基于改进YOLOv8的轻量化小麦病害检测方法

为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable convolution, DepthSepConv)结构,减少模型参数量,提升模型检测性能;其次,在颈部网络部分添加全局注意力机制(global attention mechanism, GAM)模块,强化特征中语义信息和位置信息,提高模型特征融合能力;然后,引入轻量级通用上采样内容感知重组(content-aware reassembly of features,CARAFE)模块,提高模型对重要特征的提取能力;最后,使用Wise-IoU(weighted interpolation of sequential evidence for intersection over union)边界损失函数代替原损失函数,提升网络边界框回归性能和对小目标病害的检测效果。试验结果表明,对于大田环境下所采集的小麦病害数据集,改进后模型的参数量及模型大小相比原YOLOv8n基线模型分别降低了12.5%和11.3%,同时精确度(precision)及平均精度均值(mean average precision,m AP)相较于原模型分别提高了4.5和1.9个百分点,优于其他对比目标检测算法,可为小麦病害检测无人机等移动端检测装备的部署和应用提供参考。

浅谈隧道病害研究发展现状及展望

隧道病害普遍存在于运营隧道中,对病害进行研究分析将有助于隧道养护工作的开展。本文就病害成因分析、隧道病害检查与量测的研究、病害分类及量化、隧道病害结构安全性评估等方面进行研究。

小麦条锈菌突变菌株相对寄生适合度测定

测定了CY17,CY31突变菌系在感病品种铭贤169上的相对寄生适合度属性,并利用“病害量”衡量突变菌株的相对寄生适合度。结果表明:CY17各突变菌株的相对寄生适合度均高于原始菌株,其中CY17mut-4最高,CY17mut-1较高,CY17mut-3,CY17mut-2相差不大,居中;而CY17mut-5最低,各突变菌株之间的差异主要表现在夏孢子萌发率、夏孢子堆长度、严重度3个属性上。CY31突变菌株的相对寄生适合度均低于原始菌株。其中CY31mut-1,CY31mutS-1,CY31mut-2,CY31mutS-2的相对寄生适合度高,CY31mutH-1,CY31mutH-2,CY31mut-6次之,CY31mut-3,CY31mut-5,CY31mut-4最低,其突变菌株间的相对寄生适合度属性在夏孢子萌发率、夏孢子堆长度和夏孢子堆密度上有较显著差异。

Investigation and Analysis of Continuous Cropping of Flue-cured Tobacco in Henan Province

The continuous cropping of flue-cured tobacco in the major producing areas of Henan Province by designing questionnaire, fieldwork, enquiry and phone calls, mails, and other forms, the data were obtained then classified and analyzed. The results showed that the main planting areas of flue-cured tobacco were in Nanyang, Xuchang, Luoyang, Sanmenxia, Pingdingshan, and Luohe where were the major producing areas of succession cropping of flue-cured tobacco with percentage of 20%-40% for three years and over three years, and a few places up to 50%. Morbidity was common with wide distribution, and the main diseases were black shank, viral disease, and black rot. It proved that tobacco was not suitable for continuous cropping. Both of tobacco disease and pest rate and mortality significantly increased by more than 40% under continuous cropping for three years and over three years, and the yield and quality of flue-cured tobacco also decreased after continuous cropping. For many places, the tobacco yield started to decrease in the second year of continuous cropping, and after three-year cropping, the yield decreased in the range of 9%-24%. Continuous cropping for a long time would make a serious decline in the quality of tobacco, resulting in non-economic benefits. Therefore, in order to reduce the occurrence of diseases and economic loss in tobacco production, it is recommended to avoid continuous cropping, or to adopt appropriate measures to control tobacco continuous cropping obstacles in the unavoidable case.

