转基因抗虫棉研究的现状、问题与对策

本文在介绍转基因抗虫棉研究现状的基础上,评述了转基因抗虫棉的使用价值,指出了转基因抗虫棉抗性的持久性,时空性,安全性等问题,从培育转多基因抗虫棉,培育多种类型的抗虫品种轮换种植或混系种植,选用特异启动子或理经因素调控外源基因高效表达,筛选广谱性抗虫基因培育广谱性抗虫棉花和采用农业技术措施改善棉田生态环境延长转基因抗虫棉的使用寿命等方面,提出了提高转基因抗虫棉抗虫性和持久性的几种策略,从而为转基因抗     

转基因棉花抗虫基因的分子辅助选择

为提高棉花新品种选育过程中外源抗虫基因选择的准确性,以常规非转基因抗虫棉花品种、单价转基因抗虫棉品种、双价转基因抗虫棉品种为试验材料,选择能扩增Bt基因通用引物和棉花内源基因SAD1的引物,建立了抗虫基因的PCR检测方法。利用该方法对常规非转基因抗虫棉品系和转基因棉花品系进行了检测。结果表明,该方法可明确区分常规非转基因抗虫棉品系和转基因棉花品系;对高代育种品系进行检测表明40%转基因品系中存在单株不能扩增出预期的特异片段,而在非转基因系冈197中存在8.0%的单株扩增出预期的特异片段。该方法可应用于棉花新品种选育过程中对外源抗虫基因的检测,提高了选择的准确性和目的性。     

3个水稻杂交种的早代测试及其对选择的反应

虫害是影响棉花高产稳产的重要因素之一，防治棉花虫害最有效的措施是种植抗虫棉花新品种。美国利用生物技术合成苏云金芽孢杆菌杀虫基因＆并导入棉花获得转基因抗虫棉植株，因其抗虫性能够稳定遗传，进而培育出转基因抗虫棉花新品种，使美国成为第一个拥有转基因抗虫棉的国家。我国谢道昕、郭三堆等将Bt和Bt＋CpTI（豇豆胰蛋白酶抑制剂）杀虫基因导入棉花并成功应用于棉花育种，陆续培育出一批国产转基因抗虫棉新品种，使我国成为第二个自主成功研制转基因抗虫棉的国家，我国抗虫育种研究己处于国际领先水平。     

转基因抗虫棉风险性分析及应对策略

主要针对转基因抗虫棉抗虫的时空性问题,棉花不同生育期、植株部位、不同害虫世代抗虫性的变化,抗虫棉对棉田害虫和天敌种群结构的影响,害虫对抗虫棉毒蛋白的抗性,抗虫棉抗性基因的漂移以及抗虫棉子产品的生物安全性等问题进行了分析,进而提出了降低转基因抗虫棉潜在生态风险性的措施。     

转基因抗虫棉的抗性研究与利用

转基因抗虫棉是我国唯一获准商品化生产的转基因作物,本文对抗虫基因的分离与转基因棉株的获得及抗虫棉的抗性原理进行了探讨。转Bt基因抗虫棉不同生育阶段,不同部位对棉铃虫的抗性,抗虫棉的研制成功与大规模产业化保障我国棉花稳步发展,增加农民收入保护环境作出了重要贡献。     

全球转基因棉花商业化进程

分析了全球转基因棉花商业化种植进程,结果显示:1996年美国、澳大利亚、墨西哥3国率先商业化种植转基因棉花以来,此后迅速发展,至2010年已有13个国家种植转基因棉花,种植面积达2100万hm2,占全球棉花总面积的64%;2011年转基因棉花的普及率更是高达82%,并首次超过大豆成为转基因品种普及率最高的作物,揭示了转基因棉花的普及已成为必然趋势。我国于1998年开始规模化种植转基因棉花,到2011年普及率仅71.5%。普及速度比任何一个种植转基因品种的主要植棉国都慢,而且我国的转基因棉花研究与美国也有很大的差距,抗除草剂的转基因棉花尚未面世,双抗(既抗虫又抗除草剂)和转其他基因的棉花可能需要更长的时间才能研发出来。     

