棉小造桥虫的初步研究

棉小造桥虫(Anomis flava F.)是棉花蕾铃期暴食性害虫之一。近年来随着棉田面积的扩大和雨量的增加,棉小造桥虫发生也随之扩展。现将研究结果报导如下。     

江苏沿江棉区3代棉铃虫对棉花的为害及经济阈值

通过人工接虫为害,研究了3代棉铃虫对蕾铃脱落及结铃的影响,观察了不同年份棉铃虫卵和各龄幼虫的自然存活率及棉花蕾、幼铃的成铃率。结果表明,蕾铃的虫害脱落率对结铃的影响最大,直接通径系数达－0.8917,虫量和蕾铃脱落数主要通过接虫期间的虫害脱落率影响棉花结铃,其间接通径系数分别为－0.8894和-0.891,接虫期间的自然脱落率对结铃的直接和间接通径系数均很小,表明33代棉铃虫为害时棉花4的补偿能力已基本丧失,各龄幼虫的为害量观察表明,1－6龄幼虫的单虫为害当量分别为0.02、0.14、0.31、0.47、0.84和1.54个大铃,根据防治的直接和间接收益,得出3代棉铃虫的防治指标为百株累计卵量26粒。     

蕾铃期繁殖器官的损失对棉花产量的影响——人工模拟为害试验

1994、1995连续两年在华北棉区第3代棉铃虫发生期间,通过一系列人工摘蕾模拟为害和人工接虫为害试验,研究了棉花对蕾铃期繁殖器官损失的补偿效应。试验结果表明：蕾、铃被害会诱导棉株产生补偿效应,即提高结铃数,增加生物产量。但棉花的补偿效应是有限的,蕾铃期单株被害蕾超过12个,被害铃超过4个,或被害超过2蕾2铃,都会导致皮棉显著减产。通过数学模型分析,1994年,单株被害0-11．80个蕾或0—2．26个铃都不会造成减产;1995年．单株损失0—10．58个蕾或0—3．8个铃,同样不会降低棉花产量。模型中各决策变量的边际产量表明,棉花蕾铃期铃的损失对皮棉产量的影响最大。     

两种棉花新象虫

本文记述了两种棉花象虫。依据棉区昆虫工作人员的观察,棉尖象Phytoscaphusgossypii(新种)为害幼苗,能咬断嫩尖,影响棉苗正常发育。它也为害蕾铃期的叶片、苞叶、嫩尖、花蕾等部分。除棉花外,此虫还为害玉米、大豆、大麻等作物的幼苗。它发生于关中、华北、苏北、内蒙古、甘肃等地区。 棉小卵象Calomycterus obconicus(新种)就是刘国士、范秉法1934年报道过的棉小象鼻虫Calomycterus sp.。据他俩的观察,此虫主要为害幼苗,能咬断叶柄,蚕食落叶,有时竟把整块棉田的幼苗、叶片全部咬断,仅剩下顶芽。其为害程度可想而知。在幼苗生出前,它为害桑树嫩芽,所以桑园附近的棉田先受其害。此虫分布于江苏南部和浙江北部,即太湖周围。其危害早在1934年前便引起人们的注意,并由刘国士、范秉法报道了对其生活史的研究。     

棉花生育时期及蕾铃发生发育模拟模型研究

通过定量分析南京、安阳、保定和石河子4个试验点2002年不同播期3个品种(早熟品种中棉所36号、中早熟品种中棉所35号、中熟品种中棉所41号)的生育时期与环境因子之间的动态关系,建立了基于生理发育时间(DPT)的棉花生育期、果枝出现时间及其蕾铃发育阶段的模拟模型.模型的热效应计算考虑了不同棉区昼夜温较差对棉花发育速率的影响以及薄膜覆盖的增温效应,在模型中引入了果枝始节系数(I_FIN)、日照时数因子(F_SH)和果枝节位光照系数(I_FBR).利用不同年份、生态区、基因型的试验资料对模型进行了测试检验.结果表明,不同条件下模拟值与观测值的符合度较好.不同生育时期的模拟值与观测值的根均方差(RMSE)从播种到出苗、出苗到现蕾、开花到吐絮及播种到吐絮分别为0.9、2.2、17和2.1d,平均2.1d;棉株各果节点从现蕾到开花日期的模拟值与观测值的RMSE为1.8～3.7d,从开花到吐絮日期的RMSE值为4.6～5.8d.     

