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近年来,随着转基因抗虫棉良种的选育成功,棉农的植棉积极性逐年提高,抗虫棉的种植面积也越来越大.但是由于种种主客观因素的影响,导致抗虫棉抗虫性减退和种子混杂退化现象日趋严重.如何避免和杜绝这些现象已成为当前不容忽视的问题.影响转基因抗虫棉品种混杂退化的原因主要有: 相似文献
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近年来 ,随着转基因抗虫棉良种的选育成功 ,棉农的植棉积极性逐年提高 ,抗虫棉的种植面积也越来越大。但是由于种种主客观因素的影响 ,导致抗虫棉抗虫性减退和种子混杂退化现象日趋严重。如何避免和杜绝这些现象已成为当前不容忽视的问题。影响转基因抗虫棉品种混杂退化的原因主要有 :天然杂交 棉花是常异交作物 ,其天然杂交率在 5 %~ 10 %左右 ,如果抗虫棉良繁田与其它常规棉种植田相邻过近 ,极易造成天然混杂。机械混杂 原种纯度的高低、播种机械的混用、籽棉收贮和加工等诸多环节中的任一方面出现疏漏 ,都会人为造成品种的混杂。自然… 相似文献
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根据河南周口市273户棉农对转基因抗虫棉的认知评价调查对采用转基因抗虫棉行为发生逆转的原因进行分析。结果表明,农户对转基因抗虫棉品种不满意是采用逆转的主要原因,不满意的原因主要集中在抗虫性单一且下降、产量低等方面。科研育种部门需要有针对性地加强多抗、高产等品种特性育种。 相似文献
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转基因抗虫棉研究的现状、问题与对策 总被引:22,自引:0,他引:22
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 相似文献
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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。 相似文献
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论我国转基因抗虫棉育种 总被引:1,自引:0,他引:1
本文论述了由于棉花害虫为害严重必须进行防治,而化学防治失控必须开辟新途径,利用棉花自身抗虫性是最佳选择,转基因抗虫棉已显示出无可比拟的优势。还分析总结了转基因抗虫棉的现状,并针对当前存在的主要问题,研究提出转基因抗虫棉育种发展趋势。 相似文献
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莫曾梅 《农产品加工.学刊》2019,(7):78-80
随着生活水平的提高,果蔬产品成为人们摄取营养元素的重要食品之一。分析了我国果蔬采后存在的问题,并对低温及气调保鲜、化学保鲜剂、涂膜保鲜技术及超声保鲜技术等贮藏保鲜技术研究进行了综述,指出我国果蔬贮藏保鲜技术持续、稳定、健康的发展要倚重于科技创新。 相似文献
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Oil and protein crops are of growing importance in cropping systems. This study was carried out to compare oil crops of linseed, rapeseed, sunflower and protein crops of faba bean and white lupin for grain production, residual plant dry matter and nitrogen. Two field experiments with either oil or protein crops were conducted in 1993 and 1994, respectively. Total dry matter production, grain yield, residues, N concentrations and mineral N in the soil were measured. Dry matter production and distribution as well as N uptake and residues varied greatly among species and between years. In 1993, oil crops gave up to 3 t ha−1 grain and 16 t ha−1 residues with sunflower, while in 1994 up to 5 and 11 t ha−1, respectively, were recorded with winter rape. Protein crops showed an opposite reaction in years. Nitrogen uptake and residual N amounts were correlated with dry matter production. Plant residues of oil crops contained 20–140 kg N ha−1; those of protein crops up to 80 kg N ha−1. Despite the variation of residual plant N the variability of mineral N in the soil at harvest was hardly influenced by crops and amounted to only 20–50 kg NO−3-N ha−1. 相似文献
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我国蔬菜产业和科学技术的发展与展望 总被引:1,自引:0,他引:1
1 我国蔬菜产业的发展现状蔬菜是人们日常生活中不可缺少的副食品,也是我国目前种植业中最具活力的经济作物。改革开放以来,随着市场经济的发展,农产品产销体制的不断改革和完善,特别是1988年实施“菜篮子工程”以来,蔬菜产业得到了蓬勃发展。1.1 播种面积1987~1999年,全国蔬菜播种面积由533.3万hm2,发展到1333.3万hm2,增长139.5%。1.2 总产量1987~1999年,全国蔬菜总产量由1.55亿t增加到4.05亿t,增长161.3%,使年人均鲜菜占有量达到330.7kg(世界各国人均105kg…… 相似文献
