二化螟人工饲料关键因子的优化及其优化配方的饲养效果

采用5因子4水平正交试验,将作者在以前筛选出的二化螟Chilosuppressalis(Walker)人工饲料的5个关键因子进行了进一步的优化,并得出了二化螟人工饲料的优化配方,其成分如下:稻茎粉18.75g、大豆粉15.00g、麦芽粉15.00g、稻糠粉6.25g、茭白茎粉7.50g、干酪素10.00g、酵母粉18.75g、纤维素7.50g、蔗糖15.00g、葡萄糖7.50g、维生素C7.50g、复合维生素B3.00g、胆固醇0.375g、氯化胆碱0.25g、Beck氏盐2.50g、山梨酸1.35g、琼脂13.49g和自来水809.25g。通过连续3代继代饲养试验,比较了该优化配方和二化螟天然饲料水稻茎的饲养效果。结果表明,在一些关键指标上(如存活率、化蛹率和羽化率等),所优化的二化螟人工饲料配方的饲养效果明显的好于其天然饲料水稻茎的;而在许多其它的指标上(如蛹期、成虫期、产卵量、卵期和孵化率等),该优化配方对二化螟的饲养效果与水稻茎的相当;但该配方饲养的二化螟在第3代时幼虫历期明显的比水稻茎的有所延长。     

辽河流域栽培稻对二化螟(Chilo suppressalis)的抗性

采用活体成株鉴定法测定了辽河流域主栽水稻品种对二化螟发育和为害的影响,同时测定了不同品种的主要形态特性、硅细胞数量和主要生化特性,评价这些品种对二化螟的抗性、分析其发生的可能机制。盐丰47对二化螟幼虫表现出较好的抗性,在沈农265上二化螟幼虫体重最小。在所测定的特性中,螟害株率与不同品种倒二叶叶角的自然对数之间具有显著的正相关关系,与稻茎Si含量之间具有显著的负线性相关关系;二化螟幼虫体重只与不同品种稻茎直径之间具有显著的正线性相关关系．研究结果对水稻品种杭件利用和未来水稻抗件育种的意义。     

东北稻区二化螟越冬幼虫的生物学研究

二化螟Chilosuppressalis是我国东北地区最重要的水稻害虫。连续 3年在东北稻区的二化螟越冬幼虫调查表明 ,在通河和方正两地 (北纬 46°附近 )出现不完全第 2代 ;在东北稻区 ,二化螟幼虫多以高龄幼虫在稻茎内越冬 ( 1 999～ 2 0 0 1年分别占总数的 44 47% ,5 3 47%和 63 48% )。在盘锦、五常、吉林和龙井 4地区的平均高度分别为 8 0 2 ,1 6 2 5 ,1 8 2 9和 2 0 3 4cm。同时 ,在东北稻区的越冬幼虫的头向多朝上 ( 65 74%～ 76 77% )。     

稻纵卷叶螟人工饲料配方的优化研究

应用二次正交旋转组合设计对稻纵卷叶螟Cnaphalocrocis medinalis Guenée人工饲料的配方进行了优化,以化蛹率为目标函数建立了二次回归模型,结果表明稻叶粉、麦胚粉、玉米粉、干酪素、酵母对稻纵卷叶螟幼虫发育与化蛹率影响较大,大豆粉的影响不明显。通过统计寻优获得的优化配方为:每135 g人工饲料中,稻叶粉3 g、麦胚粉8 g、玉米粉4 g、干酪素4 g、酵母粉4 g。在温度27℃,相对湿度80%左右,光照L∶D=16∶8的条件下,使用该优化配方饲养稻纵卷叶螟,25.6%的供试初孵幼虫能完成幼虫发育并化蛹,幼虫期平均26.9 d,蛹重16²2mg。与以前的研究结果比较,化蛹率与蛹重均有显著提高,而幼虫历期略短。     