关于棉花落蕾落铃问题的初步报告

概言在党的总路线光辉照耀下,农民群众鼓足干劲,积极钻研,减少了棉花蕾铃的脱落,取得了史无前例的大丰收。今年,在7省14个县和1市对棉花丰产的调研,我们认为:棉花蕾铃的生理脱落是由于营养生长和生殖生长发生了矛盾,通过有机养料不平衡分配而引起。棉株蕾铃脱落的主要类型有二:     

苏北沿海垦区三代棉铃虫卵峰日的预测

<正> 三代棉铃虫Helithis armigera Hübner发生期正值棉花蕾铃生长盛期,若防治不适,则引起蕾铃脱落,直接影响棉花产量。而三代棉铃虫卵峰日年度间差异较大,经验预报准确率往往不高。做好三代棉铃虫卵峰日的预测,对于掌握有利时机,科学防治三代棉铃虫有实际的指导意义。本文根据我场历年的资料,应用条件频率法,对我场三代棉铃虫卵峰日进行了预测研究,现介绍如下。     

飞机喷药防治棉花蕾铃期害虫效果初步研究

近年来使用飞机喷药防治棉花害虫已取得了一些成绩。所用农药一般为单纯DDT。1960年江西九江市曾将DDT和敌百虫混用。但我们在湖北黄梅县使用过程中发现单纯使用25％DDT乳剂对棉叶跳虫效果不稳定;DDT和敌百虫混用因敌百虫价高,增加成本。棉花蕾铃期害虫种类很多,为解决“一药多治”和防治适期,我们在1960年在湖北黄梅县结合飞机治虫作了一些试验研究,并在生产上进行应用。现将初步结果介绍如下,以供参考。 一、室内药效测定结果 在飞机喷药后于当天摘回棉叶放在培养皿或马灯罩内饲养斜纹夜蛾幼虫,并接种羽化后1—2天的红铃虫、金钢钻的雌雄成虫。以未经喷药的棉叶作为对照。结果如表1、2。     

转Cry1Ac+Cry2Ab基因棉对棉蚜生命表参数及种群动态的影响

为研究新型转Cry1Ac+Cry2Ab基因棉对棉蚜Aphis gossypii Glover生命表参数及种群动态的影响。2010—2011年以常规棉中棉所49为对照,对新型转Cry1Ac+Cry2Ab基因棉在室内进行了生物测定和田间进行了系统的调查。结果表明,和常规棉相比,转Cry1Ac+Cry2Ab基因棉花上棉蚜的净增值率降低81.69%,差异达显著水平;内禀增长率和周限增长率分别降低65.00%和13.01%,但差异不显著;平均世代周期和种群加倍时间分别增加5.54%和154.19%,后者差异达显著水平。和常规棉相比,2010年转Cry1Ac+Cry2Ab基因棉花百株苗蚜、伏蚜和秋蚜的数量分别降低10.79%、37.18%和17.49%,差异均未达显著水平;2011年转Cry1Ac+Cry2Ab基因棉花百株苗蚜的数量增加2.03%,伏蚜和秋蚜的数量分别降低37.41%和64.03%,差异均未达显著水平。     

