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911.
采用生物化学方法研究不同剂量吡虫啉对禾谷缢管蚜酯酶活性和酶动力学参数的影响.结果表明,不同浓度吡虫啉处理禾谷缢管蚜后,可极显著诱导禾谷缢管蚜蛋白含量增加和酯酶活力增强,且不同处理组间蛋白含量差异显著,但不同剂量吡虫啉处理并未对禾谷缢管蚜酯酶动力学参数产生明显影响.不同浓度吡虫啉处理禾谷缢管蚜后,并未改变其酯酶的性质,但酯酶的表达量显著增加. 相似文献
912.
913.
为明确茉莉酸甲酯(MeJA)诱导柿树(Diospyros kaki Linn.f.)挥发物成分的变化对蚧虫的天敌昆虫红点唇瓢虫(Chilocorus kuwanae Silvestri)吸引力的持续效应,应用3种剂量(20、100μL和200μL)的MeJA处理柿树,通过"Y"型嗅觉仪测试瓢虫的行为反应,并采用顶空收集和气质联用(GC/MS)分析挥发物的组成和相对含量。结果表明,MeJA可以诱导树体挥发物成分发生改变,对瓢虫产生吸引力,其持续效应可达1d以上。而不同剂量的处理组之间存在差异,高剂量组中萜烯类物质含量最多,在处理后3h瓢虫的趋性最强,相应的α-蒎烯含量高达34.05%。处理3~5d后吸引力显著下降,α-蒎烯等化合物的含量也逐渐减少。因此,茉莉酸甲酯的连续应用可以招引更多的瓢虫来控制蚧虫。 相似文献
914.
Paul H. Goodwin Weilong Xie Moez Valliani 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(4):795-810
Expression of three Nicotiana benthamiana miraculin-like protein genes, NbMLP1, NbMLP2 and NbMLP3, showed almost identical responses to wounding, an incompatible interaction with Pseudomonas syringae pv. tabaci and compatible interactions with P. syringae pv. tabaci, Colletotrichum destructivum or Colletotrichum orbiculare. However, only NbMLP1 expression responded to exogenous methyl jasmonate or ethylene. None exhibited expression in healthy leaves and stems, and all showed highest expression in seeds, except for NbMLP1, which had highest expression in roots. NbMLP1, NbMLP2 and NbMLP3 were in different subfamilies of miraculin-like protein sequences of N. benthamiana and Nicotiana tabacum. Subfamilies correlated well with predicted features of the reactive-site loop potentially affecting the bond that could react with serine proteinases. Despite considerable predicted structural diversity that might affect biological activity, the apparently coordinated expression of these genes to pathogen attack may reflect the need to produce diverse proteinase inhibitors to act against a potentially broad range of secreted microbial proteinases during basal resistance to pathogens. 相似文献
915.
建立了测定马铃薯及土壤中丙炔噁草酮及其代谢物RP017272和RP025496残留的气相色谱检测方法。植株、块茎样品以乙腈作为提取溶剂,土壤以二氯甲烷作为提取溶剂,选用KB-5(30m×320m×0.33m)色谱柱分离,电子捕获检测器定量检测丙炔噁草酮及其代谢物。该方法丙炔噁草酮及其代谢物的最小检出量均为5×10-12g,丙炔噁草酮、RP017272、RP025496的线性相关系数分别为0.999 2、0.998 6、0.997 2。丙炔噁草酮在马铃薯植株、块茎及土壤中的加标回收率为90.6-96.7%,相对标准偏差(RSD)为1.1-2.4%,RP017272和RP025496在土壤中的加标回收率为88.1-95.4%,相对标准偏差(RSD)为1.5-3.3%。方法具有简便、快捷,准确的特点,适合马铃薯植株、块茎及土壤中丙炔噁草酮及其代谢物残留量的测定。 相似文献
916.
BACKGROUND: The combination of 1,3‐dichloropropene (1,3‐D) and dazomet (DZ) offers a potential alternative to methyl bromide (MB) for soil disinfection. MB is scheduled to be withdrawn from routine use by 2015 in developing countries. Combination treatments of 1,3‐D + DZ were evaluated in a laboratory study and in two commercial cucumber fields. RESULTS: Laboratory studies found that nearly all of the tested combinations of 1,3‐D and DZ displayed positive synergistic activity on root‐knot nematodes (Meloidogyne spp.), two major soilborne fungi (Fusarium spp. and Phytophthora spp.) and the seeds of two major weed species (Digitaria sanguinalis and Abutilon theophrasti). Field trials revealed that the combination of 1,3‐D and DZ (at 10 + 25 g m?2) successfully suppressed Meloidogyne spp. root galling, sharply reduced Fusarium spp. and Phytophthora spp. and maintained high cucumber yields. The combination treatment of 1,3‐D + DZ was more effective than 1,3‐D or DZ alone and provided results similar to methyl bromide with respect to pest control, plant mortality, plant height, yield and income. All of the treatments were significantly better than the non‐treated control. CONCLUSION: The results indicate that the tested combination of 1,3‐D and DZ offers an efficient alternative to methyl bromide for cucumber production. Copyright © 2012 Society of Chemical Industry 相似文献
917.
