黑绒金龟成虫虫体研磨物水悬液对其成虫的驱避作用

黑绒金龟[Serica orientalis(Motschulsky)]是一种重要的多食性林木食叶害虫,严重影响苹果、核桃和卫矛等经济和绿化树种的经济和生态效益。为研究黑绒金龟成虫虫体研磨物水悬液对其成虫的驱避作用,探索经济有效、环境友好的黑绒金龟行为控制技术,利用Y-型嗅觉仪测定了黑绒金龟对4种不同寄主植物[卫矛Euonymus alatus(Thunb.)Sieb.、苹果Malus pumila Mill.、箭杆杨Populus nigra var.thevestina(Dode)Bean、白梨Pyrus bretschneideri Rehd.]的趋性,以及不同寄主喷施其成虫虫体研磨物水悬液前后黑绒金龟的趋性差异。结果表明:雌、雄成虫对不同寄主的反应率,以及不同寄主对雌、雄成虫的诱引率和驱避率无显著差异(P0.05)。黑绒金龟对卫矛、苹果、箭杆杨和白梨均有极显著的正趋性(P0.01);对卫矛、苹果、白梨的趋性无显著差异(P0.05)。在4种寄主植物嫩枝叶上喷施黑绒金龟成虫虫体研磨物水悬液,以相应寄主嫩枝叶作为对照,比较对黑绒金龟的诱引率,发现黑绒金龟成虫虫体研磨物水悬液对黑绒金龟成虫有极显著的驱避作用(P0.01),黑绒金龟成虫的不反应率高于40%。研究结果可为害虫自身研磨物作为忌避剂应用于农、林业生产提供行为学依据。     

黄河三角洲人类活动强度的湿地景观格局梯度响应

为了研究黄河三角洲湿地景观格局沿人类活动强度的梯度变化规律,该文基于土地科学和景观生态学原理,在RS、Arc GIS和FRAGSTATS软件支持下,以1989、1999、2009和2014年四期遥感影像为数据源,利用人工目视解译方法构建研究区景观类型图。基于解译结果,选取耕地、工矿用地、居民点和交通用地等土地利用指标来反映人类活动强度,采用自然间断法将人类活动强度从强到弱分带。文章分析了黄河三角洲不同人类活动强度样带不同时期的湿地景观格局变化特征,以及2014年主要景观类型的格局特征对人类活动强度的梯度响应。结果表明:人类的干扰活动使得不同景观类型在人类活动强度各样带表现出明显的空间差异。在景观水平上,随着人类活动强度的降低,样带景观的丰富度和斑块数增加,2009年斑块数量达到8 000个;多样性和均匀度指数呈先增后减趋势,景观聚集度和连通性持续增加,在第10样带达到99.42%,破碎化程度不断降低;在类型水平上,水库坑塘、水产养殖场、盐田和未利用地在梯度带中较好地反映了景观格局的变化特征,其中各景观类型的形状指数和分维数随人类活动强度的梯度变化呈现明显的变化趋势,景观形状趋于复杂化,面积比例、斑块密度和最大斑块指数的梯度变化较大,波动明显,盐田在人类干扰最大时斑块指数达到26%。该文揭示了景观格局沿人类活动强度的梯度变化规律,可为研究区湿地生态恢复及可持续利用提供参考。     

6种宿根花卉植物的光合特性研究

目前,我国北方地区园林应用中宿根花卉的种类相对较少、品种单一。为了进行宿根花卉的引种栽培进而有效丰富园林宿根花卉的种类,以黑心菊、芙蓉葵、蜀葵、赛菊芋、紫茉莉、醉鱼草等6种宿根花卉为试验材料,利用CIRAS-3光合仪,研究其光合有效辐射、二氧化碳的响应以及光合速率日变化。结果表明,黑心菊、赛菊芋和醉鱼草净光合速率日变化表现为单峰曲线,未出现"午休"现象;芙蓉葵、蜀葵和紫茉莉为明显的双峰曲线,有明显的"午休"现象,且第2峰值均出现在14:00,其中黑心菊的光补偿点最低、光饱和点也较低,分别为18.69μmol/(m~2·s)和1 506.49μmol/(m~2·s),可以在遮阴环境下生长,而赛菊芋的光补偿点最高、光饱和点也较高,分别为32.45μmol/(m~2·s)和1 616.41μmol/(m~2·s),表现出较强的喜阳性。     

