基于SRAP的叶子花种质资源遗传多样性及遗传关系分析

为探讨叶子花(Bougainvillea sp.)品种间的遗传关系,应用SRAP(Sequence-related amplifi ed polymorphism)标记技术对48个叶子花品种的遗传多样性及遗传关系进行了分析。结果表明,从208对引物中筛选出25对多态性较高的引物组合,共扩增出773条清晰条带,其中多态性条带750条,平均多态性条带百分率达97.02%。UPGMA聚类分析结果表明,48个叶子花品种的遗传相似性系数为0.4058~0.8568,在遗传相似性系数0.558水平上,可分为4个类群,福摩萨叶子花与毛叶紫花叶子花各自成一类,其它品种分为两大类群。SRAP标记可较好地反映叶子花种质间的遗传关系,为合理利用叶子花种质资源及提高育种效率提供了科学基础。     

'挽春'(Paeonia rockii 'Wan Chun')——中国西北紫斑牡丹品种群中的一个优良品种

紫斑牡丹品种群是中国的主要牡丹品种群之一。文中描述了一个优良紫斑牡丹品种‘挽春’(Paeoniarockii‘W an Chun’)的特征、习性和表现,该品种在紫斑牡丹品种群中具有代表性。紫斑牡丹品种可用于园艺观赏、经济林营造、荒山绿化以及荒漠治理。根据多年的调查和相关文献,按照紫斑牡丹品种的生长适应程度和引种栽培难易程度,将中国有可能引种栽植紫斑牡丹品种的地区划分为4类。介绍了各类地区在引种栽培方面需要注意的关键技术措施,分析了紫斑牡丹品种向全国各地推广过程中存在的问题,并提出了建议。     

青花菜SRAP-PCR体系优化与品种分子鉴定

本试验对青花菜基因组DNA的SRAP-PCR体系中主要影响因子Mg2+、dNTPs和引物浓度进行了优化。结果表明,反应体系中适宜浓度为Mg2+1.5-3.0mmol/L,dNTPs0.4mmol/L,引物0.25-0.50μmol/L(模板DNA约20ng,16μL反应体系)。运用优化的反应体系,对20个青花菜品种进行分子鉴定,从10个引物组合中筛选到7个多态性引物组合,获得60个多态性位点,平均每个引物组合在供试品种中产生8.6个多态性位点,鉴别品种数4.3个。双引物组合me1/em6与me2/em9可以区分所有供试材料。     

Roots play a vital role in flood-tolerance of poplar demonstrated by reciprocal grafting

Poplar is one of the most important multipurpose afforestation trees in river floodplains and arable farmland which are subject to frequent flooding. To determine the relative roles that the roots and shoots have in responses to waterlogging, six root-shoot grafting combinations of full-sib poplar clones LS1 (flood-tolerant) and LS2 (flood-susceptible) were compared for waterlogging effects on them, using reciprocal and self-grafts. Plants of the six combinations comprised non-grafted (LS1) and (LS2), self-grafted (LS1/LS1) and (LS2/LS2), LS1 grafted onto LS2 (LS1/LS2), and LS2 grafted onto LS1 (LS2/LS1) experimental plants. The two clones LS1 and LS2 originated from Populus deltoides cv. Lux ex. I-69/55 (flood-tolerant) × P. simonii (flood-susceptible). Growth, morphological and ecophysiological parameters of plants belonging to the six grafting combinations were subjected for 21 days to flooding, followed by a six-day drainage and recovery stage. Results showed that flooding stress affected adversely growth, biomass accumulation, morphological and ecophysiological characteristics in all flooded plants. The more severe influences were found in the plants with LS2 roots (LS1/LS2, LS2/LS2, LS2), whereas plants having roots of LS1 (LS2/LS1, LS1/LS1, LS1) were less negatively affected. At the end of the study, 100%, 100%, 93.3%, 26.7%, 6.7% and 20% survival rates, respectively, were observed in flooded plants of LS1, LS1/LS1, LS2/LS1, LS1/LS2, LS2/LS2 and LS2. In conformity with the results for growth, biomass accumulation and morphology, responses to flooding of gas exchange, chlorophyll fluorescence, relative membrane permeability of leaves, the overall root metabolism parameter dehydrogenase activity (TTC assay), as well as malonaldehyde contents of leaves and roots also indicated that flood injury was significantly more pronounced in plants having LS2 roots than in those with LS1 roots. Plants with roots of LS1 displayed clearly faster recovery after flooding than the plants with LS2 roots. The results indicate that flooding-tolerance of poplar is based more on influences from the rootstock than on those of the scion. It is thus the root genotype that plays the decisive role in flood-tolerance of poplar.     

Caraway essential oil composition and morphology: The role of location and genotype

Caraway (Carum carvi) is used as a vegetable; more commonly, the fruits are used to flavour foods or as a preservative. Quality is a key issue; however, little is known about the respective influences of type of material and location and the interaction of these factors on essential oil composition. In this study, wild populations and commercial cultivars from the Nordic germplasm collection were examined. Plants were grown in two locations (Iceland and Sweden) and essential oil composition and phenotypic characteristics identified. Carvone and limonene were the two major compounds detected at levels around 14 and 70% of total peak area, respectively. Also p-cymene, trans-β-ocimene, α-Terpinolene and myrcene each were detected at levels above or around 2%. In total, 47 compounds were detected of which 40 were identified. The effects of material type and location were established, where location had a greater impact than genotype. In 15 out of the 35 compounds detected at levels below 2%, significant location-dependent differences were detected. For morphological traits, genotype had a more significant effect than location.     

