种子辅助化学法合成ZnO纳米棒及其表征

低温条件下(95℃),采用ZnO种子辅助化学反应法,成功制备了宏量直、细的ZnO纳米棒;用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等分析手段对纳米棒的结构和形貌进行了表征;同时还对ZnO纳米棒的形成机理作了分析;并以ZnO纳米棒作为光催化剂,对甲基橙(MO)溶液进行了光催化实验。结果表明,ZnO与Zn源的摩尔比对ZnO纳米棒的形貌影响很大,PVA通过空间位阻效应控制ZnO纳米棒的长度,ZnO纳米棒有较好的光催化活性。

Supporting Nursing Technology for the Marker-Assisted Selection of Castanea mollissima Blume

[Objective] The aim was to study the supporting raising technology of Castanea mollissima Blume molecular marker-assisted selection to reduce the cost and time for chestnut breeding.[Method] To find the best cutting method,10 treatments were designed according to transverse diameter and vertical diameter of the chestnut including different cutting ratios in 1/2,1/3,1/4 and different directions about cross cutting,vertical cutting,bevel cutting and two side-cutting.The germination rate,seedling survival rate and morphological indicators of the treatments were measured;significant difference among them was also analyzed.[Result] 1/3 bevel cutting was the best,which not only could give high germination rate and survival rate,but also could guarantee high quality of nursery stock,which did not grow so differently with the untreated seedlings.[Conclusion] This way can not only reduce too much cost and time for seedling breeding,but also promote the germination of chestnut in advance,which could do much good to production.

Artificial Pollination and Seed Germination of Dendrobium candidum Wall. ex Lindl.

The artificial pollination and the seed germination on Dendrobium candidum were conducted. Results showed that the percentage of fruit-setting reaches the highest under cross pollination before 10 o＇ clock in the morning after blooming 2 d to 4 d. The optimal medium for seeds germination was MS＋ NAA 0.5 mg/L ＋ potato juice 10% ＋ active charcoal 0.5%, and cultured for 7 d in the dark then under light.

Genetic Analysis of Yield and Yield Components Based on the Three Controlled Hybrid Populations in the Robusta Coffee （Coffea canephora Pierre）

Genetic analysis of yield and yield components were carried out on three parental clones of Coffea canephora Pierre and their controlled hybrid progenies. There is a possibility to estimate coffee yield capabilities in simply via the easier measuring traits of yield components since significant correlation between them were detected. We found that among parental show very few significantly differences of all observed characters and even not found between the overall mean of the descendants and their donor parents, whereas some particular descendants show higher values rather than their donor parent in one or more characters. Increased value between the best parent to the best descendent were detected varies from zero to 102%. This situation suggests the difficulty to find out the optimum yield in a single plant by accumulating all of yield components that actually can increase 143% to 278% from actual to potential yields. In addition, observed characters among population were also actually found highly varies from 159% in out-turn in population B to 28,333% in number of productive branch among population A. Low heritability （h2） that generally found in quantitative traits due to polygenic control was present in our studies in almost all characters observed. Therefore, selection for actual high yielding through conventional breeding will not efficient, and more convincing the power of selection using molecular markers to assist for cumulate additive effects in a single genotypes that resulted of high yielding in the future.

Using Marker Assisted Selection to Hasten Screening of Cassava Cultivars Developed through Introgression of Cassava Mosaic Disease （CMD） Resistance into Cassava Landraces in Ghana

Cassava mosaic disease （CMD）, the most important disease of cassava （Manihot esculenta Crantz） is a potential threat to Africa＇s cassava production. The disease is embedded in most landraces resulting in low yields. Host plant resistance has been found to be the best control strategy. A breeding programme using genetic hybridisation and Marker Assisted Selection was initiated in 2007 to improve the resistance levels of farmer-preferred landraces and reduce the long breeding cycle for developing improved cassava varieties. Thirty farmer-preferred landraces were selected and crossed with a high yielding and mosaic resistant cultivar （TMEI l） from International Institute of Tropical Agriculture （IITA）. The resultant progenies found to have a reasonable level of resistance （score, 1-3） to the CMD were AW 18, 273 Nyamebekyere, NK 43, AW 3, NK 26, K 25, Dabodabo, Ahwengyankwa, 674 Debor, Degarti, Agric Bankye, and NK 57. These resultant progenies were backcrossed to the resistant cultivar. The backcross one （BC l） progenies totaling 224 were screened with molecular markers that are associated to the CMD 2 gene. De-oxyribonucleic Acid （DNA） was extracted from leaves of the 224 BC1 progenies and 13 parents. Two Simple Sequence Repeats （SSR） markers （SSY28 and NSl58） and one Sequenced Characterized Amplified Region （SCAR） marker RME1, were used to screen and select for the resistant BC l progenies. Marker Assisted Selection （MAS） revealed that 82% of the genotypes had at least a marker allele for the CMD2 gene, indicating resistance. The study further revealed that by using MAS, the breeding cycle of cassava in the generation of varieties could be reduced from 8 years to 2 years. The resistant genotypes identified will be evaluated for yield and starch cooking quality in future breeding work.

