马哈利樱桃矮化砧的DNA甲基化水平及模式分析

该研究利用MSAP技术,对25株矮化马哈利樱桃和25株半矮化马哈利樱桃进行甲基化水平和模式分析,以探讨其矮化的表观性状与其基因组甲基化修饰的关系。结果表明:(1)从64对引物中筛选出15对引物,在半矮化组中共扩增4 577个条带,其中半甲基化336个,全甲基化1 274个;在矮化组中共扩增4 444个条带,其中半甲基化349个,全甲基化1 383个;t检验和方差分析表明,矮化组与半矮化组在总甲基化水平和全甲基化水平上差异极显著,在半甲基化水平上差异显著,矮化组甲基化水平高于半矮化组。(2)半矮化组单态性位点23个,多态性位点136个;矮化组单态性位点17个,多态性位点142个,表明矮化组多态性高于半矮化组。(3)多态性类型分析表明,矮化组出现A4类型的频率较半矮化组高,A2类型的频率较半矮化组低,即矮化组中发生超甲基化的位点多于半矮化组,且‘马哈利’基因组甲基化多态性位点主要发生在双链内侧甲基化位点以及超甲基化位点上。研究认为,马哈利樱桃矮化和半矮化的基因组甲基化水平及模式存在差异,马哈利砧木的矮化性状与其基因组甲基化修饰有关。     

多效唑复合剂对几种观赏植物生长的控制

为了控制生长，使植株矮化，例枝增多，株形紧凑，从而创造出造型美观的中小盆花，我们以生长延缓剂──多效唑复合剂对数种观赏植物进行了试验。材料有菊花（Chrysanthemummorifolium）、扶桑（Hibiscusrosa-sinensis）、一品红（Euphorbiapulcherrima）和4种绿篱植物──叶子花（Bougainvilleaspectabilis,又称三角梅）、冬青（Ilexchinensis）、小蜡树（ligustrumsinense）、九里香（Murrayapaniculata）。药剂成份和配方见前文[植物生理学通讯，1995，31（5）：349]。采用土施和喷施两种方法。土施用药量每盆（7寸盆，2kg土）分别为0…     

CBF/DREB转录因子与植物矮化的相关性研究进展

CBF/DREB转录因子即干旱应答元件结合蛋白,是一类可以调控多个与干旱、高盐及低温耐性有关的功能基因表达的转录因子家族。很多报道称CBF/DREB转录因子的过量表达使转基因植株产生矮化、晚花现象。着重探讨CBF/DREB转录因子与植物矮化现象相关性与其矮化机理,并对草坪草育种新方向进行展望。     

水稻矮化相关基因的研究进展

矮秆水稻的培育成功是20世纪农业最主要的成就之一.本文综述了水稻矮化相关基因的遗传学、激素对矮化基因突变体的调控以及矮化相关基因的克隆等方面的研究进展,并分析了利用基因工程手段控制农作物生长的巨大潜能.     

植物矮化突变体的来源及矮化机理研究进展

植物矮化是一种重要的农艺学性状,是生命科学领域研究的重要内容之一,矮化研究是植物育种工作的热点。矮化来源分为诱变矮化和自发矮化,其中诱变矮化中的物理诱变研究的内容分类详细,在航天诱变领域取得了有效的研究成果。植物矮化机理的研究主要集中于植物内源激素,主要是赤霉素、油菜素内酯,也有少量关于生长素的研究。针对不同种类植物具体详细的矮化机理,还没有明确的分类和细化的研究。总结了植物矮化突变体的来源及矮化机理。     

用基因操作开发矮性的重组花

麒麟啤酒基础技术研究所利用基因操作成功地育成矮性而且长着很多花芽的土耳其桔梗和牵牛花。这种技术有可能是适用范围广,可以随意操作矮化和花芽增加等品种特性,能开发实用品种。该公司目前集中精力进行矮性重组土耳其桔梗的商品化。这次成功的技术中心是用Ti质粒将存在于植物病原菌发根土壤杆菌(Agrobacterium rizogenesis)的Ri质粒上的rol C基因导入植物体。西德Maxplank研究所先发现的是一旦导入rol C就会矮化并增加     