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以Y05-222A和Y06-136R杂交得到的135株F2群体为研究材料,测定过氧化物酶(POD)、超氧化物歧化酶(SOD)、脯氨酸(Pro)、过氧化氢酶(CAT)、可溶性蛋白和丙二醛(MDA)等6个生理指标,并进行方差分析、相关性分析和通径分析,对F2群体进行偏度及峰度分析。结果显示,以上6个生理指标在F2群体中P>0.05,分布频率符合正态分布,同时存在双向超亲分离现象;相关性分析和通径分析显示,这些指标与抗盐碱系数均呈极显著相关(正相关或负相关),且相关系数与总间接通径系数方向一致。POD活性的直接通径系数为0.5003,可见POD直接影响抗盐碱性;CAT活性和Pro含量的直接通径系数分别为-0.1317和-0.0384,间接影响抗盐碱性;SOD活性、MDA及可溶性蛋白含量直接或间接影响抗盐碱性。POD、SOD、Pro、CAT、可溶性蛋白和MDA各生理指标的抗盐碱作用表现为POD>CAT>Pro>可溶性蛋白>MDA>SOD。叶片数、株高、茎粗和盘径与抗盐碱系数呈极显著正相关,其相关性表现为叶片数>盘径>株高>茎粗。以上结果可为研究油用向日葵抗盐碱性提供一定的理论基础。 相似文献
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LI Zhi-liang~ 《保鲜与加工》2004,(7):82-85
Some novel concepts of chemomics/molomics are proposed including hydrocarbomics, alcophenomics, carboxomics, pepitomics, metabonomics, etc. like genomics, protomics and glycomics in bioomics. Some examples are given to demonstrate the chemomics and/or molomics methodology and technology based chemoinformatics and bioinformatics and their wide applications in Chemistry and Biology. 相似文献
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《Journal of Landscape Research》2013,(Z1)
Definition of Fengshui and the theories of selecting mountain and water environment in Fengshui were elaborated. Theories about mountain-water relationship were expounded from the perspective of piling of rockeries and layout of water, a residential area in Hefei City, Beijing Olympics Park, Hangzhou Prince Bay Park, mineral pit of Shanghai Chenshan Botanic Garden, Beijing Beihai Park, Shanghai Changfeng Park were taken for example to demonstrate the influence of traditional rockery and mountain layout in Fengshui on modern landscape design. 相似文献
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果蔬食品的褐变与控制 总被引:9,自引:0,他引:9
结合生产实际,对果蔬食品产生褐变的机理及其控制途径进行探讨。通过遗传学途径,培育果蔬新品种,使之不含易氧化变色物质,增强其天然抗褐变性,是控制果蔬褐变的根本途径。 相似文献
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Acidity and sweetness in apple and pear 总被引:2,自引:0,他引:2
Summary Sweetness and acidity in apple and pear inherit independently and can be organoleptically evaluated separately, but less accurately in pear than in apple. For breeding purposes an analysis of fruits for acidity and sweetness with pH indicator paper and a hand refractometer is to be prefered to the organoleptic method.In apple, the acidity-decreasing with time-of the unripe fruit was already strongly indicative of that of the eating-ripe fruit; sugar-increasing with time-not before the fruit was picking ripe. Sugar content in apple and pear, and the pH in pear, appeared to be normally distributed; the pH in apple showed a segregation into an acid and a low-acid group, which occurred in both the unripe and ripe stage. The segregation ratio between these groups was found to be highly variable. On the whole, the mean acidity and sugar content of apple and pear progenies is significantly determined by that of the parents. Most of the observations made did not support the theory that low acidity in apple is determined by one recessive gene. The relationship between the pH of leaf juice and fruit juice in apple may offer a possibility for pre-selection. 相似文献