三种类型油菜(Brassica spp.)和野芥菜(B.juncea var.gracilis Tsen et Lee)杂交亲和性及F_1的适合度——潜在基因转移的研究

通过人工去雄授粉 ,采用荧光显微镜观察了 3种类型栽培油菜花粉在两地采集的野芥菜柱头上的萌发生长情况 ,结合杂交后的结实率 ,探讨了 3种类型油菜和野芥菜杂交的亲和性 .结果表明 ,甘蓝型油菜和芥菜型油菜与野芥菜的亲和性都非常高 ,亲和性指数达 10 .0以上 ,而白菜型油菜和野芥菜的亲和性较低 ,亲和指数小于 0 .2 .子一代的适合度研究结果表明 ,芥菜型油菜向野芥菜杂交一代的适合度没有降低 ,而甘蓝型及白菜型和野芥菜杂交一代的适合度明显下降 ,表现在花粉活力降低 ,结实率极低 .上述结果表明 ,白菜型油菜和野芥菜的基因转移可能性最小 ,甘蓝型居中 ,而芥菜型极易向野芥菜发生基因转移 .表 4参

基于改进YOLOv3-SPP算法的道路车辆检测

针对在城市道路场景下视觉检测车辆时,车辆密集和远处车辆呈现小尺度,导致出现检测精度低或者漏检的问题,提出了一种基于改进的YOLOv3-SPP算法,对激活函数进行优化,以DIOU-NMS Loss作为边界框损失函数,增强网络的表达能力。为提高所提算法对小目标和遮挡目标的特征提取能力,引入空洞卷积模块,增大目标的感受野。实验结果表明,所提算法在检测车辆目标时m AP提高了1.79%,也有效减少了在检测紧密车辆目标时出现的漏检现象。

Genetic Diversity of Jute Mallow (Corchorus spp.) Accessions Based on ISSR Markers

Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported. In the present study, inter sequence simple repeats (ISSR) molecular markers were employed to assess genetic diversity and relationships of 83 accessions of Jute mallow from different parts of Africa and Asia conserved at the World Vegetable Center East and Southern Africa. A total of 89 bands were amplified by 8 ISSR primers. Number of polymorphic bands per primer ranged from 2 to 6 with an average of 2.75 bands per primer. Polymorphic information content (PIC) values ranged from 0.390 to 0.760 with average of 0.53. Average Nei’s gene diversity (h) and Shannon’s information index (I) were 0.335 and 0.494 respectively. The highest pairwise genetic distance was 0.431 observed in a population from East Africa accessions. PC1 and PC2 axis explained 21.69% and 11.66% of the total variation respectively. UPGMA cluster analysis grouped the accessions into six main clusters at genetic similarity coefficient of 0.53 as standard value for classification. These results have important implications for jute mallow breeding and conservation.

Molecular mechanism of flowering time regulation in Brassica rapa:similarities and differences with Arabidopsis

Properly regulated flowering time is pivotal for successful plant reproduction.The floral transition from vegetative growth to reproductive growth is regulated by a complex gene regulatory network that integrates environmental signals and internal conditions to ensure that flowering takes place under favorable conditions.Brassica rapa is a diploid Cruciferae species that includes several varieties that are cultivated as vegetable or oil crops.Flowering time is one of the most important agricultural traits of B.rapa crops because of its influence on yield and quality.The transition to flowering in B.rapa is regulated by several environmental and developmental cues,which are perceived by several signaling pathways,including the vernalization pathway,the autonomous pathway,the circadian clock,the thermosensory pathway,and gibberellin(GA)signaling.These signals are integrated to control the expression of floral integrators BrFTs and BrSOC1s to regulate flowering.In this review,we summarized current research advances on the molecular mechanisms that govern flowering time regulation in B.rapa and compare this to what is known in Arabidopsis.

