基于稳态空间分辨光谱的猪肉肌红蛋白检测方法

The objective of this work was to determine the concentration of myoglobin in fresh pork meat and establish a fast non-invasive method using steady spatially-resolved spectroscopy (SRS). The concentration of myoglobin was calculated based on absorbance coefficients at 640, 760, 800, 850 nm. The results showed that the value of myoglobin using SRS was significantly correlated (r2=0.955) to traditional methods with the accuracy of 3.6%F.S. The results showed that the concentration of myoglobin can be measured by using near infrared steady spatially-resolved spectroscopy.     

延边地区农民旅游市场现状特征分析

基于城乡比较、远近比较及民族比较的视角，利用实地调查数据及文献数据分析得出延边地区农民旅游市场的特征。城乡居民旅游差异较大，远郊及近郊农民的差异主要表现在出游组织方式、出游距离、旅游目的地选择、消费额等4个方面，民族差异性主要表现为旅游交通工具的选择、旅游时间长度、旅游消费额度等3个方面。     

The Influence of Plant Developmental Stage on Expression of Resistance to leaf Rust (Puccinia recondita) in Two Near Isogenic Lines of Wheat

Cultivar ‘Thatcher’, and ‘Thatcher’ lines with Lr 21 and Lr 22 were studied against a number of races of Puccinia recondita for seedling and adult plant reaction. The study has established that Lr 21 and Lr 22 are genes effective against P. recondita at adult plant stage. It has also shown that these genes confer resistance against all races when plants are inoculated at boot leaf stage.     

Effectiveness of Twenty-Four Barley Resistance Genes Against Powdery Mildew (Erysiphe graminis DC f. sp. hordei Em. Marchal) in Spain

Twenty-four near-isogenic barley lines, with a cv.‘Pallas’ background, carrying different mildew resistance genes were subjected in 1987, 1989 and 1990 to natural infection by the pathogen at several different and contrasting Spanish sites in order to study its virulence. The virulence genes proved to be geographically grouped into three regions: western (Valladolid), southern (Sevilla) and northern and northeastern (Navarra, Lleida and Girona). The mildew population of Lleida was more variable when compared with Navarra and Valladolid. Overall, the most effective resistance genes were: Ml-a13 + Ml-(Ru3), mlo and Ml-(1402).     

Parial resistance in the barley (Hordeum vulgare L.) cultivar 'Chikurin Ibaraki 1' to two PAV-like isolates of barley yellow-dwarf virus: allelic variability at the Yd2 gene locus

The Japanese barley cultivar, ‘Chikurin Ibaraki 1’, is partially resistant to the PAV serotype of barley yellow-dwarf virus (BYDV), but its induced mutant line, Ea52, is susceptible. The inheritance of resistance in cv. ‘Chikurin Ibaraki 1’ to BYDV-PAV was investigated. The F, and F2 plants of crosses of cvs ‘Chikurin Ibaraki 1’, Ea52, ‘Vixen’, carrying the Yd2 gene of resistance, and ‘Plaisant’, a susceptible French cultivar, were tested in growth chamber and field conditions. Isolate RG, against which ‘Chikurin Ibaraki 1’ is partially resistant in growth chamber and field conditions, and isolate 2t, which overcomes the partial resistance of ‘Chikurin Ibaraki 1’ in field conditions (Chalhoub et al. 1994) were used. The segregation of F2 plants of crosses between ‘Chikurin Ibaraki 1’ and the susceptible cultivars to isolate RG (one resistant to three susceptible) suggests that the resistance of ‘Chikurin Ibaraki 1’ is controlled by a single recessive gene. All 537 F2 plants of ‘Chikurin Ibaraki 1’בVixen’ tested with isolate RG in growth chamber and field conditions were resistant. The F2 plants of this cross were all resistant to isolate 2t in growth chamber conditions but segregated with a ratio of one resistant to three susceptible in field conditions owing to the susceptibility of ‘Chikurin Ibaraki 1’ to this isolate. Results suggest that the resistance gene in ‘Chikurin Ibaraki 1’ is tightly linked or allelic with the Yd2 gene in ‘Vixen’. However, it differs from this gene in ‘Vixen’ in that it can be overcome by isolate 2t in field conditions.     

CO39近等基因系抗稻瘟病性分析

利用14个稻瘟病菌菌株在温室分别接种和在自然病圃两个年度对CO39近等基因系进行鉴定.结果表明,这套近等单基因系和近等多基因系具很好的鉴别能力.抗病基因Pi-3提供抗病性的时间较长,病斑数较少,并且与其他基因组合而成的累加系也能高抗稻瘟病.     