安徽省城镇化与耕地利用集约化的动态响应关系

为分析城镇化与耕地利用集约化的动态关系,促进新型城镇化与农业现代化协调发展,该文在构建城镇化与耕地利用集约化动态响应关系理论框架的基础上,基于传统农区安徽省1998—2014年相关数据,建立向量自回归(vector autoregression VAR)模型,检验两者之间的协整关系,并在此基础上运用脉冲响应分析和方差分解分析城镇化与耕地利用集约化的互馈关系。结果表明,复种指数对城镇人口比例冲击的响应先为负向后为正向,贡献率为14.4%;对二三产业比例和土地城镇化则均产生负向响应,并呈先增加后减少的趋势,贡献率分别为10.4%、15.6%。化肥投入对城镇人口比例的冲击产生正向的响应,贡献率为12.1%;对二三产业比例有正向和负向响应,反应强度先增加后减少,解释水平为1.2%;对土地城镇化产生先增加后趋于平稳的负向响应,贡献率为22.3%。农业机械总动力对城镇人口比例的反应为正向的先增加后趋于平稳,贡献率为20.3%;对二三产业比例的负向响应的解释水平为2.4%;对土地城镇化的冲击呈现负向增加的响应,且贡献率高达66.3%。总体来看,城镇化水平的提高对耕地利用集约化有正向推动作用,但集约化需要适度发展,过快的城镇化不利于可持续集约化的实现;耕地利用集约化对城镇化的影响程度相对较低,说明耕地集约利用水平的提高仅可在一定程度上支持城镇化的发展。     

Selecting cotton yield response function to estimate profit-maximizing potassium fertilization rates for cotton production in Tennessee

Recent research has shown that stochastic yield response functions fit data better than deterministic yield response functions; however, little research exists comparing profit-maximizing fertilizer rates for upland cotton (Gossypium hirsutum L.) using stochastic and deterministic yield response functions. The objective of this research was to determine the most appropriate yield response functional form from which to determine the profit-maximizing potassium (K) rate for cotton in Tennessee. Data were used from a nine-year K fertilizer experiment in Jackson, Tennessee. Quadratic, quadratic-plus-plateau, linear response plateau, and linear response stochastic plateau response functions were estimated to determine the yield response function that best fit the data. The linear response stochastic plateau function was the most suitable yield response function for the data. The profit-maximizing K rate ranged from 65.2 to 74.3 kg K ha^?1. Misspecification of the yield response function recommended over-application of K fertilizer and decreased the producer's short-term profits.     

Effectiveness of Fe3+-citrate and Fe3+-edta in ameliorating arsenic-toxicity (chlorosis) in hydroponic rice

Effectiveness of iron (Fe³⁺)-citrate and Fe³⁺-EDTA (ethylenediaminetetraacetic acid) in reducing arsenic (As)-toxicity in rice was evaluated. The treatments: 1) 0 µM As + 10 µM Fe³⁺-citrate (control), 2) 13.4 µM As + 10 µM Fe³⁺-citrate (As-treated), 3) 13.4 µM As + 10 µM Fe³⁺-citrate + 40 µM Fe³⁺-citrate (additional Fe³⁺-citrate), and 4) 13.4 µM As + 10 µM Fe³⁺-citrate + 40 µM Fe³⁺-EDTA (additional Fe³⁺-EDTA) were studied for 14 days. Chlorosis was found in the young leaves of the As-treated plants. Additional Fe³⁺-citrate failed to remediate the chlorosis, however, additional Fe³⁺-EDTA removed the chlorosis almost completely, indicating that the effectiveness of Fe³⁺-EDTA was much higher than Fe³⁺-citrate. The Fe³⁺-EDTA treated plants were greener than the additional Fe³⁺-citrate treated plants. Iron concentration in the shoots of additional Fe³⁺-EDTA plants was much higher than that of additional Fe³⁺-citrate plants, indicating that Fe³⁺-EDTA might have been more readily available to the plants roots than Fe³⁺-citrate.     