Real-Time PCR Technique and Its Application in Quantification of Plant Nucleic Acid Molecules

Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of initial template copy numbers as PCR products are generated. This technique significantly simplifies and accelerates the process of producing reproducible quantification of nucleic acid molecules. It not only is a sensitive, accurate and rapid quantitative method, but it also provides an easier way to calculate the absolute starting copy number of nucleic acid molecules to be tested. Together with molecular bio-techniques, like microarray, real-time PCR will play a very important role in many aspects of molecular life science such as functional gene analysis and disease molecular diagnostics. This review introduces the detailed principles and application of the real-time PCR technique, describes a recently developed system for exact quantification of AUX/IAA genes In Arabidopsis, and discusses the problems with the real-time PCR process.

A Limited Dependent Variable Analysis of Integrated Pest Management Adoption in Uganda

Integrated Pest Management （IPM） technologies can reduce pest damage to crops by emphasizing non-chemical control methods thereby reducing potential negative effects of chemicals on the environment while preserving profitability. This study investigates the adoption of eight IPM practices including intercropping, crop rotation, two improved varieties, incorporating a ＂striga chaser＂ in sorghum production, changing planting dates, altering planting density and fertilizer use. Explanatory variables include economic factors, social factors, management factors, and institutional factors. Results were consistent across logit and ordered logit analyses. Most factors affecting adoption across all crops and technologies are economic factors, including labor availability, technology resource requirements, technology complexity, and the level of expected benefits. Social factors are generally less associated with IPM technology adoption than either market or institutional factors. Results indicate that the evaluated technologies were scale-neutral and that farmer age and education level did not affect technology adoption.

Diffusion tensor imaging of the brain in patients with Alzheimer's disease and cerebrovascular lesions

Background:Recent autopsy study showed a high incidence of cerebrovascular lesions in Alzheimer's disease(AD).To assess the impact of cerebrovascular pathology in AD,we used diffusion tensor imaging(DTI) to study AD patients with and without cerebrovascular lesions.Materials and Methods:Conventional and DTI scans were obtained from 10 patients with probable AD,10 AD/V patients(probable AD with cerebrovascular lesions) and ten normal controls.Mean diffusivity(D) and fractional anisotropy(FA) values of some structures involved with AD pathology were measured.Results:D value was higher in AD patients than in controls in hippocampus and the cingulate gyrus.In AD/V patients,increased D value was found in the same structures and also in the thalamus and basal ganglia compared to controls.There was a significant difference of D value between AD and AD/V patients.FA value reduced in the white matter of left inferior temporal gyrus and in the bilateral middle cingulate gyrus in patients with AD/V compared with controls.The MMSE(mini-mental state examination) score significantly correlated with FA value in the right hippocampus(r=0.639,P<0.019),in the right anterior cingulate gyrus(r=0.587,P<0.035) and in left parahippocampal gyrus(r=0.559,P<0.047).Conclusion:Cerebrovascular pathology had stronger impact on the D value than the AD pathology alone did.Elevated D value in thalamic and basal ganglia may contribute to cognitive decline in AD/V patients.Reduced FA values in AD/V patients may indicate that cerebrovascular pathology induced more severe white matter damage than the AD pathology alone did.

Effect of Silicon and Nitrogen Nutrition on Pest and Disease Intensity in Rice

Nutrition management is the most important for high yield production but it may affect the response of rice plants to pest and diseases due to the change of microclimate under rice plant canopy. The knowledge of nutrition management and its relation with pest and diseases are basis for setting up a high yield production system. Most of the pest and disease control procedures used by farmers can be considered as soil fertility management and these nutrition practices can have impact on the physiological susceptibility of crop plants to pest and diseases by affecting the plant resistance. Silicon content of plants is particularly effective against pest and diseases in rice and certain rice genotypes are more efficient accumulators of silicon, thus making them more resistant. In the absence of natural heritable resistance in rice varieties, resistance could be induced by altemate strategies to suppress certain pest and pathogens. Hence experiments were carried out in two stages during kharif 2010 and 2011 to assess the concentration of silicon in the index leaves of rice plant utilizing 133 varieties in four locations. The silica content of promising varieties ranged from 1.50% to 3.20%, 1.60% to 3.15%, 1.49% to 3.20% and 1.55% to 3.06% with a mean values of 2.50%, 2.48%, 2.51% and 2.43% at Jagtial, Warangal, Rajendranagar and Rudrur centres of Telangana region and not much variation in mean silica content in index leaves at different places. The overall yield from four locations ranged from 2,653 kg/ha to 6,860 kg/ha with a mean of 5,624 kg/ha. The yields recorded at Jagtial, Warangal, Rajendranagar and Rudrur centres ranged from 2,886 to 7,198, 2,653 to 6,831, 2,653 to 6,860 and 4,399 to 5,950 kg/ha, respectively. The lowest mean yield 5,069 kg/ha was noticed at Rudrur and the highest yield 5,940 kg/ha was found at Warangal. The variations in yields might be due to genotypic variations and also due to variations in climatic conditions of different locations.

