切花非洲菊多倍体诱变初报

 以非洲菊‘阳光海岸’和‘白马王子’ (2n=2x=50) 品种为供试材料, 采用秋水仙素对其组培丛生芽进行离体诱导, 成功获得了四倍体植株。秋水仙素处理浓度和处理时间分别为0.02%、0.05%、0.10%和24、36、48 h。试验结果表明, 以0.10%的秋水仙素处理48 h诱导效果最佳, ‘阳光海岸’和‘白马王子’的丛生芽变异率分别为16%和10%。总体上看, 非洲菊对秋水仙素的敏感性较低。经气孔鉴定、染色体计数和形态学观察, 变异材料染色体数加倍(2n=4x=100) 。与二倍体相比, 变异材料气孔面积增大, 花序变大, 叶色变深, 叶尖变钝圆, 叶片质感变厚, 花梗直径变粗, 花梗基部花青素着色变深。最终分别获得稳定的‘阳光海岸’和‘白马王子’多倍体植株200余株和300余株。     

Modeling the water budget in a deep caldera lake and its hydrologic assessment: Lake Ikeda, Japan

The hydrologic assessment of a lake water budget can be helpful in achieving proper water management and sustainable water use. A model to analyze a lake water budget was developed and verified for Lake Ikeda, Japan. Lake evaporation was estimated by numerical analyses of lake water temperature and the lake energy budget. Inflow from the lake catchment area and leakage from the lake bottom were estimated based on the tank model and Darcy's law, and the model parameters were optimized by the shuffled complex evolution method. The estimated monthly lake evaporation rate is consistent with the evaporation rate estimated by the energy budget Bowen ratio method based on in situ data from 2004 to 2005. Moreover, the calculated time series of daily lake levels agrees well with those of measured lake levels during 1983 to 1999. Thus, the model is useful for evaluating the lake water budget. Numerical analysis reveals seasonal and annual variation characteristics in the water budget components. Precipitation, inflow from the catchment area, and river water supply are generally high during the rainy season from June to July with substantial annual variation. Lake evaporation is greatest in October and least in April, but the annual variation is relatively small. Agricultural water use is relatively high from April to September. There are no marked seasonal changes in leakage and drinking water use. The lake level is generally highest in September and lowest in March, which is characterized by seasonal changes in water budget components. The model was also applied to 17-year simulations under hypothetical hydrologic conditions to examine the effect of water use and agricultural water management on the lake level. Results indicate that river water supply, provided under the agricultural water management system, effectively compensates for the decrease in lake water resulting from agricultural water use.     

Integrated management of irrigation water and fertilizers for wheat crop using field experiments and simulation modeling

The reported study aimed at developing an integrated management strategy for irrigation water and fertilizers in case of wheat crop in a sub-tropical sub-humid region. Field experiments were conducted on wheat crop (cultivar Sonalika) during the years 2002–2003, 2003–2004 and 2004–2005. Each experiment included four fertilizer treatments and three irrigation treatments during the wheat growth period. During the experiment, the irrigation treatments considered were I₁ = 10% maximum allowable depletion (MAD) of available soil water (ASW); I₂ = 40% MAD of ASW; I₃ = 60% MAD of ASW. The fertilizer treatments considered in the experiments were F₁ = control treatment with N:P₂O₅:K₂O as 0:0:0 kg ha⁻¹, F₂ = fertilizer application of N:P₂O₅:K₂O as 80:40:40 kg ha⁻¹; F₃ = fertilizer application of N:P₂O₅:K₂O as 120:60:60 kg ha⁻¹ and F₄ = fertilizer application of N:P₂O₅:K₂O as 160:80:80 kg ha⁻¹. In this study CERES-wheat crop growth model of the DSSAT v4.0 was used to simulate the growth, development and yield of wheat crop using soil, daily weather and management inputs, to aid farmers and decision makers in developing strategies for effective management of inputs. The results of the investigation revealed that magnitudes of grain yield, straw yield and maximum LAI of wheat crop were higher in low volume high frequency irrigation (I₁) than the high volume low frequency irrigation (I₃). The grain yield, straw yield and maximum LAI increased with increase in fertilization rate for the wheat crop. The results also revealed that increase in level of fertilization increased water use efficiency (WUE) considerably. However, WUE of the I₂ irrigation schedule was comparatively higher than the I₁ and I₃ irrigation schedules due to higher grain yield per unit use of water. Therefore, irrigation schedule with 40% maximum allowable depletion of available soil water (I₂) could safely be maintained during the non-critical stages to save water without sacrificing the crop yield. Increase in level of fertilization increases the WUE but it will cause environmental problem beyond certain limit. The calibrated CERES-wheat model could predict the grain yield, straw yield and maximum LAI of wheat crop with considerable accuracy and therefore can be recommended for decision-making in similar regions.     

广东省水稻生产机械装备水平灰色预测与分析

利用广东省水稻生产主要环节机械装备保有量的历史数据,建立了灰色GM(1,1)预测模型,对2006-2020年广东省水稻生产机械装备水平进行了预测,并参考广东省水稻生产机械化作业水平值,对其预测结果进行了修正,以便能为政府主管部门制定提高水稻生产机械装备水平的政策措施提供参考依据.     

