氯虫苯甲酰胺和氟虫腈对黏虫细胞色素P450基因表达的影响

为筛选出黏虫Mythimna separata参与杀虫剂解毒代谢的主效细胞色素P450基因,采用叶片浸渍法测定了用于处理黏虫3龄幼虫的亚致死浓度,通过构建转录组测序文库并结合数字基因表达(digital gene expression,DGE)对不同处理的黏虫进行测序,并运用实时荧光定量PCR(realtime quantitative polymerase chain reaction,RT-qPCR)技术验证12个P450基因的表达情况。结果表明,用于处理黏虫的氯虫苯甲酰胺和氟虫腈亚致死浓度LC_(10)分别为0.15、13.66 mg/L;对照样品、氟虫腈处理样品和氯虫苯甲酰胺处理样品分别获得59 521 504、64 838 148和41 722 990个原始序列数据,分别获得57 441 216、62 368 912和40 285 164个过滤后的序列数据;过滤后的序列长度分别为8.62、9.36和6.04 G;碱基错误率均为0.02%;Phred数值大于20、30的碱基占总碱基的百分比均高于90.59%;鸟嘌呤+胞嘧啶(guanine cytosine,GC)含量分别为47.16%、48.94%和47.55%,表明转录组测序质量较高;黏虫受氯虫苯甲酰胺胁迫后,29个P450基因表达量上调,27个P450基因表达量下调;黏虫受氟虫腈胁迫后,23个P450基因表达量上调,26个P450基因表达量下调;12个P450基因表达量的RT-qPCR技术检测结果与DGE测序文库显示的结果基本一致。     

云南省元阳县籼/粳型稻瘟病菌无毒基因Avr-Pia、Avr-Pita1和Avr-Pii多样性分析

为明确云南省元阳县籼/粳型稻瘟病菌中无毒基因的多样性及差异,采用接种鉴别品种方法和PCR技术对9株粳型菌株和21株籼型菌株中无毒基因Avr-Pia、Avr-Pita1和Avr-Pii的多样性进行分析。结果显示,30株稻瘟病菌菌株中无毒基因Avr-Pia、Avr-Pita1和Avr-Pii的平均出现频率分别为33.3%、76.7%和0,Avr-Pia、Avr-Pita1在籼型菌株和粳型菌株中的出现频率分别为4.8%和100.0%、66.7%和100.0%。Avr-Pia主要为存在/缺失的多样性,籼/粳型菌株对水稻品种Achiasahi(Pia)的致病率分别为100.0%和11.1%;Avr-Pita1可划分为3个类群,除菌株CH1195属于PO类群外,籼型菌株均属于J1类群,粳型菌株则属于J2/J3类群;籼/粳型菌株对水稻品种K1(Pita)的致病率分别为100.0%和0,且籼/粳型菌株Avr-Pita1蛋白序列在第83位和第192位氨基酸差异明显。Avr-Pii在30株稻瘟病菌菌株中均未检出,籼/粳型菌株对水稻品种Fujisaka No. 5(Pii)的致病率分别为100.0%和0。表明Avr-Pia和Avr-Pita1在粳型菌株中的出现频率高于籼型菌株且变异程度低,粳型菌株中可能存在其它无毒基因使其不能侵染Fujisaka No. 5。     

Q型烟粉虱芳香基硫酸酯酶B基因的克隆及表达分析

为明确烟粉虱Bemisia tabaci取食感染番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的番茄植株后,其体内的芳香基硫酸酯酶B基因(arylsulfatase B,ARSB)是否能够做出应答反应,基于Q型烟粉虱基因组数据克隆得到ARSB基因cDNA全长,采用生物信息学方法分析其序列特征,并通过实时荧光定量PCR技术测定ARSB基因在Q型烟粉虱不同发育阶段、不同组织及携带TYLCV前后的表达量变化情况。结果显示:Q型烟粉虱ARSB基因的cDNA全长为1 731 bp,编码576个氨基酸,分子量为64.89 kD,具有ARSB的保守结构域。ARSB基因在Q型烟粉虱不同发育阶段均有表达,在卵期表达量最高,成虫期表达量最低;该基因在Q型烟粉虱头胸部的表达量显著高于腹部;Q型烟粉虱获取TYLCV 72 h后其体内ARSB基因表达量显著提高。表明ARSB基因在Q型烟粉虱不同龄期、不同组织内存在差异表达,并可能参与Q型烟粉虱对TYLCV的响应和传毒过程。     

