核桃整形修剪技术

阐述了核桃的修剪时期、树形、结果树修剪、老树更新改造、放任树修剪五个方面的整形修剪技术要点。     

Alternative vegetable lipid sources in diets for grouper, Epinephelus coioides (Hamilton): effects on growth, and muscle and liver fatty acid composition

The aim of this study was to investigate the effects of different oils on growth performance and lipid metabolism of the grouper, Epinephelus coioides. Five experimental fish meal‐based isonitrogenous and isolipidic diets were formulated containing either 5.5%‐added fish oil (FO), soybean oil (SBO), corn oil (CO), sunflower oil (SFO) or peanut oil (PO). Each diet was fed to triplicate groups of 20 fish (initial body weight 13.2±0.02 g) grown in seawater at 28.0–30.5 °C for 8 weeks. Fish were fed twice a day to visual satiety. No significant differences in the survival, weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio or hepatosomatic index were found between fish fed the FO or vegetable oils (VO) diets. Dietary lipid sources did not affect whole‐body composition among grouper fed the various diets. Muscle of fish fed the FO diet had significantly higher levels of 14:0, 16:0, 16:1n‐7, 20:5n‐3[eicosapentaenoic acid (EPA)] and docosahexaenoic acid (DHA)+EPA (except for PO fed fish) compared with those of fish fed VO diets. However, the levels of 18:1n‐9, 18:2n‐6 and DHA/EPA ratios in the muscle of fish fed FO diet were significantly lower than those of fish fed the VO diets. The liver of fish fed the FO diet had significantly higher levels of 18:0, 20:5n‐3, 22:6n‐3, n‐3 highly unsaturated fatty acids and DHA+EPA than those of fish fed the VO diets, whereas increases in 18:1n‐9, 18:2n‐6 and mono‐unsaturated fatty acid levels were observed in the liver of fish fed the VO diets.     

光合细菌在水产养殖业的应用研究概况

光合细菌在养鱼、养虾等方面作为饲料添加剂的应用以及光合细菌净化水质，防病，治病方面的应用。     

亚硫酸法降解沙棘籽原花色素的条件优化

以沙棘籽原花色素为原料、亚硫酸为降解剂,应用均匀设计法设计试验,考察降解时间、降解温度、料液比和亚硫酸用量对原花色素降解效果的影响.结果表明:亚硫酸法最佳降解条件为:温度80℃、时间60 min、料液比1:8(g:L)、亚硫酸体积分数为12％,在此条件下亚硫酸降解效果明显,降解前平均聚合度为13.42,降解后平均聚合度为7.53.     

岩溶山区磷石膏堆场重金属迁移对耕地质量的影响及污染风险管控

[目的]探讨磷石膏堆场周边耕地土壤重金属含量的变化、成因及污染风险,为磷化工产业可持续发展及水土环境重金属污染的治理提供科学依据。[方法]通过对贵州省中部磷石膏堆场进行实地调查与采样开展分析和研究。[结果]磷石膏堆场排水、侵蚀冲沟水及洼地积水中Cd,Hg,As的含量都超过农田灌溉水质一类标准(水作)水质限值,特别是Cd。在磷石膏堆场周边50～300 m范围内,玉米地、蔬菜地、水稻土中Cd的含量分别超过农用地土壤污染风险筛选值的4.87～9.43倍、8.83～19.13倍和3.83～13.42倍,堆场周边旱作土主要是Cd,As,Zn的污染风险,而水稻土则主要是Cd,As,Hg,Zn的污染风险;大部分蔬菜地土壤和水稻土中Cd的含量超过农用地土壤污染风险管控值。[结论]天然降雨对露天磷石膏堆场产生的侵蚀及淋溶作用是重金属迁移的主要原因,在地表水流方向上耕地重金属污染风险随着堆场距离的增加而逐步减小。兴修排灌设施及调整种植结构是减少磷石膏堆场周边耕地重金属污染的有效途径。     

西瓜四倍体与二倍体正反交果实发育过程中内源激素的变化

为了探究西瓜四倍体与二倍体反交种子败育的原因,以蜜枚的二倍体和四倍体为材料,采用酶联免疫法(ELISA)对授粉后1~13 d果实内赤霉素(GA)、玉米素核苷(ZR)、脱落酸(ABA)和生长素(IAA)4种内源激素进行测定。结果表明:蜜枚二倍体与四倍体西瓜正交果实发育过程中,ZR和ABA呈现升高-降低-升高-降低的趋势,GA_3和IAA呈现降低-升高-降低-升高的趋势,蜜枚二倍体与四倍体西瓜反交授粉后3~4 d ABA含量较高,授粉后7 d GA和IAA含量较低,授粉后5 d GA_3平均水平低于正交。这样的差异可能就是反交种子败育的原因。     

Effects of rhythmic temperature change on the growth,body composition and energy budget of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