Utilizing resequencing big data to facilitate Brassica vegetable breeding:tracing introgression pedigree and developing highly specific markers for clubroot resistance

Clubroot caused by Plasmodiophora brassicae is a devastating disease of Cruciferous crops.Developing cultivars with clubroot resistance(CR)is the most effective control measure.For the two major Brassica vegetable species B.rapa and B.oleracea,several commercial cultivars with unclear CR pedigrees have been intensively used as CR donors in breeding.However,the continuous occurrence of CR-breaking makes the CR pedigree underlying these cultivars one of the breeders'most urgent concerns.The complex intraspecific diversity of these two major Brassica vegetables has also limited the applicability of CR markers in different breeding programs.Here we first traced the pedigree underlying two kinds of CR that have been widely applied in breeding by linkage and introgression analyses based on public resequencing data.In B.rapa,a major locus CRzi8 underlying the CR of the commercial CR donor‘DegaoCR117’was identified.CRzi8 was further shown to have been introgressed from turnip(B.rapa ssp.rapifera)and that it carried a potential functional allele of Crr1a.The turnip introgression carried CRb^(c),sharing the same coding sequence with the CRb that was also identified from chromosome C07 of B.oleracea CR cultivars with different morphotypes.Within natural populations,variation analysis of linkage intervals of CRzi8,PbBa8.1,CRb,and CRb^(c)yielded easily resolved InDel markers(>20 bp)for these fundamental CR genes.The specificity of these markers was tested in diverse cultivars panels,and each exhibited high reliability in breeding.Our research demonstrates the value of the practice of applying resequencing big data to solve urgent concerns in breeding programs.

BnaWRKY75 positively regulates the resistance against Sclerotinia sclerotiorum in ornamental Brassica napus

With the development of tourism at home and abroad,Rapeseed(Brassica napus)has become an important ornamental plant.However,its ornamental value at the inflorescence stage is greatly reduced by Sclerotinia sclerotiorum.Identification of important genes in the defense responses is critical for molecular breeding,which is an important strategy for controlling the disease.In this study,we isolated a B.napus WRKY transcription factor gene,BnaWRKY75.BnaWRKY75 was found to encode a nucleus-localized protein and exhibited relatively high expression in the stems.Arabidopsis thaliana transgenic plants expressing BnaWRKY75 showed enhanced resistance to S.sclerotiorum,and both ProBnaWRKY75:GUS and gene expression analyses showed that BnaWRKY75 was highly responsive to S.sclerotiorum infection,indicating the involvement of BnaWRKY75 in response to this infection.Furthermore,overexpression(OE)of BnaWRKY75 in B.napus significantly enhanced the resistance to S.sclerotiorum,whereas the resistance was reduced in RNAi transgenic B.napus plants.Moreover,the BnaWRKY75-OE B.napus plants exhibited constitutive activation of salicylic acid-,jasmonic acid-,and ethylene-mediated defense responses and the inhibition of both H_(2)O_(2)and O_(2)·^(-)accumulation in response to this pathogen.By contrast,BnaWRKY75-RNAi plants showed a reverse pattern,suggesting that BnaWRKY75 is involved in hormonal signaling pathways and in the control of reactive oxygen species accumulation.In conclusion,these data indicate that BnaWRKY75,a regulator of multiple defense responses,positively regulates resistance against S.sclerotiorum,which may guide the improvement of resistance in rapeseed.

Strawberry (Fragaria spp.): Cultivation, Production, Consumption, and Marketing in Cameroon

Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas.

Landscape of Sequence Variations in Homologous Copies of FAD2 and FAD3 in Rapeseed(Brassica napus L.)Germplasm with High/Low Linolenic Acid Trait

Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har-bors four and six homologous copies,respectively,of the two fatty acid desaturases FAD2 and FAD3,which con-trol the last two steps of ALA biosynthesis during seed oil accumulation.In this study,we compared their promoters,coding sequences,and expression levels in three high-ALA inbred lines 2006L,R8Q10,and YH25005,a low-ALA line A28,a low-ALA/high-oleic-acid accession SW,and the wildtype ZS11.The expression levels of most FAD2 and FAD3 homologs in the three high-ALA accessions were higher than those in ZS11 and much higher than those in A28 and SW.The three high-ALA accessions shared similar sequences with the pro-moters and CDSs of BnFAD3.C4 and BnFAD3.A3.In A28 and SW,substitution of three amino acid residues in BnFAD2.A5 and BnFAD2.C5,an absence of BnFAD2.C1 locus,and a 549 bp long deletion on the BnFAD3.A3 promoter were detected.The profile of BnFAD2 mutation in the two low-ALA accessions A28 and SW is different from that reported in previous studies.The mutations in BnFAD3 in the high-ALA accessions are reported for thefirst time.In identifying the sites of these mutations,we provide detailed information to aid the design of mole-cular markers for accelerated breeding schemes.