转基因棉对土耳其斯坦叶螨生命参数的影响

为了研究转基因棉花对北疆叶螨优势种土耳其斯坦叶螨Tetranychus turkestani(Ugarov et Nikolskii)种群生命参数的影响,本实验以常规棉中棉49作为对照,构建了叶螨在单价转基因棉新棉33B(Bt)、双价转基因棉中棉41(Bt+CpTI)上的室内种群生命表。结果表明,单双价转基因棉对叶螨的生长发育历期及生殖参数并没有明显影响;且取食常规棉的叶螨种群参数净生殖率、内禀增长率、平均世代周期、种群加倍时间、周限增长率、存活曲线也与单双价棉无显著差异,这说明转基因棉对棉叶螨的生长发育、繁殖及种群增长并无显著影响。     

Photosporogenesis of Coprinus congregatus: Correlations between the physiological age of lamellae and the development of their potential for renewed fruiting

When the hymenial lamellae of Coprinus congregatus Bull ex Fr. are used as implants, their potential for renewed fruiting varies according to the photocontrolled meiosis and the consecutive sporogenesis. In the case of young lamellae, whose basidia are still at the dikaryon stage, one can observe immediate start of mycelial growth all around the lamellae and production of the first mature sporophores directly on the lamellae (direct fruiting). Simultaneously, meiosis does not occur in hymenial cells. Conversely, in the case of implantation of the oldest lamellae, whose basidia are characterized by meiotic nuclei beyond prophase 1 and rather near telophase 2 (tetranucleate stage), vegetative growth starts slowly and the first mature sporophores are not produced on the lamellae but on the surrounding vegetative mycelium (indirect fruiting). When the lamellae are isolated from photoindifferent primordia – for instance, 12 h before maturity – sporogenesis in hymenial cells proceeds normally until autolysis of the isolated lamellae. Such isolated lamellae no longer show direct fruiting where the first flush is concerned.     

苗期遮荫对棉花产量与品质形成的影响

为揭示棉麦两熟共生期遮荫对棉花产量与品质形成的影响。在棉花苗期利用模拟棉麦两熟共生期遮荫的方法进行了研究。结果表明,遮荫对棉铃形成的影响因果枝,果节部位而异,遮荫有利于棉株下（1-3果枝）,中（4-6果枝）,上（7-9果枝）部果枝内围（1-2果节）铃的形成,对外围（≥3果节）尤其顶部果枝（≥10果枝）外围铃形成不利,从而决定铃重也随果枝,果节部位相应地变化,但遮荫对单株平均铃重的影响畔 小,变遮荫棉花籽棉产量而论,下,中部果枝的内围铃籽棉产量高于常规棉,在上,顶部果枝则相反,各部位果枝外围铃的籽棉产量均低于常规棉,遮荫棉花内,外围铃分布为1：0.36(常规棉为1：0.58),产量分布为1：0.42(常规棉为1：0.72)。苗期遮荫对棉纤维,棉籽品质性状的影响也主要在顶部果枝和上部果枝外围铃,综合分析遮荫棉花产量与品质的形成,棉花苗期耐遮荫性品种间存在差异。在本研究中以中9418耐遮荫性最强,中棉所19和春矮早次之。     

Cataloging and profiling genes expressed in Lentinula edodes fruiting body by massive cDNA pyrosequencing and LongSAGE

