黑龙江鱼类开发利用浅析

黑龙江流域地处我国高寒地区,地理环境和鱼类区系组成特殊,形成了许多特有的名贵经济鱼类,为我国的渔业经济发展做出重大贡献。本文简要概述黑龙江流域的鱼类资源、黑龙江省渔业发展现状,以及主要经济鱼类的养殖状况,分析讨论黑龙江鱼类的生物学种质特点,以及目前名优鱼类的市场需求,并针对黑龙江鱼类的开发利用提出了几点建议。     

Local adaptation studies and conservation: Parasite–host interactions between the endangered freshwater mussel Unio crassus and its host fish

1. Parasite–host interactions can involve strong reciprocal selection pressure, and may lead to locally adapted specializations. The highly threatened unionoid mussels are temporary parasites on fish, but local adaptation has not yet been investigated for many species.
2. Patterns of local adaptation of one of Europe's most threatened unionoids, the thick‐shelled river mussel (Unio crassus) were investigated. Eurasian minnows (Phoxinus phoxinus) from two rivers (separate drainage areas) were cross‐infested in the laboratory with sympatric and allopatric mussel larvae, while bullheads (Cottus gobio), inhabiting only one of the rivers, were infested with sympatric or allopatric mussel larvae. Larval encystment, juvenile mussel excystment and survival were measured.
3. For one river, but not the other, juvenile excystment from P. phoxinus was highest when infested with sympatric mussels. The opposite pattern was found for C. gobio in this river, where juvenile excystment and post‐parasitic juvenile survival from allopatric C. gobio were highest. The results thus cannot confirm local adaptation of U. crassus to P. phoxinus in the study rivers, as excystment was not consistently higher in all sympatric mussel–host combinations, whereas there were potential maladaptive signs of U. crassus in relation to C. gobio. There was no loss of encysted larvae 3 days after infestation until juvenile excystment. Most juveniles were excysted between 17 and 29 days after infestation, and the numbers of excysted juveniles increased with fish size.
4. The results have implications for parasite–host ecology and conservation management with regard to unionoid propagation and re‐introduction. This includes the need to (1) test suitability and adaptation patterns between U. crassus and multiple host fish species, (2) evaluate the suitability of certain unionoids and host fish strains after more than 3 days, and (3) determine whether large fish produce more juvenile mussels than smaller fish.

     

The importance of dietary HUFA for meagre larvae (Argyrosomus regius; Asso, 1801) and its relation with antioxidant vitamins E and C

Despite the interest of meagre (Argyrosomus regius) as a fast‐growing candidate for Mediterranean aquaculture diversification, there is a lack of information on nutrition along larval development. Importance of highly unsaturated fatty acids (HUFA) and the antioxidant vitamins E and vitamin C has not been investigated yet in this species. Six diets with two levels of HUFA (0.4% and 3% dw), two of vitamin E (1500 and 3000 mg kg^?1) and two of vitamin C (1800 and 3600 mg kg^?1) were fed to 15 dah meagre larvae. Larval growth in total length and dry body weight was significantly lowest in larvae fed diet 0.4/150/180 and showed few lipid droplets in enterocytes and hepatocytes and lower HUFA contents than the initial larvae. Increase in dietary HUFA up to 3%, significantly improved larval growth and lipid absorption and deposition. Besides, among fish fed 3% HUFA, increase in vitamin E and vitamin C significantly improved body weight, as well as total lipid, 22:6n‐3 and n‐3 fatty acids contents in the larvae. Thus, the results showed that 0.4% dietary HUFA is not enough to cover the essential fatty acid requirements of larval meagre and a high HUFA requirement in weaning diets is foreseen for this species. Besides, the results also pointed out the importance of dietary vitamin E and C to protect these essential fatty acids from oxidation, increase their contents in the larvae and promote growth, suggesting high vitamin E and C requirements in meagre larvae (higher than 1500 and 1800 mg kg^?1 for vitamin E and vitamin C respectively).     

青藏高原草地降水利用效率时空动态及对气候变化的响应

本研究利用CASA(Carnegie-Ames-Stanford Approach)模型模拟了2000—2013年青藏高原草地净植被生产力(Net Primary Production，NPP)，结合实测数据、气象数据和土地覆被数据计算了草地降水利用效率（PUE），探究其时空分布特征，以及不同草地类型PUE及其对气候变化的响应。结果表明：青藏高原草地PUE在研究年限内呈现波动增加趋势，增加速率为每年0.0035 g·m^-2·mm^-1，14 a的平均值为0.38 g·m^-2·mm^-1。PUE的空间分布具有明显的异质性，呈现东部高、中西部低的基本格局。PUE分布在0.2～0.4 g·m^-2·mm^-1之间的比例最大，占青藏高原总面积的55.63%，呈减少趋势的区域主要分布在青藏高原的北部和西部，以及东部的边界地区，呈增加趋势的地区集中在研究区的中部和南部。研究年限内PUE的变异系数分布在0.07～0.85之间，变化稳定的区域所占面积最大，为总面积的43.43%，主要分布在唐古拉山脉和横断山脉附近。不同草地类型间PUE均值存在差异，具体表现为：草甸（1.06 g·m^-2·mm^-1）>坡面草地（0.80 g·m^-2·mm^-1）>平原草地（0.30 g·m^-2·mm^-1）>高山与亚高山草甸（0.29 g·m^-2·mm^-1）>荒漠草地（0.23 g·m^-2·mm^-1）>高山与亚高山草地（0.094 g·m^-2·mm^-1）。总体上，青藏高原草地PUE与降水成负相关关系，而与气温呈正相关，PUE的变化对降水响应更加敏感。     

