水稻染色体片段代换系对氮反应的QTL分析

利用来源于93-11(受体)和日本晴(供体)构建的染色体片段代换系,采用盆栽试验分析其在两种氮水平下产量相关性状的差异,包括株高、每穗实粒数、单株产量、根干重、地上部干物重以及氮素利用效率等。结果表明,与正常条件相比,低氮胁迫条件下代换系的单株产量与生物学产量显著降低。两种氮水平下共定位到54个QTLs,其中仅有6个在两种氮水平下同时检测到,说明水稻对不同氮肥反应由不同的基因调控。定位到5个氮肥农学利用效率QTLs,其中,第6染色体的qNAE6解释表型变异较大(14%)。同时,我们还发现存在一些QTL区域同时影响多个性状,如第2染色体RM2634区域,第6染色体RM510-RM225区域,第10染色体RM228和第11染色体RM536区域,暗示其可能是一因多效或紧密连锁的基因的效应。该结果将为鉴定分析氮利用相关基因以及氮高效育种提供一定试验依据。     

黄檗种质资源研究进展

黄檗用途广泛,在木材、药用方面均有开发利用价值,并因其优良的抗性和观赏性,园林绿化应用前景良好。从基础研究、应用基础研究、应用研究3个递进层次对黄檗近年来的研究进展进行了综合评述,并在此基础上,提出了科学开发黄檗资源的几点建议,以实现资源的合理利用和可持续发展。     

Sequence characterized amplified region markers tightly linked to the dwarf mosaic resistance gene <Emphasis Type="Italic">mdm1 (t)</Emphasis> in maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

Maize dwarf mosaic is one of the devastating and wide spread viral diseases in the world. The present investigation was carried out to develop DNA markers closely linked to the resistance gene mdm1 (t). Linkage between the markers and phenotypes was confirmed by analyzing an F₂ population obtained from a cross between a resistant parent ‘Huangzaosi’ and a susceptible parent ‘Mo17(478)’. Four AFLP markers were found in the maize dwarf mosaic resistant plants. By using (BSA) bulked segregant analysis, two of the four AFLP markers were transformed into Sequence-characterized amplified regions markers (SCARs), nominated Rsun-1 and Rsun-2. The two amplified fragment length polymorphism (AFLP) markers, RHC-1and RHC-2, from the amplification products of primer combination E-AGC/M-CAA and E-AGC/M-GAA, showed linkage with the mdm1 (t) gene in a genetic distance 1.6 and 2.0 cM, respectively. The results indicate that the new SCAR markers will be valuable to distinguish resistant plants from susceptible plants in plantlets growing in seedbeds. The markers developed in this study are suitable for marker-assisted selection for maize dwarf mosaic resistance.     

不同产地及生长年限鸡血藤药材质量研究

研究不同产地和不同生长年限鸡血藤浸出物含量和灰分含量,以探讨鸡血藤药材的采收年限。结果表明,广西各地和越南产野生鸡血藤药材其浸出物含量、总灰分含量、酸不溶性灰分含量均符合《中华人民共和国药典》鸡血藤项规定的标准;随着鸡血藤生长年限的增加,浸出物含量增加,但是小枝条的含量低;栽培4年浸出物即能达到中国药典的标准;不同饮片类型浸出物含量也有所不同,薄片明显比厚片高。这说明人工栽培鸡血藤切实可行,在加大对其鸡血藤植物资源保护的同时应加大人工栽培及繁育选育研究工作。     

Spatial vegetation patterns as early signs of desertification: a case study of a desert steppe in Inner Mongolia,China

