羊蹄甲果荚中总RNA提取的新方法

高质量RNA的获得是开展羊蹄甲分子生物学研究的基础,但要获得高质量的植物总RNA比较困难,RNA的提取方法会因植物材料的不同而有较大差异。目前已有多种从植物组织中提取RNA的方法。但是由于羊蹄甲中的次生物质含量较高,这些常用方法并不适用于羊蹄甲RNA的提取。本文介绍一种羊蹄甲果荚中总RNA的提取方法,它可以有效的排除羊蹄甲组织中大量存在的多酚类和多糖类物质的干扰。所得RNA样品经紫外分光光度计检测和1%琼脂糖凝胶电泳分析证明无明显降解,且具有较高的纯度。获得的RNA样品在纯度和浓度上都可以满足RT-PCR,Northernblot和cDNA文库构建等分子生物学实验的要求。本方法尤其适用于多酚和多糖含量较高的植物组织的RNA提取,且试剂简单经济,试验结果稳定,重现性强。     

牡丹种子总RNA提取方法比较

采用CTAB法、Trizol法及改进的RNA提取试剂盒方法提取牡丹种子的总RNA,比较三种方法的优劣,从而筛选出一种适合于牡丹种子高质量RNA的提取方法。结果表明,以RNA提取试剂盒为基础,当每管样品是25 mg(700μL裂解液)时,六管合一管过吸附柱的方法操作简单,且能够有效地去除牡丹种子中脂肪、多糖、多酚等代谢物质,从而提取出高质量的RNA。琼脂糖凝胶电泳检测结果显示该法提取的RNA完整性好,紫外分光光度计检测其OD260/OD280比值为2.03。而且,该法提取得到的RNA被成功应用于荧光定量PCR表达分析等后续的分子生物学研究。     

三种改良提取长雄野生稻根叶总RNA方法的比较研究

为探讨野生稻总RNA的提取,笔者尝试了改良SDS、CTAB和TRIzol三种提取方法分别提取长雄野生稻根和叶总RNA,通过琼脂糖凝胶电泳和分光光度计检测,比较这三种方法的提取效果.结果表明,改良SDS、CTAB法提取的根总RNA的电泳条带清晰,几乎没有污染,无明显降解,OD260/OD280在1.75～2.0之间,能满足一般的分子操作要求,但所提取的叶片总RNA则有明显的DNA污染和少量的蛋白质污染.用TRJzol法提取的总RNA,无论是根还是叶片,均有不同程度蛋白质污染.若要进行下一步的分子操作,需先进行RNA的纯化,以去除蛋白质.可见改良SDS、CTAB法提取根的总RNA是首选.     

利用改良CTAB法提取澳洲坚果成熟叶片高质量DNA

澳洲坚果的成熟叶片中次生物质含量很高,因此给DNA的提取造成很大困难.CTAB法可有效去除多糖等杂质,但常规CTAB法的提取效果并不好.为此,我们在此基础上进行改进.采用改良后的CTAB法提取了7个澳洲坚果样品的总DNA.结果表明:使用CTAB free缓冲液进行前处理可去除大部分的杂质.所获得的DNA纯度较高,OD260/OD280均在1.7～1.9之间,RNA消化彻底,DNA无明显降解,进行ISSR分析(UBC-835)条带清晰,多态性好.说明该方法获得的基因组DNA适合于进行以PCR为基础的DNA多态性的研究.     

血红鸡爪槭叶片总RNA提取方法的比较研究

血红鸡爪槭叶片中富含多糖、多酚物质,严重影响了RNA提取纯度和质量。为了获得适宜血红鸡爪槭叶片总RNA提取的方法,采用柱式植物RNAout法、TRIZOL法和改良CTAB法3种提取方法对其叶片总RNA提取效果进行比较分析。结果显示,采用柱子法提取获得的总RNA产率最高,但是有DNA污染;TRIZOL法提取的总RNA OD260∕OD280为1.65,可能有多糖和酚类物质的污染,并且产率最低;改良CTAB法提取的总RNA纯度很高,OD260/OD280平均值在2.0左右,产率在上述两种方法之间,电泳图清晰,而且改良CTAB法提取的总RNA,经RT-PCR获得了清晰的特异性条带。表明改良CTAB法提取的总RNA纯度和产率高,完全可以满足进一步分子生物学研究的需要,是血红鸡爪槭叶片总RNA提取的适宜方法。     

