1999年东北稻区北部二化螟出现不完全第二代

1999年 9月 2 6日至 1 0月 1 1日 ,水稻收获季节 ,作者在黑龙江省五常市及通河县进行大面积调查 ,在稻杆中发现大量二化螟 Chilosuppressalis(Walker)的 3～龄幼虫及蛹壳 ,其中在五常市的调查结果为 :有幼虫株率1 0 .8% ,有蛹壳株率为 4.9%。按幼虫历期推算 ,调查时 3～ 4龄幼虫应当是由 8月下旬到 9月上旬的成虫所产的卵块孵化而来 ,这些成虫应属第 1代 ,从而表明以上地区今年出现了二化螟不完全第 2代。1 999年夏季我国东北稻区气温较常年偏高 ,高温持续时间较长 ,如黑龙江省五常市和通河县出现 3 0℃的高温 ,比常年高 1～ 2℃ ,前后达 2…     

利用茭白、荸荠及水稻饲养二化螟的技术研究

分别用水稻苗、茭白、水稻 +荸荠 3种方法 ,喂饲二化螟Chilosupperssalis初孵幼虫 ,比较室内 3种饲养方法对二化螟生长发育和繁殖力的影响 ,从而为二化螟的实验室饲养提供方法和依据。其中 ,在整个幼虫期用茭白饲养的二化螟幼虫发育历期和化蛹历期最短 ,分别为 ( 1 7 8± 0 5 )d和 ( 9 8± 0 8)d ,而用水稻苗饲养的二化螟幼虫发育历期和化蛹历期最长 ,分别为 ( 3 0 4± 1 2 )d和 ( 2 0 0± 1 6)d。水稻苗喂饲二化螟的雌雄蛹的比例较低 ,仅为 0 44;荸荠有利于雌性个体的分化 ,用水稻 +荸荠相结合喂饲二化螟的雌雄蛹比例为 1 1 8。用荸荠喂饲的蛹最重 (雌和雄蛹重分别为 71和 5 1mg 头 )。 3种饲养方法对二化螟的产卵率和孵化率无显著影响 ,但是 ,用水稻饲养二化螟蛹的羽化率比其它 2种饲养方法显著降低。由此可见 ,用茭白、水稻苗 +荸荠饲养方法进行二化螟饲养是切实可行的 ,它们有利于二化螟的生长发育。     

二化螟越冬幼虫三种寄生蜂发生动态

本文报道浙江部分地区二化螟Chilo suppressalis越冬幼虫寄生蜂的主要种类、寄生率以及它们在冬前与冬后的羽化动态.在兰溪,寄生蜂对二化螟越冬幼虫的寄生率较低,常见种类仅有二化螟绒茧蜂.在安吉与嘉兴两地,除二化螟绒茧蜂为主外,稻螟小腹茧蜂和中华钝唇姬蜂也较为常见,三者对双季晚稻田二化螟越冬幼虫寄生率为18～19%.明显高于单季晚稻田的寄生率(8～15%).3种寄生蜂的羽化动态有较大差异,二化螟绒茧蜂和稻螟小腹茧蜂在进入11月后即不再羽化,而中华钝唇姬蜂的羽化则持续到11月中旬之后;越冬后,后者的羽化时间明显早于前两者.     

麦红吸浆虫幼虫脂肪酸变化的分析测定(英文)