硅介导的水稻对二化螟幼虫钻蛀行为的影响

采用对二化螟敏感(汕优63)和中抗(盐丰47)的水稻品种,设置硅酸钙处理,观察二化螟蚁螟和三龄幼虫在不同处理稻茎上的钻蛀率、蛀入率和蛀入耗时,同时测定不同处理植株的硅细胞数量及植株与土壤的二氧化硅含量,旨在明确水稻施用硅肥对二化螟幼虫钻蛀行为的影响以及这种影响在不同龄期幼虫和不同抗虫性水稻品种间是否存在差异。蚁螟和三龄幼虫钻蛀率随硅肥施用量增加而降低(幅度为5%—28%)。蚁螟蛀入率在硅肥处理之间和水稻品种之间均没有差异;三龄幼虫蛀入率随硅肥施用量增加而显著下降10%—40%,盐丰47上的蛀入率显著低于汕优63(差异10%—30%)。蚁螟蛀入耗时随硅肥施用量增加而显著延长,三龄幼虫蛀入耗时与品种抗性有显著关系。稻茎硅含量随硅肥施用量增加而增大,并且与三龄幼虫蛀入率呈负相关、与三龄幼虫蛀入耗时呈正相关关系。因此,施用硅肥可直接抑制二化螟幼虫钻蛀,蛀入耗时的延长可间接地延长幼虫暴力于其它防治措施的时间;施用硅肥对三龄幼虫成功蛀入的影响大于对蚁螟的影响;相对于抗虫品种,施用硅肥能在更大程度上增强感虫品种对二化螟幼虫钻蛀行为的抑制作用。     

二化螟与稻纵卷叶螟幼虫取食诱导的水稻挥发物比较

前期研究结果表明,二化螟和稻纵卷叶螟幼虫为害所诱导的水稻挥发物能对二化螟绒茧蜂Apanteles chilonis Munakata、二化螟Chilo suppressalis(Walker)和稻纵卷叶螟Cnaphalocrocis medinalis(Guene)雌成虫的行为产生影响,并且两者的影响效应存在明显差异,但至今仍不清楚2种害虫危害后水稻挥发物的变化情况。利用动态吸附法对健康水稻苗、二化螟或稻纵卷叶螟幼虫为害苗的挥发物进行捕集与鉴定。在3种处理水稻苗中,共捕集到28种挥发物组分,包括萜类化合物、烷烃类化合物、酮类、醇类、水杨酸甲酯和一些未知化合物。二化螟和稻纵卷叶螟为害均能导致水稻挥发物总量和大多挥发物组分释放量的上升;同时,二化螟幼虫危害能诱导水稻新释放2-heptanonol,(E)-linalooloxide和2种未知挥发物组分,稻纵卷叶螟为害则可诱导水稻产生2-heptanonol,(E)-linalooloxide,MeSA和β-caryophyllene4种新化合物。2种虫害稻株间的比较表明,β-caryophyllene和MeSA是稻纵卷叶螟危害水稻后诱导产生的特有挥发物组分,并且linalool,α-copaene,(+)-cedrol,n-heptadecane和n-nonadecane在二化螟为害苗与稻纵卷叶螟为害苗之间差异显著。这一结果也许可以解释2种害虫诱导水稻挥发物对天敌和害虫行为影响不同的原因。     

二化螟越冬代幼虫在稻根外化蛹

我所看到的国内外文献报导,二化螟越冬代幼虫的化蛹部位,都是在稻草(茎稈)和稻根内化蛹。但在实际工作中,还发现有在稻根外部化蛹的。 1964年5月24日,检查二化螟发育进度时,从中晚稻田间拔起的稻根中,发现有两头活蛹,分别紧夹在两丛稻根基部软松的泥土上。其“根外”化蛹占总蛹数     

