割手密叶绿体DNA的高效提取方法

为了提取高质量的割手密叶绿体DNA(chloroplast DNA,cp DNA),本研究立足于高效、省时、低耗的原则,以割手密幼叶为材料,采用改进的高盐-低p H法经差速离心分离叶绿体、DNaseⅠ处理、10%SDS和蛋白酶K裂解叶绿体、DNA萃取、乙醇沉淀等一系列操作。所提取的割手密cp DNA经显微观察、紫外吸收光度测定、琼脂糖凝胶电泳、叶绿体基因特异引物PCR扩增等进行检测,结果表明该提取方法简单高效,A260/A280的比值介于1.9~2.0,cp DNA纯度高,浓度为2.90μg/μL,适用于基因扩增等分子操作。研究结果为进一步开展割手密叶绿体基因功能、系统发育、遗传多样性等方面的研究奠定了基础。     

胡萝卜叶片线粒体DNA的提取方法

提取高质量的线粒体DNA,对植物细胞质雄性不育的研究起着关键性的作用。以胡萝卜叶片为材料,通过高盐差速离心和蔗糖沉淀差速离心2种方法提取线粒体DNA。通过改变分离和沉淀线粒体离心力大小、使用DNaseⅠ处理得到了无核DNA污染的线粒体。用SDS和蛋白酶K裂解线粒体经酚/氯仿/异戊醇抽提除去蛋白,并用RNaseA消化从而得到单纯线粒体DNA。还特别设计了叶绿体特,异性引物检测线粒体DNA纯度。结果表明:利用优化后的蔗糖沉淀差速离心法提取胡萝卜线粒体DNA,不仅操作简单,而且所得线粒体DNA纯度高、产量高,每克叶片能够得到34.46μg线粒体DNA。     

胡萝卜叶片线粒体DNA提取方法研究

本实验以胡萝卜叶片为材料,通过高盐差速离心和蔗糖沉淀差速离心两种方法提取线粒体DNA。通过改变分离和沉淀线粒体离心力大小、使用DNaseⅠ处理得到了无核DNA污染的线粒体。用SDS和蛋白酶K 裂解线粒体,经酚/氯仿/异戊醇抽提除去蛋白,并用RNase A 消化从而得到单纯线粒体DNA。本实验还特别设计了叶绿体特异性引物检测线粒体DNA纯度。结果表明：利用优化后的蔗糖沉淀差速离心法提取胡萝卜线粒体DNA,不仅操作简单,而且所得线粒体DNA纯度高、产量高,每克叶片能够得到34.46 μg 线粒体DNA。     

胡萝卜肉质根线粒体DNA提取方法研究

本研究以胡萝卜根为材料,通过高盐差速离心和蔗糖沉淀差速离心两种方法提取线粒体DNA。通过改变缓冲液、使用DNaseⅠ处理得到了无核DNA污染的线粒体。用SDS和蛋白酶K裂解线粒体,经酚:氯仿:异戊醇抽提除去蛋白,并用RNaseA消化从而得到单纯线粒体DNA。本实验还特别设计了叶绿体特异性引物检测线粒体DNA纯度。结果表明:利用优化后的蔗糖沉淀差速离心法提取胡萝卜线粒体DNA,所得线粒体DNA纯度高、产量高,每克肉质根能够得到27.60μg线粒体DNA。     

梭梭属2种植物线粒体基因组的提取

为了分离提取高质量梭梭(Haloxylon ammodendron)、白梭梭(Haloxylon persicum)线粒体DNA,以藜科梭梭属植物梭梭、白梭梭黄化苗为材料,通过采用蔗糖密度梯度离心和差速离心相结合的方法,使用DNaseⅠ处理得到了无核DNA污染的线粒体,用3% CTAB裂解线粒体,经氯仿/异戊醇抽提除去蛋白,从而得到单纯线粒体DNA。结果表明,所提取的线粒体DNA经电泳检测条带清晰,无拖尾现象,且A260/A280≈1.8,说明纯度较高、质量好,可满足后续有关线粒体DNA的相关实验。梭梭、白梭梭高纯度线粒体DNA提取技术的建立,为开展梭梭、白梭梭线粒体基因组研究奠定了基础。     

