基于自媒体的旅游景区营销策略研究——以常州天目湖景区为例

在分析天目湖网络营销尤其是自媒体营销影响旅游者态度以及购买决策的背景下,设计了天目湖景区自媒体营销对旅游者决策影响调查问卷。通过问卷调查,分析了到访天目湖景区游客的基本出游特征,自媒体营销对游客出游影响的程度,旨在为天目湖景区进一步开展自媒体营销提供参考。     

Genetic and Geographic Patterns of Duplicate DPL Genes Causing Genetic Incompatibility Within Rice: Implications for Multiple Domestication Events in Rice

Strong genetic incompatibilities exist between two primary rice subspecies,indica and japonica.However,the wild ancestors of rice,O.nivara Sharma et Shastry and O.rufipogon Griff.,are genetically compatible.How this genetic incompatibility became established has not been clearly elucidated.To provide insights into the process,we analyzed a pair of hybrid sterility genes in rice,DOPPELGANGER 1(DPL1)and DOPPELGANGER 2(DPL2).Either of the two loci can have one defective allele(DPL1-and DPL2-).Hybrid pollen carrying both DPL1-and DPL2-alleles is sterile.To explore the origination of DPL1-and DPL2-,we sequenced the DPL1 and DPL2 genes of 811 individual plants,including Oryza sativa(132),O.nivara(296)and O.rufipogon(383).We then obtained 20 DPL1 and 34 DPL2 sequences of O.sativa from online databases.Using these sequences,we analyzed the genetic and geographic distribution patterns of DPL genes in modern rice and its wild ancestors.Compared with the ancestral populations,DPL1-and DPL2-showed reduced diversity but increased frequency in modern rice.We speculated that the diversity reduction was due to a historic genetic bottleneck,and the frequency had likely increased because the defective alleles were preferred following this artificial selection.Such results indicated that standing variances in ancestral lines can lead to severe incompatibilities among descendants.Haplotype analysis indicated that the DPL1-haplotype of rice emerged from an O.nivara population in India,whereas the DPL2-haplotype emerged from O.rufipogon in South China.Hence,the evolutionary history of DPLs conforms to the presumed multiple domestication events of modern rice.     

水稻东野型不育系异交不亲和性的鉴定和遗传分析

目的 在东野型新三系杂交水稻研究过程中,发现不育系与部分品种杂交或回交存在异交不亲和性。对该性状开展研究,为东野型不育系异交不亲和性的改良提供理论依据,促进东野型三系体系的应用。方法 采用东野型同质异核不育系和野败型异质同核不育系分别与保持系品种进行杂交,研究东野型不育系异交不亲和性的产生原因,进而利用一套染色体单片段代换系分别与东野型不育系DY1A杂交,开展遗传分析,并进行基因初步定位。结果 异交不亲和性由核质互作产生,且有两种类型,分别发生在杂交当代和回交世代。针对第一种类型,初步遗传分析显示异交不亲和性在细胞核内受单隐性基因控制,暂命名为CI_1(t),将该基因初步定位在第8染色体RM6838和RM5767两个标记之间,与RM3395连锁。结论 东野型不育系的异交不亲和性可以通过分子手段进行遗传改良。     

人工合成甘蓝型油菜的繁育特性与试管繁殖

通过甘蓝品种(2n=18，CC)与白菜品种(2n=20，AA)杂交并借助胚珠培养和染色体加倍，获得一系列人工甘蓝型油菜新品系。对18个人工合成甘蓝型油菜新品系的花粉育性、自交结实性、异交结实性等研究表明，人工油菜品系花期自交不结实或结实率很低。蕾期自交一朵花平均获3．6粒种子，平均结角率为19．7％。但是，人工甘蓝型油菜无论作父本还是作母本与天然甘蓝型油菜杂交的结实率都较高。以人工油菜作父本与天然油菜杂交。42个组合平均杂交一朵花获得10．3粒杂交种子；以人工油菜作母本与天然油菜杂交，15个组合平均杂交一朵花获得8．5粒杂交种子。分析结果表明。本试验的人工油菜品系具有很强的自交不亲和性，蕾期自交结实率也较低，但对异交结实影响不大，因此可以直接用于杂种生产。试验对自交结实特别困难的5个人工甘蓝型油菜新品系进行了试管繁殖，采取子叶、下胚轴和茎尖联合培养方式。22株无菌苗经过2个月快繁，获得260株苗。平均繁殖系数为12．4。不同基因型繁殖系数差异较大。变幅为3．3～21．0。     

Microtubule dynamics in compatible and incompatible interactions of soybean hypocotyl cells with Phytophthora sojae

The arrangement of microtubules in soybean ( Glycine max ) cells was examined during compatible and incompatible interactions of hypocotyls of soybean cv. Harosoy (susceptible) and cv. Haro 1272 (resistant) with race 1 of the soybean-specific pathogen Phytophthora sojae . Both reaction types were similar during the first 3 h after zoospore inoculation in terms of the number of cells penetrated, and depth penetrated into the cortex. By 3 h postinoculation, clear differences had developed between the two interaction types: incompatible interactions were characterized by a hypersensitive response that was confined to single penetrated cells; while compatibly responding cells appeared unchanged. Both types of response were characterized by autofluorescence of cell walls or cytoplasm and, at 6 h after inoculation, complete disorganization of cell cytoplasm. Reorientation and loss of microtubules was seen in the early stages of the incompatible interaction in association with cellular hypersensitivity, but not in compatible responses. In cells adjacent to those that reacted hypersensitively, there was little evidence of change in microtubule orientation. Treatment of hypocotyls with the microtubule depolymerizer oryzalin prior to inoculation did not alter the compatible response, but led to breakdown of the incompatible response. Changes in microtubule orientation and state are thus among the first structural changes that are visible within cells during incompatibility in this system.     