Evaluation of ground grain versus pre- and post-pellet whole grain additions to poultry diets via a response surface design

1. The objective of this study was to compare the effects of pre- and post-pellet whole grain wheat additions to diets on growth performance, gizzard and pancreas development, nutrient utilisation and starch and protein (N) digestibility coefficients in broiler chickens via an equilateral triangle response surface design.

2. The three apical treatments of the equilateral triangle comprised (1A) a standard diet containing 600 g/kg ground wheat, (2B) the same diet containing 600 g/kg pre-pellet whole wheat and (3C) the same diet containing 300 g/kg ground wheat and 300 g/kg post-pellet whole wheat. Seven blends of the three apical diets were located within the triangle to complete the design and a total of 360 male Ross 308 chicks were offered the ten experimental diets from 7 to 28 d post-hatch. Model prediction and response surface plots were generated with R 3.0.3 software.

3. The most efficient FCR of 1.466 was observed in birds offered an almost equal mixture of the pre- and post-pellet whole grain apical dietary treatments, which corresponded to 172 g/kg ground grain, 256 g/kg pre-pellet whole grain, 172 g/kg post-pellet whole grain in a diet containing 600 g/kg wheat.

4. The most efficient energy utilisation (ME:GE ratio of 0.766) was observed in birds offered a blend of the ground grain and pre-pellet whole grain apical dietary treatments which corresponded to a mixture of 384 g/kg pre-pellet whole grain and 216 g/kg ground grain.

5. Pre-pellet whole grain feeding generated the most pronounced responses in increased relative gizzard contents, reduced gizzard pH and increased relative pancreas weights. Consideration is given to the likely differences between pre- and post-pellet whole grain feeding.     

城市经济增长与环境污染关系的动态响应过程

在介绍研究区域概况的基础上,依据《柳州市经济统计年鉴》、《柳州环境状况公报》相关数据,采用广义脉冲响应函数分析了城市经济增长与环境污染关系的动态响应过程。     

遮荫条件下9个紫花苜蓿品种苗期形态及生长响应

采用遮荫试验,研究了光对9个苜蓿品种苗期形态特征及生长动态的影响。结果表明,不同遮荫处理下苜蓿品种间株高变化有较大的差异,游客表现出最弱的耐阴性;随光照减弱,各品种根颈分枝数、主根粗、二级侧根数、根瘤数、叶片厚度和叶片数均显著下降,表现出较强光环境下更强的形态可塑性;各品种主根长无显著变化,总叶面积动态中新疆大叶、苜蓿王和德宝变化不显著,其他品种显著下降。各品种生物量随遮荫强度增加而显著下降,弱光下各品种生物量对根系的分配明显下降,对茎和叶的分配增加,叶面积比随光强减弱明显增大,相对生长速率随光强减弱显著下降。不同品种同一器官对光环境变化的反应程度不一致,反映了苜蓿各品种耐阴机制的差异。     

磷脂酶C参与ParA1诱导的烟草悬浮细胞死亡和防卫反应

【目的】研究寄生疫霉Phytophthora parasitica分泌的蛋白激发子ParA1诱导烟草悬浮细胞后,磷脂酶C(phospholipase C,PLC)参与ParA1诱导烟草过敏细胞死亡(hypersensitive cell death,HCD)和防卫反应。【方法】采用药理学方法,在烟草悬浮细胞中添加PLC抑制剂,比较烟草悬浮细胞受ParA1诱导后细胞死亡和多种防卫反应的差别。【结果】PLC特异性抑制剂U73122能完全抑制ParA1引起的烟草悬浮细胞死亡,氧迸发、胞外基质碱化和植保素scopoletin(7-羟基-6-甲氧基香豆素)积累都能显著地被抑制,5种防卫基因hin1、hsr203J、PR(pathogenesis-related)-1a、PR-1b和PAL等的转录表达也都受到U73122不同程度的抑制。【结论】ParA1处理烟草悬浮细胞后,PLC参与了ParA1诱导细胞死亡和防卫反应的信号传导过程。