边界线分析法评价小麦/西瓜/玉米间作体系产量的限制因子

本研究旨在分析小麦/西瓜/玉米间作体系限制作物产量的关键因子,为该体系的优化提供科学依据。采用农户调研的方式,对河北省曲周县的小麦/西瓜/玉米间作模式展开调查,主要调研内容是小麦和玉米的播种量、养分投入量和产量以及西瓜的养分投入量和产量,应用边界线分析方法评价小麦/西瓜/玉米间作高产体系的限制因子。结果表明,限制小麦产量的关键因子为小麦播种量,贡献率达17.8%,而养分投入量的贡献率分别为:P₂O₅ 12.5%、K₂O 11.7%、N 8.0%。限制西瓜产量的关键因子为钾肥投入量,贡献率达15.8%,N、P₂O₅的贡献率分别为14.2%和11.8%。限制玉米产量的关键因子为氮肥投入量,贡献率达20.6%,其他因子的贡献率分别为:K₂O 14.2%,P₂O₅ 11.5%,播种密度9.2%。因此,在小麦/西瓜/玉米间作体系中,应适当调控小麦播量,优化西瓜的钾肥和玉米的氮肥投入量,促进该间作模式的产量优势。     

4种氯制剂对养殖废水中高硝酸盐和亚硝酸盐的影响

在高硝酸盐和亚硝酸盐养殖水体中添加一定浓度氯制剂,研究了漂白粉、漂粉精、强氯精和二氧化氯对养殖水体高亚硝酸盐和高硝酸盐消除能力的影响。结果发现：4种氯制剂对硝酸盐和亚硝酸盐消除都有显著性效果(P<0.05),水体中氨氮在试验过程中无显著变化,浓度为0.00 mg/L;二氧化氯组消除效果最明显,30 min时硝酸盐和亚硝酸盐的消除率高达99%、100%,处理组和空白组的硝酸盐浓度为(0.15±0.72)、(16.82±0.97) mg/L,亚硝酸盐浓度为(0.07±0.01)、(19.95±0.61) mg/L,强氯精次之,漂白粉效果最差,30 min时消除率分别为50%、38%,漂白粉和空白组硝酸盐的浓度为(8.49±0.66)、(16.82±0.97) mg/L,亚硝酸盐浓度为(12.33±0.48)、(19.95±0.6) mg/L;水体的pH值在试验后,各处理组都发生了显著的变化(P<0.05),空白组pH 7.63±0.10,强氯精和二氧化氯添加组,pH值都为降低趋势,二氧化氯组pH值降幅最大(pH 2.68±0.06),漂白粉和漂粉精添加组,pH值呈升高趋势,漂白粉组pH值升幅最大(pH 9.6)。通过本试验的研究,4种氯制剂在消除养殖废水中高亚硝酸盐效果显著,并且无氨氮累积,不产生二次污染物,对于养殖废水的处理排放及循环使用有重要意义。     

应用营养调控技术保护奶牛养殖环境的措施

随着奶牛集约化程度的提高,奶牛粪便中氮、磷的排放也逐渐增加,减少奶牛粪便氮、磷排放已成为奶牛生产研究的热点问题。文章从奶牛营养调控技术阐述了降低奶牛粪便中氮、磷排放的调控措施,为减少奶牛氮、磷的排放,保护养殖环境提供可行方法。     

Optimum Level of Dietary n‐3 Highly Unsaturated Fatty Acids for Juvenile Sea Cucumber,Apostichopus japonicus

A feeding trial was conducted to estimate the optimum level of dietary n‐3 highly unsaturated fatty acids (HUFAs) for juvenile sea cucumber, Apostichopus japonicas, based on growth performance and fatty acid compositions. Diets with five n‐3 HUFAs levels (0.15, 0.22, 0.33, 0.38, and 0.46%) were fed to sea cucumber juveniles (1.97 ± 0.01 g) once a day for 60 d. The sea cucumbers fed diets containing 0.22% n‐3 HUFAs showed significantly (P < 0.05) higher body weight gain, feed efficiency, and protein efficiency ratio than the sea cucumbers fed diets containing 0.15% n‐3 HUFAs, but not significantly different (P > 0.05) from those of sea cucumbers fed diets containing 0.33, 0.38, and 0.46% n‐3 HUFAs. The sea cucumbers fed diets containing 0.46% n‐3 HUFAs showed significantly (P < 0.05) higher eicosapentaenoic acid and saturated fatty acid than the sea cucumber fed diets containing 0.15% n‐3 HUFAs, but not significantly different (P > 0.05) from those of sea cucumbers fed diets containing 0.22, 0.33, and 0.38% n‐3 HUFAs. The results of growth performance and n‐3 HUFA compositions of body wall indicated that the optimum level of dietary n‐3 HUFAs for juvenile sea cucumber is between 0.22 and 0.46%.     