人工饲料、转Bt水稻及其亲本稻苗饲养下二化螟种群适合度的比较研究

以人工饲料、转Bt水稻"克螟稻"(cry1Ab纯和基因型)及其对照亲本"秀水11"稻苗为供试寄主植物开展二化螟Chilo suppressalis(Walker)1～5龄幼虫的室内饲养试验,以明确不同龄期二化螟种群的生活史参数。试验结果表明:二化螟在低龄时死亡率最高。克螟稻对二化螟各个龄期表现出高抗性,其各个龄期在克螟稻上均不能化蛹,随着龄期的增加二化螟的耐受性增强。以秀水11和人工饲料饲养二化螟对其蛹期、成虫期、单雌产卵量、羽化率的影响无显著性差异,以人工饲料饲养的二化螟蛹重显著高于以秀水11饲养的二化螟的蛹重,蛹重与人工饲料饲养时间呈正相关。与秀水11幼苗相比,人工饲料饲养下有利于二化螟雌虫的分化。     

扬州地区水稻二化螟寄生蜂种类及主要寄生蜂发生动态

本文报道了江苏扬州地区水稻二化螟Chilo suppressalis(Walker)寄生蜂主要有10种,即中华钝唇姬蜂Eriborus sinicus(Holmgren)、二化螟盘绒茧蜂Cotesia chilonis(Munakata)、稻螟小腹茧蜂Microgaster russata Haliday、螟甲腹茧蜂Chelonus munakatae Munakata、中华茧蜂Amyosoma chinensis(Szepligeti)、螟黄足盘绒茧蜂Cotesia flavipes(Cameron)、夹色姬蜂Auberteterus alternecoloratus(Cushman)、桑蟥聚瘤姬蜂Iseropus(Gregopimpla)kuwanae(Viereck)、螟蛉瘤姬蜂Itoplectis naranyae(Ashmead)以及二化螟盘绒茧蜂的重寄生蜂绒茧灿金小蜂Trichomalopsis apanteloctena(Crawford)。田间系统调查表明:扬州地区7-9月水稻二化螟寄生蜂的主要种类为二化螟盘绒茧蜂、中华钝唇姬蜂、螟甲腹茧蜂、稻螟小腹茧蜂、螟蛉瘤姬蜂、桑蟥聚瘤姬蜂,但这些寄生蜂对一代水稻二化螟幼虫的寄生率较低,对二代水稻二化螟幼虫的寄生率高。水稻二化螟越冬期的系统调查表明:扬州地区二化螟越冬幼虫的寄生蜂主要有3种,即二化螟盘绒茧蜂、中华钝唇姬蜂和稻螟小腹茧蜂,其中二化螟盘绒茧蜂和中华钝唇姬蜂是寄生水稻二化螟越冬幼虫的优势种。水稻二化螟越冬幼虫的寄生率调查表明,扬州地区水稻二化螟越冬幼虫的寄生率在不同年份间有一定的波动,但一般都在15%以上,有的甚至高达89.88%,因此寄生蜂对二化螟越冬幼虫具有很好的控制作用,能有效压低来年水稻二化螟的田间越冬基数。此外,3种寄生蜂出茧时间在1月和2月之间达到最长,分别达到19.79 d、17.26 d和27.00 d,该结果表明,在扬州地区这3种寄生蜂可能都存在滞育现象。     

瓜实蝇幼虫人工饲料设计及其优化

采用正交试验设计,对瓜实蝇幼虫人工饲料四种主要组成成分南瓜∶玉米粉=1∶1、酵母粉、蔗糖、苯甲酸钠进行优化筛选,以瓜实蝇幼虫的存活率、幼虫历期、老熟幼虫化蛹率、平均蛹重和羽化率作为试验考察指标,筛选出上述4种成分在瓜实蝇幼虫基础人工饲料中的最优量为南瓜∶玉米粉=200 g∶200 g、酵母60 g、蔗糖15 g、苯甲酸钠1.2 g。     

Comparison of artificial diets for rearing Corcyra cephalonica (Stainton, 1865) (Lep., Pyralidae) for Trichogramma mass production