Spring Wheat Disease and Yield Responses to Nitrogen Fertilization and Chemical Treatments

P. tritici-repentis, B. graminb and C. sativus are important diseases of spring wheat in Estonia. Field trials were carried out during 2006 and 2008 in JiSgeva PBI. Two kinds of treatments were used： Tl consisted of four different rates of basic fertilizer： NO = NOPOK0; N1 = N60P13K23, N2 = N 100P22K39; N3 = N140P31K54 kg ha^-1. T2 treatment consisted of same rates of basic fertilizers and in addition growth regulator, fungicides and leaf fertilizers. Seeds of the varieties ＂Monsun＂ and ＂Vinjett＂ were untreated. Results of the effects of fertilizers on the infections of fungal diseases on spring wheat monoculture revealed that test years had the biggest influence on infection intensity of B. graminis （REy = 50.7-59.2） in T1 and T2 and P. tritici-repentis in T2 （REy = 31.6）, whereas infection of C. sativus was more dependent on year in Tl （R2y = 37.3）. Yield correlated highly with a fertilizer rate and year. In the treatment T2, the yield depended more on weather conditions （REy = 40.7） and in T1, the yield was more dependent on fertilization rate （REF = 60.2）. We found TI to be more economic as the optimum N rate varied from N60 to N100 kg hat and the benefit in monetary terms raised from 297ε hal （＂Monsun＂ 2007） to 9056 hal （＂Vinjett＂ 2008）. In T2, N rate 60 kg ha^-1 raised the monetary benefit from 806 ha^-1 （＂Monsun＂ 2007） to 731ε ha^-1 （＂Vinjett＂ 2008）. The highest economic profit was gained by using low rates of fertilizer for ＂Monsun＂ and the highest rates of fertilizer for ＂Vinjett＂.

Wheat Genetic Transformation as Efficient Tools to Fight against Fungal Diseases

Wheat ranks first among cereal crops cultivated in the world. In its production, diseases like powdery mildew, fusarium head blight and rusts caused by fungal pathogens represent a major problem. They produce different symptoms that cause severe crop damage by infecting the spikes, leaves, roots, stems and grains. They are causing losses both by reducing the quantity of the harvested crop and the quality of the product. Quality problems of the harvested product can be due to shrivelled seed, which are frequently found as a consequence of the infection by leaf pathogens, such as mildews, rusts and Septoria. Fusarium head blight is the major culprit for mycotoxin contamination from the harvested grain, causing economic losses and in the worst casing human and animal health problems. In severe epidemics, all these fungal diseases can significantly reduce yield. Resistance to fungi is beneficial not only from a commercial point of view （yield）, but also because of the reduced levels of mycotoxins. The integration of transgenic approaches offers a potential chemical-free and environment-friendly solution for controlling fungal pathogens. This is an essential asset for wheat world food security.

Technology of Mass Rearing Clostera anachoreta and Production of CaGV

A new technique for mass rearing Clostera anachoreta(C.) was developed through a large numberof experiments, so the problem of mass produce of CaGV was solved. The process of CaGV was discussedin detail.