1%和50.0%;在112份云南省地方稻种质资源中,有20份地方稻品种含有抗性基因Pia,主要分布在9个市(州)中。表明云南省13个市(州)绝大部分水稻产区水稻Pia基因已丧抗性,含Pia基因的水稻种质在云南省分布较广。  相似文献   

90年代江苏淮南小麦产量性状演变及品质分析     

姚国才  姚金保  杨学明  黄胜东  钱存鸣  周朝飞  金德洲 《金陵科技学院学报》2000,(3)

分析了江苏省淮南片 1 989～ 1 999年连续 1 0年 (5轮 ) 4 5个小麦品种 (系 )的区试结果 ,其平均产量为 5 .0 661 t.hm- 2 ;年度 (轮次 )间的产量呈现低 -高 -低的演变趋势 ;在产量构成因素中 ,穗数较为稳定 ,且与产量关系不密切 ;而每穗粒数随着产量的起伏表现较大增减 ,与产量呈显著正相关 ;千粒重与产量呈极显著正相关 ,粒重大小基本决定产量高低。本地区目前应用推广小麦品种的出粉率均较低 ;蛋白质和面筋含量以苏麦 6号较高 ,但由于其面团稳定时间短 ,仍不适于制作面包 ;扬麦 1 5 8和宁麦 8号适合制作面条和馒头 ;宁麦 9号为较优质的饼干、糕点小麦。此外 ,还探讨了小麦产量育种的策略和品质改良的重点及要求。  相似文献   

世界苹果属植物的起源演化研究新进展   总被引：6，自引：2，他引：4  

李育农 《果树学报》1999,(Z1)

引用了瓦维诺夫Ｎ．Ｉ．Ｖａｖｉｌｏｖ，兰格菲尔德Ｖ．Ｔ．Ｌａｎｇｅｎｆｅｌｄ，斯泰司Ｃ．Ａ．Ｓｔａｃｅ 及俞德浚等关于苹果属等植物种、属起源和演化的学说，结合作者对世界苹果属植物今昔的自然分布和分类的研究工作，论证了世界苹果属植物的起源演化的中心位于中国的西南四川、云南、贵州三省。但不是苹果属的祖先种皆起源于该地或亚洲东南的亚热带地区，有不少种是直接起源于今天的北温带—它们过去在第三纪曾经有过亚热带气候。作者认为兰格菲尔德所作关于苹果属植物起源演化的系统发育树图谱中的六个分枝，都是指的次生遗传基因中心，而苹果属植物的初生遗传多样化中心是与其近缘的花揪属、梨属和山楂属相融合的。由于苹果属现代大多数的种都集中在中国西南云、贵、川三省，其中含有古老的多胜海棠等种类，因此将该地区视为苹果属的初生基因中心，是符合Ｃ．Ａ．Ｓｔａｃｅ 和Ｖ．Ｔ．Ｌａｎｇｅｎｆｅｌｄ 关于属的起源中心定位学说的，但苹果属古代的起源中心位置是否与现代起源中心位置相符，值得再行研究  相似文献   

Soil CO2 evolution from Korean pine virgin forest at Changbai Mountain     

Ma Yueqiang  Yan Xiaodong  Yang Sihe 《林业研究》1998,9(3):192-194

The soil CO₂ evolution rate was measured in a virgin Korean pine forest. The results in June showed that the lowest value of evolution rate was 220 mg/(m²·h) and appeared at 6:00 a.m. The highest value was 460 mg/(m²·h) at 18:00. The rates of CO₂ evolution were related with soil temperature. On the basis of the constructed regression equation and the monthly average values of temperature, the magnitude of CO₂ evolution from Korean pine forest soil was 10.4 t/hm² during a growing season. This project was funded by the Opened Research Station of Changbai Mountain Forest Ecosystem, Chinese Academy of Sciences. Responsible editor: Zhu Hong  相似文献   

Methyl Jasmonate Counteract UV-B Stress in Barley Seedlings     

I. Fedina  D. Nedeva  K. Georgieva  & M. Velitchkova 《Journal of Agronomy and Crop Science》2009,195(3):204-212

The role of exogenously applied phytohormone methyl jasmonate (MeJA) in counteracting the ultraviolet B (UV‐B) stress in barley seedlings was investigated. Barley seedlings (Hordeum vulgare L., cv. Alfa) 4 days old were supplied with 5 × 10^?5 m MeJA through the roots for 3 days and then exposed for 2 days for 5 h per day to UV‐B (312 nm, biological effectiveness of UV‐B radiation 28.8 kJ m^?2day^?1). The rate of ¹⁴CO₂ fixation, PSI and PSII activities and chlorophyll content decreased, but flavonoids, H₂O₂, malondialdehyde, proline and UV‐B induced compounds increased after UV‐B treatment. The rate of photosynthetic oxygen evolution was more strongly inhibited by UV‐B‐irradiation than PSI and PSII efficiency. MeJA itself increased the content of free proline, which acts as a stress protector due to its radical scavenging ability. Increased superoxide dismutase, catalase and peroxidase (POX) activities in the leaves and in the roots and the POX isoforms induction revealed the MeJA involvement in plant tolerance to oxidative stress caused by UV‐B irradiation. It was shown that pre‐treatment with MeJA counteracted UV‐B stress. Therefore, it was suggested that MeJA could acts as a mediator in plant defense responses to UV‐B irradiation by enhancing the activity of antioxidant system and free radical scavenging capability of plant cells.  相似文献   