基于无线传感网络隧道亮度信号采集系统的研究

亮度信号是高速公路隧道节能照明控制系统必须检测的物理量。本文基于zigbee的技术特点,设计了一款基于无线传感网络的隧道亮度信号采集系统。系统的传感器节点负责亮度信号的采集,经CC2530处理发送,通过逐级跳转的方式把数据传输到协调器。协调器通过RS232串口与灯具控制器通信,以此实现对亮度信号的实时采集和可靠性传输。通过实验表明,该系统达到了设计的目的,并适用于高速公路隧道节能照明控制系统。     

Development of male-specific markers and identification of sex reversal mutants in papaya

Papaya is a productive and nutritious fruit grown in tropical and sub-tropical regions worldwide. It is polygamous with three sex types: female, male and hermaphrodite. Sex determination in papaya is controlled by an XY sex chromosome system with two slightly different Y chromosomes, Y for males and Y^h for hermaphrodites. Comparative analysis of the hermaphrodite-specific region of Y^h chromosome (HSY) and male-specific region of Y chromosome (MSY) revealed 99.6% sequence identity, which explains why DNA markers that amplify for both males and hermaphrodites have easily been developed, but not for the male trait specifically. We examined the 0.4% sequence differences, and found 1887 indels and 21,088 SNPs between MSY and HSY. The vast majority of indels are single nucleotide or few base pairs. A large male-specific retrotransposon insertion of 8396 bp was used to develop two papaya male-specific markers, PMSM1 and PMSM2 that amplify 585 and 548 bp fragments, respectively. These two markers were tested in 11 gynodioecious and four dioecious varieties along with autosomal DNA marker 71E and male/hermaphrodite marker W11, and the results showed clear separation of male from hermaphrodite and female. PMSM1 and PMSM2 were also used to test the sex type of six sex male-to-hermaphrodite reversal mutants which are crucial materials for validating candidate genes for sex determination in papaya. Our result showed all six mutants were positive for the male-specific markers. These male-specific markers can be used to distinguish gynodioecious and dioecious cultivars in papaya seed market, and facilitate genetic and genomic research for papaya improvement.     

Interspecific cross‐hybrids of Nicotiana tabacum L. cv. (gla.) S ‘K326’ with Nicotiana alata

In order to introduce the Tomato Spotted Wilt Virus (TSWV) resistance from Nicotiana alata into Nicotiana tabacum, a cytoplasmic male sterility (CMS) line of N. tabacum (N. tabacum L. cv. (gla.) S ‘K326’), was successfully crossed with N. alata. Despite a high DNA content variability, F₁ hybrids could be classified in two subgroups, a major one encompassing fertile hybrids morphologically similar to their tobacco maternal parent but TSWV sensitive, and a minor one displaying sterile hybrids showing an intermediate phenotype and TSWV resistant. In order to elucidate the unexpected fertility recovery of the fertile F₁ plants, some N. alata fertility restoration ppr genes were cloned and were shown to be differentially expressed between parental lineages as well as between both F₁ subgroups, suggesting that N. alata contains fertility restoring allele able to overcome the CMS of N. tabacum.     

烤烟带电育苗病虫害与生长调查

利用双层带电育苗技术，研究其对烟苗育苗期间常见的病虫害预防效果以及苗的生长状况。结果表明:带电育苗对根茎类和气传病害有预防效果。烟苗生长速度快，能有效缩短成苗时间、提高烟苗质量；但底层有无人工补光和营养液碳酸氢根离子浓度高低对预防白粉病影响很大，对调控生长效果影响显著。带电育苗时底层补光并在原液中添加碳酸氢钾或在环境中增施烟气CO2，对预防白粉病效果显著。带电育苗上、下层在蚜虫密集环境中仍然不能有效趋避蚜虫，而使用物理植保液防治蚜虫非常有效。      

梨树栽培管理关键技术

指出了梨树具有高度的营养价值、经济价值、生态价值,从林地的选择、林地整地、苗木栽植、树园管理、树形期修剪、果实采收贮运及梨树栽培管理技术等方面提出了关键技术实施要点,并对梨树的发展前景做出了评估.