Application of AFLPs to the characterization of grapevine Vitis vinifera L. genetic resources. A case study with accessions from Rioja (Spain)

 AFLPs were used to characterize 67 different grapevine accessions from a collection of D.O.Ca. Rioja in Spain. A correct selection of primers and selective nucleotides allowed us to maximize the number of amplified fragments analyzed per reaction yielding an average of 100 per reaction, 49% of which were polymorphic. Based on the presence or absence of amplified fragments for each genotype resulting from a reaction with two primer combinations, we have established the genetic similarity between the different accessions in the collection. These results allowed us to resolve different genotypes maintained under the same name (homonyms) and to identify the same genotype under different names (synonyms) thus permitting the elimination of redundant germplasm. Furthermore, by providing information on more than 50 polymorphic loci per reaction, a few reactions were sufficient to identify distinct AFLP patterns characteristic of specific clones, with different agronomic and organoleptic features, belonging to the same cultivar. The possibility for clonal identification, shown here for grapevines, can have important implications in the protection and management of clonal selections. Received: 1 February 1998/Accepted: 25 February 1998     

Impact of crop genetic diversity on a litter consumer

Belowground communities, and especially earthworms, provide numerous services in agroecosystems. In the current context of crop genetic erosion, this study aims at assessing the effect of wheat cultivar diversity on earthworm growth and survival. Our laboratory experiment was divided into two periods: (1) the “feeding period” (4 months), simulating conditions in autumn with cool temperatures and high food availability, and (2) the “non-feeding period” (1 month) simulating conditions in winter with cold temperatures and low food availability because litter had already been consumed without replacement. The aerial biomass of mixtures of wheat cultivars was used as food for earthworms and their growth was measured twice during the feeding period and once during the non-feeding period. We found two major effects on earthworm growth. Increasing the cultivar number (i) increased juvenile earthworm growth and earthworm survival and (ii) decreased adult earthworm growth. A consistent positive effect of nitrogen concentration of the biomass was found on growth and this effect was independent of biodiversity effects. This study suggests that the loss of litter intraspecific genetic diversity has an impact on earthworm populations, probably through mechanisms linked to the variance in edibility or the balanced diet hypotheses. While they remain to be tested in the field, these results suggest that the current losses of crop genetic diversity could potentially impact processes at the community or ecosystem level through a decrease in food quality.     

A comparative study of edible canna (Canna edulis) starch from different cultivars. Part II. Molecular structure of amylose and amylopectin

Molecular structures of starches isolated from Japanese-green, Thai-green and Thai-purple cultivars of edible canna (Canna edulis Ker) were investigated. The absolute amylose content ranged from 19 to 25%. Degrees of polymerization (DPn) values of amylose determined by fluorescence-labeling method were 1590 for Thai-purple, 1620 for Japanese-green and 1650 for Thai-green cultivars. Mole% of branched fraction of amyloses from edible canna starches examined by a HPLC system after β-amylolysis of labeled amyloses was 13–16%. Branch chain-length distributions of amylopectin analyzed by HPSEC after debranching with isoamylase, followed by fluorescence-labeling of unit chain, showed bimodal distribution with the DPn range of 25–28. The amylopectin of edible canna starches contained high amounts of organic phosphorus (391–420 ppm). The distribution profile of phosphorylated chains, separated from non-phosphorylated chains by DEAE-Sephadex A-50 chromatography, indicated that the phosphate groups were located mostly in long B-chains of amylopectin molecules.     

Comparison of unpredictable environmental variation generated by year and by seeding-time factors for measuring type 4 stability

Summary Type 4 stability has been proposed to measure a cultivar's homeostatic property to resist unpredictable environmental variation. The requirement for calculating this stability is that the experiment must contain a time factor in addition to the cultivar x location factors. Of the two time factors, year and seeding-time, the latter is less attractive biologically because it represents only a part of the broader context of unpredictable variation represented by years, but it is attractive in terms of shortening the test period. Investigation of historical data from the Eastern Cooperative trials and the Ontario Production trials in Canada indicates that the unpredictable variation generated by seeding-time was about half that generated by year. Although type 4 stability measured by both factors appears to be the same, the stability measured by seeding-time is more prone to variation. The implication is that complete substitution of the year factor by seeding-time is not appropriate, but use of both factors in combination may be sensible.Contribution No. C-055 from the Engineering and Statistical Research Centre, Research Branch, Agriculture Canada, Ottawa, K1A 0C6, Canada     

Biochemical analysis as a measure of dynamic equilibrium in genomic setup during processing of tea

The genetic characteristic such as ‘fermentability’ of a tea cultivar could be utilised to obtain maximum colour/bloom during manufacture of black tea. Pigment profile analysis has been used as a tool to assess the characteristic of a black tea brew. Fine plucking and optimum processing conditions are two basic requirements in producing good quality black tea. The assamica variety is characterised by linalool content while geraniol is specific in chinary clones. The higher amounts of terpenoids improved the flavour characteristic of second flush tea of north east India in general and Darjeeling in particular. Further, the surplus fatty acid degradation products lower the quality of black tea during monsoon flush. Presented at the 3rd National Symphosium on Bioorganic Chemistry, 1987, Hyderabad.