Characterization of segregation distortion on chromosome 3 induced in wide hybridization between indica and japonica type rice varieties

We previously surveyed chromosomal regions showing segregation distortion of RFLP markers in the F₂ population from the cross between a japonica type variety ‘Nipponbare’ and an indica type variety ‘Milyang23’, and showed that the most skewed segregation appeared on the short arm of chromosome 3. By comparison with the marker loci where distortion factors were previously identified, this region was assumed to be a gametophytic selection-2 (ga2) gene region. To evaluate this region, two near isogenic lines (NILs) were developed. One NIL had the ‘Nipponbare’ segment of this region on the genetic background of ‘Milyang23’ (NIL9-23), and the other NIL had the ‘Milyang23’ segment on the genetic background of ‘Nipponbare’ (NIL33-18). NIL9-23 and ‘Milyang23’, NIL33-18 and ‘Nipponbare’, and ‘Nipponbare’ and ‘Milyang23’ were respectively crossed to produce F₁ and F₂ populations. The F₁ plants of NIL9-23 × ‘Milyang23’ and NIL33-18 × ‘Nipponbare’ showed high seed fertility and the same pollen fertility as their parental cultivars, indicating that ga2 does not reduce seed and pollen fertility. Segregation ratio of a molecular marker on the ga2 region in the three F₂ populations was investigated to clarify whether segregation distortion occurred on the different genetic backgrounds. Segregation distortion of the ga2 region appeared in the both F₂ populations from the NIL9-23 and ‘Milyang23’ cross (background was ‘Milyang23’ homozygote) and the ‘Nipponbare’ and ‘Milyang23’ cross (background was heterozygote), but did notin the F₂ population from the NIL33-18 and ‘Nipponbare’ cross (background was ‘Nipponbare’ homozygote). This result indicates that ga2 interacts with a ‘Milyang23’ allele(s) on the different chromosomal region(s) to cause skewed segregation of the ga2 region. In addition, segregation ratio was the same between the F₂ populations from NIL9-23 × ‘Milyang23’ and ‘Nipponbare’ × ‘Milyang23’ crosses, suggesting that the both genotypes, ‘Milyang23’ homozygote and heterozygote, of gene(s) located on the different chromosomal region(s) have the same effect on the segregation distortion. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic basis of plant regeneration in hexaploid triticale

Summary Glume cultures of monogenic recessive mutants PGTSLS1 (Plant Genetics triticale selection large spike 1) and PGTSLG2 (Plant Genetics triticale selection long grain 2) were employed along with their parent PGTS control (Plant Genetics triticale selection control) and their F1 and F2 progenies, to determine the genetic basis of plant regeneration in hexaploid triticale. The mutant PGTSLS1 exhibited greater efficiency of plant regeneration (22.4%) followed by PGTS control (7.6%) and PGTSLG2 did not exhibit any regeneration. All the three F1's exhibited plant regeneration frequency on par with that of control (6.9–7.3%), suggesting dominant nature of control genotype over the isogenic mutants. The F2 results suggested that genetic control over the high frequency regeneration of PGTSLS1 was monogenic recessive in nature, and genetic control over the recalcitrant nature of PGTSLG2 also was monogenic recessive. The F2 of the cross PGTSLS1 × PGTSLG2 segregated into four classes. Of the 114 F2 plants, 19 showed no regeneration, 70 of them exhibited 6–8% regeneration, 20 of them 19–24% regeneration, and 5 of them exhibited highest frequency regeneration (57–60%). These observations suggest dihybrid segregation for regeneration. The highest frequency of plant regeneration (57–60%) exhibited by 5 F2 plants may be due to the interaction of non-allelic genes in recessive condition. These results clearly demonstrate the association of at least two genes with plant regeneration in hexaploid triticale.     

黄瓜花叶病毒番茄蕨叶分离物外壳蛋白基因的克隆和序列分析

在北京延庆的番茄上分离到1株黄瓜花叶病毒(Cucumber mosaic virus,CMV)分离物CMV-YQ,该分离物在番茄上造成严重的蕨叶、矮化,在烟草上表现花叶、矮化和畸形,表现出很强的致病性。根据黄瓜花叶病毒外壳蛋白(coat protein,CP)基因的保守序列设计引物,利用RT-PCR技术对其CP基因片段进行了扩增并克隆,获得了含该基因全长657 bp的cDNA片段。序列测定与比较分析结果表明,北京地区造成番茄蕨叶的CMV分离物CP基因片段核酸序列与GenBank上CMV亚组Ⅰ其他分离物同源性高达90%～99%,属于CMV亚组Ⅰ。该分离物与分离于我国芭蕉的另一亚组Ⅰ分离物GB同源性为94.37%,两分离物之间存在寄主适应性变异。     

莴苣花叶病毒北京分离物基因组3′末端序列分析

笔者通过RT-PCR方法对LMV北京分离物（LMV-BJ）基因组3＇端1620nt的核苷酸片段进行了克隆和序列分析（GenBank登录号为EF423619）。所获片段含有NIb基因3＇端的574nt,编码NIb C-端190个氨基酸;完整的CP基因,全长为834nt,编码一个由277个氨基酸组成的分子量约为30kDa的结构蛋白;3＇非编码区含有209nt。通过序列分析软件将LMV-BJ与已经报道的法国分离物O（X97704）、法国分离物E（X97705）,美国分离物（X65652）,巴西分离物（AJ278854）和余杭分离物（AJ306288）基因组3＇末端和CP基因的核苷酸序列与氨基酸序列分别进行了比较。