Infection processes and soft wheat response to root rot and crown rot caused by Fusarium culmorum

An isolate of the fungus Fusarium culmorum constitutively expressing green fluorescent protein was used to investigate the infection process and host response of primary seedling roots and stem base leaf sheaths of soft wheat cv. Genio. Disease progress was assessed macroscopically by visual symptoms, microscopically by confocal laser scanning microscopy (CLSM) and via gene expression analysis of fungal and wheat genes by real‐time quantitative RT‐PCR. In the roots, CLSM investigations revealed an initial intercellular and subsequent intracellular colonization by fungal hyphae. The fungus invaded the rhizodermal layer and cortex but was not seen to colonize the stele. The fungus consistently expressed TRI5 (24, 48 and 96 h post‐inoculation), indicating that trichothecenes were being synthesized throughout this phase of infection and colonization. The expression of the six host defence‐associated genes (Wheatwin 1‐2, PR1, Chitinase, PAL, WIR1 and LOX) increased early in infection and decreased during later stages. In the stem base, CLSM observations revealed the fungus sequentially penetrating though the first, second and third basal leaf sheaths. Expression of TRI5 was initiated early in the infection of each leaf sheath. The expression of the host defence‐associated genes varied over time and across leaf sheaths, and all were also expressed in leaf sheaths which had not yet been in contact with the fungus. Expression of LOX and WIR1 were particularly enhanced in the third leaf sheath.     

河北园林蚧虫名录

本文报道了河北地区为害园林植物的蚧虫8科42属73种,同时对其寄主、为害程度及分布作了介绍。     

云南松毛虫越冬代幼虫自然种群空间分布型的研究

通过样方调查计算，采用聚集度指标法，测定云南松毛虫越冬代幼虫的空问分布型，建立了最适抽样数关系式，并对其进行了序贯抽样分析。结果表明：云南松毛虫越冬代幼虫种群在林内呈聚集分布，其Iwao回归方程为m*=5．2181 1．0207x^-、复相关系数R=0．9918；最适抽样株数为：N=621．81/x^- 2．07。     

臭椿、新疆杨混交林对光肩星天牛选择寄主行为的影响

利用3年生臭椿、新疆杨在室内建立混交林进行光肩星天牛成虫放飞试验.结果表明:臭椿、新疆杨混交林对天牛成虫的寄主选择有显著影响,天牛成虫的交尾行为只在新疆杨植株上进行;天牛成虫在林内植株上着落的总虫次随新疆杨株数的减少而下降,交尾次数也减少;臭椿、新疆杨植株数量在林分中所占比例在一定范围时,天牛成虫在新疆杨和臭椿上着落的虫次比均趋于稳定;新疆杨与臭椿以行状3:2和2:3混交时林分的抗虫效果较好.     

紫胶虫优良寄主植物久树的繁殖技术

综述了紫胶虫优良寄主植物及久树繁殖技术的研究进展，特别是久树的种类、生物学、生理学和生态学的研究与进展，提出了寄主植物无性繁殖研究的思路和对策，展望了寄主植物的研究发展方向。     

寄主植物对舞毒蛾生长发育的影响

该文选择了青杨Populus cathayanaRehd.、华北落叶松Larix principis-rupprechtiiMayr.和山杏Aarmeniaca sibiricaLinn.,研究植物对舞毒蛾Lymantria disparL.生长发育历期、蛹重、产卵量的影响。结果表明舞毒蛾发育历期、蛹重及产卵量与所取食的寄主植物有明显的相关性,取食华北落叶松的舞毒蛾个体发育历期最短,平均为38.22±0.56 d,蛹最重,平均为1.48±0.09g,产卵量最多,平均每雌560.65±41.67粒;取食青杨的舞毒蛾发育历期最长,平均为46.68±0.65 d,蛹最轻,平均为1.17±0.08 g,产卵量最少,平均每雌315.47±49.07粒;取食山杏的舞毒蛾间于二者之间,平均历期为39.53±0.58 d,平均蛹重为1.24±0.08 g,每雌产卵量394.50±58.65粒。可以认为,在供试范围内华北落叶松最适宜舞毒蛾生长发育,山杏次之,青杨最不适宜。     

河北天牛名录初志

本文报道了在河北省境内为害林木、果树的天牛科昆虫5亚科64属99种,并对其已知分布地点和寄主植物作了介绍。     

胭脂虫与寄主仙人掌的关系

对采自10个地方的仙人掌进行胭脂虫放虫试验,并对仙人掌进行解剖及营养成分分析,结合胭脂虫的生长情况对胭脂虫与仙人掌种类、内部构造及营养成分的关系进行研究,结果表明,胭脂虫在梨果仙人掌、朱耳掌及缩刺仙人掌上均能寄生,但以梨果仙人掌最好;从秘鲁引进的梨果仙人掌及云南禄丰的梨果仙人掌上胭脂虫生长较好;少刺型的梨果仙人掌上胭脂虫生长比多刺型梨果仙人掌好;仙人掌的表皮越厚,胭脂虫的生长越差,而胭脂虫的寄生能刺激仙人掌维管束的发育;仙人掌中蛋白质、水分含量对胭脂虫的生长具有显著影响。     

Influence of host plant species on the development and reproduction of hawthorn spider mites

A leaf disc bioassay was employed to investigate the influence of host species of deciduous fruit trees, like apple, peach, plum, cherry and apricot, on the development and reproduction of the hawthorn spider mite Tetranychus viennensis Zacher in the laboratory under conditions of 25±1°C, 60±10% RH and a photoperiod of 16 h: 8 h light: dark. This was done by determining the duration of each life stage of the mites, the intrinsic rate of population increase (r _m ), mean generation time (T) and net reproductive rate (R ₀) of the spider mites on each of the host plant species. Differences in life table parameters of the spider mite among host plants were analyzed with the jack-knife method. The results indicated that plum might be the best suitable plant for the spider mite among the plants tested due to shorter developmental period and higher intrinsic rate of increase, whereas cherry and apricot were least suitable due to their long developmental duration and low intrinsic rates of increase. When the spider mites were transferred from apple to other fruit trees, negative effects on developmental duration, fecundity and life table parameters were found in the first generation, but the effects faded out in succeeding generations. When transferred onto plum and peach, the spider mite adapted to the new hosts in the second generation; however, on cherry and apricot, it adapted in the third generation. __________ Translated from Acta Ecologica Sinica, 2005, 27(7) [译自: 生态学报, 2005, 27(7)]