角蒿和铁线莲的矮化试验

为了提高株型较高的毛子草 (Incarvilleaarguta)和半藤本性状的毛茛铁线莲 (Clematisranuncu loides)的观赏价值 ,我们用多效唑、矮壮素和丁酰肼对它们进行了多种矮化处理。试验结果表明每盆用 0 .4g5 0 %多效唑可湿性粉剂施于土壤 ,每两周全株喷 0 .2 5 %的矮壮素并结合打顶可明显抑制第三年生毛子草的株高、花穗和羽状复叶的生长 ,增加了花穗数和花蕾总数 ,开花期比对照延长约 1 0d。每两周全株喷 0 .76%丁酰肼并结合打顶可抑制毛茛铁线莲的枝条生长 ,促进分枝 ,增加花蕾数。对两种植物的矮化均表明矮化处理过的植株对白粉病有较强的抗性     

玉米矮杆基因研究进展

玉米已成为我国种植面积最大的农作物,提高玉米的种植密度是提高玉米产量的重要技术手段。玉米的株型改良成为玉米遗传育种研究的重点之一。合理株型和抗倒伏能力是影响玉米产量的重要农艺性状,也是衡量优良玉米品种的重要指标之一。通过玉米矮化基因的分离及研究,开发相应的分子标记,培育出矮化或半矮化玉米植株,从而改善玉米株型结构,增加种植密度,提高群体光合效能,提高玉米产量。主要从玉米矮化育种的概况、玉米矮化基因遗传特点、玉米矮化基因的表型以及激素对玉米矮化的影响等方面的研究进行了总结和概述,为玉米矮化基因的开发利用及分子机制的阐明提供新的信息。     

长白山区柳兰的开发利用及园艺栽培技术

柳兰Chamaenerion angustifolium在长白山野生花卉中具有较高的观赏价值,通过引种及园艺栽培,探讨了繁育及园艺栽培技术,机械矮化用摘心法矮化效果和观赏效果突出。药用矮化选用B9矮化效果明显,花茎比例均衡。为其开发利用资源提供了科学依据。     

植物矮化相关基因研究进展

矮化植株株型紧凑,冠幅小,抗倒伏,且生产管理方便,丰产性能好,矮化育种是植物育种的发展趋势。国内外学者对植物矮化的机理、矮化基因、矮化育种等进行了比较深入的研究。我们对植物矮化的遗传特点、分子标记在矮化基因研究上的应用、矮化基因的定位、矮化基因的分离与克隆、矮化转基因等方面的研究进展进行了概述。     

树木病虫害缺陷精准检测方法的综述和展望

我国疆土辽阔,有着丰富的森林资源。近年来,随着外来昆虫的入侵,全国树木病虫害的暴发率逐年上升,对我国生态经济造成了巨大的影响,但是树木病虫害的监测只能在局部地区,因而只能在已经暴发了较严重的病虫害后才能够发现和治理。树木病虫害如在早期未被发现和处理,可能会造成暴发的严重形势,且预防和治理将变得被动,因此,进行树木内部病虫害缺陷精准检测尤为重要。为更早和更加准确预报树木病虫害的发生,需要进行定期的检测和监控。针对早期传统方法如目测法、敲击辩声法和解剖观测法等方法的准确性低、时效性差和易对树木造成不可逆损害等缺点,近些年研究出了新的检测方法,包括指向性好、能量大的超声波检测法,低成本、穿透性强的应力波检测法,以及成像准确、适用于不同环境的电磁波检测法等。不同的检测方法分别有着相对应的成像算法,如走时法、频域分析法和Born近似法等。这些成像算法在分辨率、准确度、精度和计算速度上各有优势。通过对这3种检测方法的发展现状进行总结,了解各类检测方法的优缺点,有助于更好地针对不同情况下的树木病虫害做出精准检测,能够把树木病虫害暴发后的被动治理变成暴发前的主动预防,以提早做出应对方案。     

Resistance of kale populations to lepidopterous pests in northwestern Spain

Kale (Brassica oleracea L. acephala) is common in northwestern Spain where it is severely damaged by different insect pests. Damage could be reduced by using resistant varieties. The objectives of this work were to evaluate the resistance of kale populations to leaf damage by lepidopterous pests, to determine which traits are the best indicators of resistance, and finally to study the relationship between the glossy phenotype and resistance. Fifteen kale populations, sowed early and late, were evaluated at two locations in northwestern Spain. Significant differences among genotypes were found for all damage traits. Damage was not related to planting dates. Highest levels of damage were observed from July to November. Some populations with different performance under natural infestation in 1999 were again evaluated in 2000 under artificial infestation with Mamestra brassicae (L.) eggs. Two accessions, MBC-BRS0142 and MBG-BRS0170, showed resistance to attack by lepidopterous pests. Correlation coefficients among damage traits show that general appearance rating may be an useful indicator of resistance. Phenotype of kale with glossy leaves seems to be related to resistance although further research is needed.     