采用气相色谱法测定了不同时期麦红吸浆虫Sitodiplosismosellana (Gehin)幼虫脂肪酸的变化。结果表明 :幼虫脂肪酸组分有 1 0～ 1 6种 ,其中主要以棕榈酸 (C1 6:0 )、油酸 (C1 8:1 )和亚油酸 (C1 8:2 ) 3种组分为主 ,占全部脂肪酸总量的 95 %以上 ;其次是硬脂酸 (C1 8:0 )含量较高 ,约占 2 %～ 3 .5 % ;其它组分脂肪酸含量很少 ,均在 1 %以下。从 5月中下旬麦红吸浆虫幼虫离穗入土进入越夏至翌年 4月化蛹羽化前 ,脂肪酸组分表现了由少到多的变化趋势。越夏、越冬幼虫及越冬后未进入活动状态的圆茧其脂肪酸组分中不含花生酸 (C2 0 :0 ) ,而且饱和脂肪酸含量明显少于越冬后进入活动状态的幼虫和麦穗幼虫 ;而越冬后进入活动状态的幼虫和麦穗幼虫脂肪酸组分中含有一定量的花生酸 ,不饱和脂肪酸含量明显少于越夏、越冬幼虫及越冬后未进入活动状态的圆茧 ,故花生酸的有无及饱和脂肪酸与不饱和脂肪酸含量的比例变化可作为判断麦红吸浆虫幼虫活动状态 ,特别是滞育不同深度的生化指标之一     

高粱条螟在湘北地区的发生动态

用越冬幼虫及其后代研究了高粱条螟Procerasvenosatus (Walker)的年生活史和未成熟的发育分级特征。结果表明 :卵、幼虫、蛹分级分龄选用的特征比较明显、稳定 ;高粱条螟在湘北地区为兼性滞育昆虫 ,幼虫既能以滞育方式越冬、越夏 ,也能以滞育方式越冬连越夏或者越夏连越冬 ,每年发生 1～ 2代 ;各虫态历期为 :成虫产卵前期 2～ 3d ,卵期 7～ 1 0d ;1龄幼虫期 2～ 3d,2龄 6～ 7d ,3龄 5～ 7d,4龄 9～ 1 1d ,5龄 8～ 1 0d ,6龄 1 1～ 1 2d ,蛹期 9～ 1 1d。     

台湾稻螟越冬习性与冬季防治研究简报

一、越冬习性考查 1.越冬场所调查:台湾稻螟Chilotraea auricilia(Dudgeon)幼虫越冬场所主要是在稻根内,几年来的田间调查资料指出:以中稻田稻根内密度较大;晚稻田稻根内密度较小。此外,中、晚稻稻草内也有幼虫越冬,但密度很小,约占0.06％株。作者曾先后在百色专区的百色、田东、靖西、睦边、东兰、田林等县实地解剖观察高粱稈、玉米稈、小米稈、甘蔗宿根等均尚来发现有越冬幼虫。 2.虫口密度与稻田的关系:1)与稻田耕作制度有关。中稻田台湾稻螟越冬幼虫最多,每苗平均有效越冬幼虫4,745头,占4种稻螟总数的37.5％,二化螟次之,占30.39％,大螟较少,占25.2％,三化螟最少,占6.88％。晚稻田台湾稻螟越冬幼虫较少,每亩平均有效越冬幼虫540头,占4种稻螟总数的14.06％,二化螟也少,占13.14％,大螟最少,占     

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。     

茶黑刺粉虱蛹和卵的发育分级及与其防治适期的相关性

20 0 0年 4～ 6月 ,每 5日在皖南黑刺粉虱Aleurocanthusspiniferus(Quaintance)常发茶园中以平行跳跃法选 5 0个样方。每样方为 1m茶行 ,查其上、中、下层各 2片成叶上各虫态粉虱的数量 ;采回 2 0 0头蛹于立体显微镜下解剖。越冬代蛹期 32～ 38d。据蛹体形态和颜色的显著变化而分为 4级 :体液乳白色( 1 2～ 1 4d)、体液淡黄色 ( 6～ 8d)、体液橙红色 ( 1 1～ 1 2d)和体液淡紫色阶段 ( 3～ 4d)。引入该粉虱于盆载茶苗上 ,观察其生物学习性。第 1代卵期 2 2～ 2 8d ,据卵颜色的显著变化分为 4级 :乳白色 ( 2～ 4d)、淡黄色 ( 2～ 3d)、橙红色 ( 1 5～ 1 7d)和紫黑色阶段 ( 3～ 4d)。第 1代幼虫期 2 5～ 2 8d ,其中 1龄 9～ 1 2d ,2龄 9d ,3龄 7d ,蛹期 7～ 8d。越冬代成虫盛期和第 1代 1龄盛期为防治适期 ,可较好地用蛹或卵的分龄分级法预测。越冬代蛹全部羽化之时 ,又恰是 1龄幼虫盛期 ,易于掌握     