Effects of rhythmic temperature change on the growth, body composition and energy budget of hybrid grouper (Epinephelus lanceolatus ♂ × E. fuscoguttatus ♀) were investigated. Nine groups of fish received repeating cycles of low‐temperature manipulation (22°C) for 1, 2 and 4 days followed by recovery temperature (28°C) for (3, 7 and 11 days), (6, 14 and 22 days) and (12, 28 and 44 days) respectively, designated as L1R3, L1R7, L1R11, L2R6, L2R14, L2R22, L4R12, L4R28 and L4R44 respectively. In the control group (C), fish were reared at 28°C throughout the whole experiment. After 96‐day feeding trail, the final weight, relative weight gain rate, specific growth rate, food conversion efficiency and apparent digestibility coefficient of fish in L4R28 were significantly higher than those of control (p < .05). The crude protein contents of fish in L2R14, L2R22, L4R12, L4R28 and L4R44 were significantly higher compared to the control (p < .05). According to energy budget, fish in L4R28 exhibited significantly higher proportion of food energy assimilated into growth and lower proportion consumed for excretion than the control fish (p < .05). These results indicated the occurrence of complete or over growth compensation in hybrid grouper, and the use of repeated cycles of low temperature (22°C) for 4 days followed by recovery temperature (28°C) for 28 days could obtain enhanced growth, that is overcompensation, with improved apparent digestibility coefficient, food conversion efficiency and energetic efficiency into growth. This technique would be more practically applicable in indoor culture for this species.     

Impact of short‐term climate effects and sea ice coverage variation on Japanese scallop aquaculture in Saroma Lake,Japan

Saroma Lake is the southernmost lagoon exhibiting seasonal sea ice coverage in the Northern hemisphere and one of the most important aquaculture areas for Japanese scallops (Mizuhopecten yessoensis). Under conditions of adequate food and appropriate temperature, scallops grow well from the time of ice melting in April to harvesting starting in July. However, over the past decade, Saroma Lake frequently has not been completely covered by ice in winter, and the production of Japanese scallops has shown significant changes. Therefore, this study integrated data from satellite remote sensing, buoys, and in situ observations with climatic events [the winter East Asian Monsoon (EAM) and El Niño/La Niña–Southern Oscillation events] to investigate the impact of ice coverage variations on scallop growth in Saroma Lake between 2007 and 2015. Daily ice conditions were detected using Moderate Resolution Imaging Spectroradiometer false colour images and an unsupervised classification method. The results indicated that EAM strongly influenced the ice coverage variation in Saroma Lake through their effects on temperature during winter. Ice coverage variations show a strong correlation with water temperature and spring phytoplankton blooms, which are the two most important environmental factors for scallop growth. In addition, extreme climate events could cause water temperature anomalies (as in 2015) which are unfavourable for scallop growth. Monitoring ice conditions should be considered when developing plans and management strategies for scallop aquaculture in Saroma Lake.     

夏蜡梅天然群体表型变异及分布特征

选取夏蜡梅自然分布区8个群体,对花部、叶部、果部和种子的22个性状进行了系统调查与分析,以揭示夏蜡梅天然群体的表型变异特征及变异规律。结果显示:夏蜡梅天然群体存在丰富的表型变异,20个表型性状在群体间与群体内差异均达到极显著水平(P0.01),平均变异系数为12.15%(6.40%～45.87%),平均表型分化系数为41.87%(1.14%～85.07%),群体内变异(58.13%)大于群体间变异(41.87%);夏蜡梅花色(外被片颜色)表现为白、浅粉、粉、粉红4种类型,不同群体间各花色比例各有不同;各表型性状与生态因子间相关性分析结果显示,22个表型性状中有8个和生态因子呈显著相关。通过表型性状UPGMA聚类分析可以将8个群体划分为4个类群,表型性状分化体现为连续性的地理分布格局。     

基于深度学习与多尺度特征融合的烤烟烟叶分级方法

为实现烤烟等级的快速准确识别,降低人工分级中主观因素对分级结果的影响,提高烟叶分级的准确性和一致性,提出一种基于烤烟RGB图像和深度学习的多尺度特征融合的烟叶图像等级分类方法,采用ResNet50提取烟叶图像特征,并引入基于注意力机制的SE模块(压缩激发模块),增强不同通道特征的重要程度;同时,采用FPN(特征金字塔网络)对提取的由浅及深不同层级的烟叶特征进行融合,以实现烟叶多尺度特征的表达。采集皖南地区6068个烤烟的正面和背面图像用于建模和分析。结果表明,提出的烟叶分级方法的分级正确率比经典CNN(卷积神经网络)高出5.21%,分级模型在新批次7个等级烟叶上的分级正确率为80.14%,相邻等级的分级正确率为91.50%。因此,采用RGB图像结合深度学习技术可实现烤烟烟叶等级的良好识别,可为烤烟烟叶收购等级评价提供一种新方法。