玛咖贮藏根总RNA提取方法的比较

为了筛选出适合玛咖贮藏根总RNA的提取方法,本研究比较了改良异硫氰酸胍法、CTAB法、Trizol法和E.Z.N.A.TM Plant mi RNA Kit试剂盒法等4种方法对玛咖根总RNA提取的效果。结果表明:改良异硫氰酸胍法提取效果不理想,CTAB法存在DNA污染;Trizol法和E.Z.N.A.TM Plant mi RNA Kit试剂盒法能有效去除多糖,提取出质量高、完整性好的RNA,OD260/OD280值大部分都在1.8~2.0之间,但Trizol法提取RNA的平均得率(156.3μg/g)是E.Z.N.A.TMPlant mi RNA Kit试剂盒法提取RNA的平均得率(48.6μg/g)的3.2倍,说明Trizol法可作为玛咖根总RNA提取的首选方法。     

草莓果实总RNA提取方法的比较

为建立草莓果实总RNA的提取方法,针对草莓成熟果实中富含多糖、多酚和色素等次级代谢物质,总RNA提取难度大的特点,比较改良的EASYspin 植物RNA提取试剂盒法和改良的CTAB法提取草莓果实中总RNA的质量。通过琼脂糖凝胶电泳和核酸蛋白测定仪(NanoDrop 2000)检测2 种方法提取总RNA的浓度、纯度及完整性等。改良的EASYspin 植物RNA提取试剂盒法和改良的CTAB法都能够完成草莓果实总RNA 的提取,电泳检测在28S 和18S 处呈2 条清晰的条带,OD260/OD280值和OD260/OD230值均在2.0 左右;改良的EASYspin 植物RNA提取试剂盒法成本较高,且提取总RNA质量劣于改良的CTAB法,但是EASYspin植物RNA提取试剂盒法操作简便,安全可靠,节省时间。通过RT-PCR验证,2种方法所获得的草莓果实总RNA质量较好,可达到分子生物学试验对RNA质量的要求。     

魔芋叶片中4种总RNA提取方法的比较

本研究分别利用TRIzol法、异硫氰酸胍法、改良的CTAB法及试剂盒这4种方法提取魔芋叶片的总RNA,并用紫外光谱和琼脂糖凝胶电泳对各个提取效果进行鉴定。反复试验的结果表明:TRIzol法难以提取魔芋叶片总RNA,异硫氰酸胍法提取的总RNA浓度低、杂质较多且有部分降解,这两种方法不适宜用于魔芋叶片总RNA提取;试剂盒方法提取的总RNA产率和纯度较高,但稳定性差、成功率低且成本较高;改良的CTAB法利用PVP和β-巯基乙醇去除酚类物质,水饱和酚-氯仿去除蛋白质,醋酸钾去除多糖,该方法提取得到的总RNA的纯度较高,OD260/OD280值为1.893,而且效果稳定,有良好的可重复性。因此,我们认为改良的CTAB法是一种简便、快速且经济的提取魔芋叶片总RNA的方法。     

超声波辅助提取山药总多酚的研究

以山药为原料,采用超声波辅助提取从山药中提取多酚类物质,通过单因素试验和正交试验得到总多酚的最佳提取条件是:体积分数50%的丙酮溶液、料液比1∶20,提取60 min,提取温度50℃,提取2次、超声功率800 W,多酚提取率为16.97%。     

菊芋叶多酚的超声辅助提取及抗氧化活性研究

以菊芋叶为原料,以料液比、乙醇浓度、超声时间、超声功率为考察因素,在单因素试验的基础上,通过响应面设计优化菊芋叶多酚的提取工艺,并探究菊芋叶多酚的体外抗氧化活性.结果表明,菊芋叶多酚的最佳提取条件为:料液比1:20(g/mL),乙醇浓度50％,超声时间50 min,超声波功率500 W,在该条件下多酚得率为31.923 mg/g.抗氧化试验表明:菊芋叶多酚具有明显的抗氧化活性,对DPPH自由基(DPPH·)、羟基自由基(·OH)和超氧阴离子自由基(O2·)有较好的清除能力;与VC的抗氧化活性相比,菊芋叶多酚对O2·的清除作用明显高于VC.     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

Flag Leaf Senescence, as Evaluated by Numerical Image Analysis, and its Relationship with Yield under Drought in Durum Wheat

Senescence was evaluated at different stages of the grain‐filling period in eight durum wheat varieties using numerical image analysis (NIA). The varieties were grown under early, severe drought conditions on the high plains of Sétif in Algeria. After flowering, three different irrigation treatments were applied. Treatment effect was small, while a genotypic effect was noted for most of the senescence parameters. Senescence correlated to biomass, while the maximal rate of senescence, V_smax, correlated to thousand‐kernel weight. The potential of the method of numerical image analysis for monitoring flag leaf senescence, detecting genotypic variability and selecting genotypes with delayed senescence is discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.