Knock-out of BnHva22c reduces the susceptibility of Brassica napus to infection with the fungal pathogen Verticillium longisporum

Verticillium longisporum(Vl43)is a soilborne hemibiotrophic fungal pathogen causing stem striping on oilseed rape(OSR)and severe yield losses.Breeding for resistant varieties is the most promising approach to control this disease.Here,we report the identification of Hva22c as a novel susceptibility factor and its potential for improving OSR resistance.Hva22c is a member of the Hva22 gene family,originally described for barley(Hordeum vulgare).Several Hva22 members have been located at the endoplasmic reticulum.Hva22c is up-regulated in response to Vl43 in both Arabidopsis and OSR.We demonstrate that knock-out of Hva22c in OSR by CRISPR/Cas9 and its homolog in Arabidopsis by T-DNA insertion reduced plants’susceptibility to Vl43 infection and impaired the development of disease symptoms.To understand the underlying mechanism,we analysed transcriptomic data from infected and non-infected roots of hva22c knock-out and wild type plants.We identified a homozygous mutant with frame-shifts in all four BnHva22c loci displaying a vastly altered transcriptional landscape at 6 dpi.Significantly,a large set of genes was suppressed under mock conditions including genes related to the endomembrane systems.Among the up-regulated genes we found several defense-related and phytohormone-responsive genes when comparing mutant to the wild type.These results demonstrate that Hva22c is functionally required for a fully compatible plant-fungus interaction.Its loss of function reduces plant susceptibility,most likely due to endoplasmatic reticulum and Golgi dysfunction accompanied by additionally activated defense responses.These findings can help improve OSR resistance to V.longisporum infection.

Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso

Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.

基于SPPs的二维多凹槽结构MIM波导透射特性的研究

不规则结构对波导的传播特性有着很大的影响,但对于MIM(Metal-Insulator-Metal,金属-介质-金属型)波导双边矩形槽并添加多凹槽结构对传播特性的影响方面的研究尚少。在研究内嵌凹槽位置对MIM波导透射特性影响的基础上,提出了在双矩形波导模型基础的内部添加多凹槽结构来影响波导的透射特性,并对波长与透射的关系及不同凹槽位置、不同凹槽数目的电场模图进行了对比分析。在凹槽位置改变时,Fano共振峰位置发生了移动,在小波长区域共振峰的数目也有所改变。随着上凹槽位置的增大,最大透射峰位置发生了蓝移,透射强度也有一定的增强;增加凹槽对数,得到波长与透射特性的关系曲线发生了改变,随着凹槽对数的增加,Fano共振峰的位置发生了一定的红移,且在小波长600~1 000 nm区域,Fano共振峰数目及透射峰值均发生了变化。这些研究结果可为预测金属缝隙波导制备过程中小尺度、多凹槽局部缺陷结构对其传播特性的影响提供理论依据。

青菜(Brassica campestris spp.chinensis var.)TPS雄性不育系的转育

在甘蓝型油菜中发现一个非常优良的不育源─—TPS雄性不育系，本研究通过远缘杂交和连续回交等手段，把TPS不育胞质从甘蓝型油菜转入青菜，选育出3个回交五代的青菜TPS不育系即青1A；青2A；青3A。不育系的不育性彻底而稳定，没有发现任何低温黄化、蜜腺退化和花器畸形等不良的细胞质负效应，群体基本稳定一致，结实性状良好。现已进入杂交组合测配阶段。

