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71.
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73.
Introduction of new traits into cotton through genetic engineering: insect resistance as example 总被引:1,自引:0,他引:1
C. Pannetier M. Giband P. Couzi V. Le Tan M. Mazier J. Tourneur B. Hau 《Euphytica》1997,96(1):163-166
The main goal of gene transfer into cotton is the development of insect-resistant varieties. The stakes are important since
cotton protection against insects uses almost 24% of the world's chemical insecticides market, which is not without consequences
on the environment. The first approach was to introduce and express in the cotton genome, genes from the bacterium Bacillus
thuringiensis (B.t.) which produces entomopathogenic toxins. The development of an efficient Agrobacterium tumefaciens mediated
transformation system was the first step. The expression of B.t. genes was studied and synthetic genes more adapted to a plant
genome have been constructed. Studies on their expression in cotton is underway. The second focus was to develop strategies
that would minimize the risks of inducing insect resistance. The main approach is to associate several genes coding for entomopathogenic
proteins with different modes of action. Genes encoding protease inhibitors were chosen. One possibility is to associate a
B.t. gene and a gene encoding a protease inhibitor. Several protease inhibitors were tested in artificial diets on major pests
of cotton. The corresponding genes have been introduced into the cotton genome. These various orientations of the research
program will be presented.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
74.
5株芽孢杆菌对棉花病害的防治效果及其对棉苗生长的影响 总被引:4,自引:0,他引:4
来自5种植物根围土壤的5株芽孢杆菌对棉花立枯病菌、炭疽病菌、黄萎病菌、枯萎病菌、棉铃疫霉病菌和棉叶斑病菌均有较强抑制效果。室内发芽试验表明,C一62菌株显著促进棉子发芽,其余4个菌株对发芽无显著影响。5个菌株的培养液处理棉子后对棉苗病害的防治效果为60.O%~75.7%,株高、苗鲜重、真叶数及茎粗均高于对照及灵福合剂处理。以综合效果较好的C一62、C一37和C一54制成水剂和粉剂在江苏、河南和山东等地进行了2~3年小区试验,得到了一致的结果。以种子重5%~25%浸种或拌种对棉花苗期立枯病、炭疽病等有40%~60%的防治效果,处理的棉子顶土快,棉苗素质。 相似文献
75.
苦楝果实提取物对Bt-8010和Bt-7216的抑菌活性 总被引:6,自引:1,他引:6
将采摘的苦楝果实烘干、粉碎,以甲醇为溶剂,用超声波法提取苦楝果实的提取物,配成不同浓度的苦楝果实提取液,用于测定2种生物农药Bt_8010和Bt_7216的抑菌圈和抑菌率。结果表明:苦楝果实提取液浓度越高,其抑菌程度越大。其中,对Bt_7216的抑菌活性较大,Bt_8010次之。高浓度的苦楝提取物与生物农药(Bt)混用会降低Bt的药效。 相似文献
76.
Summary Colonization patterns of Pseudomonas fluorescens and Bacillus subtilis on roots of wheat seedlings growing on water agar were studied qualitatively by replica printing and quantitatively by the plate count method. The results indicated a stronger colonization potential for P. fluorescens (up to 107 cfu/cm root) than for B. subtilis (up to 105 cfu/cm root). Although the numbers of both species were lower when inoculated together, the observed colonization patterns on the roots were comparable to those found with single inoculations. For none of these bacteria was active migration along the root surface in any direction observed, indicating that distal positions are reached mainly by a passive displacement on the root tip and elongating cells. Ecological implications of the observed phenomena are discussed. 相似文献
77.
78.
胨冻样芽孢杆菌(Bacillus mucilaginosus)的分离、筛选及其发酵培养基研究 总被引:4,自引:3,他引:4
本文报道了胨冻样芽孢杆菌 (Bacillusmucilaginosus)的分离、筛选及其对小麦苗期生长的作用 ,并对胨冻样芽孢杆菌的发酵培养基进行了优化 .结果表明 ,胨冻样芽孢杆菌 (B .mucilaginosus)生长的最适培养基 (g/L)为 :蔗糖 1 4、Na2 HPO4 1 .5、FeCl3 0 .0 0 2、CaCO3 1 .5、酵母膏 1 0 ,自来水 1 0 0 0ml、pH7.0~ 7.5;有机氮和无机铵态氮抑制胨冻样芽孢杆菌的生长 ;胨冻样芽孢杆菌液体培养物对小麦苗期生长具有促进作用 . 相似文献
79.
将苏云金芽孢杆菌(Bacillus thuringiensis)缺失C端154个氨基酸编码区的vip3A基因(vip3T)插入原核表达载体pQE30,构建了重组表达载体pQEvip3T,并转化大肠杆菌(Escherichia coli ) M15进行IPTG诱导表达,比较了完整的Vip3A蛋白和C端缺失的蛋白Vip3T的可溶性和杀虫活性。与Vip3A不同,融合蛋白Vip3T以不可溶的包含体形式存在,诱导表达的菌液中没有检测到可溶性Vip3T蛋白。生物测定结果表明,M15(pOTP)诱导表达的Vip3A蛋白对初孵斜纹夜蛾(Spodoptera litua)和甜菜夜蛾(S. exigua)幼虫具有较高的杀虫活性,其提纯的包含体无毒,但包含体的碱性裂解液却又恢复了对夜蛾科害虫的活性;M15(pQEvip3T)菌液、包含体及其碱性裂解液对这两种昆虫幼虫则完全无毒,说明在大肠杆菌中,Vip3A蛋白C端氨基酸可能对Vip3A蛋白的可溶性和杀虫活性具有重要的影响。 相似文献
80.
We performed a comparative experiment to investigate: (1) how the ubiquitous soil bacterium Bacillus subtilis weathers granite; and (2) which granite-forming minerals weather more rapidly via biological processes. Batch system experiments (granite specimen in a 500 ml solution including NaCl, glucose, yeast extract and bacteria B. subtilis at 27 °C) were carried out for 30 days. Granite surfaces were observed by SEM before and after the experiment. B. subtilis had a strong influence on granite weathering by forming pits. There were 2.4 times as many pits and micropores were 2.3 times wider in granite exposed to B. subtilis when compared with bacteria-free samples. B. subtilis appear to preferentially select an optimum place to adhere to the mineral and dissolve essential elements from the mineral to live. Plagioclase was more vulnerable to bacterial weathering than biotite among the granite composing minerals. 相似文献