高山红景天生殖生态学——有性生殖与无性生殖的调查

通过原产地调查、栽培试验、分根扦插及种子萌发实验等，研究了高山红景天的繁殖及扩散方式。结果表明：高山红景天有两条生殖途径，一条是有性生殖，另一条是无性生殖。在原产地生境条件恶劣的情况下，有性生殖能力弱，主要靠无性生殖来产生大量后代，保存物种；而在太平沟人工移栽条件下，两种生殖方式都能正常进行。     

海南特有兰科植物华石斛的繁殖分配规律

华石斛为兰科石斛属多年生附生植物,在自然条件下结实率低,种子萌发条件苛刻。除了有性生殖,华石斛也可以克隆繁殖。笔者在海南省霸王岭设置5条样带,对样带内的华石斛进行种群监测,通过研究不同株龄华石斛个体的繁殖分配规律来为附生兰科植物的保育提供科学依据。结果表明,在华石斛整个生活史阶段,个体具备至少4根假鳞茎才能开始有性生殖,且对有性繁殖的投入逐年增大。华石斛的克隆生长则没有个体大小限制。根据繁殖器官生物量与植株总生物量的比例来看,随着华石斛个体株龄的增长,投入给繁殖活动的资源比例始终维持在27%左右,并且克隆繁殖始终占据2种繁殖方式的优势地位。     

Conditional use of sex and parthenogenesis for worker and queen production in ants

The near-ubiquity of sexual reproduction in animal species has long been considered a paradox because sexually reproducing individuals transmit only half of their genome to their progeny. Here, we show that the ant Cataglyphis cursor circumvents this cost by using alternative modes of reproduction for the production of reproductive and nonreproductive offspring. New queens are almost exclusively produced by parthenogenesis, whereas workers are produced by normal sexual reproduction. By selectively using sex for somatic growth and parthenogenesis for germline production, C. cursor has taken advantage of the ant caste system to benefit from the advantages of both sexual and asexual reproduction.     

青藏高原高寒草地退化与人工恢复过程中植物群落的繁殖适应对策

以三江源区不同退化程度高寒草甸和不同恢复年限人工草地作为研究对象,通过野外调查与采样、实验室分析,探究了高寒地区退化天然草地与人工恢复草地的植被群落繁殖构件数量变化。结果表明：在群落水平上,天然草地退化和人工草地建植会对植物繁殖构件的数量和生物量产生影响。随着天然草地退化程度的增加,营养枝数量和生物量则明显下降,而繁殖枝的数量和生物量明显升高（P<0.05）;随着人工草地恢复年限的增加,营养枝的数量和生物量逐渐增加,而繁殖枝的数量和生物量则逐渐降低（P<0.05）;随着恢复年限的增加,人工草地繁殖构件的变化逐渐接近未退化天然草地。在功能群水平上,植物繁殖构件数量亦随草地退化程度和人工恢复年限而变化。随着恢复年限的增加,禾本科、莎草科、杂类草的营养枝数量和生物量均呈现显著增加（P<0.05）,而繁殖枝数量和生物量则显著下降,禾本科的繁殖构件数量远远大于莎草科和杂类草;随着退化程度的增加,三大功能群的营养枝枝数和生物量显著增加（P<0.05）,而繁殖枝则呈现相反的趋势。本研究实证了草地退化和人工恢复改变植物群落繁殖分配对策的科学假设,为高寒草地植被恢复重建技术的发展和更新提供理论支撑。     

蚜虫翅型分化研究进展

综述了蚜虫生物学特性以及蚜虫翅型分化的系统发育学分布和影响因子,分析了蚜虫翅型分化的进化特点,并对其翅型分化研究进行了展望。     

Transitions to asexuality result in excess amino acid substitutions

Theory predicts that linkage between genetic loci reduces the efficiency of purifying selection. Because of the permanent linkage of all heritable genetic material, asexual lineages may be exceptionally prone to deleterious-mutation accumulation in both nuclear and organelle genes. Here, we show that the ratio of the rate of amino acid to silent substitution (Ka/Ks) in mitochondrial protein-coding genes is higher in obligately asexual lineages than in sexual lineages of the microcrustacean Daphnia pulex. Using a phylogeny-based approach to quantify the frequency of mutational-effect classes, we estimate that mitochondrial protein-coding genes in asexual lineages accumulate deleterious amino acid substitutions at four times the rate in sexual lineages. These results support the hypothesis that sexual reproduction plays a prominent role in reducing the mutational burden in populations.     

