Isoenzyme and cotyledon protein variation for identification of black beans (Phaseolus vulgaris L.) with similar seed morphology

Summary Methods developed to identify genetically diverse varieties of beans (Phaseolus vulgaris L.) were applied to closely related lines that were difficult to distinguish on the basis of seed morphology. Seedling tissues and seeds of black beans, were examined electrophoretically for isoenzyme and cotyledon proteinn protein patterns. Seven enzymes, extracted from seeds or from seedling stem, root or leaf tissues, were compared for polymorphism. Peptidase, polyphenol oxidase, phosphoglucoisomerase and glutamate oxaloacetate transaminase patterns were the same for all lines. Some differences were observed for acid phosphatase, peroxidase and esterase patterns, but complete discrimination of the six selected lines was not possible on the basis of isoenzyme patterns alone. Using polyacrylamide gel electrophoresis (PAGE) of dissociated 0.1 M acetic acid soluble proteins at pH 3.1 (acid-PAGE), or sodium dodecyl sulphate PAGE (SDS-PAGE) of residual protein extracts, all but one pair of samples in each case could be distinguished from the other samples. Using both techniques all of the lines could be identified unequivocally.     

Inter simple sequence repeat (ISSR) markers as a tool for the assessment of both genetic diversity and gene pool origin in common bean (Phaseolus vulgaris L.)

In this study, we report the use of ISSR to assess genetic diversity and to determine the relationships among ten cultivars of common bean developed in Argentina and three materials from France. ISSR markers resolved two major groups corresponding to the Andean and Mesoamerican gene pools of common bean. We compared the results of previous analysis, performed with RAPD markers (Galván et al., 2001), with the results generated by means of ISSR. It appears that ISSR are better tools than RAPDs to identify beans by gene pool of origin though they did not revealed as many differences between individuals as RAPDs. This revised version was published online in July 2006 with corrections to the Cover Date.     

Marker-assisted selection for complex trait in common bean (Phaseolus vulgaris L.) using QTL-based index

A procedure was developed for marker-assisted selection of complex traits for common bean (Phaseolus vulgarisL.) using an index based on QTL-linked markers and ultrametric genetic distances between lines and a target parent. A comparison of the mean seed yields of the top five lines selected by different schemes demonstrated that the highest yielding group was selected on the basis of a combination of phenotypic performance and a high QTL-based index,followed by groups identified by a high QTL-based-index, conventional selection,and a low QTL-based-index. This study demonstrated a simple way to use information obtained from QTL studies to make selection decisions. The study also showed that the use of the QTL-based-index in conjunction with the ultrametric genetic distance to the target parent would enablea plant breeder to select lines that retain important QTL in a desirable genetic background. Therefore, this type of MAS would be expected to be superior to the phenotypic selection. This revised version was published online in August 2006 with corrections to the Cover Date.     

QTL analysis for early-maturing traits in cotton using two upland cotton (Gossypium hirsutum L.) crosses

Making use of the markers linked closely to QTL for early-maturing traits for MAS (Marker-assisted selection) is an effective method for the simultaneous improvement of early maturity and other properties in cotton. In this study, two F₂ populations and their F_2:3 families were generated from the two upland cotton (Gossypium hirsutum L.) crosses, Baimian2 × TM-1 and Baimian2 × CIR12. QTL for early-maturing traits were analyzed using F_2:3 families. A total of 54 QTL (31 suggestive and 23 significant) were detected. Fourteen significant QTL had the LOD scores not only > 3 but also exceeding permutation threshold. At least four common QTL, qBP-17 for bud period (BP), qGP-17a/qGP-17b (qGP-17) for growth period (GP), qYPBF-17a/qYPBF-17b (qYPBF-17) for yield percentage before frost (YPBF) and qHFFBN-17 for height of first fruiting branch node (HFFBN), were found in both populations. These common QTL should be reliable and could be used for MAS to facilitate early maturity. The common QTL, qBP-17, had a LOD score not only > 3 but also exceeding permutation threshold, explaining 12.6% of the phenotypic variation. This QTL should be considered preferentially in MAS. Early-maturing traits of cotton are primarily controlled by dominant and over-dominant effects.     

Review of doubled haploid production in durum and common wheat through wheat × maize hybridization

Production of doubled haploids (DHs) is an important methodology to speed the process of breeding and development of mapping populations in crops. The procedure for DH production includes two major steps: haploid induction and chromosome doubling. In recent years, wide hybridization between wheat and maize has become a main approach for haploid production in wheat. In this method, the maize chromosomes are completely eliminated during the early development of the hybrid seeds after wheat spikes were pollinated with maize pollen. Numerous wheat cultivars and mapping populations have been developed using wheat–maize hybridization. In this study, we review the procedures of DH production of durum and common wheat via wide hybridization with maize, the factors which affect the efficiency of DH production, and the mechanism of selective elimination of the maize genome during the early development of the hybrid embryos. We also report a highly efficient protocol for DH production in durum and common wheat, which was established based on the optimal conditions for each of the factors that affect the efficiency of DH production.     