深松对春玉米根系分布及氮素积累与利用的影响

2015—2016年以先玉335和郑单958为试验材料，设置深松+旋耕（S+R）和旋耕（R）2个处理，研究了深松对春玉米根系分布及氮素积累与利用的影响。结果表明：深松疏松了土壤，有利于根系的生长，促进根系下扎，深松措施下先玉335和郑单958完熟期总根干重较旋耕处理分别提高了7.35%和9.25%，其中20~40 cm土层分别提高了15.52%和24.07%，30 cm以下土层根条数和根幅明显增加。深松改善根系形态特征，增加了根系与氮素的接触机会，促进了春玉米对氮素的吸收和累积，使单位重量根系氮素吸收量明显提高，吐丝前S+R处理的先玉335和郑单958单位重量根系氮素吸收量较R处理分别提高了11.22%和12.03%，处理间差异达到了显著水平。S+R处理的氮素吸收效率先玉335和郑单958较R处理分别提高6.11~6.40 kg·kg^-1和7.17~7.51 kg·kg^-1，氮肥偏生产力分别提高了3.86~8.00 kg·kg^-1和5.40~9.86 kg·kg^-1，氮素积累量分别提高了33.73~35.66 kg·hm^-1和27.85~36.61 kg·hm^-1。与先玉335相比，郑单958对深松更为敏感。     

不同浓度NAA/6BA配比对不同品种甘薯茎尖培养特性的影响

为明确不同品种甘薯茎尖培养的最佳NAA/6BA配比,设置0.1 mg/L/2.5 mg/L、0.2 mg/L/2.5 mg/L、0.2 mg/L/1.0 mg/L 3组NAA/6BA浓度配比处理,观测不同浓度激素处理对‘北京553’、‘红香蕉’、‘苏薯8号’、‘烟薯25’、‘安吉芋’、‘济徐23’、‘渝紫7号’、‘商薯19’茎尖培养成苗率、愈伤组织直径、不定根数目、叶片数和植株高度的影响,同时调查不同品种试管苗的移栽成活率。结果表明,‘红香蕉’、‘济徐23’、‘渝紫7号’、‘商薯19’在0.1 mg/L/2.5 mg/L的处理下培养效率最高;‘安吉芋’在0.2 mg/L/2.5 mg/L的处理下培养效率最高;‘苏薯8号’、‘北京553’、‘烟薯25’在0.2 mg/L/1.0 mg/L的处理下培养效率最高。因此,在甘薯茎尖培养过程中,不同甘薯品种适宜的NAA/6BA配比存在显著差异,在实际生产中应根据品种特性来进行调整激素的用量和比例。     

基于水-能源-粮食纽带关系的农业资源投入产出效率研究

为研究我国2010—2017年农业资源投入产出效率及时序演化特征，采用数据包络分析（DEA）方法，以中国内地31个省份为研究对象，基于农业生产中的水-能源-粮食纽带关系，构建了以农业用水量、能源产品使用量、排灌耗能量、能源产品生产用水量作为输入变量，以主要农产品生产总量、第一产业国内生产总值（第一产业GDP）为输出变量的评价指标体系。结果表明，我国有19个省份尚未达到DEA有效状态，大部分省份的农业资源投入产出效率有较大上升空间。研究表明，我国大部分省份（20个）的综合效率主要受纯技术效率的影响，其中最典型的宁夏、甘肃、新疆三个西北省份的纯技术效率明显落后，资源利用效率和管理水平有待提高。     

我国农作物绿色食品的生产瓶颈和生产前景

生产农作物绿色食品是农业的发展方向，也是可持续发展的必然要求，是世界范围都要引起 重视的普遍课题，我国更需迫切重视。使用一般的无公害杀虫剂是不能生产出绿色食品的，而目前病 虫害绿色防控技术还不成熟，现在可用于绿色食品生产的高效无毒的杀虫剂在我国已首先研究出来 了，当前缺少的仅是农产品市场完备的农药残留检测机制，解决这个瓶颈问题可给绿色食品创造存在 的空间，从而实现农业绿色产业大发展，这一天的到来已为期不远。     

Grain yield,nitrogen use efficiency and tillage intensity in wheat as affected by precision nutrient management

ABSTRACT

The present studies were conducted to evaluate the effect of different nutrient management practices under two tillage options in wheat. The experiments were laid out in split-plot design with a combination of two varieties (WH 1105 and HD 2967) and two tillage options (Conventional and No tillage) in the main plot and six precision nutrient management practices [absolute control, site-specific nutrient management with Nutrient Expert for wheat (SSNM-NE)(170 kg nitrogen (N)/ha), SSNM NE+GreenSeeker (GS)(153/158 N kg/ha), N₁₂₀ (120 kg N/ha) before irrigation, N₁₂₀ after irrigation and N Rich (180 kg N/ha)] in subplot replicated thrice. The grain yield and quality characters in no tillage (NT) and conventional tillage (CT) were similar but agronomic efficiency was higher in NT. Both the varieties (WH 1105 and HD 2967) gave similar grain yield and quality. Wheat variety WH 1105 recorded significantly higher sodium dodecyl sulfate sedimentation (SDS) and gluten index. The treatment SSNM NE+GS had resulted in 107.1% higher grain yield than no nitrogen control but similar to enriched N plot (180 kg N/ha). The grain protein, SDS and gluten index in need-based nutrient management (SSNM+GS) treatment were found to be similar as recorded in SSNM-NE (170 kgN/ha) and N enriched plot (180 kg N ha^?1). The agronomic efficiency and recovery efficiency in SSNM+GS were also better than SSNM NE.