The objective of this research was, based on biological studies, to determine and adequate diet for rearing Corcyra cephalonica (Stainton, 1865) in the laboratory so as to permit the rearing of this factitious host for Trichogramma mass production. The research was conducted at 25 +/- 1 degrees C, RH 60 +/- 10% and photophase of 14 hours. Six artificial diets were compared: a) whole wheat flour (48.5%), ground rice (48.5%) and sugar (3%); b) ground rice (97%) and sugar (3%); c) whole wheat flour (48.5%), rice flour (48.5%) an sugar (3%); d) whole wheat flour (97%) and yeast (3%); e) wheat germ (97%) and yeast (3%); f) rice bran (94%), sugar (3%) and yeast (3%); f) rice bran (94%), sugar (3%) and yeast (3%). All of the diets studied permitted the development of C. cephalonica although the diets with wheat germ and yeast and that consisting of rice bran, sugar and yeast proved to be the most adequate for rearing the moth. These diets reduced the total (egg-adult) cycle, shortened the egg laying period, and produced heavier adults. Studies on the fertility life tables showed that higher net reproduction rates (Ro) and finite ratio of increase (lambda) were obtained from adults reared on these diets.     

Host suitability of various stored food products for the cigarette beetle, <Emphasis Type="Italic">Lasioderma serricorne</Emphasis> (Coleoptera: Anobiidae)

We investigated the attraction to, and ovipositional activity and egg-to-adult survival rate on, 11 stored products of Lasioderma serricorne (F.). These products included polished rice, unpolished rice, wheat flour, corn flour, cocoa powder, roasted coffee beans, green tea leaves, black tea leaves, soybean flour, flue-cured tobacco leaves, and dried small sardines. Tobacco, cocoa, soybean flour, black tea, and wheat flour significantly attracted the beetles. Corn flour, green tea, and coffee tended to attract the beetles. Ovipositional activity of beetle was higher on the food materials than on nonfood materials. The highest ovipositional activity was observed on coffee, followed by cocoa. Ovipositional activity on black tea, unpolished rice, and green tea was also relatively high. Methanol extracts of coffee beans showed oviposition-stimulatory activity. Therefore, the high ovipositional activity observed on coffee beans could be attributed to oviposition stimulants contained in the beans. In the egg-to-adult survival test, all eggs laid on polished rice or tobacco leaves developed successfully into adults, whereas none of the eggs laid on black tea, green tea, or coffee beans developed into adults. These findings suggest that suitability as an attractive target, suitability as an oviposition site, and suitability as larval food are not always compatible.     

Immunoblotting detection of lectins in gluten and white rice flour

The gluten lectin was isolated by affinity chromatography, separated by sodium dodecyl sulphate-gel electrophoresis together with purified wheat germ agglutinin (WGA) and electrotransferred to nitrocellulose filters. The binding pattern of anti-WGA to the blotted filters confirmed the presence of WGA in gluten. A lectin from rice bran and white rice flour, respectively, was isolated by affinity chromatography. Both lectins reacted with anti-WA in immunoblotting. As patients with coeliac disease are known to tolerate rice flour, the finding of a WGA-like lectin questioned the suggestion that WGA in gluten is involved in the pathogenesis of coeliac disease. A second lectin was also isolated from rice flour which reacted only with antibodies against soybean lectin on immunoblots. This may indicate a contamination of soybean proteins in rice flour.     

Effect of culture substrates on virulence of Beauveria bassiana (Ascomycota: Cordycipitaceae) conidia against the browntail moth,Euproctis chrysorrhoea (Lepidoptera: Lymantriidae)

We studied the effect of different solid substrates on virulence of two Beauveria bassiana isolates against the browntail moth, Euproctis chrysorrhoea (L.) (Lep.: Lymantriidae). Conidia produced on wheat grains, wheat flour, wheat bran, rice flour, rice bran, rice paddy, corn flour, millet, and Sabouraud's dextrose agar with 1% yeast extract (SDAY) as control were compared. There were significant differences among these substrates for their effects on the virulence of produced conidia. Applying 10⁷ conidia/mL of B. bassiana EUT105, produced on rice bran caused the highest (84.9%) and on rice flour, the lowest (57.6%) mortalities. Bioassay on fifth-instar larvae using aerial conidia harvested from wheat grains, rice paddy, and SDAY indicated that conidia from wheat grains had the highest virulence while those from rice paddy, the lowest.     