Horizontal transmission of hypoviruses between vegetative compatibility types of <Emphasis Type="Italic">Cryphonectria parasitica</Emphasis> in Macedonia

Biological control of chestnut blight with hypovirulence depends on the successful transmission of hypoviruses between individuals of the chestnut blight fungus, Cryphonectria parasitica. Vegetative incompatibility inhibits horizontal virus transmission, but not completely. In an effort to assess the potential for the spread of hypoviruses in the Republic of Macedonia, we studied the transmission of Cryphonectria hypovirus 1 (CHV-1) among the five observed vegetative compatibility (vc) types of C. parasitica. One fungal isolate of each vc type was infected with CHV-1 and was paired in vitro with isolates of all other vc types for a total of 20 combinations of virus donors and recipients, and 250 replicate trials per combination. Virus transmission was scored after 7 days as successful if the recipient isolate took on an unpigmented culture phenotype typical of virus infection. Transmission occurred at high frequencies between some pairs of vc types, but in <1% of the trials for 10 of the 20 combinations of donors and recipients. Asymmetric transmission was observed between some vc types that had different alleles at vegetative incompatibility loci vic1 or vic7; i.e., transmission occurred at high frequencies in one direction, but very low frequencies between the same pair of isolates in the opposite direction. The expected virus transmission, calculated as the average transmission predicted for any two randomly chosen individuals from a population, was highly negatively correlated to vc type diversity. Results for isolates of C. parasitica from Macedonia were similar to those from Italy, but less transmission was generally observed. Differences in genetic background effects on transmission may vary among different populations even when isolates differ by the same vic alleles.     

Mating Behaviour and Vegetative Compatibility in Spanish Populations of Botryotinia fuckeliana

Mating behaviour and vegetative compatibility were studied in Spanish populations of Botryotinia fuckeliana. Fifty-seven isolates out of the 61 tested were sexually fertile with one or more of the reference strains of known mating type (MAT1-1 or MAT1-2). Thirty-nine isolates were heterothallic, giving fertile crosses when mated with the MAT1-1 (24 isolates) or the MAT1-2 (15 isolates) reference strain. Eighteen isolates crossed successfully with both MAT1-1 and MAT1-2 reference strains, and were referred to as homothallic or MAT1-1/2. Both mating types were widespread, being represented in isolates from two regions, from the same and different greenhouses, from different hosts, and from different years of isolation. Isolates were paired on Malt Extract Agar + NaCl to evaluate vegetative compatibility. Most of the paired isolates were unable to fuse and showed a different reaction of incompatibility. Nitrate-non-utilising (nit) mutants were selected by growth on a medium amended with 30–50gl^–1 potassium chlorate. Over 600 chlorate-resistant sectors were recovered from 40 isolates at a mean frequency of 0.15–2.39 sectors per colony, but only 11% were identified as nit mutants by their thin growth with no aerial mycelium on minimal medium. However, most of these nit mutants reverted to wild type during six months of storage on chlorate-amended medium. Genetic complementation between nit mutants occurred only in two cases between mutants from the same isolate.     

羊草自交不亲和性初步研究

在自然条件下进行羊草自交、异交结实性实验。采用FDA染色法检测羊草小孢子活力，观测雌、雄蕊发育的时空特点。结果表明，在草原上羊草异交结实率远大于其自交结实率。在成熟花药中有生活力的花粉平均达95．2％以上。在发育时间顺序和空间结构上，雌、雄蕊并不妨碍自体授粉。另外，利用禾本科植物自交不亲和性（SI）有关的硫氧还蛋白h基因设计的引物在羊草DNA中检测到预期片断。因此，笔者认为，羊草自交不结实或结实率低的主要原因可能在于基因控制下的自交不亲和反应机制，硫氧还蛋白h基因可能与羊草的自交不亲和性有关。这仅为初步结论，仍需在细胞学和分子生物学方面取得更多的依据。     

Low diversity of vegetative compatibility types and mating type of Cryphonectria parasitica in the southern Balkans

The diversity of vegetative compatibility (vc) types and mating type was estimated in populations of the chestnut blight fungus, Cryphonectria parasitica , throughout Macedonia and from selected areas in Greece. Nearly all of the 786 isolates (94%) from Macedonia were in a single vc type, EU-12; all 379 isolates from Greece were EU-12. Only six of 20 populations in Macedonia had more than one vc type. The diversity of vc types in the most diverse populations of Macedonia was comparable with the least diverse populations found previously in Italy. All but six of the 313 isolates assayed had the same mating type, MAT-1 , and no perithecia of Cryphonectria parasitica were observed in any population. These results lead to the conclusion that sexual reproduction does not occur in these populations. The lack of vc type diversity may indicate a high potential for the spread of hypoviruses and successful biological control with transmissible hypovirulence. However, if sexual reproduction should occur in Macedonian populations, up to 32 vc types would be possible by recombination among vegetative incompatibility loci.