This study investigated the molecular mechanism of the fruiting body development and sporulation in the cap of the Shiitake mushroom, Lentinula edodes. Although there has been much research into L. edodes, there remain significant gaps in our knowledge of how the species reproduces. In order to provide molecular resources and to understand the molecular mechanism of the fruiting body development in basidiomycete comprehensively, we searched for the genes which are important for fruiting body development and sporulation in the cap of mature fruiting body of L. edodes by using the whole-genome approach. Massive cDNA pyrosequencing was used to generate >7000 sequence contigs from mature fruiting bodies. We used Gene Ontology to categorize the contigs to form the catalog of genes expressed at the stage of the mature fruiting body. We also assigned the contigs into the KEGG pathways. The catalog of expressed genes indicates that the mature fruiting bodies (1) sense the external environment, (2) transmit signals to express genes through regulatory systems, (3) produce many proteins, (4) degrade unwanted proteins, (5) perform extensive biosynthesis, (6) generate energy, (7) regulate the internal environment, (8) transport molecules, (9) carry out cell division, and (10) differentiate and develop. After establishing the catalog of expressed genes in L. edodes, we used the LongSAGE approach to analyze the expression levels of genes found in mature fruiting bodies before (FB) and after (FBS) spores appeared. Gene-expression patterns according to GO categories were similar in these two stages. We have also successfully identified genes differentially expressed in FB and FBS. Fold-changes in expression levels of selected genes based on LongSAGE tag counts were similar to those obtained by real-time RT-PCR. The consistency between real-time RT-PCR and LongSAGE results indicates reliability of the LongSAGE results. Overall, this study provides valuable information on the fruiting processes of L. edodes through a combination of massive cDNA pyrosequencing and LongSAGE sequencing, and the knowledge thereby obtained may provide insight into the improvement of the yield of commercially grown Shiitake mushrooms.     

Evaluation of the effect of cryopreservation of Pleurotus spp. strains on carpophore production.

The effect of the cryopreservation of six Pleurotus strains was evaluated. Primordia initiation, number of flushes, biological efficiency and fruiting body size obtained with respect to pileus diameter was recorded. These strains were previously evaluated before storage in liquid nitrogen. Variation in the number of flushes (3-4), the fruiting body size (< 5 cm at > 15 cm) and biological efficiency was observed. This varied according to the strain used, ranging from 55-105.6%. The fruiting bodies of the cryopreserved strains did not differ with respect to the untreated strains.     

Multicellular development in Myxococcus xanthus is stimulated by predator-prey interactions

Myxococcus xanthus is a predatory bacterium that exhibits complex social behavior. The most pronounced behavior is the aggregation of cells into raised fruiting body structures in which cells differentiate into stress-resistant spores. In the laboratory, monocultures of M. xanthus at a very high density will reproducibly induce hundreds of randomly localized fruiting bodies when exposed to low nutrient availability and a solid surface. In this report, we analyze how M. xanthus fruiting body development proceeds in a coculture with suitable prey. Our analysis indicates that when prey bacteria are provided as a nutrient source, fruiting body aggregation is more organized, such that fruiting bodies form specifically after a step-down or loss of prey availability, whereas a step-up in prey availability inhibits fruiting body formation. This localization of aggregates occurs independently of the basal nutrient levels tested, indicating that starvation is not required for this process. Analysis of early developmental signaling relA and asgD mutants indicates that they are capable of forming fruiting body aggregates in the presence of prey, demonstrating that the stringent response and A-signal production are surprisingly not required for the initiation of fruiting behavior. However, these strains are still defective in differentiating to spores. We conclude that fruiting body formation does not occur exclusively in response to starvation and propose an alternative model in which multicellular development is driven by the interactions between M. xanthus cells and their cognate prey.     

Temperature affects the timing and duration of fungal fruiting patterns across major terrestrial biomes

The Earth's ecosystems are affected by a complex interplay of biotic and abiotic factors. While global temperatures increase, associated changes in the fruiting behaviour of fungi remain unknown. Here, we analyse 6.1 million fungal fruit body (mushroom) records and show that the major terrestrial biomes exhibit similarities and differences in fruiting events. We observed one main fruiting peak in most years across all biomes. However, in boreal and temperate biomes, there was a substantial number of years with a second peak, indicating spring and autumn fruiting. Distinct fruiting peaks are spatially synchronized in boreal and temperate biomes, but less defined and longer in the humid tropics. The timing and duration of fungal fruiting were significantly related to temperature mean and variability. Temperature-dependent aboveground fungal fruiting behaviour, which is arguably also representative of belowground processes, suggests that the observed biome-specific differences in fungal phenology will change in space and time when global temperatures continue to increase.     

