Administration of gulonolactone does not evoke ascorbic acid synthesis in teleost fish

Evidence is presented that for common carp (Cyprinus carpio L.), intraperitoneal injection of L-gulonolactone, a precursor of ascorbic acid synthesis in the D-glucuronic acid pathway, does not result in an increased concentration of ascorbate in tissue. Control fish injected with an equimolar amount of ascorbic acid have shown a significant increase in ascorbic acid concentration in the kidney, hepatopancreas, plasma and spleen. The ascorbate status in the carp body,i.e., the ascorbate nutritional history, produced significant differences in ascorbate withdrawal from circulation and probably in the catabolic rate. Acute fasting decreased ascorbate uptake into tissues as compared to fish fed a diet lacking ascorbate. Intraperitoneally injected ascorbate affects common carp being fed a diet containing 295 mg of total ascorbic acid kg^–1 by causing tissue to become saturated with vitamin C, similar to the tissues in the group undergoing acute fasting. There was no gulonolactone oxidase activity in the hepatopancreas of the common carp. These results suggest that the metabolic rate induced by feeding is the primary factor regulating ascorbate requirement.     

栽培稻与普通野稻杂交杂种优势和农艺性状的遗传分析

按不完全双列杂交方式组配了12个栽培稻与普通野稻种间杂交组合,定量分析其杂种优势和利用加性-显性模型对11项农艺性状进行遗传分析。结果表明:12个栽野交组合的平均杂种优势为-0.608~3.031,穗数和籽粒长宽比表现强优势是其主要特征。栽野交的穗数、籽粒长宽比、结实率和抽穗期的优势显著高于籼粳交。各性状具有较高的广义遗传力(0.50~0.92);狭义遗传力为0.24~0.84,籽粒长宽比和抽穗期的狭义遗传力较高,其它性状中等偏低。各项农艺性状间具有显著或极显著水平的表型相关和遗传相关,可作为育种间接选择时的有效参考指标。     

中国冬小麦puroindoline类型分布及其对溶剂保持力的影响

 以中国4个冬麦区的244份小麦品种（系）为材料，对籽粒硬度、面粉颗粒度大小、puroindoline等位变异类型和溶剂保持力进行了研究。结果表明，中国冬小麦中有5种puroindoline类型，分别为Pina-D1a/Pinb-D1a（野生型）、Pina-D1b/Pinb-D1a、Pina-D1a/Pinb-D1b、Pina-D1a/Pinb-D1d和Pina-D1a/Pinb-D1p。 Pina-D1a/Pinb-D1p为新变异类型，目前仅在我国品种（系）中发现。硬质麦中以Pina-D1a/Pinb-D1b类型最为广泛，占硬质麦的81.2%，Pina-D1b/Pinb-D1a、Pina-D1a/Pinb-D1d和新类型Pina-D1a/Pinb-D1p分别占硬麦的9.7%、1.2%和7.9%。籽粒硬度及面粉颗粒大小与4种溶剂保持力之间的相关均达1%显著水平，其中以水溶剂保持力与硬度之间的关系最为密切，与SKCS和NIR硬度值之间的相关系数分别为0.73和0.64。Pina-D1b/Pinb-D1a类型的水溶剂保持力和碳酸钠溶剂保持力平均值最大，分别为68.1和85.8，均与Pina-D1a/Pinb-D1b类型之间差异达5%显著水平。同时，各个麦区间的硬度值和溶剂保持力也有所不同，其中北部冬麦区和西南冬麦区的水溶剂保持力间及北部冬麦区和长江中下游冬麦区的碳酸钠溶剂保持力间差异也达到了5%显著水平。这为改进我国小麦籽粒硬度及将溶剂保持力用于早代选择提供了理论基础。     

快速导入小麦多个优质HMW-GS基因方法和效果的研究

 采用回交转育、特异性PCR分子标记辅助选育与蛋白质电泳筛选，结合温室和大田种植，将Soissons携带的多个优质HMW-GS基因导入高产小麦品系1718。特异性PCR检测BC1、BC2、BC3和BC3F1代随机群体的Dx5基因分布符合1对等位基因的遗传分离比例1:1；从BC2代到BC3F2代，结合HMW-GSDx5基因分子标记辅助选育和其它农艺性状常规选择，筛选出携带优质HMW-GSDx5基因、又与轮回亲本农艺性状相似的单株后，进行回交或者自交；在BC3F2代中已获得携带优质HMW-GSDx5基因、农艺性状稳定、且又与轮回亲本相似的株系1718-4；在BC3F2后代中，蛋白质电泳筛选出携带1、7+8、5+10亚基的单株1718-4-6和1718-4-10。两新品系1718-4-6和1718-4-10保留了轮回亲本高产特性，且品质性状明显提高。在聚合多种优质HMW-GS基因和改良高产小麦品系品质育种中，回交转育、HMW-GS基因分子标记辅助选育与高代蛋白质电泳筛选相结合是一种定向、快速、有效的育种途径。     

