3种重金属离子对不同产地卤虫卵孵化率的影响

实验室条件下,在经过沉淀以及过滤的自然海水中分别加入不同浓度的Hg^2＋、Pb^2＋、Cd^2＋离子,分别对国产和进口2个产地的卤虫卵进行了孵化试验.结果表明：与对照组相比,3种重金属离子都降低了2个产地卤虫卵的孵化率,且浓度越高降低的百分率越大,3种重金属离子降低孵化率大小顺序为：Hg^2＋＞Cd^2＋＞Pb^2＋;3种离子对2个产地的卤虫卵产生了不同的影响：进口卤虫大于对国产卤虫卵的降低率.     

Phosphorus Fertilization and Fungal Inoculations Affected the Physiology,Phosphorus Uptake and Growth of Spring Wheat Under Rainfed Conditions on the Canadian Prairies

Some fungal species have been shown to improve plant growth under drought conditions and to increase plant phosphorus (P) uptake from the soil. How moisture limitation, P availability and fungal inoculation interact to affect plant physiology and growth is, however, poorly understood. Here, we studied the combined effects of fungal (arbuscular mycorrhizal fungi (AMF) or Penicillium spp.) inoculations and phosphorus (P) fertilization (0, 45 and 90 kg ha^?1) on the net rate of photosynthesis, water‐use efficiency, P uptake and growth of spring wheat (Triticum aestivum var. Superb) under field conditions at two locations (Castor and Vegreville) in Alberta, Canada. Both fungal inoculation and P application increased the rate of photosynthesis. Under the same P level, AMF inoculation had a greater positive effect on the rate of photosynthesis than Penicillium inoculation. The AMF inoculation increased the instantaneous water‐use efficiency (WUEi) of plants at Castor, but not at Vegreville. Leaf carbon isotope discrimination (CID, Δ¹³C) increased with the rate of P application but was not affected by fungal inoculations. Phosphorus concentrations of stem and seed increased with both fungal inoculation and P application irrespective of location, with AMF inoculation showing the largest effects. The interaction between P addition and fungal inoculation was significant for stem P concentration in Vegreville. Both fungal inoculation and P application increased the leaf area index (LAI), biomass production and grain yield at both locations. Under the same P level, AMF inoculation had a greater positive effect on LAI, biomass production and grain yields than Penicillium inoculation. Morphological characters such as spike length and kernels/spike were also improved by fungal inoculation and P application at both locations. We conclude that the studied sites were deficient in P availability, and both fungal inoculation and P application improved P uptake and crop productivity, while the effect of fungal inoculation on water‐use efficiency was site specific.     

马铃薯种薯质量对生长和产量的影响Ⅰ .种薯大小

对影响马铃薯的几个主要因素及相互作用进行研究,结果表明,当播种密度一定时,种薯大小无一例外地显著影响产量,即种薯越大产量越高,而其他因素包括品种、来源、季节和海拔不同程度地影响生长和产量。播种时,单位面积的种薯出芽数调整为相同时,种薯大小对单位面积产量不产生影响。证明了种薯单位面积产生的主茎数对产量起决定性作用,特别是单株结薯较少的品种和秋冬作。     

杂草稻分类及起源研究进展

杂草稻已成为影响全球水稻生产的恶性杂草.关于分类及起源一直是杂草稻研究的热点问题,但至今尚无定论.杂草稻是指在人工栽培稻田中或稻田周边耕地里,通过种子落粒等对自然环境的极强适应能力而自然繁衍其群体,对稻田生态系统产生不利影响的稻属植株或群体.一般可根据形态特性、籼粳亚种属性、栽培型和野生型对杂草稻进行分类.杂草稻可能起源于栽培稻与野生稻的基因渐渗、籼粳亚中间杂交和栽培稻种间杂交,部分杂草稻可能是普通野生稻演化成原始栽培稻的过渡形态,栽培稻与杂草稻自然异交可产生更多的杂草稻类型.因此,提出了杂草稻分散起源的假说,认为杂草稻很可能是多次起源,而且杂草稻在不同地区可能是分散起源.对利用籼粳基因组分化和稻属驯化相关基因研究杂草稻起源的可行性及重要意义进行了分析.     

柳树名源与史前木材切割技术

结合柳树生物特性和功用特点、训诂学、考古学等知识分析了柳树一名的起源,运用玉石加工技术考古成果,提出＂卯＂字本义就是发端于新石器时代的木材切割技术,即砂绳切割和片切割技术,并对这些技术的起源进行了初步探讨。     

南海短尾大眼鲷线粒体Cyt b 基因序列及种群判别分析

对采集于中国南海北部近岸和南沙西南部陆架海域7个采样点共246尾短尾大眼鲷(Priacanthus macracanthus)样品进行了线粒体细胞色素b基因(cytochrome b,cyt b)序列的扩增与分析,获得了长度为684 bp的同源序列。碱基A、T、C、G含量分别为22.7%、28.4%、33.4%、15.5%,共检测到多态位点92个,定义了90个单倍型。其遗传多样性表现出高单倍型多样性(0.8130~0.9012)和低核苷酸多样性(0.0040~0.0053)的特点。两两群体间的Fst分析显示,大部分群体间的Fst值均小于0.05,且差异不显著(P0.05),样本总体分化指数仅为0.012,群体间分化程度很低。分子方差分析(AMOVA)表明,群体间的遗传变异仅占总遗传变异的1.25%,98.75%的遗传变异源于群体内,群体之间有较高的遗传同质性。基于邻接法构建的系统发育树和基于中间连接法构建的单倍型网络图均显示,南海短尾大眼鲷不存在与地理群体对应的支系,遗传分化不显著。中性检测和不对称分布分析发现,南海短尾大眼鲷群体在更新世晚期发生过种群扩张。结果表明南海短尾大眼鲷群体间的遗传交流较频繁,可以认为是一个大的种群。     

