Molecular characterization of Miraflores peach variety and relatives using SSRs

Some traditional peach varieties, originated from the region of Aragón (Spain), were analysed by SSRs (simple sequence repeats). The aim of this research was to characterize 19 clones related to Miraflores variety, with unknown pedigrees, to assess their genetic diversity and to elucidate their possible relationships with 10 traditional peach varieties. Twenty SSR primer pairs with high levels of polymorphism, which have been previously developed for peach, were used in this study. A total of 46 alleles were obtained for all the microsatellites studied, ranging from one to six alleles per locus, with a mean value of 2.3 alleles per locus. Fourteen SSRs were polymorphic in the set of varieties studied and permitted to distinguish 16 different genotypes out of the 30 initially studied, although fourteen ‘Miraflores’ clones showed identical gel profiles. The genetic distance matrix was used to construct neighbor joining cluster and to perform principal coordinate analysis which allowed the arrangement of all the genotypes according to their genetic relationships. The genetic relationships among these traditional peach varieties, and in particular among ‘Miraflores’ clones are discussed. The obtained results confirm that microsatellite markers are very useful for these purpose.     

Molecular characterization and genetic relationship among almond cultivars assessed by RAPD and SSR markers

RAPDs and SSRs were used to study the genetic diversity of Iranian almond cultivars and their relationship to important foreign cultivars and three related species. Eight unidentified almond Shahrodi cultivars and three wild almonds (Prunus communis, Prunus orientalis and Prunus scoparia) were also included. Of the primers tested, 42 (out of 80) RAPD and 18 (out of 26) SSR primers were selected for their reproducibility and high polymorphism. A total of 664 polymorphic RAPD bands were detected out of 729 bands. The number of presumed alleles revealed by the SSR analysis ranged from 3 to 10 alleles per locus with a mean value of 6.64 alleles per locus. Both techniques discriminated the genotypes very effectively, but only RAPDs were able to discriminate the cultivars Monagha and Sefied. Results demonstrated an extensive genetic variability within the tested cultivars as well as the value of SSR markers developed in peach for characterization of almond and related species of Prunus. Dice similarity coefficient was calculated for all pair wise comparisons and was used to construct a UPGMA dendrogram. For both markers a high similarity in dendrogram topologies was obtained although some differences were observed. All dendrograms, including that obtained by the combined use of both the marker data, depicted the phenetic relationships among the cultivars and species, depending upon their geographic region and/or pedigree information. Almond cultivars clustered with accession of P. communis showing their close relationship. P. orientalis and P. scoparia were clustered out of the rest of P. dulcis.     

基于线性混合模型的蓝点马鲛叉长和体重关系的月间及性别差异

为了研究蓝点马鲛（）生活史特征的异质性,根据2018年10月至2019年3月在东海外海渔场的拖网调查采样数据,对其叉长和体重关系的月间及性别差异进行了研究。依据收集的367尾蓝点马鲛样本,求得其叉长和体重关系（b的估计均值为2.794。本研究构建了广义线性模型和9个线性混合模型,用于研究蓝点马鲛的叉长和体重关系（）在时间及性别上的差异。贝叶斯信息准则（BIC）值和均方根误差值均表明,最复杂的线性混合模型（即月份和性别对两个参数P<0.01）。在最优模型中,a值则与此相反。本研究表明,月份和性别对蓝点马鲛叉长和体重关系具有显著的影响,线性混合模型能把月份和性别的异质性通过随机效应在单个模型中更准确、快速地体现,从而进一步证实了此模型在数据来源异质性研究中的优势。     

Phylogenetic analysis in some Diospyros spp. (Ebenaceae) and Japanese persimmon using chloroplast DNA PCR-RFLP markers

Ten universal primer pairs of chloroplast genome were used to amplify non-coding regions of chloroplast DNA (cpDNA) in 7 Diospyros L. species including 29 genotypes and approximately 20.4 kb, 12.6% of the chloroplast genome were analyzed. The amplified products were digested by seven restriction enzymes. The results showed that there were abundant polymorphisms in inter-specific cpDNA within the genus Diospyros. However, it was not observed intra-species variations in 22 tested genotypes of Diospyros kaki (Japanese persimmon), except for ‘Male strain No. 9’. Persimmon had close relationship with Diospyros lotus and Diospyros glaucifolia, but distantly with Diospyros virginiana and Diospyros rhombifolia in diagram based on principal coordinates analysis and Wagner parsimony method. The discrepancy of digesting pattern in cpDNA suggested that the genotype Jinzaoshi was distinct with the remaining Diospyros spp., which revealed that Jinzaoshi may be a new species of the genus Diospyros.     

