杨树溃疡病病原——葡萄座腔菌科真菌间关系的系统学初探

利用ITS rDNA序列对我国杨树溃疡病的葡萄座腔菌科病原真菌进行系统发育学分析,共得到4种葡萄座腔菌科病原真菌:Botryosphaeria dothidea,Neofusicoccum parvum,Diplodia seriata和D.mutila。它们与相应的无性型或有性型一一对应。其中,D.seriata在我国是第一次报道为杨树的病原。研究了试验菌株与国内外已报道菌株间的系统发育学关系,分析了它们与环境间的联系。结果表明B.dothidea具有高度的种内遗传多样性。这些结果对葡萄座腔菌科真菌在全球的分布作了必要的补充,也为杨树溃疡病的研究和防治提供进一步的理论基础。     

苜蓿新品系Dy-2006亲缘关系的SSR分析

应用SSR分子标记对苜蓿新品系Dy-2006等6个苜蓿品种(品系)亲缘关系进行了分析.8对SSR引物共扩增出128个位点,106个位点显多态性,多态位点比率82.81%;不同苜蓿品种(品系)SSR多态性百分率存在一定差异,在32.81%～45.31%之间.遗传相似度(F)和遗传距离(D)的变化分别范围在0.9062～0.9689和0.0326～0.0762.聚类分析结果显示,新品系Dy-2006与龙牧801亲缘关系相对较近,与阿尔冈金亲缘关系较远,并与其它供试品种存在一定差异,为一个相对独立的品系.     

区域经济发展的土地利用及生态安全管理——以宝鸡地区为例

区域社会经济发展与土地利用结构关系密切。文中采用耕地动态度、相对变化率、转移率、新增耕地率、线性回归分析以及洛伦兹曲线等方法,以宝鸡地区为例分析了土地动态变化以及与区域经济发展关系、耕地与粮食匹配关系。结果表明：市区和山区县土地变化率大,川原县区相对较小,耕地变化与经济发展呈高度负相关关系。面对区域经济发展中土地资源出...     

Evaluation of insecticidal activity of podophyllotoxin derivatives against Brontispa longissima

Twenty podophyllotoxin analogues were first tested for their insecticidal activity against the fifth-instar larvae of Brontispa longissima in vivo. Among them, compounds 6-9 and 19 showed more promising and pronounced insecticidal activity than toosendanin, a commercial insecticide derived from Melia azedarach. The different insecticidal activity ranges of compounds 1-20 indicated that variation of chemical structures in the podophyllotoxin skeleton markedly affected the activity profiles of this compound class, and some important SAR information has been revealed from it. The results obtained from SAR analysis show good correlation with the docking models as well as with QSAR studies, which allows for the rational design of more potent podophyllotoxin derivatives in the development of potential new insecticides.     

Assessment of Genetic Diversity in Upland Cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) Breeding Lines by using Amplified Fragment Length Polymorphism (AFLP) Markers and Morphological Characteristics

Genetic diversity in 24 advanced breeding lines of cotton was studied by using six amplified fragment length polymorphism (AFLP) primer-pairs and 14 morphological characters. The six selected AFLP primer-pairs generated a total of 535 amplification products, of which 460 were found to be polymorphic resulting in 85.9% polymorphism. The observed genetic distances using AFLP markers ranged from 30% to 87% with an average of 34%. A wide range of variability was observed for all the morphological traits studied. The range in taxonomic distance was from 0.60 to 2.77. Most of the lines could be clustered in two major clusters in both the analyses. But the correlation coefficient between the pair-wise distances estimated from AFLPs and the average taxonomic distances estimated from morphological characters was found to be 0.04. UPGMA cluster analysis revealed inconsistencies in the clustering patterns, as the co-phenetic correlation coefficient between the dendrograms for morphological and AFLP data indicated a poor fit for the two data types. From combined information, genotypes ‘RST-12’, ‘H 1226’, ‘P 348’, ‘KDCAKD’, ‘CISV 24’ and ‘H1222’ were found to be distinct from rest of the material.     

Karyotypic Studies on Some Cultivated and Wild Species of Chenopodium (Chenopodiaceae)

Detailed karyotypic studies have been done in 20 wild and cultivated taxa of Chenopodium, which belong to three ploidy levels 2x, 4x and 6x. C. quinoa (4x) shows minor but consistent differences in the arm ratio of various chromosomes within the complements of different accessions. The chromosomes can be arranged in 18 pairs that suggest allotetraploid nature. The karyotype of C. berlandieri subsp. nuttalliae (4x) is basically similar to that of C. quinoa. C. bushianum (6x) is distinctly different from the above two species in showing highest ratio between longest and shortest chromosomes. C. album complex is characterized by consisting of 2x, 4x and 6x cytotypes. Marked karyotypic differentiation is seen even among various 2x accessions. The 4x cytotype has a more asymmetrical karyotype as compared with 2x and 6x cytotypes. The karyotypic differences are also apparent between two 6x cytotypes studied. C. strictum (6x) and C. giganteum (6x) show close similarity to 6x types of C. album.     