稳定性氢同位素在羊肉产地溯源中的应用

 【目的】探讨稳定性氢同位素在羊肉产地来源鉴别中的作用,为羊肉产地同位素溯源指标体系的确定和构建提供依据。【方法】利用稳定性同位素比率质谱仪（IRMS）测定来自内蒙古自治区锡林郭勒盟、阿拉善盟和呼伦贝尔市3个牧区,重庆市和山东省菏泽市2个农区脱脂羊肉中的δ2H值,通过方差分析和相关分析,探讨稳定性氢同位素组成的地域特征及其变化规律;结合C、N同位素指标,采用聚类分析及判别分析,进一步了解氢同位素在羊肉产地来源判别中的作用。【结果】不同地域来源羊肉中的δ2H值具有显著性差异,其δ2H值主要与当地饮水中的δ2H值高度相关。判别分析结果表明,δ2H值可使δ13C、δ15N指标对羊肉产地的正确判别率由80.8% 提高到88.9%。【结论】稳定性氢同位素能够提供可靠的地域信息,可作为追溯和鉴定羊肉产地来源的一项有效指标。     

基于深度学习网络实现番茄病虫害检测与识别

为利用计算机或人工智能技术协助番茄病虫害防治,以存在病虫害侵害问题的番茄植株图像为研究对象,针对番茄病虫害目标小而密的特点提出基于Swin Transformer的YOLOX目标检测网络,用于精确定位图像中的病虫害目标,并采用基于经典卷积神经网络构建的旋转不变Fisher判别CNN分类网络,以此提高病虫害分类的准确率。结果表明:1)将测试结果与传统的目标检测模型和分类模型作对比,基于Swin Transformer的YOLOX网络在番茄病虫害测试集上的精确度比Faster R-CNN和SSD分别高了7.9%和9.5%,旋转不变Fisher判别CNN对病虫害类别的识别准确率与AlexNet、VGGNet相比分别提升了8.7%和5.2%;2)与基于Transformer的目标检测模型DETR和近年来新兴的图像分类模型Vision Transformer(ViT)在番茄病虫害测试集上的结果相比较,本研究的检测和分类方法也存在优势,病虫害检测精度和分类准确率分别提高了3.9%和4.3%。此外消融试验也证明了本研究方法改进的有效性。总之,本研究所构建的网络在番茄病虫害的目标检测和分类识别方面的性能优于其他网络,有助于提升番茄病虫害的防治效果,对计算机视觉在农业领域的应用具有重要意义。     

不同产地红茶香气成分的测定及分析

通过同时蒸馏萃取法(SDE)提取8个不同产地红茶的香气成分,采用气质联用(GC-MS)测定了各香气成分含量,对其差异进行了分析。结果表明:8种红茶共检测出182种香气化合物,其中信阳红茶60种、祁门红茶75种、正山小种59种、凤庆红茶72种、英红九号64种、石门怡红87种、锡兰红茶75种、印度大吉岭红茶96种;红茶香气化合物以醇类、醛类为主,其含量超过了总香气物质的50%;祁门红茶、凤庆红茶和印度大吉岭红茶以醇类的相对含量偏高,信阳红、英红九号、石门怡红和锡兰红茶以醛类的相对含量偏高,而正山小种二者相对含量较接近;祁门红茶和正山小种萜烯指数较低,其香气类型为香叶醇占主导地位的典型中国变种红茶香气;英红九号、石门怡红、锡兰红茶、凤庆红茶、印度大吉岭红茶、信阳红茶的萜烯指数较高,它们的香气属于芳樟醇占优势的香型。     

Effects of Rice Straw and Its Biochar Addition on Soil Labile Carbon and Soil Organic Carbon

Whether the biochar amendment could affect soil organic matter （SOM） turnover and hence soil carbon （C） stock remains poorly understood. Effects of the addition of ^13C-labelled rice straw or its pyrolysed biochar at 250 or 350℃ to a sugarcane soil （Ferrosol） on soil labile C （dissolved organic C, DOC; microbial biomass C, MBC; and mineralizable C, MC） and soil organic C （SOC） were investigated after 112 d of laboratory incubation at 25℃. Four treatments were examined as （1） the control soil without amendment （Soil）; （2） soil plus ^13C-labelled rice straw （Soil＋Straw）; （3） soil plus 250℃ biochar （Soil＋B250） and （4） soil plus 350℃biochar （Soil＋B350）. Compared to un-pyrolysed straw, biochars generally had an increased aryl C, carboxyl C, C and nitrogen concentrations, a decreased O-alkyl C and C：N ratio, but similar alkyl C and δ^13C （1 742- 1 877 %）. Among treatments, significant higher DOC, MBC and MC derived from the new C （straw or biochar） ranked as Soil＋Straw〉Soil＋B250〉Soil＋B350, whilst significant higher SOC from the new C as Soil＋B250〉Soil＋Straw≈Soil＋B350. Compared to Soil, DOC and MBC derived from the native soil were decreased under straw or biochar addition, whilst MC from the native soil was increased under straw addition but decreased under biochar addition. Meanwhile, native SOC was similar among the treatments, irrespective of the straw or biochar addition. Compared to Soil, significant higher total DOC and total MBC were under Soil＋Straw, but not under Soil＋B250 and Soil＋B350, whilst significant higher total MC and total SOC were under straw or biochar addition, except for MC under Soil＋B350. Our results demonstrated that the application of biochar to soil may be an appropriate management practice for increasing soil C storage.