我国稻螟灾害的现状及损失估计

我国稻螟为害的确切记载始于 1 0 2 2年。 2 0世纪 5 0年代中期以前 ,以二化螟Chilosuppressalis(Walker)为害为主。此后十几年中 ,三化螟Tryporyzaincertulas(Walker)普遍大发生。 70年代 ,我国螟害轻微。 1 993年 ,二化螟急剧回升 ,三化螟也随之回升。 1 996年 2种稻螟大发生 ,此后连年暴发成灾。目前我国螟灾的主要特点是虫口密度高、受害范围广、受害程度重、持续时间长、经济损失大。首要螟灾区是沿江稻区 ,二化螟和三化螟分别约占 2 3和 1 3。全国年发面积约 1 5 0 0万hm2 ,防治约 3 80 0万hm2 次。该文首次估计年防治代价约 45 7～ 60亿元 ,残虫造成作物损失近 65亿元 ,总经济损失约 1 1 5亿元。由此可见 ,当前稻螟已取代稻飞虱、棉铃虫成为影响我国国计民生的头号害虫。     

月相对两种稻螟灯下诱蛾量的影响

经圆形统计分析安徽省庐江县 1 962～ 2 0 0 1年灯光诱蛾资料 ,发现三化螟和二化螟的诱蛾量受到月相的显著影响。诱蛾量的平均角或集中趋势 ,三化螟对应于农历月 2 7日 1 0时 1 3分 (P <0 0 0 1 ) ,二化螟对应于 2 4日 1 6时 2 2分 (P <0 0 0 1 )。两种稻螟诱蛾量的集中时间差异不显著 (P >0 0 5 )。二者合并 ,得到平均集中时间为 2 5日 1 4时 40分。     

Origin,dispersal, cultivation and variation of rice

There are two cultivated and twenty-one wild species of genus Oryza. O. sativa, the Asian cultivated rice is grown all over the world. The African cultivated rice, O. glaberrima is grown on a small scale in West Africa. The genus Oryza probably originated about 130 million years ago in Gondwanaland and different species got distributed into different continents with the breakup of Gondwanaland. The cultivated species originated from a common ancestor with AA genome. Perennial and annual ancestors of O. sativa are O. rufipogon and O. nivara and those of O. glaberrima are O. longistaminata/, O. breviligulata and O. glaberrima probably domesticated in Niger river delta. Varieties of O. sativa are classified into six groups on the basis of genetic affinity. Widely known indica rices correspond to group I and japonicas to group VI. The so called javanica rices also belong to group VI and are designated as tropical japonicas in contrast to temperate japonicas grown in temperate climate. Indica and japonica rices had a polyphyletic origin. Indicas were probably domesticated in the foothills of Himalayas in Eastern India and japonicas somewhere in South China. The indica rices dispersed throughout the tropics and subtropics from India. The japonica rices moved northward from South China and became the temperate ecotype. They also moved southward to Southeast Asia and from there to West Africa and Brazil and became tropical ecotype. Rice is now grown between 55°N and 36°S latitudes. It is grown under diverse growing conditions such as irrigated, rainfed lowland, rainfed upland and floodprone ecosystems. Human selection and adaptation to diverse environments has resulted in numerous cultivars. It is estimated that about 120000 varieties of rice exist in the world. After the establishment of International Rice Research Institute in 1960, rice varietal improvement was intensified and high yielding varieties were developed. These varieties are now planted to 70% of world's riceland. Rice production doubled between 1966 and 1990 due to large scale adoption of these improved varieties. Rice production must increase by 60% by 2025 to feed the additional rice consumers. New tools of molecular and cellular biology such as anther culture, molecular marker aided selection and genetic engineering will play increasing role in rice improvement.     