前向拉曼兼容光纤激光器的优化设计

高功率全光纤结构激光系统中，后向受激拉曼散射光会被合束器等器件吸收，产生热量并对器件造成破坏，成为限制功率提升的因素之一。提出前向拉曼兼容光纤激光器概念，通过注入辅助种子光抑制后向光来提高输出功率。建立了含有受激拉曼散射效应（SRS）的主振荡功率放大（MOPA）结构数值模型，模拟分析了后向光的特性，且比较了注入不同功率、不同波长辅助种子光对输出总功率的影响。计算结果表明，当注入辅助种子光在特定波长特定功率时，系统输出功率可提升一倍以上。

Development and application of biological technologies in fish genetic breeding

Fish genetic breeding is a process that remolds heritable traits to obtain neotype and improved varieties.For the purpose of genetic improvement,researchers can select for desirable genetic traits,integrate a suite of traits from different donors,or alter the innate genetic traits of a species.These improved varieties have,in many cases,facilitated the development of the aquaculture industry by lowering costs and increasing both quality and yield.In this review,we present the pertinent literatures and summarize the biological bases and application of selection breeding technologies(containing traditional selective breeding,molecular marker-assisted breeding,genome-wide selective breeding and breeding by controlling single-sex groups),integration breeding technologies(containing cross breeding,nuclear transplantation,germline stem cells and germ cells transplantation,artificial gynogenesis,artificial androgenesis and polyploid breeding)and modification breeding technologies(represented by transgenic breeding)in fish genetic breeding.Additionally,we discuss the progress our laboratory has made in the field of chromosomal ploidy breeding of fish,including distant hybridization,gynogenesis,and androgenesis.Finally,we systematically summarize the research status and known problems associated with each technology.

High-throughput development of genome-wide locus-specific informative SSR markers in wheat

Dear Editor,Although simple sequence repeat（SSR）markers are not new,they are still useful and often used markers in molecular mapping and marker-assisted breeding,particularly in developing countries.However,locus-specific SSR markers could be more useful and informative in wheat breeding and genetic studies.In the present study,221,911 locus-specific SSR markers were designed.Verification of polymorphisms showed that the proportion of polymorphic markers increases with an increase in SSR size.

MHC polymorphism and disease resistance to Singapore grouper iridovirus(SGIV) in the orange-spotted grouper, Epinephelus coioides

Major histocompatibility complex （MHC） genes are critical members in both innate and adaptive immunity, and the association between their polymorphism and disease resistance has been reported in many teleosts. In the present study, we first investigated the genetic variation at the MHC II β gene in orange-spotted grouper （Epinephelus coioides） after a challenge with Singapore grouper iridovirus （SGIV）. The results reveal that a high polymorphism level of the MHC II β gene （H = 1.000; K = 20.206; π=0.081） and at least three loci exist in grouper. The rate of dN/dS in the peptide-binding region （PBR） and non-PBR were both 〉1, suggesting the loci were evolving under positive selection. A high ratio of heterozygous individuals （37.26 %） and high rate of dN/dS were discovered, suggesting that both heterozygote advantage and frequency-dependent selection might result in the high polymorphism levels in MHC II β genes in grouper. A total of 33 MHC II β alleles were identified from 40 high-susceptibility （HS） and 40 high-re- sistance group （HR） individuals, and 15 alleles were used in the association analysis. Three alleles, EPCO-DBB＊0302, EPCO-DBB＊0307, EPCO-DBB＊0603, and EPCO- DBB＊1001 were significantly associated with resistance ability to SG1V, and the EPCO-DBB＊0607 and EPCO-DBB＊1303 alleles were associated with susceptibility （P 〈 0.05）. To further confirm the association, another independent challenge experiment was performed. The result of association analysis in the verification test found that only EPCO-DBB＊1001 alleles were significantly asso- ciated with resistance to SGIV （P 〈 0.05）, while the other alleles showed no significance （P 〉 0.05） in the frequency distribution between HR and HS groups. Therefore, the EPCO-DBB＊ 1001 alleles could be used as a disease resis- tance-related MHC marker in the molecular marker-assisted selective breeding program of grouper.