Identification of candidate genes for early-maturity traits by combining BSA-seq and QTL mapping in upland cotton(Gossypium hirsutum L.)

Cotton breeding for the development of early-maturing varieties is an effective way to improve multiple cropping indexes and alleviate the conflict between grains and cotton in the cultivated fields in China.In the present study,we aimed to identify upland cotton quantitative trait loci(QTLs)and candidate genes related to early-maturity traits,including whole growth period(WGP),flowering timing(FT),node of the first fruiting branch(NFFB),height of the node of the first fruiting branch(HNFFB),and plant height(PH).An early-maturing variety,CCRI50,and a latematuring variety,Guoxinmian 11,were crossed to obtain biparental populations.These populations were used to map QTLs for the early-maturity traits for two years(2020 and 2021).With BSA-seq analysis based on the data of population 2020,the candidate regions related to early maturity were found to be located on chromosome D03.We then developed 22 polymorphic insertions or deletions(InDel)markers to further narrow down the candidate regions,resulting in the detection of five and four QTLs in the 2020 and 2021 populations,respectively.According to the results of QTL mapping,two candidate regions(InDel_G286-InDel_G144 and InDel_G24-InDel_G43)were detected.In these regions,three genes(GH_D03G0451,GH_D03G0649,and GH_D03G1180)have nonsynonymous mutations in their exons and one gene(GH_D03G0450)has SNP variations in the upstream sequence between CCRI50 and Guoxinmian 11.These four genes also showed dominant expression in the floral organs.The expression levels of GH_D03G0451,GH_D03G0649 and GH_D03G1180 were significantly higher in CCRI50 than in Guoxinmian 11 during the bud differentiation stages,while GH_D03G0450 showed the opposite trend.Further functional verification of GH_D03G0451 indicated that the GH_D03G0451-silenced plants showed a delay in the flowering time.The results suggest that these are the candidate genes for cotton early maturity,and they may be used for breeding early-maturity cotton varieties.

Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect control.The green peach aphid,Myzus persicae,feeds on over 400 species of host plants.Brassica napus(rape)is the second most important oilseed crop worldwide.Myzus persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life cycle.In this study,we tested the RNAi effects of transgenic rape plants on M.persicae.By in vitro feeding M.persicae with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi target.Tissue-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of M.persicae.We next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic lines.Compared to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to M.persicae.Feeding assays revealed that feeding transgenic rape plants to M.persicae significantly decreased MpPar6 expression and survival rate and impaired fecundity.Furthermore,we showed that the resistance levels to M.persicae are positively correlated with ds Par6 expression levels in transgenic rape plants.Our study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from M.persicae.Interfering with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

Strategies and Economic Benefit Analysis for Productive Landscape of Rape Flower Sea in Cold Regions

The cold regions are located in high latitudes and cold climates.The local excellent ornamental plant resources are relatively scarce.The plant species that are suitable for both ornamental and productive benefits of landscape of flower sea construction are also even fewer.Therefore,it is imperative to introduce and screen the plant resources suitable for cold regions to create the landscape of flower sea.The rape,an oilseed crop,was used as a research object in order to create a productive flower landscape with both ornamental and economic values in cold regions.Four rape flower varieties,Qingza No.5,7,9,and 11,were introduced from Qinghai Hufeng Agricultural Science and Technology Group Co.,Ltd.They were planted in the experimental practice base of Northeast Agricultural University in three batches.Development characteristics and seed yield of rape flowers on different sowing dates were studied.The fuzzy probability method was used to comprehensively evaluate the varieties.The results showed that the rape flowers grew well in Harbin City during the experimental sowing period,which could form a good landscape of flower sea and had a considerable rapeseed yield.It could be widely used in cold urban and rural areas,such as Harbin City.In view of the experimental results,the strategies of creating a productive landscape of rape flower sea were proposed and the economic benefits were analyzed.It could change the status quo of a uniform landscape of flower sea in cold regions,help the development of rural tourism,and promote local economic income.