Cadmium,copper, and zinc levels in the rice and rice field soil of Houston,Texas

Fifty-one pairs of hulled rice samples and the soil from which each rice sample was grown were analyzed for heavy metals in August, 1979, in order to estimate the background contamination of cadmium (Cd), copper (Cu), and zinc (Zn) in rice grown in the Houston, Texas area. Both samples were divided into three groups by soil types and colors. The cadmium concentration in Texas rice was only one-half to one-quarter lower than that of Asian rice. However, the levels of Cu and Zn in rice in Texas were similar to those reported. Soil heavy metals were lower than ever reported, but these values were consistent with the geochemical characteristics of the Texas Houston area. No particular relationship was found between the three metals in rice and the metals in soil where the sampled rice was grown.     

Arsenic tolerance, uptake and translocation by seedlings of three rice cultivars

By simulating the anaerobic conditions with agar nutrient solutions, effect of arsenic (As) on the growth and As uptake by hybrid, conventional and glutinous rice cultivars were studied. It showed insignificant effect of As on the root dry weights of three rice cultivars when treated by As of different concentrations. The shoot dry weights of hybrid and glutinous decreased with As concentrations increasing, while low concentrations of As (0.5 mg L^?1) could enhance the growth of conventional rice. Generally, As concentrations in roots and shoots increased as As concentrations of treatment solutions increasing. The root system had strong ability to uptake and accumulate As. The root As concentrations ranged from 156 to 504 mg kg^?1, representing 63.40%–81.90% of the total As concentrations in rice, which were much higher than shoot As concentrations. The fact that the glutinous rice had higher biomass, higher tolerance, and lower As concentrations in its roots and shoots than the other two rice cultivars proved that the glutinous rice was more applicable to As-polluted soils.     

The Magnaporthe grisea snodprot1 homolog, MSP1, is required for virulence

Secreted proteins play central roles in plant-microbe interactions acting as signals, toxins, and effectors. One important group of small secreted proteins is the snodprot1 family, members of which have demonstrated phytotoxic properties. A split-marker transformation system was applied for gene deletion of the snodprot1 homolog, MSP1, in the rice blast fungus Magnaporthe grisea. msp1 mutants were phenotypically indistinguishable from wild type and elaborated apparently normal appressoria. However, the deletion mutants were greatly reduced in virulence primarily due to impaired growth in planta. Western blot analysis showed that the protein was secreted and not associated with the fungal cell wall. When purified MSP1 protein was applied to wounded leaf tissue, no apparent phytotoxic effects were noted. This is the first report to the authors' knowledge that directly implicates a snodprot1 protein as a virulence factor.     

不同水稻品系幼苗对砷（As）的耐性、吸收及转运

利用琼脂培养基模拟水稻生长的厌氧环境,研究了As对不同水稻品系幼苗生长的影响以及As在其体内的积累及转运特性.结果表明,不同浓度(0～4.0mg/L)的As对供试水稻品系根部干物质积累无显著影响(P>0.05).杂交稻与糯稻的地上部干物质积累随基质中As浓度的增加呈减小趋势,但低剂量的As(0.5mg/L)促进常规稻的生长.水稻地上部的As积累量随基质中As浓度的升高总体均呈增加趋势.水稻根系对As具有较强的吸收与累积能力.水稻根部As的积累量为156.31～504 03mg/kg,占总As含量的63.40～81.90%,远远高于其地上部As的积累量.相比于其它两个品系,糯稻的生物量积累高,耐性指数较大,根部及地上部对As的积累量较低,因此更适合种植在As污染土壤.     

gid1, a gibberellin-insensitive dwarf mutant, shows altered regulation of probenazole-inducible protein (PBZ1) in response to cold stress and pathogen attack

