群居型、散居型亚洲小车蝗形态特征的数量分析

亚洲小车蝗(Oedaleus decorus asiaticus Bei-Bienko)是草原蝗虫的主要优势种之一,为了明确亚洲小车蝗两型现象与形态特征的关系,本文利用11个形态指标和5个形态指标比值采用数值分类学的方法对两型亚洲小车蝗成虫进行了测量和分析。结果表明,11个形态指标在亚洲小车蝗种群中均表现出一定的差异性,与能量储存、运动和飞行相关的体长(L)、前翅长度(E)、后足股节长度(F)在群居和散居型种群中具有极显著性差异(P0.01)。形态指标比值中,前翅长度和后足股节长度的比值(E/F)对两型蝗虫区分效果明显,群居型亚洲小车蝗成虫的E/F比值在1.68~1.74之间,散居型成虫的E/F比值在1.44~1.59之间,群居型E/F比值显著大于散居型(P0.05)。主成分分析构建了3个反映形态特征及其比值信息的综合指标,前两个主成分累积贡献率为99.84%,同时确定了E/F比值在两型区分上具有重要的指示作用,可以作为亚洲小车蝗成虫两型现象的判定指标。     

土壤强还原消毒过程中产生气体对土传病原菌的抑制作用

土壤强还原(reductive soil disinfestation,RSD)是一种高效、环保的土壤消毒方法,为明确RSD杀菌机理,采用气相色谱和荧光定量PCR等技术研究RSD过程中产生的气体对土传病原菌的杀菌作用。结果表明:RSD过程中土壤能够产生H_2S和NH_3;当在装有25 g病土的三角瓶中分别加入25 m L的H_2S和NH_3时,土壤中尖孢镰刀菌的数量均显著下降,其杀菌效果分别为90.3%和100.0%;当在病土中加入0.125%(w/w)氨水时,尖孢镰刀菌、茄劳尔氏菌、辣椒疫霉和立枯丝核菌的数量分别下降至对照土壤的1.0%、0.3%、0.1%和0.9%;此外,加入10μL氨水即可显著抑制尖孢镰刀菌菌丝生长和孢子萌发,抑制率分别为52.8%和100.0%。表明RSD过程中产生的H_2S和NH_3对RSD过程的杀菌效果起着一定的作用。     

烟草青枯病菌在烟草根际的定殖及最适发病条件

为明确烟草青枯病菌在根际的定殖情况和最适发病条件,采用绿色荧光蛋白(gfp)标记病原菌,监测其在根际的定殖位置及数量动态变化,并运用荧光定量PCR法测定病原菌在根际和土体土壤的数量,通过响应曲面法探索病原菌致病的临界浓度、发病最适温湿度以及对烟株青枯病发病的影响。结果表明,从贵州省烟田土壤中分离到烟草青枯病病原菌茄科劳尔氏菌Ralstonia solanacearum,gfp-标记的茄科尔劳尔氏菌主要定殖于根尖和根毛区,少数菌落定殖于初生根的延长区,定殖部分表现为非连续性;第10、15、20天根际土壤的茄科劳尔氏菌数量均显著高于土体土壤数量,分别是土体土壤中的1.15、1.33、1.42倍;当土壤中每克土病原菌数量为106.82 CFU、温度为30.55℃、相对湿度为81.42%以上时,烟草青枯病的病情指数最高为91.13,烟株易发生青枯病。表明茄科尔劳尔氏菌在根际土壤中比土体土壤更易定殖,烟草青枯病发病条件主要取决于病原菌浓度、温度以及相对湿度3项指标。     

Large‐scale assessment of soil erosion using a neuro‐fuzzy model combined with GIS: A case study of Hubei Province,China

