Construction of a New Molecular Barcode for Discriminating Plants and Animals with a Close Genetic Relationship

DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism (F-AFLP) and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.     

十字花科植物C2H2型锌指蛋白新基因BcMF20同源序列克隆与进化分析

为获取C2H2型锌指蛋白基因在物种间的分类和进化关系,分析其在基因结构上的保守性,更好地研究该基因在植物花粉发育中的功能,根据白菜花粉发育相关基因BcMF20 DNA序列设计引物,运用PCR技术分别从十字花科芸薹属和萝卜属18种材料中克隆了C2H2型锌指蛋白基因BcMF20的同源序列。经序列比对分析,BcMF20同源基...     

十字花科植物黑斑病的研究进展

十字花科植物黑斑病是由死体营养型致病菌链格孢属(Alternaria spp.)真菌侵染引起的重要病害之一。链格孢菌侵染植物的过程,首先通过释放毒素诱导侵染处植物细胞的程序性死亡,再通过细胞壁降解酶分解死亡的细胞。同时,植物也会通过激发先天性免疫反应,调节植物内源激素和植物抗毒素等分子抵御病菌的侵染。本文重点综述了链格孢菌侵染十字花科植物过程中,双方在基因组(致病和抗病基因)、转录组(调控因子)、代谢组(毒素和抗毒素)和蛋白组(酶类)等方面的相关变化及其作用机制,以期为培育抗黑斑病的十字花科蔬菜提供有价值的参考。     

新疆8种十字花科植物的染色体数目

采用常规根尖压片法对十字花科8种植物的染色体数目进行了研究,试验结果表明,绒毛假蒜芥2n=14;无茎光籽芥2n=14;扭果花旗杆2n=14;厚壁荠2n=14;对枝菜2n=12;甘新念珠芥2n=14;爪花芥2n=4x=28;涩芥2n=4x=28.其中前6种为二倍体,后2种为四倍体;染色体基数除对枝菜n=6外,其余均为n=7,属较进化类型,8种染色体数目均为首次报道.     

Peroxidase Activity in Relation to Plant Height and Seed Yield in Indian Mustard (Brassica juncea L. Coss)

Peroxidase levels were assayed in 12 genotypes and in 36 F₁cross progenies of Indian mustard ( Brassica juncea L. Coss) at twelve stages of development, starting from seed germination till seed formation. The levels of peroxidase activity and the coefficient of variation emphasized the role of differential enzyme activity at different stages of development. Genotypes were also evaluated for plant height and seed yield. The correlations of peroxidase activity in 24 h soaked seeds with plant height and seed yield were significantly positive while those of enzyme activity in 45 days old plants with these traits were significantly negative. The study suggests the changing role of enzyme at two critical stages of plant development.     

Effects of different rotation patterns on the occurrence of clubroot disease and diversity of rhizosphere microbes

Clubroot disease, caused by Plasmodiophora brassicae, is one of the most destructive soil-borne diseases in cruciferous crops worldwide. New strategies are urgently needed to control this disease, as no effective disease-resistant varieties or chemical control agents exist. Previously, we found that the incidence rate and disease index of clubroot in oilseed rape decreased by 50 and 40%, respectively, when oilseed rape was planted after soybean. In order to understand how different rotation patterns affect the occurrence of clubroot in oilseed rape, high-throughput sequencing was used to analyze the rhizosphere microbial community of oilseed rape planted after leguminous(soybean, clover), gramineous(rice, maize) and cruciferous(oilseed rape, Chinese cabbage) crops. Results showed that planting soybeans before oilseed rape significantly increased the population density of microbes that could inhibit P. brassicae(e.g., Sphingomonas, Bacillus, Streptomyces and Trichoderma). Conversely, consecutive cultivation of cruciferous crops significantly accumulated plant pathogens, including P. brassicae, Olpidium and Colletotrichum(P0.05). These results will help to develop the most effective rotation pattern for reducing clubroot damage.     

毛乌素沙地沙芥和斧形沙芥根系分布特征

以毛乌素沙地沙芥和斧形沙芥为试材,采用全挖法,研究了其根系周围土壤含水量变化、根系分布及水平根系空间分布特征。结果表明:在自然生境中,沙芥和斧形沙芥1a生植株根系周围的平均土壤含水量分别为(2.68±0.11)%、(2.50±0.45)%;2a生的分别为(3.13±0.46)%、(1.90±0.68)%。沙芥和斧形沙芥主根垂直,水平根系数目较少、但长度极其发达。沙芥和斧形沙芥2a生主根长均约为120cm,最长水平根分别为380、400cm,水平根累计总长分别为1 590、3 340cm。沙芥和斧形沙芥2a生水平根系均在深度40～60cm、距主根0～40cm的空间范围内分布最多,均在40～60cm的土层深度分布最大,因此,沙芥和斧形沙芥主要依靠延长水平根系寻找远距离水源来适应低土壤含水量环境,斧形沙芥比沙芥更能适应低土壤含水量。     

十字花科蔬菜花粉电镜扫描分析

用扫描电子显微镜对十字花科蔬菜的花粉进行了观察分析。结果表明：（１）十字花科蔬菜花粉的基本形态特征为长椭圆形，具三沟，沟长几乎达两极；（２）花粉外壁纹饰多为典型的 网状雕纹，但花粉大小，Ｐ／Ｅ值，网眼形状、大小和密度，网眼内颗粒状物的有无和多少等在种间存在明显差异；（３）与二位体比较，四位体的花 粉显著变大，Ｐ／Ｅ值减小，网眼密度降低，网眼内颗粒状特增多，这些变异可以认为是基因剂量增加的遗传效应。     

萝卜硫苷生物合成相关基因RsFMO_(GS-OXs)的预测及分析

以控制拟南芥硫苷生物合成相关基因家族FMO GS-OXs全长cds为参考序列,在萝卜ESTs数据库中进行blastn检索,得到具备Score≥100、E-value≤10-10和coverage≥70%条件的24条萝卜ESTs作为候选的拟南芥FMO GS-OXs基因的同源ESTs,并进行序列聚类拼接、注释及分析。结果显示:在萝卜中发现两个旁系同源基因(RsFMO GS-OXa和RsFMO GS-OXb)。RsFMO GS-OXs与拟南芥FMO GS-OXs间在核酸水平上的一致性为68.0%~83.2%;RsFMO GS-OXs旁系同源基因间的一致性仅为67.3%;RsFMO GS-OXs与白菜FMO GS-OXs同源基因间的一致性为67.3%~92.9%。系统进化分析发现,RsFMO GS-OXa和白菜FMO GS-OX2基因亲缘关系最近,而RsFMO GS-OXb和白菜FMO GS-OX5a亲缘关系更近一些,同时认为,RsFMO GS-OXa和RsFMO GS-OXb的直系同源基因分别为FMO GS-OX2和FMO GS-OX5。     

广州地区十字花科主要杂草种子微形态的观察研究

本文描述了几种十字花科杂草种子的外形、种脐的形状以及种皮的微形态特征。