施硅对水稻幼苗吸收锌、铜的影响

目的 研究不同硅(Si)肥水平下水稻幼苗的生长状况及锌(Zn)、铜(Cu)的吸收和转运情况。方法 试验以水稻‘皖稻71号’为材料,通过水培方式,设置硅肥(以SiO₂计)水平分别为0(对照,CK)、30、60、90、120和150 mg·L^-1共6个处理,研究不同Si肥水平处理下水稻幼苗的生物量、Zn和Cu含量及积累状况。结果 施用Si肥后,水稻幼苗叶片数、株高和根长均高于对照,水稻地上部和根部生物量(鲜质量)分别增加5.44%~52.81%和4.83%~42.49%,叶片数、株高、根长和地上部生物量均在90 mg·L^-1 SiO₂处理达到最高值。施Si处理的水稻幼苗根部Zn净吸收量提高了5.79%~77.43%,Cu净吸收量提高了6.51%~44.96%。60和90 mg·L^-1 SiO₂处理的Zn转运系数较对照分别提高10.91%和38.18%,Cu转运系数较对照分别提高8.70%和26.09%。水稻地上部Zn、Cu含量随着Si肥水平的提高而增加,90 mg·L^-1 SiO₂处理达到峰值,之后随Si肥水平的增加开始出现下降的趋势。结论 综合考虑水稻生长指标、生物量和对Zn、Cu的吸收等因素,本研究中90 mg·L^-1 SiO₂处理是微量营养元素Zn、Cu吸收的最佳施用Si肥水平。     

Genetics and molecular mechanisms of resistance to powdery mildews in tomato (Solanum lycopersicum) and its wild relatives

Powdery mildews (PMs) cause disease in a wide range of plant species including important crops. Taking tomato as an example, here we review findings on the genetic basis and mechanisms of plant resistance to PMs. First, we present a summary of our research on tomato resistance to two PM species, with the focus on Oidium neolycopersici. We discuss the genetics of resistance to this pathogen in tomato. Then, we compare different forms of resistance mediated by different resistance genes based on molecular and cytological data. Also, we provide a comparison between these resistance genes in tomato with those in barley, Arabidopsis and wheat, in order to present a model for the genetic basis of resistance to PMs in plants. We try to accommodate these resistance mechanisms in the current model of plant innate immunity. At the end we discuss possibilities to translate these findings to practical approaches in breeding for resistance to PMs in crops.     

A simple and efficient method for the long-term preservation of plant cell suspension cultures

Background  

The repeated weekly subculture of plant cell suspension is labour intensive and increases the risk of variation from parental cells lines. Most of the procedures to preserve cultures are based on controlled freezing/thawing and storage in liquid nitrogen. However, cells viability after unfreezing is uncertain. The long-term storage and regeneration of plant cell cultures remains a priority.     

Post‐mortem examination of the reproductive organs of female wild boars (Sus scrofa) in Sweden

In recent decades, wild boars (Sus scrofa) have increased in numbers and distribution in Europe. Compared to other wild ungulates of similar body size, wild boars have a high reproductive capacity. To increase the knowledge of wild boar reproduction, the objective of this study was to investigate characteristics of reproductive organs, and to provide information on the occurrence of abnormalities in reproductive organs from free‐ranging female wild boars. Between December 2011 and December 2015, reproductive organs from female wild boars (>30 kg body weight), were collected during hunting in four Swedish counties at estates where supplementary feeding was applied. The organs were macroscopically examined and measured. The stage of the reproductive cycle was defined according to the ovarian structures and in relation to uterus characteristics. Observed abnormalities were noted. The results from 569 animals that met the requirements to be included in this study showed significant differences in weight and length of the uterus between the various reproductive stages. Sampling region had significant effect on these differences. Abnormalities in the reproductive organs were present in approximately 10% of the examined animals. The prevalence of abnormalities increased significantly with age and was significantly affected by sampling region.     

Artificially applied plant volatile organic compounds modify the behavior of a pest with no adverse effect on its natural enemies in the field

The use of volatile organic compounds (VOCs) derived from plants to manipulate insect pest behavior can be applied in an integrated pest management strategy (IPM) using a combination of attractive and repulsive stimuli. The “push–pull” strategy was developed on this idea in order to disturb and modify the distribution and abundance of pests to protect crops and reduce the use of agrochemicals. This field experiment investigates, in a “push–pull” context using broccoli as a target crop and Chinese cabbage as a pull component, the stimulo-deterrent effect of five synthetic VOCs (dimethyl disulfide, linalool, geraniol, eucalyptol and citronellol) on the oviposition of the cabbage root fly Delia radicum. With the exception of linalool, all compounds tested had a significant effect in the field and eucalyptol showed the most promising results, reducing oviposition on broccoli by 45 %. Moreover, eucalyptol was the only VOC able to reduce the final infestation of D. radicum, i.e., the number of pupae. The other VOCs reduced oviposition by 20–30 %. No adverse effect of the treatments was found on major parasitoids (Trybliographa rapae and Aleochara bipustulata) and potential predators of D. radicum. This study highlights the potential of VOCs as deterrent stimuli against agricultural pests in the field.     