夏季庐山常绿阔叶林4种常见植物根际AM真菌分布特征

为了探索夏季庐山常绿阔叶林土壤丛枝菌根真菌（Arbuscular mycorrhizal fungi,AM真菌）资源分布特征,推动其地下AM真菌资源的开发利用。研究基于孢子形态学分类方法对夏季庐山典型常绿阔叶林中4种常见植物（老鼠矢Symplocos stellaris、檵木Loropetalum chinense、连蕊茶Camellia fraterna、山胡椒Lindera glauca）根际土壤AM真菌群落的分布特征进行调查。结果表明：共分离、鉴定出44个AM真菌物种,其中包括4个优势种AM真菌、5个广布种AM真菌、12个常见种AM真菌与23个稀有种AM真菌。（1）不同植物根系侵染率之间存在显著差异,同时根系侵染率与优势种和广布种AM真菌的孢子密度和物种丰富度均呈正相关,与常见种和稀有种AM真菌的孢子密度和物种丰富度则呈负相关,但均不显著;（2）不同植物根际总AM真菌孢子密度不存在显著差异,但AM真菌物种丰富度存在显著差异;此外,不同植物根际只有常见种AM真菌的孢子密度不存在显著差异,也只有广布种和稀有种AM真菌的物种丰富度不存在显著差异;（3）不同优势度AM真菌的孢子密度之间和物种丰富之间均存在负相关,但只有优势种AM真菌的孢子密度与常见种和稀有种AM真菌的孢子密度存在显著负相关;（4）AM真菌分布受土壤养分（全氮、全磷、全钾、氨态氮、硝态氮）、pH和水分影响较小,但受土壤氮影响相对较大;不同优势度AM真菌受土壤养分、pH和水分影响程度不同,影响程度从大到小依次为稀有种AM真菌、常见种AM真菌、广布种AM真菌和优势种AM真菌。在夏季庐山常绿阔叶林中,常见植物与AM真菌的共生模式可能是以优势种AM真菌和广布种AM真菌共生为主,以常见种AM真菌和稀有种AM真菌补充共生的共生模式。在该共生模式下,植物根际AM真菌资源较为丰富且分布不均;AM真菌与植物共生程度由不同优势度AM真菌共同决定;不同优势度AM真菌之间相互影响较弱;AM真菌受土壤养分（全氮、氨态氮、硝态氮、全磷、全钾）、pH和水分影响较小,但不同优势度AM真菌受土壤养分、pH和水分影响程度不同。     

柴油机高压共轨喷射系统喷油量测量现状概述

对测量柴油机电控高压共轨喷射系统喷油量的重要性做了阐述,分析了测量的基本原理,重点介绍当今国外典型的高压共轨喷油量测量技术及装置,提出今后的研究目标及发展方向。     

高压共轨柴油机喷油控制策略研究

通过对高压共轨柴油机喷油控制的需求分析,发现在转速突变时进气系统具有明显的迟滞性,这种迟滞性表现为进气增量跟不上喷油增量,所设计的转速变化主喷油量修正算法能够重新修正原喷油量,以获得合理的空燃比,改善燃烧过程。多次喷射会造成轨压波动,经过多次喷射轨压波动油量修正算法对喷油量脉宽进行预修正,可以提高喷油执行精度。利用ETAS公司的ASCET建模软件工具和自主开发的ECU电路板,在YN33CR型高压共轨柴油机上进行了台架试验。试验结果表明:该喷油控制策略符合预期效果,能够有效改善喷油控制。     

山西省中部地区主栽小麦品种的标记分析

【研究目的】山西省中部地区是山西小麦生产的重要地区,了解该地区目前主栽小麦品种的基因组成特点,对于进一步选育新品种具有重要的指导作用。【方法】采用SDS-PAGE方法对10个山西省中部地区主栽小麦品种的高分子量谷蛋白亚基组成进行了分析,同时用黑麦1RS 上特有的醇溶蛋白标记对上述材料进行1BL/1RS易位检测,并进一步利用已经开发的小麦矮杆基因Rht8和PPO功能基因标记PPO18,分析了10个小麦品种的基因组成。【结果】结果表明,供试材料在编码HMW-GS 位点上具有较大的变异,其中晋太9923高分子量谷蛋白亚基评分为10分。携带有1BL/1RS易位的材料为4份,占供试材料的40.0%。Rht8基因的平均分布频率为70.0%,Ppo-A1b基因在参试品种中出现的频率达100%。     

Agronomic Potential of Three Vetches (Vicia spp.) Under Rainfed Conditions

The major limiting factor to livestock production in West Asia and North Africa is the inadequate feed supply. The introduction of leguminous forage species into fallow lands represents a means of increasing feed supplies for the rapidly growing livestock population.
Twenty five lines each of common vetch ( Vicia sativa L.) wooly-pod vetch ( Vicia villosa ssp. dasycarpa Ten.), and bitter vetch ( Vicia ervilia L.) were tested over three seasons with contrasting rainfalls and winter temperatures. For each species, seedling vigour, winter growth, cold effect, spring growth, leafiness, herbage yield at 100 % flowering, grain yield, harvest index and aspects of herbage quality were recorded. There were considerable variation among entries with the same species, entries of V. ervilia were the earlier in flowering and maturity, and V. villosa ssp. dasycarpa almost the latest by 45 days. V. sativa , was the most affected by frost whilst both V. villosa ssp. dasycarpa and V. ervilia proved to be cold tolerant.
Although V. villosa ssp. dasycarpa produced high herbage yield in springs its grain yield is low resulting in a low harvest index. Both V. ervilia and V. sativa produced high grain yield with high harvest index. Seed yield was negatively correlated (P < 0.01) with days to flowering and maturity indicating the need of earlier types.
Quality of the herbage in term of digestibility was far lower (46 % IVDMD) in V. villosa ssp. dasycarpa than the other two species (69 % and 72 %).
The possible niches and utilization of each species as animal feed in the prevailing farming systems are discussed.