Analysis of Genetic Diversity in Barley Cultivars Reveals Incongruence Between S-SAP,SNP and Pedigree Data     

V. D. Soleimani  B. R. Baum  D. A. Johnson 《Genetic Resources and Crop Evolution》2007,54(1):83-97

Accurate assessment of genetic similarity is important for plant breeding, germplasm enhancement and conservation of plant genetic resources. A comparative analysis of genome diversity among a group of six-rowed spring barley (Hordeum vulgare L.) cultivars was carried out using sequence-specific amplified polymorphism (S-SAP) and single nucleotide polymorphism (SNP), with the results compared to the kinship coefficients derived from the pedigree data. Mean pair-wise GS values were estimated to be 0.0957 ± 0.144 (Kinship), 0.491 ± 0.189 (SNPs), and 0.602 ± 0.098 (S-SAPs). S-SAP and SNP-based genetic similarity (GS) values were normally distributed but kinship values had a non-normal and skewed distribution. Pair-wise correlation of GS values were lowest for the S-SAP and the SNP matrices (r =; 0.040, p<0.230) and highest for the SNP and pedigree matrices (r =; 0.240, p < 0.001). Analysis of molecular variance (AMOVA) attributed about 90.4% of observed variation to the cultivars within each of the malting and feed groups. Variance component between malting and feed groups was 6.6% for both SNP and S-SAP data suggesting lack of a significant genetic differentiation along this agronomic division. The remaining 3% of variation was attributed to genetic diversity within cultivars. Although both DNA-based marker systems were able to differentiate all barley cultivars, significant difference were observed in the pattern of genetic relationships obtained by the two marker systems and the pedigree data.  相似文献   

Cloning, characterization and expression of cDNA containing major histocompatibility complex class I, IIα and IIβ genes of Japanese flounder Paralichthys olivaceus     

Prapansak  SRISAPOOME  Tsuyoshi  OHIRA  Ikuo  HIRONO  Takashi  AOKI 《Fisheries Science》2004,70(2):264-276

ABSTRACT:   The nucleotide sequences of Japanese flounder Paralichthys olivaceus , major histocompatibility complex (MHC) cDNA, classical MHC class Iα, non-classical MHC class Iβ, MHC class IIα and IIβ, were determined. The domain structures and antigen binding motifs of vertebrate MHC are conserved in the Japanese flounder MHC. A phylogenetic analysis supports the classification of these genes into class I and class II MHC. Classical MHC class Iα was ubiquitously expressed, whereas the non-classical MHC class Iβ was expressed mainly in lymphoid organs, gills, intestine and stomach. The MHC classes IIα and IIβ were also ubiquitously expressed.  相似文献   

Isolation,Identification, 16S rRNA Gene Sequencing and Genetic Evolution Analysis of Aeromonas aeruginosa from Duck     

QIAO Hongxing  DING Yong  ZHANG Liheng  SONG Yuzhen  DONG Qing  BIAN Chuanzhou  ZHAO Junqiang 《中国畜牧兽医》2022,49(2):435-442

【Objective】 The experiment was aimed to study the pathogenic bacteria of acute death of ducklings in a duck farm in Henan province and its phylogenetic status.【Method】 The liver and spleen of dead ducks in the diseased duck farm were collected.The bacterial morphology, Gram-staining, biochemical characteristics, sequence analysis of 16S rRNA gene, drug sensitivity test and pathogenicity test were carried out.【Results】 The isolated bacteria grew on blood agar medium with smooth, convex, milky white and α-hemolytic Gram-positive cocci.Biochemical test results showed that the isolated bacteria were positive for maltose, sucrose, raffinose, nitrate reduction reaction, MP-VP test, urea, lysine decarboxylase, ornithine decarboxylase and aescin, and negative for xylose, lactose, glucose, sorbitol, hydrogen sulfide, citrate, peptone, mannitol, phenylalanine and methyl red.The results of 16S rRNA gene sequencing and BLAST comparison results showed that the 16S rRNA gene sequence of the isolated strain was 94.8%-99.9% similar to that of Aerococcus viridans published on NCBI, and the similarity with strains Mnlv1, Mnlv2 and W66 was the highest, up to 99.9%.The similarity with strain GXBl-1 was the lowest, which was 94.8%.Phylogenetic tree analysis showed that the isolated bacteria belonged to the same genus and group on the same branch as strains of Aerococcus viridans FL09, 15MS and Mnlv2 etc., and had the closest genetic relationship with FL09.The results of drug sensitivity showed that the isolated strain was sensitive to fosfomycin, ampicillin and amoxicillin, moderately sensitive to penicillin, neomycin and amikacin, it was resistant to rifampicin, neomycin, bacitracin, erythromycin and enrofloxacin.The results of pathogenicity test showed that the strain was lethal and increased with the increase of inoculation concentration.【Conclusion】 This study determined that the pathogen causing the acute death of ducklings in a duck farm in Henan province was Aerococcus viridans, which provided a reference basis for clinical diagnosis and treatment of the diseases caused by this bacteria.  相似文献