3种实蝇基因组DNA提取及ISSR-PCR反应体系的建立

为探讨高品质实蝇基因组DNA提取,研究模板DNA浓度、引物浓度、Taq DNA聚合酶用量、dNTP浓度、退火温度及时间对ISSR-PCR扩增结果的影响,以3种实蝇为材料,建立通用且稳定的实蝇ISSR-PCR反应体系。结果表明：获得了高品质实蝇基因组DNA;确立了通用且稳定的实蝇ISSR-PCR反应体系：10×PCR Buffer 2.5 μL,模板DNA 50 ng,引物0.25 μmol/L,Taq DNA聚合酶0.50 U,dNTP 200 μmol/L,最后加ddH2O至25 μL;明确了ISSR-PCR扩增程序：94℃预变性5 min,94℃变性30 s,52.4℃退火45 s,72℃延伸90 s,循环36次,最后72℃延伸7 min,4℃保存。体系的建立弥补了实蝇传统形态检测的不足,为快速准确鉴定、种群异质性及遗传多样性分析奠定了基础。     

盆栽榕树蓟马的发生与防控药剂配方筛选

以福建漳州盆栽榕树种植示范基地为观测和实验点,调查鉴定蓟马的种类、为害过程和发生规律,选择测定阿维菌素+啶虫咪、速灭威+啶虫咪和毒死蜱+啶虫咪等3组配方药剂对榕树蓟马的防控效果,筛选确定防控榕树蓟马的最佳配方药剂及田间使用浓度。结果表明:对盆栽榕树造成为害的主要是榕管蓟马;速灭威+啶虫咪4∶1配比对榕管蓟马防治效果最理想,药后3～10 d的防治效果均在93.48%以上,无药害产生,性价比最好,是防治榕管蓟马的最佳配方药剂,田间推荐使用500～1 500倍液。     

Differing nitrogen use strategies of two tropical rainforest late successional tree species in French Guiana: Evidence from 15N natural abundance and microbial activities

Previous studies in lowland tropical rainforests of French Guiana showed that, among non-N₂-fixing trees, two groups of late successional species contrasting in their leaf ¹⁵N natural abundance coexist, suggesting two different main ways of nitrogen acquisition. Two abundant late-successional species typically co-occurring in rainforests in French Guiana, namely Eperua falcata and Dicorynia guianensis, were chosen as representative of each group. Stable isotope techniques and measurements of potentials of microbial N transformation were performed to assess to what extent leaf ¹⁵N natural abundance of these species could be related to (i) δ¹⁵N signatures of soil mineral N sources and (ii) the capacity of soil to express nitrification and denitrification (both processes being directly involved in the balance between NH₄⁺ and NO₃^–). Soil δ¹⁵N-NH₄⁺ was roughly similar to leaf δ¹⁵N of D. guianensis (around 3.5‰), suggesting a preferential use of NH₄⁺, whereas in E. falcata, leaf δ¹⁵N values were closer to root δ¹⁵N-NO₃^? values (0.2 and ?2.0‰, respectively), suggesting a preferential use of NO₃^?. These differences in N source utilization were not accompanied by differences in availability in soil NO₃^? or in intensity of microbial functions responsible for soil N mineral evolution. However, (i) under both tree species, these functions showed clear spatial partitioning, with denitrification occurring potentially in soil and nitrification in the litter layer, and (ii) E. falcata fine roots colonized the litter layer much more strongly than D. guianensis fine roots. This strongly suggests that (i) the contrasted leaf δ¹⁵N values found in the two late-successional species reveal distinct N acquisition strategies and (ii) the ability of roots to predominantly exploit the litter layer (E. falcata) or the soil (D. guianensis) may constitute an important explanation of the observed differences. A complementarity between tree species, based on mineral N resource partitioning (itself resulting from a spatially structured location of the microbial functions responsible for the balance between NH₄⁺ and NO₃^–), can thus be supposed.     

韩国森林福祉现状及对北京的启示

自20世纪70年代以来,韩国由于全体国民的努力,植被恢复取得极大成功,韩国提出利用森林为国民提供从出生到死亡包括休养、文化、保健、教育等多种福利服务。文中概述了韩国林业发展历程以及森林福祉类型、发展历程、机构、法律、人才培养等方面内容,并对北京如何借鉴韩国森林福祉发展经验提升森林服务功能提出了制定总体规划、打造示范基地、加大政策扶持力度等对策。     

夏玉米调亏灌溉的生理机制与指标研究

在人工控制试验条件下,采用子母盆栽土培法,以夏玉米为材料进行了调亏灌溉试验研究。结果表明,玉米调亏灌溉是可行的,可以实现节水、高产和高效的目标。适时适度地水分亏缺显著抑制蒸腾速率,而光合速率下降不明显,复水后光合速率又具有超补偿效应,光合产物具有超补偿积累,且有利于向籽粒运转与分配;抑制营养生长,增大作物根冠比,提高了根系传导力,增强了植株抗旱性。玉米节水高产的调亏灌溉指标是：调亏时段为三叶一心—拔节（七叶一心）,调亏度为４５％～６５％的田间持水率（θ_ｆ）,历时２１天;或拔节～抽穗调亏,调亏度为６０％～６５％,历时２１天;平均比对照增产２５．２４％,节水１５．４１％,水分利用效率提高４５．０５％。