Proper assessment and early detection of land degradation and desertification is extremely important in arid and semi-arid ecosystems. Recent research has proposed to use the characteristics of spatial vegetation patterns, such as parameters derived from power-law modeling of vegetation patches, for detecting the early signs of desertification. However, contradictory results have been reported regarding the suitability of those proposed indicators. We used an experiment with multiple grazing intensities as an analog of a desertification gradient and evaluated the performance of two predictors of desertification: percent plant cover and a transition from a patch-area distribution characterized by a power law to another portrayed by a truncated power law, in a desert steppe in Inner Mongolia, China. We found that spatial metrics, such as the largest patch index and coefficient of variation of mean patch area had negative linear relationships with grazing intensity, suggesting that vegetation patches became more fragmented and homogeneous under higher grazing pressure. Using a binning-based method to analyze our dataset, we found that the patch-area relationship deviated from a power-law to a truncated power-law model with increasing grazing pressure, while the truncated power law was a better fit than the power law for all plots when binning was not used. These results suggest that the selection of methodology is crucial in using power-law models to detect changes in vegetation patterns. Plant cover was significantly correlated with stocking rate and all spatial metrics evaluated; however, the relationship between cover and vegetation spatial pattern still deserves a thorough examination, especially in other types of ecosystems, before using cover as a universal early sign of desertification. Our results highlight a strong connection between the vegetation spatial pattern and the desertification associated with heavy grazing and suggest that future studies should incorporate information about vegetation spatial pattern in monitoring desertification processes.     

山核桃ISSR反应体系的优化

采用改良的CTAB法提取山核桃基因组DNA,该方法提取的DNA纯度与含量较高。以宁国山核桃居群为试材,用引物UBC810[序列为（GA）8T]研究了PCR反应体系的5种主要组分对山核桃ISSR扩增结果的影响。结果显示：除模板DNA含量外,其它因素均对扩增效果有明显影响。建立的反应体系为：20μL反应体系中DNA模板量30ng、引物浓度0.3μmol/L、dNTPs浓度0.3mmol/L、Mg2＋浓度2.0mmol/L、TaqDNA聚合酶用量1U。     

DNA分子标记技术及其在高粱育种中的应用

近年来分子技术的快速发展,使其在高粱上也得到应用。由于分子标记具有诸多优点,因此它的发展和应用为高粱研究提供了一条有效的途径。此文概述了分子标记技术的基本类型,综述了近年来分子标记技术在高粱遗传连锁图谱的构建、基因定位、关联遗传学、突变体等的研究及应用现状。最后,分析了分子标记技术在高粱遗传育种研究中存在的问题及今后发展的方向。     

枣疯病植原体的快速检测

以表现丛枝症状的‘金丝4号’枣树为试材,以叶片总DNA粗提物为模板通过PCR扩增技术克隆16S rDNA基因,建立了枣疯病植原体快速检测方法。序列分析结果显示,枣疯病植原体‘金丝4号’株系（JWB-Jinsi4,TA）与JWB-G1（AB052876）同源性为99.7%,归属于16Sr Ⅴ-B组。实验结果表明,以DNA粗提物为模板的PCR扩增技术,可快速有效地检测枣疯病植原体,为生产实践中枣疯病的诊断和防治提供技术支持。     

基于主基因+多基因混合模型的甜高粱茎秆含糖量基因遗传分析

此文以茎秆含糖量（锤度）较低的粒用高粱品系LR625（P1）和茎秆含糖量（锤度）较高的甜高粱品系Rio（P2）及其杂交后代F1、F2群体为研究对象,运用主基因+多基因混合遗传模型对茎秆含糖量的遗传进行了联合分离分析。结果表明：茎秆含糖量性状受2对加性-显性-上位性主基因和加性-显性多基因共同控制。2对主基因的加性效应分别为-4.004和-2.116,显性效应分别为0.084和-0.462,主基因遗传力为83.27%,多基因遗传力为7.38%。这说明锤度性状主要受2对主基因的作用,而且2对主基因均以加性效应为主。这一研究结果为茎杆含糖量性状的基因定位和育种选择提供了理论依据。     

CHE饲料发酵过程中蛋白酶活力的在线监测

蛋白酶（包括酸性蛋白酶、碱性蛋白酶及中性蛋白酶）是饲料复合酶制剂中最主要的酶之一。本文对CHE饲料中的酸性蛋白酶、碱性蛋白酶、中性蛋白酶进行了提取并进行了活性测定。结果表明各个酶的活性并不相同,其中酸性蛋白酶的活性最大,碱性蛋白酶最小,并且酸性蛋白的最适温度是40℃左右活性,最大值为5.203ug/min,中性蛋白酶的最适温度是30℃左右性,最大值为2.9754 ug/min,而碱性蛋白酶的最适温度是22℃左右性,最大值为0.4482 ug/min。