云南地区扁穗雀麦繁殖对策研究

对云南野生种牧草扁穗雀麦的繁殖对策进行了初步研究,结果表明:有性繁殖和营养繁殖效果都很好,种子产量可以达到270.00 g/m2,且种子发芽率在无任何处理的情况下也能达到80%以上,总繁殖效力平均为34.24%。扁穗雀麦有性繁殖苗期生长缓慢,生长速率为0.361 cm/d,但分蘖以后生长速率加大,抽穗开花期达最大;扁穗雀麦营养繁殖成活率较高,为89.7%,生长速度比有性繁殖快,并且随植株长大,生长速率呈下降趋势;种子产量随地上生物量的增加而增加。     

薇菜的生物学特性及人工繁殖

辨析了薇菜名称,详细介绍了薇菜的生物学特性、适于生长的环境条件、营养价值和经济价值,从整株移栽和分株移栽等无性繁殖、孢子有性繁殖方面介绍了薇菜的人工繁殖方法,论述了薇菜的采收和加工方法．     

Rarity of males in pea aphids results in mutational decay

When females can reproduce without males, do males become an evolutionarily weaker sex whose genes experience mutational decay? We addressed this hypothesis in aphids, whose reproduction alternates between parthenogenetic and sexual forms: Over the course of a year, there can be 10 to 20 generations of asexual females but only a single, if any, generation with males. We used microarray analyses to identify male-biased, asexual female-biased, and neutral genes. Interspecific comparisons reveal accelerated evolution of male-biased genes, and intraspecific polymorphisms exhibit a significant excess of nonsynonymous coding variation in male-biased genes. We conclude that the ability of females to reproduce asexually without males reduces selection constraints on male-based genes, resulting in their mutational decay.     

绞股蓝的繁殖特性和育苗技术

绞股蓝是富含人参皂苷类物质的药食两用植物,其繁殖方式有无性繁殖、有性繁殖和组织培养。综述了绞股蓝的3种繁殖方式及其相应的育苗技术。自然营养繁殖和人工营养繁殖(地下茎分株、地上茎和叶的扦插及藤蔓压条)是绞股蓝无性繁殖的主要方式,有性繁殖即用种子进行繁殖,组织培养主要包括以茎尖、茎段和花芽为外植体的组培方式。绞股蓝的育苗技术为绞股蓝人工栽培提供了充足的种苗。     

昭通市苹果绵蚜的生活史及习性

苹果绵蚜在昭通市1年最高发生15~16代,最低发生10代,世代重叠。10月份部分虫进入越冬期,1月份苹果绵蚜开始活动。7~8月份,完成1代仅需11~27 d,而在冬季完成1代需50.3~92.5 d。1年产生2次有翅蚜,夏季有翅蚜所产生的后代均为孤雌蚜,而秋季所产生的后代不仅有孤雌蚜,而且能够产生性蚜。各龄虫均有越冬,其中以第2龄虫为主,田间尚未发现性蚜和卵。第1龄虫为全年主要迁移虫态,占98%以上。     

对开蕨在哈尔滨地区的繁殖技术研究

研究了引种到哈尔滨地区对开蕨的繁育特性。结果表明:对开蕨既可以进行有性繁殖(孢子繁殖),也可以进行无性繁殖。孢子繁殖可以采用土培法和孢子无菌培养的方法,土培法以基质(4草炭土∶1蛭石∶1河沙)和室温25℃为最佳,孢子无菌培养以改良Knop s液体培养基为最佳;无性繁殖可以采用分株繁殖的方法,最佳分株季节是在春季。     

河西走廊荒漠绿洲过渡带沙丘不同生境沙拐枣种群扩张特征研究

我国荒漠绿洲边缘天然固沙植被如何利用有限的资源实现种群稳定和扩张一直是干旱区生态环境建设亟待解决的科学问题。本研究以河西走廊荒漠绿洲边缘关键天然固沙植物沙拐枣为研究对象,对流动沙丘、固定沙丘不同生境的沙拐枣种群扩张特征进行调查,旨在更全面的认识其种群扩张特征和对干旱高温环境的适应对策。结果表明：(1)沙丘不同生境,沙拐枣种群扩张方式存在显著差异：在流动沙丘,丘间低地和过渡带以有性繁殖为主,无性繁殖为辅;迎风坡和背风坡以无性繁殖为主;而随着流动沙丘固定,种群以有性繁殖为主,无性繁殖数量和所占比重显著下降,并导致种群数量下降。(2)不同生境中沙拐枣种群密度与年龄均呈显著负相关,种群以幼龄苗为主,种群最大年龄出现在丘间低地,为30龄。(3)流动沙丘不同生境根状茎主要为2年生,多年生根状茎长度较短：而固定沙丘不同生境根状茎年龄结构较为均衡。     