蓝变木材漂白试验表明:试剂质量分数和酸碱度对黄蓝轴色品指数b*及总色差△E*影响达到了极显著水平,处理时间也达到了次极显著的水平.蓝变木材脱色处理最佳组合为:脱色剂质量分数为3%,处理时间3h,温度为40℃,pH=7时,樟子松微薄木材蓝变可以脱出.其它木材脱色配方略有不同.质量分数3%以上的脱色剂TSBL药液即可脱出木材蓝变.pH值对蓝变木材脱色影响明显,当脱色剂处于酸性状态,蓝变木材色斑可以去除;当脱色剂处于碱性状态,大于7时,蓝变色斑不能脱出.脱色效果、脱色深度与处理时间有直接关系,处理时间越长,脱色深度越深,效果好;反之则差,甚至蓝变不能脱出.泡桐木材由于渗透性差,需要5 ~9h才能脱出蓝变.樟子松、橡胶木、香樟木和竹子较泡桐材渗透性好,3~7h即可脱出蓝变. 相似文献
918.
青钱柳愈伤组织增殖 总被引:1,自引:0,他引:1
为获得大量优质愈伤组织,以青钱柳(Cyclocarya paliurus)叶片为外植体诱导出的愈伤组织为材料,研究了基本培养基、蔗糖质量浓度、植物生长调节剂和镧稀土对愈伤组织增殖的影响。结果表明,综合愈伤组织增长率以及愈伤组织的颜色和状态因素,以MS基本培养基的增殖效果最佳;蔗糖质量浓度为20.00 g/L时愈伤组织增长率最高;植物生长调节剂对愈伤组织增殖的最佳组合为KT0.20 mg/L+2,4-D0.20 mg/L,平均增长量、增长率分别为4.38 g/瓶和1 024.51%。稀土对愈伤组织增殖的最佳质量浓度为0.50 mg/L。研究结果为进一步建立青钱柳悬浮培养体系和次生代谢调控的研究提供基础,同时也为青钱柳组培快繁技术的研究提供依据。 相似文献
919.
农业作为古老且现代的产业,其在国民经济发展中有着重要的地位.本文从产业结构的定义入手,在分析农业产业结构对农村经济增长作用的基础上,提出了农业产业结构调整在促进农业经济增长方面的应用策略.对我国农业经济的发展有一定的借鉴意义. 相似文献
920.
Trends of grain yield and plant traits in Chinese maize cultivars from the 1950s to the 2000s 总被引:2,自引:0,他引:2
Xiaoke Ci Mingshun Li Jiashun Xu Zhenyu Lu Pengfei Bai Gaolin Ru Xiaoling Liang Degui Zhang Xinhai Li Li Bai Chuanxiao Xie Zhuanfang Hao Shihuang Zhang Shuting Dong 《Euphytica》2012,185(3):395-406
Retrospective analyses may provide an understanding of unexploited genetic potential and indicate possible pathways for future yield improvement. The objectives of this study were to present maize(Zea mays L.)yield trends and plant traits changes for maize cultivars from the 1950s to the 2000s in China. Trials were conducted at three locations in 2007 and 2008, and at four locations in 2009. Twenty-seven single hybrids, four double-cross hybrids, and four open-pollinated varieties, were grown at three densities at each location each year. 56% of total yield gain was contributed to breeding from 1950 to 2000. New hybrids had more resistance to compound stress. Levels of response of all hybrids to higher-yielding environments were similar, and greater than that of OPVs. All maize cultivars showed morphological changes for all characteristics tested in a volatile manner from 1950 to 2000, except for relatively stable leaf number. ASI decreased and tolerance to root lodging improved, which were enhanced at higher plant densities. There were no trends for other characteristics at higher densities. Shorter maturity, smaller plant size and more tolerance to root and stalk lodging will be required for further yield improvement. Chinese maize yield improvement can benefit from agronomic strategies at higher plant densities. 相似文献