Development and application of functional markers in maize

Summary Functional markers (FMs) are derived from polymorphic sites within genes causally involved in phenotypic trait variation (Andersen, J.R. & T. Lübberstedt, 2003. Trends Plant Sci 8: 554–560). FM development requires allele sequences of functionally characterized genes from which polymorphic, functional motifs affecting plant phenotype can be identified. In maize and other species with low levels of linkage disequilibrium, association studies have the potential to identify sequence motifs, such as a few nucleotides or insertions/deletions, affecting trait expression. In one of the pioneering studies, nine sequence motifs in the dwarf8 gene of maize were shown to be associated with variation for flowering time (Thornsberry, J.M., M.M. Goodman, J. Doebley, S. Kresovich, D. Nielsen & E.S. Buckler, 2001. Nat Genet 28: 286–289). Proof of sequence motif function can be obtained by comparing isogenic genotypes differing in single sequence motifs. At current, the most appropriate approach for this purpose in crops is targeting induced local lesions in genomes (TILLING) (McCallum, C.M., L. Comai, E.A. Greene & S. Henikoff, 2000. Nat Biotechnol 18: 455–457). In central Europe, maize is mainly grown as forage crop, with forage quality as major trait, which can be determined as proportion of digestible neutral detergent fiber (DNDF). Brown midrib gene knock out mutations have been shown to be beneficial for forage quality but disadvantageous for overall agronomic performance. Two brown midrib genes (bm1 and bm3) have been shown to be involved in monolignol biosynthesis. These two and additional lignin biosynthesis genes have been isolated based on sequence homology. Additional candidate genes putatively affecting forage quality have been identified by expression profiling using, e.g., isogenic bm lines. Furthermore, we identified an association between a polymorphism at the COMT locus and DNDF in a collection of European elite inbred lines.     

Electronegativity Scale of Elements Calculated by Density Functional Theory and Related Methods

In chemistry and many related fields, electronegativity (EN) is an important fundamental concept and its scale is a useful physcochemical parameter. Here, calculations of both ionization potentials and electron affinities are extended toward 107 elements and done by density functional theory at the local density approximation(LDA) level and the LDB level, i.e., the local density approximation level with further non-local corrections for exchange and correlation included self-consistently as well as the modified Slater transition-state method. The definite-differentiation method is employed into calculations of the electronegativity scale and the related parameters of 107 elements with very good results due to the consideration of relativistic effects. The calculation presented is to examine both the LDA and LDB approximations in calculations for the ionization potential and electron affinity of the elements with an improved or modified Slater transition-state method, and relativistic effects have also been taken into account for 107 elements compared with 103, 86 or less in the previous report under a spin polarized density function theory with some approximations to the exchange-correlation function. The calculation results for the various quantities represent an obviously improvement over some previous calculations. It is shown that the results calculated by the extended technique and the improved Slater transition-state method in general agree well with experimental values presented by Pearson, and are better than the reported values in many previous literatures. The developed new electronegativity scale will widely be applicable in many fields such as molecular structural parameterization expression, chemobiological activity optimization prediction, structure-activity quantitation modeling, functional chemical adaptization designing, and so on.     

低值水产品及水产副产品的加工与综合利用

低值水产品及其副产品通常经过简单加工后被作为饲料利用或直接作为废物丢弃,不仅造成资源浪费,而且造成对环境的污染。研究表明,利用高新技术,可以把低值水产品或水产品下脚料加工成功能性鱼油制品、新型鱼糜制品、海鲜调味品和营养丰富的水解鱼蛋白饲料等高附加值的产品,以及骨糊、硫酸软骨素和骨胶等功能性添加剂。这些产品的研究开发为低值水产品及副产品的加工利用提供了新的途径。     

Matrix Basic Theorem and Its Application of Tvs

The matrlx basic theorem in normed linear spaces is extended to topological vec-tor spaces,by using it we also proved some important results of funcational analysis.     

发芽糙米的营养价值及其开发

简要介绍了发芽糙米的发芽机理及其营养成分的变化、功能性成分和产品开发情况.     