应用降落PCR和正交设计优化甘蔗“割手密”SSR-PCR反应体系

甘蔗野生种割手密抗逆性强,在甘蔗抗逆育种中具有较好的应用前景;割手密SSR分子标记技术体系的建立及优化可为割手密指纹图谱绘制、种质鉴定、遗传多样性及亲缘关系分析提供技术支持。本研究以21份割手密材料用改良CTAB法提取DNA,采用降落PCR和正交试验设计对扩增反应体系主要成分的浓度(DNA模板,引物,Mg2+,d NTPs,Taq聚合酶)进行了优化。结果表明建立的割手密Touchdown SSR-PCR分子标记技术体系操作简便,扩增条带清晰且多态性丰富,有较强的稳定性和可重复性,可为割手密资源的相关研究提供技术支持。     

黏类小麦细胞质雄性不育系mtDNA消减文库的构建

本研究利用抑制性消减杂交技术,构建了黏类小麦细胞质雄性不育线粒体DNA的消减文库。分别提取相同细胞质背景下的不育和可育等基因系线粒体基因组DNA(mtDNA),用RsaⅠ酶切成大小不等的片段,并各自与不同的接头连接,连续经过两次消减杂交和两次PCR扩增,将PCR产物与克隆载体连接,转化为大肠杆菌感受态细胞DH5α,经蓝白斑筛选后,再用PCR方法插入片段筛选出阳性重组质粒,构建差异DNA消减文库。在构建的不育mtDNA文库中,将SSH文库的全部扩增产物与SSH文库中的单条扩增条带分别进行胶回收和克隆转化,分别挑取54个和6个阳性克隆进行测序分析和相关功能初步比对。结果表明,不育mtDNA的SSH文库差减杂交效率较高,质量较好;回收单条扩增条带分别进行克隆测序的结果准确率较高;对测序序列进行BLASTx比对及功能注释分析发现,约90%的序列来源于线粒体基因nad1和nad5的非编码区。     

芝麻高纯度线粒体DNA提取技术研究

以2个芝麻品种黄化苗为试验材料,通过比较植物线粒体DNA(mtDNA)提取过程中的关键影响因素DNase处理时间,建立了一种经济、快速、高效的芝麻mtDNA提取方法.该方法分别通过匀浆化处理、2 400 g离心15min结合12 000 g离心12 min的差速离心方法分离获得粗制线粒体,再经过DNase酶切处理1.5...     

三种从马血中提取基因组DNA方法的比较研究

选择一种快速、简便、经济的从马血液中提取基因组DNA的方法。分别采用了常规酚—氯仿抽提法、简易酚—氯仿快速抽提法和V—gene Biotechnology Limited试剂盒三种方法从马血中提取DNA,并利用琼脂糖凝胶电泳技术和紫外分光光度计,比较各方法提出DNA的浓度和纯度,且利用PCR扩增技术检测DNA的实用性。结果表明,常规酚—氯仿抽提法适合从马血中大量提取DNA。     

一种橡胶树叶片基因组DNA快速PCR扩增方法

为解决现有的橡胶树基因组DNA提取方法步骤繁琐、耗时长等问题,摸索出一种橡胶树叶片基因组DNA快速PCR扩增方法。通过比较分析快速提法与CTAB法,结果显示快速提取方法提取的基因组DNA完整性很高,同时也适用于RAPD分型分析。相比传统的基因组DNA提取、PCR扩增等其它分子生物学流程,快速PCR扩增方法操作简单、简单快速、成本低廉,尤其适用于大批量样品的基因分型分析。     

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.     

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.     

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.     

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.     

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.     

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.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

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.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.