Iron chlorosis and the iron status of soils

Abstract

The iron status of soils and its relation to iron uptake and iron‐chlorosis is discussed. In many soils, the soluble iron level is so low that rather than having to screen against iron uptake, plants are likely limited in their iron uptake by diffusion. The relationship between the plant root‐soil‐iron environment and the plant's ability to alter this environment is related to the development of iron‐chlorosis.     

谷子抗除草剂的质体ACCase基因及系统发育分析

为进一步培育抗除草剂谷子,掌握除草剂抗性的分子机制,本研究选择抗拿捕净的谷子品系(‘Setaria italic Chum BC 6-1’)和普通敏感谷子品系(‘S.italic Sda11’)ACCase序列进行了比较,并对谷子近缘的14个物种ACCase基因序列分析,计算碱基组成、转换颠换、遗传距离,构建系统进化树。结果表明:2种谷子ACCase酶序列全长2320个氨基酸,仅有11个氨基酸不同。除已报道较多的I-1779-L对拿捕净抗性外,发现另3个位点S-105-N,D-489-Y,W-876-L突变也可能表现出拿捕净抗性。14个ACCase基因序列平均发生转换259对,颠换213对。利用邻接法和最大似然法分别构建系统进化树,显示相似的拓扑结构,奇异虉草、小子虉草先聚合,然后与燕麦和硬直黑麦草聚合。另一支大穗看麦娘、日本看麦娘先聚合,再和罔草聚合。然后这两支聚在一起。第三支上玉米与稗草首先聚在一起,再和谷子聚集,和物种分类一致。仅小麦单独分出,与传统分类物种树不同。本研究发现另外3个位点突变与拿捕净抗性有关,有利于深入理解除草剂抗性机理,为抗除草剂育种和分子系统发育奠定了基础。     

Using habitat models to identify suitable sites for marine protected areas for harbour porpoises (Phocoena phocoena)

The harbour porpoise is a highly mobile species and thus represents a considerable challenge in the context of using marine protected areas (MPAs) for conservation. The shelf waters off the west coast of Scotland have been identified as an area of year-round presence, high density in comparison to surrounding areas, and a high young to adult ratio in summer and are thus a suitable area for exploring the location of possible special areas of conservations (SACs) under the EU Habitats Directive. We carried out dedicated surveys over three summers in the southern Inner Hebrides and used generalised additive models (GAMs) to predict areas of high relative density for harbour porpoises for each year. After compensating for survey effects, static bathymetric and persistent hydrographic variables were used in a step-wise model selection procedure. In all years harbour porpoise distribution was best explained by maximum tidal current, with higher densities predicted in areas of low current, and the same high density areas predicted year-on-year. Perimeter-to-area ratio was used to identify which areas should be considered as a basis for designating SACs for harbour porpoise in this area, to form part of the Natura 2000 network. The method used here combines spatial modelling and perimeter-to-area ratio for selecting protected areas, a methodology which is suitable for the protection of other animal species.     

夏玉米简化栽培技术的研究

从满足夏玉米生育要求出发,采用麦秸还田,底施氮化肥、精量机播和化学除草等现代化综合技术,不但能促进壮苗早发和早熟高产,而且省工省力,降低成本,提高效率和培肥地力.采用这套简化栽培技术,平均每亩可增产粮食52.2公斤,少用工1.37个,节约开支8.54元,增加纯收益21.91元,耕层土壤有机质每年提高0.029%,土壤物理结构和营养供应性能也有明显提高.4年累计在京郊推广近百万亩,有力地促进了土地适度规模经营的发展.     

从数值分类角度探讨福建的栲属植物

本文用数值分类方法分析福建的栲属Castanopsis(14种、1变种和2份C.SP.)植物。根据聚类分析的结果,建议上杭锥C.lamontii var.shan-ghangensis的分类地位提升为种的等级,并鉴别一份福建未记载的某一种类。利用树状图,初步探讨了福建的栲属种间关系,并编制成接近于自然类群且较实用的分种检索表。     

A Chemoinformatics Approach to the Discovery of Lead-Like Molecules from Marine and Microbial Sources En Route to Antitumor and Antibiotic Drugs

The comprehensive information of small molecules and their biological activities in the PubChem database allows chemoinformatic researchers to access and make use of large-scale biological activity data to improve the precision of drug profiling. A Quantitative Structure–Activity Relationship approach, for classification, was used for the prediction of active/inactive compounds relatively to overall biological activity, antitumor and antibiotic activities using a data set of 1804 compounds from PubChem. Using the best classification models for antibiotic and antitumor activities a data set of marine and microbial natural products from the AntiMarin database were screened—57 and 16 new lead compounds for antibiotic and antitumor drug design were proposed, respectively. All compounds proposed by our approach are classified as non-antibiotic and non-antitumor compounds in the AntiMarin database. Recently several of the lead-like compounds proposed by us were reported as being active in the literature.