家蝇幼虫开发生态工程系统动力学仿真的研究

家蝇（Ｍｕｓｃａｄｏｍｅｓｔｉｃａ）幼虫以营养成分全、蛋白质含量高而逐渐引起人们重视,具有很高的开发利用价值和广阔的前景。系统动力学的发展为研究复杂系统提供了有效途径［１,２］。本文试用系统动力学方法建立家蝇幼虫开发生态工程仿真模型,以期解决这一研究...     

艾蒿精油对家蝇的忌避及熏蒸活性

应用“Y”型嗅觉仪对家蝇进行了生物测定。结果表明,艾蒿(Artemisia vulgars L．)精油20μL和25μL剂量对家蝇Musca domestica rieina有很强的忌避活性,平均忌避活力分别为86％和88％,显著高于5和10μL剂量。植物精油对家蝇成虫具有很好的熏蒸活性。随着精油浓度的升高和熏蒸时间的延长,试虫的死亡率显著增加。艾蒿精油浓度为20μL／mL时,家蝇成虫的死亡率在24h后即达到100％;对照在24,48,72和96h时家蝇成虫的死亡率分别为0,0,5％和11％。     

The Effect of Plant Polygalaturonase-Inhibiting Protein on the Rate of Oligouronide Formation

The effects of the polygalacturonase-inhibiting protein (PGIP) on the rate of oligouronide formation were studied in a model system containing polygalacturonic acid and polygalacturonase (PG) from the culture medium of phytopathogenic fungi. PGIP preparations were prepared from stored potato tubers and sprouts and also from apple fruits. The PGIP effects on oligouronide synthesis depended markedly on the physiological state of the source plant. Apple cultivars differing in their earliness differed in PGIP effects as well. The PGIP from potato tubers, which were in deep dormancy, suppressed oligouronide formation. The inhibitory PGIP action was decreased after dormancy release and tuber sprouting, which resulted in the oligouronide accumulation. The effects of PGIP from apple fruits on the oligouronide synthesis in the system containing PG from various phytopathogenic fungi were not correlated with tissue damage induced by these fungi. The PGIP effects on oligouronide formation are evident; however, their role in plant-cell processes related to the pectin compound conversions and plant resistance to diseases remains to be elucidated.     

Chloroplast diversity in the genus Malus: new insights into the relationship between the European wild apple (Malus sylvestris (L.) Mill.) and the domesticated apple (Malus domestica Borkh.)

To unravel the relationship between the European wild apple, Malus sylvestris (L.) Mill., and its domesticated relative M. domestica Borkh., we studied chloroplast DNA variation in 634 wild and 422 domesticated accessions originating from different regions. Hybridization between M. sylvestris and M. domestica was checked using 10 nuclear microsatellites and a Bayesian assignment approach. This allowed us to identify hybrids and feral plants escaped from cultivation. Sixty-eight genotypes belonging to 12 other wild Malus species, including 20 M. sieversii (Ledeb.) Roem. accessions were also included in the analysis of chloroplast diversity. Marker techniques were developed to type a formerly described duplication and a newly detected transversion in the matK gene. Chloroplast DNA variation was further investigated using PCR-RFLP (Polymerase Chain Reaction-Random Fragment Length Polymorphism), and haplotypes were constructed based on all mutational combinations. A closer relationship than presently accepted between M. sylvestris and M. domestica was established at the cytoplasmic level, with the detection of eight chloroplast haplotypes shared by both species. Hybridization between M. sylvestris and M. domestica was also apparent at the local level with sharing of rare haplotypes among local cultivars and sympatric wild trees. Indications of the use of wild Malus genotypes in the (local) cultivation process of M. domestica and cytoplasmic introgression of chloroplast haplotypes into M. sylvestris from the domesticated apple were found. Only one of the M. sieversii trees studied displayed one of the three main chloroplast haplotypes shared by M. sylvestris and M. domestica. This is surprising as M. sieversii has formerly been described as the main maternal progenitor of the domesticated apple. This study hereby reopens the exciting discussion on the origin of M. domestica.     