Cost analysis of the application of marker-assisted selection in potato breeding

The primary aim of plant breeders is to develop new cultivars in order to improve productivity and to combat threats from pests and diseases. Recent advances in genomics have been recognised as providing important tools for plant breeders in the form of molecular genetic markers that can be used to tag genes of interest. However, the cost-effective use of marker technology is dependent on the nature and timing of the use of such markers. A conventional potato breeding programme typically creates a large breeding population and then employs phenotypic recurrent selection over a number of generations to identify superior genotypes. Marker-assisted selection (MAS) provides the advantage of being applicable at the seedling or an early generation stage. We have analysed the cost of MAS and compared it to conventional screening, then modelled the respective costs against the breeding population size of the generation in which they would be applied to determine whether MAS in the early generations of a potato breeding programme would be cost-effective. As various potato breeding programmes employ different selection rates in early generations, these rates have also been modelled to determine the effect. Our results indicate that MAS could be applied cost-effectively in the second clonal generation for all models currently employed in potato breeding.     

Eine Methode zur Blattlaus-Massenzucht für öko-physiologische Untersuchungen

Regulatory control can prevent further spontaneous introduction of alien pests to Egypt or slow down the rate of spread of several recently introduced plant pests and diseases, limit their damage and/or allow time to develop alternative management strategies. The problem essentially is the impracticability of detecting the pest at its initial infestation site at a sufficiently early stage to have any chance of eradicating it. Pest spread to secondary foci within the country should be blocked through quarantine and certification programmes. Recognizing that zero tolerance requires sampling every unit in the lot, the default strategy is to define an acceptable tolerance limit for each pest sampled. The binomial probability distribution is presented as a base for determining probabilities of detecting various infestation levels as increasing numbers of samples are collected. Such a method saves time, labour and money in the detection and ensures the relative proportional certainty emanating from the inspected sample to the actual matter. However, a zero tolerance is required for the palm weevils. Neither Poisson nor the negative binomial distributions can be applied to such a zero tolerance or for soil sampling size to solely prove that the nematode is absent. Eventually, the tolerance limit must be backed up by sound technical information and consequent judgements for each specific case. Therefore, comprehensive precautions should be implemented for complete protection against pests and diseases as yet not found in Egypt.     

Ornamental Chrysanthemums: Improvement by Biotechnology

The in vitro tissue culture and micropropagation of chrysanthemums, important floricultural (cut-flower) and ornamental (pot and garden) plants, have been well studied. An increase in genetic transformation studies aimed at improving aesthetic and growth characteristics of the plants has been hampered by low transformation efficiencies and genotype dependence of protocols. As a result chrysanthemum regeneration studies have once again emerged as an essential complement of transformation studies. This review highlights the impact that biotechnology has had on the improvement of chrysanthemum in vitro cell, tissue and organ culture, micropropagation and transformation.     

人工红树林的生长与病虫害防治的研究

为了配合“十五”863项目研究红树林修复海水滩涂养殖水的营养污染,在深圳海上田园旅游区的科技试验区鱼塘构筑种植岛种植一年生红树植物海桑(Sonneratia caseolarisL.)、桐花树(Ageiceras corniculatum(L.)Blanco)、秋茄(Kandelia candelL.Druce)并监测了解其生长发育的情况及物候期;掌握危害红树林植物生长的主要病虫害.结果表明,海桑生长速度快,各生长形态指标都远大于秋茄和桐花树,并且具有良好的抗逆特性但怕冷冻.秋茄生长速度慢,对环境的适应能力差,怕水淹,成活率最低;桐花树抗逆性强,成活率最高.红树林植物幼龄时期容易受到病虫害严重威胁,要做好防治工作,保证红树林植物的健康生长.     

