抗疫病加工型辣椒细胞质雄性不育恢复系的创制

为加快抗疫病加工型辣椒细胞质雄性不育(cytoplasmic male sterility,CMS)恢复系的创制,该试验以单生、长果自交系481 4 10为母本,以抗疫病的恢复系939 1和1021(1) 1为父本配制杂交组合,采用花药培养技术将抗疫病恢复系的Rf基因和抗疫病基因导入单生、长果自交系中,并利用分子标记辅助选择(molecular marker assisted selection, MAS)技术鉴定DH系(Double Haploid line)的Rf基因以及抗病性,进一步用室内苗期抗性鉴定的方法验证MAS筛选的含Rf DH系对疫病的抗性。结果表明：(1)花药培养的供体亲本(481 4 10×939 1)F₁诱导出22个胚状体,成苗后经倍性鉴定获得11个花培DH系;而由供体亲本［481 4 10×1021(1) 1］F₁获得 9个DH系。(2)分子标记CRF SCAR对花培DH系进行分子标记辅助选择验证结果表明,来自供体(481 4 10×939 1)F₁的DH系中有7个可扩增出870 bp的特异条带,占63.6%;而供体［481 4 10×1021(1) 1］F₁获得的DH系中则有8个能扩增出870 bp的特异条带,占88.9%。(3)分子标记FQ01/RQ01对DH系进行分子标记辅助选择筛选结果发现,来自供体(481 4 10×939 1)F₁的DH系有5个能扩增出717 bp的特异条带,占45.5%;而来自供体［481 4 10×1021(1) 1］F₁的DH系有4个可扩增出717 bp的特异条带,占44.4%。(4)MAS技术初步筛选到7个携带Rf的抗疫病DH系,分别命名为‘渝辣选3 2/3 3/3 5/7 1/7 5/7 6/7 9’;苗期抗性鉴定结果显示,7个DH系中5个DH系抗疫病,2个中抗疫病;农艺性状调查和测交实验表明,‘渝辣选3 2’和‘渝辣选7 1’是单生朝天椒、果实较长,味辣,均为CMS恢复系。该研究创制的2个DH系为利用辣椒CMS三系配套选育抗病新品种奠定了基础。     

MicroRNA-26b/PTEN Signaling Pathway Mediates Glycine-Induced Neuroprotection in SAH Injury

Neurochemical Research - Subarachnoid hemorrhage (SAH) is a form of stroke associated with high mortality and morbidity. Despite advances in treatment for SAH, the prognosis remains poor. We have...     

Quantitative trait loci mapping for yield and its components by using two immortalized populations of a heterotic hybrid in Gossypium hirsutum L.

Quantitative trait loci (QTL) mapping provides a powerful tool for unraveling the genetic basis of yield and yield components as well as heterosis in upland cotton. In this research, a molecular linkage map of Xiangzamian 2 (Gossypium hirsutum L.)-derived recombinant inbred lines (RILs) was reconstructed based on increased expressed sequence tag–simple sequence repeat markers. Both the RILs and immortalized F2s (IF2) developed through intermating between RILs were grown under multiple environments. Yield and yield components including seed-cotton yield, lint yield, bolls/plant, boll weight, lint percentage, seed index, lint index and fruit branch number were measured and their QTL were repeatedly identified across environments by the composite interval mapping (CIM) method. From a total of 111 non-redundant QTL, 23 were detected in both two populations. In the meantime, multi-marker joint analyses showed that 16 of these QTL had significant environmental interaction. QTL for correlated traits tended to be collocated and most of the QTL for seed-cotton yield and lint yield were associated with QTL for at least one yield component, consistent with the results observed in correlation analyses. For many QTL with significant additive effects, positive alleles from CRI12, the inferior parent with lower yield performance, were associated with trait improvement. Trait performance of IF2s and the large number of QTL with positive dominant effects implied that dominance plays an important role in the genetic basis of heterosis in Xiangzamian 2 and that non-additive inheritance is also an important genetic mode for lint percentage in the population. These QTL can provide the bases for marker-assisted breeding programs of upland cotton.     