菠菜内生固氮菌的分离及其功能特性研究

内生固氮菌具有促生、病原菌的防治及生物固氮等作用,并且占据着植物组织内有利于营养供应和微环境适宜的生态位,是重要的微生物菌种资源。从菠菜根内分离筛选优势内生固氮菌7株,其中假单胞菌属(Pseudomonas)5株,红球菌属(Rhodococcus)和黄杆菌属(Flavobacterium)各1株。菌株Pseudomonas sp.BCE6和Pseudomonas sp.BC-E8固氮酶活性较高,分别为(13.19±0.32)和(12.11±0.96)C2H4nmol/(mg protein·h),与圆褐固氮菌(ACCC11103)的固氮酶活性具有极显著性差异(P0.01);菌株Pseudomonas sp.BC-E7具有固氮酶活性[(8.42±0.03)C2H4nmol/(mg protein·h)]、产IAA能力[(59.58±4.15)μg/m L]、ACC脱氨酶活性[(5.067±0.376)μmol/(mg protein·h)],拮抗立枯丝核菌ACCC36124(Rhizoctonia solani)、麦类赤霉病ACCC36272(Gibberella zeae)等4种常见土传病害。菠菜内生固氮菌Pseudomonas sp.BC-E7是一株多功能内生菌,具有较好的生产应用前景。     

高静压处理改善白果蛋白致敏性和功能特性

为了研究高静压处理对白果蛋白结构、抗原性及功能特性的影响,分别采用100,200,300,400,500,600和700 MPa的压力对白果蛋白进行处理,采用酶联免疫吸附检测法测定蛋白的致敏性,分别采用聚丙烯酰胺凝胶电泳,圆二色谱,荧光光谱和紫外吸收光谱检测白果蛋白分子量和构象的改变,功能特性的检测包括热稳定性和乳化特性。结果表明,高静压处理在300~700 MPa范围内可显著降低白果蛋白的致敏性(P0.05),同时高压处理后,白果蛋白能被分解为分子量为4~30 k Da范围内的小分子蛋白,此外,其二级结构中的α-螺旋和β-折叠结构被大量破坏形成无规则卷曲结构,其紫外吸收强度,表面疏水性和游离巯基含量明显提高(P0.05),高压对白果蛋白的致敏性影响与其结构变化密切相关,另外高压处理(300~700 MPa)可明显改善白果蛋白的热稳定性和乳化性能(P0.05)。因此,高静压技术可以作为一种降低白果蛋白致敏性和改善其功能特性的有效手段。     

电生功能水和静电场处理对草莓采后生理的影响

以“星都2号”草莓果实为试材，研究电生功能水及静电场(-50 kV/m)处理对冷藏草莓(贮藏温度为0℃，相对湿度为85%～90%)果肉最大破断应力、呼吸强度、乙烯释放量及细胞膜透性变化的影响。试验结果表明：电生功能水处理明显抑制了草莓的乙烯释放，降低了草莓果实的呼吸强度，而静电场处理也一定程度地降低了果实的乙烯释放量，但对果实呼吸强度无明显的影响。二者均可保持贮藏期间草莓最大破断应力，延缓果肉细胞相对电导率的上升，从而有效地抑制采后草莓果实的衰老过程。相比较而言，电生功能水处理效果优于静电场。     

魔芋葡甘聚糖凝胶珠硫酸酯化修饰工艺优化研究

采用二次回归旋转正交组合实验设计方法，探讨了魔芋葡甘聚糖凝胶珠的硫酸酯化修饰的最优化工艺条件。结果表明：各因子对硫酸基含量影响由大到小依次为温度、氯磺酸用量和时间，且温度和氯磺酸用量两因子间相互作用极显著。回归方程达到极显著水平，无失拟因素存在。通过预测与验证得到硫酸酯化最优化工艺条件为：10 g魔芋葡甘聚糖凝胶珠，氯磺酸用量为5.27 mL，反应温度为39.4℃，反应时间为3.88 h，在此条件下产物硫酸基含量质量分数为（24.40±1.28）%。