Biochemical characterization of cultivated Cordyceps bassiana mycelia and fruiting bodies by 1H nuclear magnetic resonance spectroscopy

In this study, nuclear magnetic resonance techniques coupled with multivariate data analysis were used for the metabolic profiling of mycelia and fruiting bodies of the entomopathogenic fungi, Cordyceps bassiana according to developmental stages. A direct extraction method using two deuterated solvents of D₂O and CDCl₃ was used to investigate the relative levels of identified metabolites in each extraction condition in the mycelium and fruiting body formation stages. There was a clear separation among mycelia and fruiting bodies with various developmental stages in partial least-squares discriminant analysis (PLS-DA) derived score plots. During the transition from mycelia to fruiting bodies, the major metabolic change observed was the conversion of glucose to mannitol, and beauvericin to phenylalanine and 1-hydroxyisovaleric acid. In the developmental stages of fruiting bodies studied, there was a clear separation between stage 3 and the other stages in PLS-DA derived score plots. Nineteen compounds including 13 amino acids, 2 nucleosides, 3 organic acids, and glucose showed the highest levels in stage 3 fruiting bodies. The flavonoid content in the fruiting bodies showed similar levels during stages 1, 2, and 3, whereas the level at stage 4 was significantly decreased compared to the other stages. Results suggest that the fruiting body of C. bassiana is richer in natural resources at stage 3 compared to the other fruiting body stages due to its high abundance of compounds including total flavonoids. The metabolome information acquired in this study can be useful criteria for the quality control of commercial use of C. bassiana.     

沪农灵芝一号生长过程中子实体各部位糖醇和海藻糖积累及其代谢酶的表达变化

食用菌子实体通常会在生长过程中积累较高含量的糖醇及海藻糖,这些碳水化合物的积累能够促进食用菌的生长,而在灵芝中的同类研究较少,本研究通过高效阴离子-脉冲安培法对沪农灵芝一号子实体发育过程中不同部位的糖类成分的含量变化进行分析,发现灵芝子实体中主要的可溶性糖类成分是阿拉伯糖醇、甘露醇和海藻糖,甘露醇在子实体成熟时的菌盖中的含量达到最高值,阿拉伯糖醇在产孢子期的子实体中含量较高,两种糖醇的含量呈现相反的变化趋势,一种糖醇积累的同时会消耗利用另一种糖醇,而海藻糖在灵芝子实体的整个生长过程中含量处于较低水平,仅在子实体初期的菌基部位检测到较高的含量;同时通过qRT-PCR技术检测灵芝子实体不同部位中这几种糖类的主要代谢酶基因的表达变化,发现这些代谢酶在子实体的菌基部位的表达水平相对其他部位较高,且随着子实体生长这一差异更加显著,这一结果表明灵芝中的糖醇和海藻糖分布差异可能是先由菌基的菌丝体中合成产物并转运到子实体不同部位,再经过一段时间的积累和代谢之后产生。     

Evolutionarily stable stalk to spore ratio in cellular slime molds and the law of equalization in net incomes

The evolutionarily stable stalk ratio (ESSR) in the cellular slime molds is studied when the fruiting body is formed by multiple clones of various size. The survival probability of a spore cell is assumed to depend on the stalk ratio and the fruiting body size. ESSR is obtained as the non-co-operative equilibrium (Nash solution) that maximizes the fitness of each clone. The following two predictions are obtained: (1) the number of spore cells produced by each clone forming a fruiting body tends to be equalized, even if a variation in clone size exists. As a result, the larger clones do not necessarily enjoy higher fitness than the smaller ones. (2) The stalk ratio and the overall fitness of the fruiting body decrease as the genetic diversity in the fruiting body increases. A condition for the stalk to spore ratio to be invariant of overall fruiting body size is also investigated. Finally, "the law of equalization in net incomes" is proposed, extending result (1) into the broader range of resource allocation problems.