金华市农业机械化发展水平评价

为促进金华市农业机械化发展,根据现有农业机械化水平评价方法,建立了金华市农业机械化水平评价指标体系,并确定了各指标的权重.在此基础上,利用1996-2006年金华市有关农业机械化统计数据,计算出金华市历年农业机械化水平,同时分析了影响当地农业机械化发展的因素.最后,结合金华市实际,提出了促进金华市农业机械化水平提高的措施与建议.     

汛期横江入流对向家坝一期围堰河段水位的顶托影响

为保证向家坝一期围堰工程汛期安全度汛,时汛期横江入流的向家坝一期河段水位的顶托影响进行了研究.研究时首先采用实测资料对横江洪水的顶托影响进行分析,在此基础上,采用BP神经网络对不同横江来流下向家坝水文站的水位变化进行预测,给出向家坝水文站的水位壅高幅度.结果表明:横江洪水对向家坝河段水位顶托影响主要发生在金沙江洪水过程的涨水段,一期围堰修建后向家坝水文站受横江来水顶托影响主要发生在屏山流量为8 OOO～17 000 m3/s,且横江流量大于1 000m3/s时的范围内,其水位壅高幅度一般在0.44～1.5 m范围内变化.     

Optimal dietary lipid level for large yellow croaker (Pseudosciaena crocea) larvae

A 30‐day feeding experiment was conducted in blue tanks (70 × 50 × 60 cm, water volume 180 L) to determine the effects of dietary lipid levels on the survival, growth and body composition of large yellow croaker (Pseudosciaena crocea) larvae (12 days after hatchery, with initial average weight 1.93 ± 0.11 mg). Five practical microdiets, containing 83 g kg^?1 (Diet 1), 126 g kg^?1 (Diet 2), 164 g kg^?1 (Diet 3), 204 g kg^?1 (Diet 4) and 248 g kg^?1 lipid (Diet 5), were formulated. Live feeds (Artemia sinicia nauplii and live copepods) were used as the control diet (Diet 6). Each diet was randomly assigned to triplicate groups of tanks, and each tank was stocked with 3500 larvae. During the experiment, water temperature was maintained at 23(±1) °C, pH 8.0 (±0.2) and salinity 25 (±2) g L^?1. The results showed that dietary lipid significantly influenced the survival and growth of large yellow croaker larvae. Survival increased with the increase of dietary lipid from 83 to 164 g kg^?1, and then decreased. The survival of larvae fed the diet with 83 g kg^?1 lipid (16.1%) was significantly lower than that of larvae fed other diets. However, the survival in larvae fed the diet with 16.4 g kg^?1 lipid was the highest compared with other artificial microdiets. Specific growth rate (SGR) significantly increased with increasing dietary lipid level from 83 to 164 g kg^?1 (P < 0.05), and then decreased. The SGR in larvae fed the diet with 164 g kg^?1 lipid (10.0% per day) was comparable with 204 g kg^?1 lipid (9.6% per day), but were significantly higher than other microdiets (P < 0.05). On the basis of survival and SGR, the optimum dietary lipid level was estimated to be 172 and 177 g kg^?1 of diet using second‐order polynomial regression analysis respectively.     

联合分析法在混合动力汽车产品定位中的应用研究

从消费者购买决策角度出发,利用联合分析法,构建我国市场A级混合动力汽车属性与水平模型,分析消费者购买混合动力汽车时赋予不同属性的相时重要性及属性水平的效用值,并模拟产品组合市场占有率情况,从而为混合动力汽车产品定位提供依据.     

大豆对大豆胞囊线虫侵染的应答机制研究

大豆胞囊线虫病(Heterodera glycines,soybean cyst nematode,SCN)是大豆生产上的重要病害,其特点为危害重、分布广、难防治,每年对大豆生产造成极大的损失。种植大豆抗性新品种是防治SCN目前最为有效的措施,研究大豆对SCN侵染的应答机制,是培育大豆持久抗病品种的前提,对加快抗线虫品种选育及SCN的防控具有重要的意义。本文综述了大豆对SCN侵染的组织细胞学应答机制;介绍了大豆在SCN侵染后酶系变化及酚类代谢的生理生化应答机制;从分子水平阐明了SCN侵染后大豆的基因转录变化,差异蛋白及DNA甲基化的应答机制,以期为大豆胞囊线虫病害的进一步研究与防治提供参考。     

施氮水平对7S亚基缺失大豆根系形态和结瘤固氮的影响

为有效推广功能型大豆7S亚基缺失品种,以7S亚基缺失大豆品系东富2号为研究对象,设置4种施氮水平(纯N),N0(0 mg·kg~(-1))、N1(25 mg·kg~(-1))、N2(50 mg·kg~(-1))、N3(75 mg·kg~(-1)),采用桶栽法研究大豆根系形态和结瘤固氮对不同施氮水平的响应。结果表明:N1(25 mg·kg~(-1))水平下根系干重加大,根冠比增大,根瘤固氮潜力高,单株产量较高。N2(50 mg·kg~(-1))水平下根长、根表面积、根体积在生育后期增长较快,根系干重较大,根冠比低,固氮酶活性最高,单株籽粒产量最高。N3(75 mg·kg~(-1))水平下植株干重较大,无效生长较多,根瘤数少,固氮潜力和根冠比低,单株产量不高。综合籽粒产量和根系特性指标,功能型大豆7S亚基缺失品系东富2号的适宜施肥量为25~50 mg·kg~(-1)。