Functional divergence of former alleles in an ancient asexual invertebrate

Theory suggests it should be difficult for asexual organisms to adapt to a changing environment because genetic diversity can only arise from mutations accumulating within direct antecedents and not through sexual exchange. In an asexual microinvertebrate, the bdelloid rotifer, we have observed a mechanism by which such organisms could acquire the diversity needed for adaptation. Gene copies most likely representing former alleles have diverged in function so that the proteins they encode play complementary roles in survival of dry conditions. One protein prevents desiccation-sensitive enzymes from aggregating during drying, whereas its counterpart does not have this activity, but is able to associate with phospholipid bilayers and is potentially involved in maintenance of membrane integrity. The functional divergence of former alleles observed here suggests that adoption of asexual reproduction could itself be an evolutionary mechanism for the generation of diversity.     

Functional characterization of the catalytic and bromodomain of FgGCN5 in development,DON production and virulence of Fusarium graminearum

FgGCN5, a GCN5 homolog in Fusarium graminearum, plays a critical role in hyphal vegetative growth, asexual and sexual reproduction, deoxynivalenol(DON) biosynthesis and plant infection. For nuclear localized GCN5, four conserved sequence motifs(I–IV) are presented in the catalytic domain and a bromodomain in the carboxy-terminus. As a lysine acetyltransferase, conserved negatively charged residues are present to neutralize the protons from lysine substrates. However, the role of conserved motifs/domains and residues in FgGCN5 are unclear. Here, we generated deletion mutant strains for each the conserved motifs/domains and a glutamate residue 130(E130) replacement mutant. Deletion of each conserved motif in the catalytic domain and replacement of E130 site resulted in manifold defects in hyphae growth, asexual and sexual development, DON biosynthesis, and plant infection. Phenotypic defects in the mutant strains were similar to deletion mutants. The deletion of the bromodomain led a significant reduction in DON production and virulence, with no effects on hyphae growth, asexual or sexual reproduction. FgGCN5 was further found to localize to the nucleus in conidia and hyphae cells. In conclusion, FgGCN5 encodes a nuclear localized acetyltransferase. The conserved motifs in the catalytic domain and E130 are essential for correct functions of the gene. The conserved bromodomain is important for DON production and pathogen virulence. This was the first report to identify the functions of conserved motifs/domains in FgGCN5, which will contribute to our understanding of the mechanism(s) by which FgGCN5 regulates F. graminearum.     

刺拐棒(短梗五加)露地栽培及反季节生产技术

利用有性繁殖和无性繁殖技术大量生产刺拐棒优质种苗,进行露地栽培和反季节生产,在保护野生资源的同时创造出可观的经济效益。     

高职院校树木栽培与养护课程项目化教学改革探讨

介绍了高职树木栽培与养护课程项目化教学改革情况,重新设定教学目标,制订树木有性繁殖、无性繁殖、容器苗管理、树木出圃、树木修剪5个新项目,教学取得了明显成效。     

Specific features of sugar beet reproduction system

Morphogenetic investigations of the sugar beet reproduction sphere are given. It is shown that the reproduction system has seed (sexual and asexual) as well as vegetative (traumatic particulation) methods of forming organisms in the life cycle of the plants. The established morphogenetic correlations in the reproduction system will promote the solution of a number of problems of seed and vegetative propagation when creating new sugar beet lines and hybrids.     

大鲵水霉病病原的形态学观察

为了解大鲵水霉病的特征及产生原因,对养殖大鲵水霉病病原的形态进行了观察.结果表明:病原是通过破坏皮肤,感染皮下肌肉,成长为具有一定长度,呈分支多而纤细的灰白色水霉菌菌丝,其生长发育分无性和有性两种繁殖方式.外菌丝主要靠出芽生殖形成新菌丝,也可形成孢子在适宜条件下发育为新菌丝;有性繁殖是在菌丝上分别形成藏卵器和雄器,受精后由孢子囊内孢子成长为新菌丝.同时还初步探讨了大鲵水霉病的发病机制和预防方法.     

印榕仙人掌引种繁殖初步研究

印榕仙人掌（Opuntia ficus-indica Mill.)是从国外引进的多用途植物,可用于生产水果、蔬菜、饲料以及饲养胭脂虫（Dactylopius coccus Costa)。通过引种繁殖初步研究,提出了有性与无性繁殖方法,分析了影响生长发育的主要生态因子。