油菜(Brassica napus)β-1,4-木糖基转移酶基因BnIRX14克隆、序列分析及亚细胞定位

糖基转移酶(Glycosyltransferase,GTs)广泛参与植物次生物质的代谢及生物和非生物胁迫,β-1,4-木糖基转移酶属于糖基转移酶GT43家族成员。为了探究油菜β-1,4-木糖基转移酶对油菜次生物质的代谢和逆境调控,利用5′RACE和3′RACE方法从甘蓝型油菜中扩增获得油菜β-1,4-木糖基转移酶基因BnIRX14全长cDNA,该cDNA具有1566 bp的完整开放阅读框,编码522个氨基酸,分子质量约58.92 ku,由8315个原子组成,分子式为C_(2631)H_(4168)N_(742)O_(753)S_(21),具有多个磷酸化位点和糖基化修饰位点,属非分泌性单次跨膜蛋白。结构域分析表明,BnIRX14具有GTs家族保守的DxD保守结构域和UGT糖基转移酶PSPG特征结构域,属于糖基转移酶GT43家族成员。BiFC亚细胞定位初步显示BnIRX14定位于细胞质中,蛋白互作预测表明BnIRX14与各类糖合成和转运蛋白高度互作。结构域预测和互作分析初步表明,BnIRX14属于油菜糖基转移酶GT43家族成员,可能通过与糖合成和转运相关蛋白互作参与油菜木糖的合成代谢进而参与生长发育及逆境响应。

智能手机BDS-3/GPS数据质量及SPP性能分析

使用可观测到BDS-3 B1I/B1C/B2a频率和GPS L1/L5频率的智能手机Xiaomi 11(青春版)作为研究对象,分别进行静态实验和不同场地的动态实验,分析手机输出的三频BDS和双频GPS原始观测数据质量及单频SPP性能。实验结果表明,智能手机的GNSS天线成本低致使其信号质量不佳,其中GPS L1频率和BDS B1C频率抗干扰性较强:BDS B1C频率定位结果在静态和动态实验中均较为稳定;GPS L1频率定位结果在动态实验中优于GPS L5频率,在静态实验中略差于GPS L5频率。

鸭SPP1基因的生物信息学分析、原核表达及其在鸭胚胎期骨骼肌中表达规律研究

分泌型焦磷酸蛋白1(SPP1)是一种具有多种功能的分泌型酸性糖蛋白,在肌肉发育过程中具有重要的调控作用,但SPP1基因在鸭骨骼肌中的结构和功能尚不明确。本研究选择胚胎期第17天(E17 d)、第21天(E21 d)、第24(E24 d)和第27天(E27 d)北京鸭和汉中麻鸭胸肌及腿肌组织作为实验材料,克隆了SPP1基因的CDS区序列并对该序列进行分析,进一步诱导基因表达,采用SDS-PAGE检测表达蛋白。同时采用qPCR方法分析SPP1基因在胚胎期北京鸭与汉中麻鸭胸肌和腿肌组织中的相对表达。结果表明:SPP1基因开放阅读框大小为915 bp,编码304个氨基酸,是有SP型信号肽的亲水性不稳定蛋白,无跨膜结构,有磷酸化和糖基化位点。qPCR结果表明,北京鸭骨骼肌SPP1的表达量在E27 d达到最高;而汉中麻鸭胸肌SPP1在E17 d的表达量最高,在E21 d的腿肌中表达量最高。在胚胎期北京鸭与汉中麻鸭骨骼肌的比较中,汉中麻鸭胸肌SPP1基因在E17 d时的表达量显著高于北京鸭,而在E27 d则低于北京鸭。北京鸭腿肌SPP1在E17 d和E27 d的表达量均高于汉中麻鸭,而在E21 d和E24 d则均低于汉中麻鸭。本研究揭示了鸭SPP1基因的结构及该基因在北京鸭和汉中麻鸭骨骼肌中的表达规律,为鸭生长发育的调控机制研究提供一定的参考。

城市复杂环境下不同加权模型对动态SPP定位性能影响分析

城市复杂环境下,由于建筑物的遮挡,卫星定位严重受到非视距信号的影响。测量值随机误差加权模型是卫星定位的关键环节,它能够合理地分配各卫星在解算中所起作用的大小。因此,加权模型常用于缓解非视距信号对卫星定位的影响。本文针对目前主流的多种加权模型进行了系统总结和阐述,比较和分析了城市复杂环境下不同加权模型对卫星动态单点定位的影响。试验结果表明,各加权模型均能够在一定程度上提高定位精度,其中综合加权模型具有最优的性能表现。