松油烯-4-醇光学异构体及外消旋体对家蝇的杀虫活性比较

【目的】比较松油烯-4-醇光学异构体对家蝇 Musca domestica 的熏蒸活性差异,为其光学异构体的应用提供理论依据。【方法】以家蝇4日龄成虫为供试昆虫,采用三角瓶熏蒸法比较测定了松油烯-4-醇光学异构体和外消旋体对其的熏蒸与击倒活性,并测定了松油烯-4-醇光学异构体及外消旋体对家蝇头部Na⁺ , K⁺-ATPase活性的影响。【结果】松油烯-4-醇外消旋体对家蝇的熏蒸活性和击倒活性最强,右旋异构体次之,左旋异构体最差,外消旋体、右旋异构体和左旋异构体对家蝇的致死中浓度（LC₅₀）分别为2.5,2.9和3.7 μL/L;在LC₉₀ 剂量下的击倒中时（KT₅₀）分别为12.6,16.7和18.9 min;松油烯-4-醇光学异构体及外消旋体均可显著抑制Na⁺, K⁺-ATPase的活性,活体条件下,松油烯-4-醇光学异构体及外消旋体对Na⁺, K⁺-ATPase活性的抑制作用随着中毒症状的加剧而增强,具有时间效应,其中左旋异构体的抑制作用最强;离体条件下,松油烯-4-醇光学异构体及外消旋体对Na⁺, K⁺-ATPase活性的抑制作用具有浓度依赖效应,其中外消旋体对Na⁺, K⁺-ATPase活性的抑制能力最强,明显高于同浓度下的右旋异构体和左旋异构体。【结论】松油烯-4-醇的光学异构体对家蝇的杀虫活性存在差异,外消旋体的活性明显高于异构体单体。开发松油烯-4-醇类杀虫剂,应以光学异构体的混合物作为有效成分。     

Genetic determinism of anatomical and hydraulic traits within an apple progeny

The apple tree is known to have an isohydric behaviour, maintaining rather constant leaf water potential in soil with low water status and/or under high evaporative demand. However, little is known on the xylem water transport from roots to leaves from the two perspectives of efficiency and safety, and on its genetic variability. We analysed 16 traits related to hydraulic efficiency and safety, and anatomical traits in apple stems, and the relationships between them. Most variables were found heritable, and we investigated the determinism underlying their genetic control through a quantitative trait loci (QTL) analysis on 90 genotypes from the same progeny. Principal component analysis (PCA) revealed that all traits related to efficiency, whether hydraulic conductivity, vessel number and area or wood area, were included in the first PC, whereas the second PC included the safety variables, thus confirming the absence of trade-off between these two sets of traits. Our results demonstrated that clustered variables were characterized by common genomic regions. Together with previous results on the same progeny, our study substantiated that hydraulic efficiency traits co-localized with traits identified for tree growth and fruit production.     

苹果一个锌指蛋白基因的cDNA克隆及其表达特性分析

采集了处于营养生长向生殖行长转化期(6~8月)的红玉苹果(Malus domestica Borkh.)茎顶,构建了其cDNA文库,并从中分离得到了一个具有锌指结构的EST序列,又通过5`RACE的方法,从cDNA文库中找到了其上游779bp的cDNA片段.最后用PCR的方法获得了苹果锌指蛋白的全长cDNA,并命为MdZF1.该cDNA序列已在GenBank登录,登录号为AB116545.MdZF1的锌指结构域与玉米的开花转换基因ID1有高度同源性.通过对苹果不同组织、器官的Northem和RT-PCR分析表明MdZF1在根、茎、叶、顶芽以及花器官(萼片、花瓣、雄蕊、雌蕊)中都有表达.Southern分析表明MdZF1的基因组中是以单拷贝存在的.