Metal-Free DNA Linearized Nuclease Based on PASP-Polyamine Conjugates

Genome manipulation controlled by small metal complexes has attracted extensive interest because of their potential application in the fields of molecular biotechnology and drug development. However, their medicinal application is still limited due to the distinct toxicity of the free radicals generated by partial metal complexes based on oxidative cleaving processes. Thus, it is still a challenge for us to use metal free agent to cleave DNA. In this work, we showed that a family of polyamine-grafted PASP (poly(aspartic acid)) conjugates is able to rapidly induce DNA cleavage in the absence of metal ions, and obtain a high-yield linearization product via a hydrolytic path. From the results of detailed control experiments, it was revealed that the formation of polyamine cation/phosphate anion pair and free ungrafted nucleophilic groups would be the key factors to improve DNA linearization. Constructing polyamine conjugates based on short peptide such as polyamine-grafted PASP, as achieved here, could provide an attractive strategy for developing mild and efficient artificial nucleases as well as researching catalytic mechanisms on DNA chemistry.     

Morphological responses of Leymus chinensis (Poaceae) to the large-scale climatic gradient along the North-east China Transect (NECT)

A field experiment was conducted to examine the morphological variations of Leymus chinensis along the climatic gradient of the North‐east China Transect (NECT), from 115° to 125° E, in the vicinity of 43.5° N, in north‐eastern China. Ten sites selected for plant sampling along the gradient have approximately uniform theoretical radiation, but differ in precipitation and geographical elevation. The results of analyses showed that vegetative and reproductive shoot heights, flag leaf lengths and widths and seed numbers per inflorescence increased from the west to the east with precipitation, but decreased with aridity. Leaf lengths and widths for most leaf types from 115° to 124° E exhibited little variations. Significant correlations of plant heights, flag leaf lengths and widths and seed numbers per inflorescence with large‐scale climatic variables (e.g. annual precipitation, aridity) and geographical variation (longitude) found in this study indicated that climatic factors have significant effects on some morphological traits of L. chinensis along the NECT.     

Seasonal Dynamics in Resource Partitioning to Growth and Storage in Response to Drought in a Perennial Rhizomatous Grass, <Emphasis Type="Italic">Leymus chinensis</Emphasis>

A natural grassland in northeastern China dominated by Leymus chinensis (Trin.) was subject to drought treatments to determine the seasonal dynamics in resource partitioning to shoot and storage organs in response to drought. The growing season was divided into six stages according to the phenology of L. chinensis. Plant samples of L. chinensis were collected at each stage to determine biomass, gross calorific value, relative water content, and key mineral contents of plant parts, including rhizomes, roots, leaves, and stems. Resource partitioning to shoot and storage organs as measured by biomass, gross calorific value, and N, K⁺, and Na⁺ contents varied significantly among phenologic stages. Drought treatment (natural precipitation, 50–60 % of field capacity) significantly reduced biomass, gross calorific value, relative water content of shoot, and N and K⁺ contents in both shoot and storage organs, but it enhanced rhizome : shoot ratio and Na⁺ content. A negative correlation in biomass, gross calorific value, and K⁺ and Na⁺ contents between shoot and storage organs was found throughout the growing season, which may have been accentuated by drought when soil moisture was limited. Our results indicate that resource partitioning to storage plays an important role in regulating plant growth of L. chinensis, especially under drought conditions.     

不同生境条件下羊草种群无性系和有性生殖特征的比较研究

比较研究了东北草原不同生境条件下4个羊草种群无性系和有性生殖数量特征的差异,结果表明,由于各种群所处立地的资源差异(特别是土壤水分),导致各种群在无性系(包括营养枝和根茎芽密度)和有性生殖(生殖枝密度、生殖枝分化率、生殖贡献)等数量特征方面差异显著,尤其在低平原种群与沙丘种群之间最为显著.与沙丘种群相比,低平原种群营养枝平均密度高50%;根茎芽平均密度高30%以上;生殖枝密度平均值高200%以上.     

放牧和刈割干扰对松嫩草原羊草草地影响的研究

放牧和刈割干扰对松嫩草原羊草草地影响的研究＊王仁忠（东北师范大学国家草地生态工程实验室长春１３００２４）＊国家自然科学基金资助项目。收稿日期：１９９５－０９－１４,修改稿收到日期：１９９７－０２－０５。ＡＳＴＵＤＹＯＮＴＨＥＥＦＦＥＣＴＳＯＦＧＲＡＺ...     

羊草种群生物量生殖分配的初步研究

对羊草种群生物量生殖分配的研究表明,在生殖生长过程中,种群用于根茎和营养生长的生物量生殖分配占有绝对优势比例,而用于有性生殖的生物量生殖分配比例较小,在10%以下。在羊草种群构件生物量生殖分配中,根茎和营养枝的叶占有较大比例(20%～40%),而用于有性繁殖体种子生产的比例很小,在1.5%以下。对有性繁殖的小比例投资是导致羊草种群有性繁殖体种子产量低的重要原因.