条形柄锈菌(小麦条锈病菌)侵染结构体外形成的观察

通过荧光显微镜和扫描电镜分别对条形柄锈菌夏孢子在寄主植物-小麦叶表和非寄主植物-水稻叶表以及小麦穗部和茎秆上的萌发过程进行了观察。结果发现,夏孢子在小麦叶片体表萌发产生芽管后,可依次分化形成气孔下囊、初生菌丝与吸器母细胞;在小麦颖片、稃片及茎秆部位表面,同样可观察到病菌在体外分化形成吸器母细胞;并且在水稻叶片上也观察到病菌侵染结构存在体外分化现象。经荧光染色发现,条形柄锈菌在体外与在小麦组织中形成的侵染结构没有明显的差别。观察结果可为条形柄锈菌侵染结构的离体诱导与调控机理研究提供依据。     

Survey of fungal counts and natural occurrence of aflatoxins in Malaysian starch-based foods

In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 103 cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 103 but less than 104 cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 102 cfu/g sample to slightly more than 104 cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69–77.50 μg/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 μ};g/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25–252.50 μg/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00–289.38 μg/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25–436.25 μg/kg. Similarly, positive wheat flour samples were mostly collected from private homes. This revised version was published online in June 2006 with corrections to the Cover Date.     

Fermentative production of dl-lactic acid from amylase-treated rice and wheat brans hydrolyzate by a novel lactic acid bacterium, Lactobacillus sp.

Rice and wheat brans, without additional nutrients and hydrolyzed by alpha-amylase and amyloglucosidase, were fermented to DL-lactic acid using a newly isolated strain of Lactobacillus sp. RKY2. In batch fermentations at 36 degrees C and pH 6, the amount of lactic acid in fermentation broth reached 129 g l(-1) by supplementation of rice bran with whole rice flour. The maximum productivity was 3.1 g lactic acid l(-1) h(-1) in rice bran medium supplemented with whole rice flour or whole wheat flour.     

Hydrophobicity of stored (15, 35 °C), or dry-heated (120 °C) rice flour and deteriorated breadmaking properties baked with these treated rice flour/fresh gluten flour

Rice flour was stored at 15 °C/9 months, at 35 °C/14 days, or dry-heated at 120 °C/20 min. The breadmaking properties baked with this rice flour/fresh gluten flour deteriorated. In addition, the rice flour was mixed with oil in water vigorously, and oil-binding ability was measured. Every rice flour subjected to storage or dry-heated at 120 °C showed higher hydrophobicity, owing to changes in proteins. Then, proteins in the stored rice flour were excluded with NaOH solution, and bread baked with the deproteinized rice flour showed the same breadmaking properties as unstored rice flour/fresh gluten flour. The viscoelasticity of wheat glutenin fraction decreased after the addition of dry-heated rice flour in a mixograph profile. DDD staining increased Lab in color meter, which suggested an increase in SH groups in rice protein. The increase in SH groups caused a reduction in wheat gluten protein resulting in a deterioration of rice bread quality.     

Contents of pollutant and nutrient elements in rice and wheat grown on the neighboring fields

Because of recent agricultural policy to suppress rice production, a rather rare situation occurred in one prefecture in Japan that rice and winter wheat were grown in fields neighboring each other, rice being grown from May to October, and wheat from November to June of the next year. Grains of such rice and wheat were analyzed for cadmium (Cd) and lead (Pb) by atomic absorption spectrometry, and eight nutrient minerals by inductively coupled plasma emission spectrometry. Concentrations of nutrient minerals were higher in wheat grains than in unpolished rice grains (without husk), and similar trends were observed also for Cd and Pb. Flour obtained by milling of the wheat grains had significantly less Cd and nutrient minerals than the mother grains, and such reduction was also observed by treatment of unpolished rice to polished grain. Pb concentration was also reduced by the polishing of rice. Pb in wheat flour appeared to be higher than that in whole grain. Comparisons between the final edible forms of the two cereals showed that K and cu were higher in polished rice than in wheat flour and that such may also be the case for Cd, whereas the reverse was the case for Ca and Fe, and possibly for Pb.