A recessive gibberellin (GA)-insensitive dwarf mutant of rice, gibberellin-insensitive dwarf1 (gid1), has been identified, which shows a severe dwarf phenotype and contains high concentrations of endogenous GA. To elucidate the function of gid1, proteins regulated downstream of gid1 were analysed using a proteomic approach. Proteins extracted from suspension-cultured cells of gid1 and its wild type were separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Of a total of 962 proteins identified from the suspension-cultured cells, 16 were increased and 14 were decreased in gid1 compared with its wild type. Among the proteins hyper-accumulated in gid1 were osmotin, triosephosphate isomerase, probenazole inducible protein (PBZ1) and pathogenesis-related protein 10. Of these four genes, only the expression of PBZ1 was increased by exogenous GA3 application. Expression of this gene was also enhanced in shoots of the wild type by cold stress or by rice blast fungus infection. Under normal growth conditions, there was more PBZ1 protein in gid1 than in the wild type. In addition, gid1 showed increased tolerance to cold stress and resistance to blast fungus infection. The entcopalyl diphosphate synthase (OsCPS) genes, which encode enzymes at the branch point between GA and phytoalexin biosynthesis, were expressed differentially in gid1 relative to the wild type. Specifically, OsCPS1, which encodes an enzyme in the GA biosynthesis pathway, was down-regulated and OsCPS2 and OsCPS4, which encode enzymes in phytoalexin biosynthesis, were up-regulated in gid1. These results suggest that the expression of PBZ1 is regulated by GA signalling and stress stimuli, and that gid1 is involved in tolerance to cold stress and resistance to blast fungus.     

Potential pathogenicity of Cladosporium tennuisimum,Phaeoisaria clematidis and Ramichloridium subulatum in a mouse model

In Sri Lanka, rice is the main staple which is mostly processed into parboiled rice. The levels of aflatoxin B₁ (AFB₁) and aflatoxin G₁ (AFG₁) in parboiled and raw milled rice collected from major rice producing areas and rice consuming townships were estimated. In almost all the samples of parboiled rice examined, the AFB₁ and AFG₁ contents were significantly higher than in raw milled rice. The highest AFB₁ content was 185 µg/kg and AFG₁ content 963 g/kg. These samples were collected from a major rice producing/milling district where the mean relative humidity is 78% and mean annual temperature 27 °C which is the highest amongst the rice growing areas in Sri Lanka. Raw rice was either free of aflatoxins or when toxins were detected, they occurred in less than 10% of the samples. The frequency of occurrence of surface fungal flora (Aspergillus/Penicillium) and aflatoxin content in market samples was closely related. Brownish or greenish moldy rice samples with fermented odour contained over 1000 g/kg of AFB₁.     

Pathogenicity of the rice root nematode,Hirschmanniella oryzae to rice plants in relation to nematode reproduction,plant growth,grain yield and biochemical changes

Influence of different inoculum levels of 0, 10, 100, 1000 and 10,000 individuals of Hirschmanniella oryzae on nematode reproduction and plant growth of rice cv. Giza171 and biochemical changes of infected plants was studied under screen-house conditions. Rate of nematode build up (P_f/P_i) was negatively correlated with the progressive increase in nematode inoculum levels. The percentage reduction in growth parameters, rice grain yield and the amount of total and reducing sugars were markedly affected showing a negative correlation with the tested inocula. The conspicuous reductions of plant growth, yield and total and reducing sugar contents were obtained by using 1000 and 10,000 nematodes per pot. The inoculum level of 1000 nematodes per pot was identified as critical population at which control programme must be started.     

Isolation,purification and characterization of adenosine triphosphatase from mitochondria of rice seedlings

A new and improved procedure is described for the isolation and purification of adenosine triphosphatase (F₁ ATPase) from rice seedling mitochondria. The enzyme has a multi-subunit structure, as revealed by electron microscopy and SDS-mercaptoethanol gel electrophoresis. Oligomycin sensitivity as well as cold lability of this enzyme clearly prove that the mitochondria of monocotyledons have an ATPase similar to the F₁ ATPases from other sources.