圆盘切割式蓖麻采摘装置设计与试验

针对现有蓖麻收获装备采摘损失率较高、对低矮植株收获适应性差的问题,该研究结合蓖麻植株的生理特性,设计一种圆盘切割式蓖麻采摘装置。该装置配套于水稻或玉米联合收获机,通过双圆盘刀对蓖麻植株进行切割分离,再经过收割机的清选完成蓖麻收获。通过对装置关键部件的受力及作业原理分析,设计其关键结构参数。并以割茬高度差和采摘损失率为评价指标,以刀盘结构、刀盘转速、前进速度为试验因素进行三因素三水平的正交试验,在保证割茬高度差的前提下,以采摘损失率为主要指标,利用综合平衡法确定较优参数组合。田间验证试验表明：刀盘结构类型为波浪形,刀盘转速为600 r/min,前进速度为1.1 m/s时,平均割茬高度差为0.85 mm、平均采摘损失率为3.13%,切割过程平稳、损失率低,对种植农艺适应性好,满足蓖麻收获的田间作业要求。该研究可为蓖麻收获装备的研究和设计提供参考。     

匹配点云结合HSI色彩分量的无人机RGB影像信息提取方法

无人机通常搭载可见光波段传感器获取红-绿-蓝（Red-Green-Blue,RGB）影像,由于无人机RGB影像波段较少,影像的地物信息提取存在一定难度。该研究提出了一种匹配点云结合色调-饱和度-亮度（Hue-Saturation-Intensity,HSI）空间色彩分量的无人机RGB影像信息提取方法。首先以饱和度分量和红光波段构造了饱和度与红光比值指数,再结合可见光波段差异植被指数以及由匹配点云获得的地形特征对研究区正射影像进行分类。试验结果表明,本文方法的总体分类精度达到了91.11%,Kappa系数为0.895,证明匹配点云结合HSI空间色彩分量的方法提取无人机RGB影像信息是可行的,提取结果具有较高精度。相较于基于光谱特征的传统方法,本文方法引入匹配点云可以简单高效地提取影像中高程差异明显的地物,同时,结合HSI色彩分量能够有效弥补无人机RGB影像光谱特征较少的不足。     

晚春造林技术研究

通过简单易行而有效的技术措施,成功试验且规模推广晚春造林技术,解决了当地春季火烧迹地更新造林季节脱节的矛盾。     

水丰水库渔获变化和鱼类资源现状及小型经济鱼虾种间关系分析

水丰水库的渔获量1961－1980年间变化于47－300t,1981-1984年增长到740－1321t,1985-2000年为2270－4926t。渔获物组成中以亚洲公鱼为主，1980－2000年亚洲蚣鱼占总渔获的29．6％－93．0％，平均为65．6％。鲁鲫鱼占6．2％－16．4％，鲢鳙鱼占8．1％－13．3％，鳊鲂占1．8％－11．3％，虾占5．9％－16．1％，其它鱼类占2．4％－9．3％。2000年大银鱼占总渔获的2．8％。1985－2000年水库鱼类资源相对稳定。亚洲公鱼、青虾和大银鱼三种小型经济鱼虾的种间关系表现为互利共生，竞争和残敌关系，可能向种间形成平衡调节方向发展。     

Effects of genetically modified and non‐genetically modified soybeans with different heat treatments on growth and health of Cyprinidae species with different feeding habits