转Cry1Ac+Cry2Ab基因棉与转Cry1Ac+EPSPS基因棉在黄萎病菌压力环境下检测技术和生存竞争能力研究

此研究为“十二五”转基因生物新品种培育项目中创建新的转基因棉花品种环境安全评价技术的建立而设。以转双价抗虫基因（Cry1Ac+Cry2Ab）棉、转双价抗虫抗除草剂基因（Cry1Ac+EPSPS）棉为观察材料,杂交抗虫棉赣棉杂1号和非转基因棉赣棉11号为对照材料,于黄萎病圃采用不同于抗病鉴定的方法,检测两种转双价基因抗虫棉在黄萎病菌压力下的发病情况、生长竞争能力和产量竞争能力。两个转双价基因棉抗黄萎病性不显著的强于两个对照;抗虫抗除草剂棉株高、覆盖度增长竞争能力相对较强,双Bt抗虫棉竞争力相对较弱;抗虫抗除草剂棉的单株成铃和果枝层数较高,增长竞争能力也较强,双Bt抗虫棉较弱;两个转双价基因棉最后的脱落率与两个对照差异不显著;抗虫抗除草剂棉籽棉、皮棉产量介于两个对照之间,而双Bt抗虫棉的产量低于两个对照。显示双Bt抗虫棉推广种植可行性相对较差,抗虫抗除草剂棉推广种植可行性一般。     

巴西转基因作物商业化进程分析

分析了巴西大豆、玉米和棉花3种主要作物转基因品种的商业化进程,结果表明：2012年转基因品种的普及率预计达到88.1%,转基因玉米的普及率达到75%,转基因棉花达到50%。大豆、玉米已经基本实现了品种的转基因化。无论是抗虫的,还是抗除草剂的,或者是既抗虫又抗除草剂（双抗）的转基因品种,都大受农民的欢迎。这揭示转基因技术为农业生产者带来了巨大的利益。转单一性状基因的玉米和棉花的种植面积呈下降趋势,转2个性状基因的种植面积呈快速增长趋势。这表明转基因技术已由转单一性状基因向转2个性状基因转变,暗示未来必然是向转多个性状基因转变。分析还表明,转基因技术的应用不同程度促进了巴西作物生产的发展,种植面积不断扩大,单产快速提高。     

我国转基因抗虫棉存在的问题及建议

转基因抗虫棉是指携带入工分离、构建、导人的外源目的基因并在体内表达且稳定遗传。自身合成一种或几种对某些害虫有毒杀作用物质的棉花。在抗虫基因方面研究最多、进展最快的是Bt基因、我国的农业生物基因工程研究始于80年代初，经过3个五年计划特别是国家“863”计划的实施，基因工程研究进入了一个新的发展阶段，目前我国培育的转基因抗虫棉已达到较高的水平，在生产上有极大的使用价值，已经进入商品化释放阶段，但是转基因抗虫棉在示范推广过程中也暴露出一些必将影响抗虫棉大面积推广应用的问题。为了使转基因抗虫棉这个高新技术产…     

我国转基因抗虫棉研究与应用

我国转基因抗虫棉研究起步于20世纪90年代,1992年人工合成了GFMcrglAcryBt基因,1995年研制成功了CrylA+CPTI双价抗虫基因,并相继育出了单价、双价和杂交抗虫棉新品种。转Bt基因抗虫棉不同生育阶段,不同部位对棉铃虫的抗性不同。对3龄以上的棉铃虫毒死率明显下降。转Bt+CPTI抗虫棉与转Bt基因抗虫棉有相似的抗虫性,但抗虫具有广谱性,且对大龄棉铃虫的杀伤效果显著高于Bt基因抗虫棉。转基因抗虫棉已推广应用847万hm²,累计创社会经济效益220多亿元。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

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.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

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.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.