转牛（羊）生长激素基因工程鲤鱼研究

生产出转牛和羊生长激素基因实验鲤鱼一万余尾，筛选出生长速度快，含有外源基因的转基因鲤鱼１４３尾，遗传实验证实外源基因可遗传给后代，经池塘生长实验证明于代仍具有生长速度快的特征，建立了把外源基直接注入鲤鱼受精卵及确定了外源基因导入鲤鱼受精卵的最佳时期等构建转基因鱼的一整套技术。     

Effect of d-Lys6 salmon sGnRH alone and in combination with domperidone on the spawning of common carp during the late spawning season

The effect of [d-Lys6] salmon gonadotropin-releasing hormone alone (sGnRH) and in combination with domperidone, a dopamine antagonist, on the spawning of common carp, Cyprinus carpio, was investigated during the late spawning season (when mature fish stop spawning under natural conditions when males and females are put together). Fish were induced to spawn by [d-Lys6]-sGnRH salmon gonadotropin-releasing hormone analogue (sGnRH-X) only when injected in combination with domperidone at doses of 10 g kg-1 and 20 mg kg-1 body weight respectively. [d-Lys6]-sGnRH-X alone did not induce spawning at a dose as high as 100 g kg-1 body weight. Fish injected with domperidone alone did not spawn either. These results demonstrate that [d-Lys6]-sGnRH-X in combination with a dopamine antagonist is effective in inducing spawning during the late spawning season.     

Stripping Fecundity of Common Bream (Abramis brama L.) from the Rivers Trent and Sow (Nottinghamshire, UK)

Results obtained with common bream (Abramis brama) originating from the rivers Trent and Sow (Great Britain) are presented with particular attention to the egg size and absolute and relative fecundity recorded during stripping of hormonally (pituitary extract) treated females. The average number of eggs obtained by stripping 1 kg of female biomass (RSF) from the river Sow and Trent were 93,642 ± 20,896 and 151,179 ± 25,123, respectively. These values were similar to the respective parameters in bream populations from north-western USSR lakes.     

Analyses of the seed protein contents on the cultivated and wild buckwheat <Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> resources

The seed protein contents of 179 accessions belonging to ten species of genus Fagopyrum were determined by means of the Kjeldahl method. The results indicated that there are significant differences of seed protein content among different accessions within the same species. The average protein content of F. esculentum is 12.94%, ranging from 8.81–18.71%, and the protein content of Sibano is the highest, up to 18.71%, Gantian 1 the lowest with 8.81%. The average protein content of tartary buckwheat is 12.17%, with the range from 7.82–18.94%, and the protein content of cultivated tartary buckwheat Qianku 2 is the highest (18.59%), and that of Ganku 1 (7.82%) the lowest. Moreover, there are significant differences of seed protein content among different buckwheat species and between the different buckwheat types (between common buckwheat and tartary buckwheat, between the diploid and the tetraploid, between the cultivated and the wild, and between the big-achene group and the small-achene group). The average seed protein content of F. giganteum is the highest in all tested species, up to 17.81% with the range of 13.91–21.27%, and that of F. callianthum the lowest, only 8.31%. This study was financed by the Natural Science Foundation of China (30270852, 30471116), Program for New Century Excellent Talents in University (NCET-2004-0913), Guizhou Key International Cooperation Project (Qianke Hewai G Zi 2005#400108), Guizhou Oversea Talent Project (Qianren Xiangmu Zizhu Hetong 2004#02), and Key Project of Students in Guizhou Normal University (GNU-SP-2005-SJXY-A01)     

Structure of genetic diversity among common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) varieties of mesoamerican and andean origins using new developed microsatellite markers

A common bean genomic library was constructed using the ‘IAC-UNA’ variety enriched for (CT) and (GT) for microsatellite motifs. From 1,209 sequenced clones, 714 showed microsatellites distributed over 471 simple and 243 compound motifs. GA/CT and GT/CA were the most frequent motifs found among these sequences. A total of 123 microsatellites has been characterized. Out of these, 87 were polymorphic (73.7%), 33 monomorphic (26.8%), and 3 (2.4%) did not amplify at all. In a sample of 20 common bean materials selected from the Agronomic Institute Germplasm Bank, the number of alleles per locus varied 2–9, with an average of 2.82. The polymorphic information content (PIC) of each marker varied from 0.05 to 0.83, with a 0.45 average value. Cluster and principal coordinate analysis of the microsatellite data were consistent with the original assignment of the germplasm accessions into the Andean and Mesoamerican gene pools of common bean. Low polymorphism levels detected could be associated with the domestication process. These microsatellites could be a valuable resource for the bean community because of their use as new markers for genetic studies. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. An erratum to this article can be found at     

间套复种小麦--早优504的选育

本文以八倍体小偃麦中₅为远缘亲本材料，通过远缘杂交，染色体工程与常规育种技术相结合的方法，选育出一个适合间套复种的小麦新品种--早优504。该品种具有特早熟、矮秆、株型紧凑、叶片上挺、抗病、优质、高产等优良性状。