根际溶磷伯克霍尔德菌Paraburkholderia spp.对马尾松苗的促生作用

为筛选溶磷效果较好的根际细菌(phosphate-solubilizing rhizobacteria,PSB),并明确其对马尾松苗的促生效果和作用机制。利用土壤稀释平板法进行PSB菌株的分离和纯化,通过形态学和16S rDNA分子测序等方法进行PSB菌株的鉴定,最后将PSB菌株接种至马尾松苗,培养60 d后测定马尾松苗生长、生理、苗根际土壤理化性质和根际细菌群落结构和组成。结果表明:由马尾松根际土中分离获得溶磷能力较强的3个PSB菌株WJ10、WJ25和WJ41均为伯克霍尔德菌Paraburkholderia spp.;3个PSB菌株对磷酸铝的增溶能力最强,其次是磷酸三钙、磷酸氢钙和磷酸铁;盆栽试验表明,3个PSB菌株均可促进幼苗的生长,其中WJ25对苗高、根长的促进效果最明显,WJ41和WJ10次之。3个PSB菌株对苗促生的主要机制包括,PSB提高了马尾松苗的根系活力、叶绿素b、可溶性蛋白等生长指标及氮、磷和钾等养分含量;同时,提升了根际土有效磷、速效钾、活性氮、土壤养分含量、土壤酶活性;此外,3个PSB菌株的添加还影响了马尾松苗根际细菌群落的组成和多样性,促进了Bacillus、Nitrosospira、Gemmata和Cytophaga等有益菌在根际土壤中的显著富集。综上,本研究筛选获得的3个溶磷伯克霍尔德菌,它们能够通过调控植物生理及改变根际微环境从而促进马尾松苗的生长。通过本研究,为马尾松根际溶磷细菌菌肥的开发和应用提供了理论依据。

基于YOLOv3-spp的汽车轮毂表面缺陷检测算法研究与分析

针对传统人工检测方法效率低且准确率不高等问题,提出一种基于YOLOv3-spp网络的自动缺陷检测方法。首先通过图像切片提取缺陷区域,然后将提取的缺陷图片经过数据增强后组成数据集并以此训练YOLOv3-spp网络,接着对比分析了不同深度学习网络及数据集筛选方法对轮毂表面缺陷的检测效果。实验结果表明:在工业现场采集的数据集上,训练好的YOLOv3-spp神经网络可以准确地定位,并识别出点状、线性、油泥油漆、针孔4类缺陷,其平均准确率分别为84.5%、93.4%、95.4%和89.5%,检测速度达到35 ms/幅,满足检测的实时性要求,且检测准确率优于Faster R-CNN和SSD两种常用神经网络。

First report of Leptosphaeria sclerotioides on Brassica napus in Northwestern China

In 2020,diseased seedlings of winter oilseed rape(Brassica napus)with cankered taproots as well as abundant sclerotium-like structures in the soil surrounding the roots were found in Longxi County of Gansu province of northwestern China.A fungus with production of pycnidia was isolated from the diseased roots,and it was identified based on morphological characteristics,molecular phylogeny(ITS,LSU)and PCR detection with the specific primers.The fungus was identified as Leptosphaeria sclerotioides Gruyter,Aveskamp&Verkley[anamorph:Phoma sclerotioides(Preuss)ex Sacc.].Re-inoculation of isolates of P9 and P10 of L.sclerotioides on winter oilseed rape(B.napus cultivar‘Zhongshuang No.9’)in Wuhan caused formation of abundant sclerotium-like structures in soil surrounding the roots,but failed to produce root cankers as those observed in Gansu possibly due to lack of long peroid of low-temperature conditioning in Wuhan.In spite of this,plant height,pod number and seed yield of oilseed rape were significantly reduced in the treatment with L.sclerotioides P9 and P10,compared to the control treatment.To the best of our knowledge,this is the first report of L.sclerotioides on B.napus in China and the finding broadened our understanding about the natural distribution of this psychrophilic fungus.

RTKLIB(b34)SPP数据处理解析

伪距单点定位(Pseudo-range Single Point Positioning,SPP)应用较早且广泛。随着GNSS相关技术的不断进步,伪距观测值与广播星历的精度也在不断提高,多GNSS系统还带来了更多的伪距观测值,SPP依然值得关注。RTKLIB作为一款广为接受的多功能GNSS数据处理开源软件,是实现二次开发的良好平台,为此,本文对新版本RTKLIB(b34)SPP数据处理进行了解析,给出了其处理流程,分析了其平差求解、结果检验、异常检测的原理,指出了其优缺点,为今后借鉴或改进提供了参考。