麦套夏播转Bt基因棉R93-6对昆虫群落的影响

以转Bt(Bacillusthuringiensis)基因棉品系R93-6为试验材料,以中棉所16号为对照,研究了在麦套夏播条件下转基因棉对昆虫群落的影响。结果表明,转基因棉田昆虫群落、害虫和天敌亚群落的多样性指数和均匀度指数均低于常规棉田,而优势集中性则高于常规棉田,所以转基因棉田昆虫群落、害虫和天敌亚群落的稳定性不如常规棉田,某种害虫大发生的可能性较大。对季节性变化格局的研究表明,转基因棉田昆虫群落可以划分为前期(6月初至7月下旬)、中期(7月底至8月底)和后期(9月份以后)三个发展阶段,根据不同阶段害虫和天敌发生的特点, 提出了害虫综合治理的策略。即前期害虫的防治应以生物生态调控为主;中期以化学防治为主,以生物生态调控为辅,协调好生物防治和化学防治的矛盾;后期应以生物生态调控为主,并加强农业防治。     

Biological Control of Basal Stem Rot of Chrysanthemum By Antagonists*

The basal stem rot of chrysanthemum caused by Rhizoctonia solani is an important chrysanthemum disease in Taiwan, Control of the disease using the antagonists of R.solani, including members of the genera Aspergillus, Gliocladium, Paecilomyces, Penicillhium, Tricboderma and Bacillus, was studied. The antagonists were grown in solid media or culture broths for preparations of rhe inoculums which were u.sed as soil amendments or coating materials for applications on the disease control. Sawdusts, rice husks and sawdust composts were used as supporting material to prepare the solid media. By planting of the chrysanthemums, the solid media growth with antagonists were put in the nursery sand beds, or the chrysanthemum cutting seedlings were coated with antagonists of culture broths; whilst the sand beds were inoculated with R. solani. The results indicated that all antagonists could protect the chrysanthemum from the infection of R. solani, and the effects of the solid media were higher than the culture broths. When the chrysanthemum seedlings were treated with the extracts of the antagonists, the disease could also be depressed. The different control effects on Rhizactonia disease of chrysanthemums resulted from the species of the antagonists and their delivery systems to be used.     

陕西榆林地区农田灯诱地下害虫种类组成及优势种群发生动态

为了明确陕西榆林地区农田地下害虫种类组成及优势种群发生动态,于2016年4月1日至2019年9月28日,在陕西省榆林市现代农业示范园,设置太阳能自动虫情测报箱对地下害虫进行收集,在室内对标本进行鉴定和数据分析。在榆林市农田一共灯诱到地下害虫12种,隶属3目5科。地下害虫混合种群发生期为4月中旬至9月上旬,盛发期为4月下旬至8月上旬。小地老虎Agrotis ypsilon、东方绢金龟Maladera orientalis、阔胫绢金龟Maladera verticalis和黄褐丽金龟Anomala exoleta是榆林农田地下害虫主要优势种群。小地老虎灯诱高峰期为4月上旬至5月中旬以及6月上旬至7月下旬,东方绢金龟的灯诱高峰期为4月中旬至6月中旬,阔胫绢金龟灯诱高峰期为6月上旬至8月上旬,黄褐丽金龟灯诱高峰期为6月中旬至7月上旬。本研究为榆林地区农田地下害虫的监测和综合治理提供了基础资料。     

Lack of structure in the gene pool of the highly polyploid ornamental chrysanthemum

Selection of clonally propagated chrysanthemums is mostly performed on F1 hybrids using phenotypic characteristics without the use of molecular information. We applied 448 amplified fragment length polymorphism markers to a set of 81 accessions, mainly from the European gene pool, covering the different horticultural types (cut, pot and garden varieties) and originating from the most important European chrysanthemum breeders. The average pairwise genetic similarity of 0.69 was moderate to rather high. Neighbour-joining clustering resulted in no grouping of the accessions, either by their common origin or their horticultural type, or by similarities in important phenotypic characteristics. The structure of the dendrogram could not be supported by bootstrap analysis. Furthermore, network analysis using SplitsTree, principal coordinate analysis via DARwin or analysis of the population with structure did not differentiate reliable and invariable clusters. Therefore, we tested the marker saturation by plotting the mean coefficient of variation for every pairwise similarity of the bootstrap analysis against the different numbers of markers. We showed that the number of markers is sufficient for a precise estimate of genetic similarity and that the lack of bootstrap support is not due to a low genetic diversity or a lack of marker information, but most likely resulted from the breeding history of the cultivars, involving repeated backcrosses and the exchange of genotypes between breeders.