Reliable and cost‐effective soil erosion assessment is an important precondition for soil conservation measures, which remains a major challenge at large scale. Considering that the neuro‐fuzzy model has the special advantage in multi‐index comprehensive assessment and GIS technology is adept at geo‐spatial information processing, through the combination of them, it is possible to provide an effective approach for this difficult problem. Taking Hubei Province as a case study area, five evaluating indicators were selected for the large‐scale assessment, in which the GIS technology was used to construct the classification maps of evaluating indicators and to divide basic assessment units, and the neuro‐fuzzy model was adopted to extract fuzzy rules for individual units assessment from available ground truth data. According to the optimized assessment criteria generated by the neuro‐fuzzy model, the soil erosion state of the entire study area was then assessed. To represent the spatial distribution of soil erosion, a detailed map was produced by statistical mapping, which was represented with six erosion levels (from slight to severe) at a map scale of 1:250 000. The resulting map showed that about 30.1% of the total land area in Hubei was affected by different levels of soil erosion problem. Western high mountains and eastern low mountains suffered from the most serious erosion damage, a strong level of soil erosion was widely observed in these mountains. Large areas of moderate level erosion occurred in the northern hills. In contrast, most of the central plains were characterized as slight level erosion effect. The validation indicated that an overall accuracy of 88% and a κ of 0.89 were achieved, proving that the resulting map was in conformity with actual conditions, which indicates this assessment approach was reasonable and applicable. Copyright © 2009 John Wiley & Sons, Ltd.     

Protective effect of Dryopteris crassirhizoma extracts in the control of the root-knot nematode Meloidogyne incognita

Journal of Plant Diseases and Protection - Root-knot nematodes (Meloidogyne spp.) are among the most damaging soilborne plant parasites and are responsible for large economic losses in a wide...     

水稻Os09g29390基因冷胁迫表达模式及亚细胞定位分析

为了研究水稻Os09g29390基因在冷胁迫条件下的功能,以水稻苗期冷胁迫基因表达谱芯片中编码水稻质体蓝素类蛋白(Plastocyanin like protein)的下调表达基因Os09g29390为研究对象,对Os09g29390基因进行冷胁迫下表达特性分析、同源性分析及亚细胞定位分析.结果表明,Os09g29390基因在冷胁迫处理下表现为下调表达模式;氨基酸相似性分析与保守结构域分析显示,Os09g29390基因与其同源基因的氨基酸编码序列具有一个保守的铜结合位点;将Os09g29390基因与增强型绿色荧光蛋白(eGFP)融合,转化烟草原生质体,结果Os09g29390基因定位于细胞叶绿体中.以上结果初步阐明该基因在冷胁迫下的表达特性及作用位点,为以后更深入的研究该基因的功能提供了指导.     

一种快速微量提取橡胶树胚基因组DNA的方法

为了建立一套快速检测橡胶树早期胚基因组变异情况的微量检测体系,需先建立一种快速微量提取橡胶树胚中基因组DNA的方法.运用CTAB改良法、尿素改良法、SDS法分别对1mm3橡胶树早期胚进行基因组DNA提取,并对其DNA进行质量检测和PCR验证.结果表明,尿素改良法的DNA提取率高于SDS法和CTAB改良法;样品的DNA适合PCR检测需要.因此尿素改良法是适宜于微量橡胶树胚基因组DNA提取的理想方法.     

溴虫腈对桑蓟马的毒力及对桑树安全性的研究

于室内采用浸虫法测定溴虫腈对桑蓟马3龄若虫的生物活性。结果表明：24h的毒力值LC50为0．0613mg／L,LC95为0．4538mg/L,杀虫活性高于吡虫啉。室外使用不同剂量的溴虫腈喷洒农桑14号、丰田5号和鲁插2号桑苗,结果溴虫腈对三个品种的生长均没有抑制作用。     

典型草地地上生物量遥感反演模型的建立

利用新疆阿勒泰地区富蕴县2011年9月野外典型草地地上生物量采样数据和同期接收的环境减灾卫星(HJ1A-CCD1)的遥感图像数据,分析了归一化植被指数(NDV)I、比值植被指数(RV)I与实测草地地上生物量的一元线性和非线性回归模型,并对不同回归模型进行分析比较。研究表明:植被指数NDVI与实测草地地上生物量之间存在较好的相关性;所建遥感植被指数与草地地上生物量的回归模型中,指数回归模型(y=3.716e26.758x,R2=0.815)最适合于监测草地地上生物量的遥感反演模型,并分析了该区域地上生物量的空间差异性。     

Micrografting speeds growth and fruiting of protoplast- derived clones of kiwifruit (Actinidia deliciosa)

Protoplast-derived shoots (protoclones) of kiwifruit (Actinidia deliciosa) were cleft grafted directly from in vitro conditions onto mature rootstocks under field conditions on several different dates from June to August in 1987 and 1988. Shoots were taken from culture vessels, prepared for a cleft graft, placed in a cleft on a rootstock, covered with a glass culture tube and sealed with cotton fibres. Other plants were self-rooted in vitro and planted in the field to compare the growth rates and maturity rates of the two plant types.