河南隐孢子虫分离株的系统发生

以线粒体功能性蛋白替代氧化酶(alternative oxidase,AOX)为研究对象,对隐孢子虫(Cryptosporidium)分离株进行扩增和测序,并对测得的序列进行种系发育关系研究,以确定不同隐孢子虫分离株之间的进化关系,并以18SrRNA和HSP70基因构建的进化树作参照,评价AOX基因是否适合作隐孢子虫基因分型和进化关系分析的基因座。结果表明,在AOX序列构建的进化树上Cryptosporidum分为两大类:Cryptosporidium baileyi和C.meleagridis处于一个进化枝上,C.hominis、C.suis、C.parvum牛基因型和C.parvum鼠基因型处于另一个进化枝上。在C.parvum内,鼠基因型分离株和猪基因I型(即C.suis)分离株与牛基因型和人基因型(即C.hominis)在AOX基因序列上都存在着差异。鹌鹑源C.meleagridis分离株与禽源C.baileyi3个分离株在AOX基因序列的同源性显著高于前者与C.parvum的同源性,在进化树上C.meleagridis与C.baileyi的亲缘关系也较其与C.parvum密切。AOX基因不仅可作为隐孢子虫分离株种系发育的遗传标记,又为发现隐孢子虫新的遗传特性提供了一种途径。     

Genetic polymorphism of plastid DNA in Tunisian date-palm germplasm (Phoenix dactylifera L.) detected with PCR-RFLP

Fifteen plastid fragments were amplified from a set of Tunisian date-palm accessions by PCR with consensus primers and analysed by RFLP. Polymorphic DNA bands were obtained as reliable molecular markers to estimate genetic distances among the accessions and to examine their phylogenetic relationships. The ctDNA PCR-RFLP method permitted the identification of two haplotypes that differ in the presence or absence of the HinfI restriction site. Phenetic groups composed of cultivars clustered together but does not constitute monophyletic groups. This typology agrees with the haplotypes' organization and provides a common genetic background within the implied varieties.     

Analysis of Genetic Relationships among Turkish Cultivars and Breeding Lines of Lens culinatis Mestile Using RAPD Markers

Randomly Amplified Polymorphic DNA markers were used to determine the genetic relationships among Turkish lentil cultivars and breeding lines. Fourteen cultivars and thirteen breeding lines were evaluated to determine genetic variability using nine random 10-mer primers (among 45 primers). Forty-one reproducible bands were obtained, 54% of which were polymorphic. Genetic distances among cultivars and breeding lines were obtained from the simple matching coefficients (SM). The lowest genetic distance was observed between the cultivars of Ali Dayi and Kafkas with 5.0%, while ‘Seyran-96’ and ‘Ozbek’ had the highest genetic distance with 58.3%. An unweighted pair-group method with arithmetic averages (UPGMA) cluster analysis was performed on the distance matrix using Phylip software. The dendrogram clearly showed two distinct groups. The first group is composed of Akm 565 and Akm 563. The second group contains all the cultivars and remaining eleven breeding lines.     

Crossability relationships between the common potato, Solanum tuberosum spp. tuberosum, and its wild diploid relatives S. kurtzianum and S. ruiz-lealii

The common potato, Solanum tuberosum spp. tuberosum (tbr), is a tetraploid species with a narrow genetic base, but with a large number of related species that harbor great genetic diversity for numerous characters of agronomic interest. S. kurtzianum (ktz) and S. ruiz-lealii (rzl) are wild diploid relatives with potential resistance to adverse biotic and abiotic factors. To evaluate if this wild germplasm can be incorporated by conventional crosses into the tbr gene pool, pollen-pistil compatibility relations and seed set in interspecific crosses with tbr were investigated. In 4x tbr × 2x ktz crosses and the reciprocals, 89% and 52.2% of genotypic combinations (respectively) were compatible at the pollen-pistil level. Seeds were obtained from some genotypic combinations in both directions of the cross, suggesting that functional 2n gametes might be produced by particular ktz genotypes. In 2x rzl × 4x tbr crosses and their reciprocals, 35% and 11.7% (respectively) of the genotypic combinations were compatible at the pollen-pistil level, but no seeds were obtained. These results indicate that the reproductive isolation between 4x tbr and 2x ktz is incomplete, and that gene exchange between them is feasible. Moreover, further studies will have to be carried out with rzl to ascertain its crossability with 4x tbr.