An 8‐week growth trial was conducted to investigate the effects of non‐genetically modified (nGM) soybean (Youchun 06‐1) and genetically modified (GM) soybean (Roundup Ready^®) with and without a heat treatment on the growth and health of three Cyprinidae species with different feeding habits (grass carp Ctenopharyngodon idellus, gibel carp Carassius auratus gibelio, and black carp Mylopharyngodon piceus; body weight: 283.0 ± 2.0 g, 60.5 ± 0.7 g, and 261.4 ± 3.1 g). Five diets (FM, nGMS, hnGMS, GMS, and hGMS) were made with fishmeal and full‐fat soybean (Youchun 06‐1, heat‐treated Youchun 06‐1, Roundup Ready^®, and heat‐treated Roundup Ready^®). The FM diet contained fishmeal as the sole protein source. The experimental diets contained full‐fat soybean meal as 60% of dietary protein. Both temperature (60, 80, 100, and 120°C) and duration (1 and 2 hr) of heating influenced trypsin inhibitor activity (TIA) and protein solubility of nGM soybean and GM soybean. The TIA in GM soybean was higher than that in nGM soybean. After heating at 120°C for 2 hr, each amino acid of soybean treatment showed a slight decline. Neither source of soybean nor heat treatment affected the growth performance, feed utilization, chemical composition of the whole fish body and muscle, and lipase or amylase activity of the three Cyprinidae species (p > 0.05). Heat treatment of soybean meal slightly increased the plasma antioxidant capacity of the three fish and plasma cholecystokinin of black carp and grass carp. The unheated soybean treatment adversely affected the height and density of black carp intestinal villi, and all the soybean treatments caused disruption of the grass carp intestinal epithelium.     

Effect of Chitosan on Intestinal Bacteria of Allogynogenetic Crucian Carp,Carassius auratus gibelio,as Depicted by polymerase chain reaction‐denaturing Gradient Gel Electrophoresis

A 16S rDNA‐based polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE) method was applied to detect intestinal bacterial communities of juvenile allogynogenetic crucian carp, Carassius auratus gibelio, fed with chitosan‐containing diet. This is the first time to use the molecular method to analyze the bacterial communities in the allogynogenetic crucian carp intestine. The DGGE profile with universal bacterial primers revealed simple communities in all treatment groups. Sequencing and phylogenetic analysis of excised DGGE bands showed that the dominant bacteria belonged to class γ‐Proteobacteria and Fusobacteria. The relative abundance and diversity of detected bacteria suggested that 0.5 and 0.75% of chitosan in diet were optimum for juvenile allogynogenetic crucian carp. As in these concentrations, some detected pathogen bacteria either disappeared or decreased. However, the DGGE profile with Aeromonas‐specific primers showed a similar composition among all treatment groups, which suggested that Aeromonas was one of relative stable bacteria components in the intestine of juvenile allogynogenetic crucian carp.     

Effect of intermittent starvation on growth and some antioxidant indexes of Macrobrachium nipponense (De Haan)

The effect of different periods of starvation (0, 2, 4 and 8 days) followed by re-feeding on growth, feed utilization, oxygen consumption and some immune indexes [reactive oxygen intermediates (ROIs), activities of superoxide dismutase (SOD) and catalase (CAT)] was evaluated over an 18-day experimental period in shrimp Macrobrachium nipponense (De Haan) that had an initial body weight of 0.52 g. As a result of compensatory growth, indicated by an increase in specific growth rate (SGR), feeding rate (FR) and feed conversion efficiency (FCE) after re-feeding, final body weight of shrimp starved for 2 days (0.63 g) and 4 days (0.65 g) did not differ ( P >0.05) from the control group (0.64 g), with feed withholding for 8 days presenting a significant lower value (0.63 g). Oxygen consumption rate (OCR) decreased during the starvation period in all groups, followed by a gradual increase to a similar ( P >0.05) value than found in the control group (0.47 mg kg⁻¹ h⁻¹) at the end of the experiment. Although ROIs and the activity of SOD and CAT fluctuated during starvation in the feed-deprived groups, values at the termination of the experiment were comparable ( P >0.05) to those found for the control group.