枇杷种质资源果实若干性状及相关性研究

对224份枇杷种质果实11个性状的分布情况及性状间的相关性进行了分析研究,结果表明：（1）枇杷种质资源果实的单果重、可溶性固形物含量、可食率、果实纵经、果实横径、果实侧径、果形指数、萼片长度、萼片基部宽度、萼筒宽度和深度等11个性状存在广泛的分布,变异系数在11.81%~48.92%之间,分布区间以单果重为最大,果形指数为最小;（2）果形指数不能完全反映果实形状;果形指数在0.91~1.10之间的种质果形最为丰富;（3）单果重与果实纵径、果实横径、果实侧径、萼片长度、萼片基部宽度、萼筒深度、可食率及果形指数等8个性状呈极显著正相关,与可溶性固形物含量呈极显著负相关;可食率与单果重、果实纵径、果实横径、果实侧径、萼片长度、萼片基部宽度、萼筒深度及果形指数等8个性状呈极显著正相关,与可溶性固形物含量呈显著负相关;果形指数与果实纵经、单果重、萼筒深度、可食率等4个性状呈极显著正相关,与可溶性固形物含量呈极显著负相关。     

Modeling waterbird diversity in irrigation ponds of Taoyuan, Taiwan using an artificial neural network approach

The study develops an approach adopted by artificial neural networks (ANN) to model the relationship between pondscape and waterbird diversity. Study areas with thousands of irrigation ponds are unique geographic features from the original functions of irrigation converted to waterbird refuges. The model considers pond shape and size, neighboring farmlands, and constructed areas in calculating parameters pertaining to the interactive influences on avian diversity, among them the Shannon–Wiener diversity index. Results indicate that irrigation ponds adjacent to farmland benefited waterbird diversity. On the other hand, urban development leads to the reduction of pond numbers, which reduces waterbird diversity. By running the ANN model, the resulting index shows a good-fit prediction of bird diversity against pond size, shape, neighboring farmlands, and neighboring developed areas with a correlation coefficient (r) of 0.72, in contrast to the results from a linear regression model (r < 0.28).     

Influence of variety on the within-plant distribution of cassava green spider mite (Acari: Tetranychidae), and leaf anatomical characteristics and chemical components in relation to varietal resistance

The within-plant distribution of the cassava green spider mite, Mononychellus tanajoa Bondar, and the anatomical characteristics and the chemical components relating to varietal resistance of cassava, were studied using 11 cassava genotypes with varying levels of resistance for two dry seasons and one wet season. The results show that M. tanajoa aggregates on the top leaves of cassava at low levels of resistance as compared with a more even within-plant distribution at higher levels of resistance. Thus, for accurate sampling of mite populations, it might be important to consider young and old leaves, not just the young leaves, in fields containing resistant and susceptible cassava genotypes. Correlations between the anatomical characteristics and mite population density and damage scores were not consistent across months, either within or over seasons. This suggests that leaf anatomical characteristics may not be important in the varietal resistance of cassava to M. tanajoa. During the dry season, mite population density was positively correlated with leaf nitrogen, potassium and phosphorus and negatively correlated with leaf calcium and fat. Only calcium was negatively associated with mite damage at the peak of the dry season (January 1993 and 1994). Breeding cassava genotypes with high levels of leaf calcium and fat, and low levels of leaf nitrogen, potassium and phosphorus, may improve the level of resistance to M. tanajoa.     

植物病害生物防治与微生态学

在概述植物病害生物防治生态学意义的基础上,从植物微生态学的角度阐述了植物根围菌及内生菌作为生防菌的依据和意义。特别是内生菌是植物体内的正常菌群,对植物病害生物防治具有重要的生态学实践意义。     

钾元素对苜蓿碳水化合物的分配及抗蓟马的影响

为了探索施钾对苜蓿（Medicago sativa）叶茎根碳水化合物的分配与苜蓿抗蓟马的关系,本试验以紫花苜蓿‘甘农3号’和‘甘农9号’为材料,以牛角花齿蓟马（Odontothrips loti）为研究对象,在网室盆栽条件下,评价不同钾水平下苜蓿的受害程度,并测定了叶茎根中可溶性糖和淀粉含量。结果表明：施钾后,苜蓿的受害指数下降,各器官中的可溶性糖与淀粉含量及其根冠比均升高。随着受害时间的持续,各钾水平下苜蓿叶中可溶性糖含量在受害10 d时最高,茎中可溶性糖含量在受害15 d时最高,根中可溶性糖含量及各器官中淀粉含量均持续增加;可溶性糖的叶茎比在受害10 d时最高,淀粉的叶茎比变化不显著,可溶性糖和淀粉的根冠比均持续升高。施钾提高了苜蓿的碳水化合物含量,并调控其在苜蓿各器官中的合理分配,进而增强了苜蓿对蓟马的耐害性。‘甘农9号’抗性表现较‘甘农3号’好,本试验中最适施钾量为0.6 g·（10 kg）^-1土。     

FAAS法测定原生态硒米中的微量元素铁和镍

[目的]测定黔东南苗族侗族自治州原生态丹寨精硒米中微量元素铁和镍的含量。[方法]采用正交试验优化仪器最佳工作条件,湿法消解硒米样品,火焰原子吸收光谱法（FAAS）测定微量元素铁和镍。[结果]原生态丹寨精硒米中微量元素铁和镍的含量分别为8.00和0.50 mg/kg。[结论]该研究方法操作简便,灵敏度高,检出限低。     

湖南长沙记录到绿背姬鹟

2019年10月3日,在湖南省长沙市烈士公园(112°59′55.74″E,28°12′48.08″N)内一池塘周边的阔叶林中观察并拍摄到一种鹟科鸟类。经查阅文献,对比该鸟的形态特征后,鉴定为绿背姬鹟(Ficedula elisae),为湖南省新纪录鸟种。     

湘中农区壶天山羊的生产性能及生态养殖技术研究

通过采用测定200只壶天山羊的体尺体重,统计66胎产仔情况、屠宰6只成年羊,将8只成年杂交羊(壶天羊×马头羊)和50只成年壶天羊作对比等办法,从而真实系统地总结了该山羊的各项生产性能.对以"七化四结合"为主要内容的山羊生态养殖关键技术进行了研究,提出了"羊→沼→稻(菜或草)"生产模式和"企业 农户"的经营模式.     

芭蕉属野生种的地理分布

芭蕉属起源于热带亚热带区域,对芭蕉属野生种质资源的研究始于20世纪40年代。通过检索INIBAP的多个数据库和相关文献,归纳整理出芭蕉属野生种的分布规律,为野生蕉的种质资源保存、利用以及品种鉴定提供一定的理论依据。经分析,目前已经报道的芭蕉属共有52个野生种,其中真芭蕉组(Eumusa)11个,观赏蕉组(Rhodochlamys)9个,澳蕉组(Australimusa)13个,红花蕉组(Callimusa)18个,不确定组(Incertae sedis)1个。马来西亚、印度尼西亚、巴布亚新几内亚、印度和中国均分布有不同的3组芭蕉属野生种,但马来西亚和印度分布的种数最多,各分布有15种,约占总数的29%,可能是芭蕉属野生种的多样性中心。     

牡丹江林区土壤分布规律浅析

牡丹江林区土壤分布规律为由东向西地带性土壤的垂直分布特点显著,随山体自下而上的土壤分布规律为:沼泽土→草甸土→暗棕壤→棕色针叶林土→亚高山灌丛草甸土;由西南向东北土壤的水平分布也有一定的变化趋势;因受各种成土条件及人为因素制约,不同地区土壤的小区分布也各有差异。