Different Foliar Fertilizer Treatments Affect the Yield and Quality of Brassica napus L.for Both Vegetable and Oil Dual-Use Rape

Field experiments were carried out to study the effect of different foliar fertilizer treatments on the agronomic traits,yield,and quality of Brassica napus L.for both vegetable and oil dual-use rape.The seedlings of‘Youtai 929’,‘Jinyoutai 1’,and‘Zhongshuang 11’were sprayed with potassium dihydrogen phosphate,naphthylacetic acid,and selenium fertilizer,and the agronomic traits,yield,and quality were determined.The results showed that the naphthylacetic acid treatment had the highest indexes before winter,followed by the selenium fertilizer treatment.At the harvesting stage,the plant height,number of siliquae,yield per plant,and number of effective branches on the main stem of the three varieties were the highest in the naphthylacetic acid treatment,followed by those in the potassium dihydrogen phosphate treatment.The fresh shoot quality was the best in the selenium fertilizer treatment and the second in the naphthylacetic acid treatment.‘Jinyoutai 1’applied with naphthylacetic acid had the highest economic benefit of 4971.78 CNY/667m^(2),which was 642.32 CNY/667m^(2) higher than that of the control.The findings suggested that naphthylacetic acid was suitable to be used as the foliar fertilizer for the seedlings of B.napus varieties for both vegetable and oilseed,and the additional application of selenium fertilizer demonstrated better effect.

Genome-wide and candidate gene association studies identify BnPAP17 as conferring the utilization of organic phosphorus in oilseed rape

Phosphorus(P)is essential for living plants,and P deficiency is one of the key factors limiting the yield in rapeseed production worldwide.As the most important organ for plants,root morphology traits(RMTs)play a key role in P absorption.To investigate the genetic variability of RMT under low P availability,we dissected the genetic structure of RMTs by genome-wide association studies(GWAS),linkage mapping and candidate gene association studies(CGAS).A total of 52 suggestive loci were associated with RMTs under P stress conditions in 405 oilseed rape accessions.The purple acid phosphatase gene BnPAP17 was found to control the lateral root number(LRN)and root dry weight(RDW)under low P stress.The expression of BnPAP17 was increased in shoot tissue in P-efficient cultivars compared to root tissue and P-inefficient cultivars in response to low P stress.Moreover,the haplotype of BnPAP17^(Hap3)was detected for the selective breeding of P efficiency in oilseed rape.Over-expression of the BnPAP17^(Hap3)could promote the shoot and root growth with enhanced tolerance to low P stress and organic phosphorus(Po)utilization in oilseed rape.Collectively,these findings increase our understanding of the mechanisms underlying BnPAP17-mediated low P stress tolerance in oilseed rape.

Yield Stability of Direct-sowing and Early-maturing Excellent Brassica napus (Attar No.8)

[Objective] The aim was to analyze yield stability of attar No.8, which is direct sowing and early-maturing. [Method] Analysis was made on yielding ability, stability and adaptability of attar No.8 in Yunnan Province during 2006-2009 with DPS software and stability assessment was conducted on yield and major economic characters of the variety in different periods and experimental plots. [Result] Average yield of attar No.8 during three years in 24 plots achieved 3 379.17 kg/hm2; it grew tightly and is featured with early matureness. In addition, grain density, pod number and annul production differed little in different years and the variety in eight ecological conditions all showed high production potential, yielding ability and stability, which proved that attar No.8 is suitable to be grown in Yunnan and southern early-maturing areas in China. [Conclusion] The research provided references for selection and breeding of rapeseeds＇ variety which enjoys high and stable yield.

Rape Breeding and Its Intellectual Property Protection in China

Rape is the third largest oil crop in the world and the first one in China.The national average rapeseed yield is only 2077.5 kg/hm^(2),and the rapeseed oil yield is 894 kg/hm^(2).This paper introduced the main types,germplasm resources,breeding bases and breeding progress of Chinese rape,and studied its high-quality varieties,breeding patents and new varieties of agricultural plants.We analyzed the main problems such as serious loss of germplasm resources in Brassica campestris L.and Brassica juncea(L.)Czern.et Coss and weak"agricultural chip"in rape field,and put forward strategies such as strengthening the protection of rape germplasm resources,encouraging the development of"agricultural chip"in rape industry clusters with national advantages and characteristics,and strengthening the protection of agricultural intellectual property rights.

Geographical Indication Intellectual Property Protection and Regional Public Brand Construction of Rape Industry in China

As China s largest oil crop,rape occupies a central position in ensuring the safety of China s cooking oil supply.This paper introduced China s rapeseed industry from the rape type,rapeseed production,planting area,national rapeseed production protected area,rape national dominant characteristic industrial clusters,and rapeseed industry,etc.Besides,from the aspects of geographical indication products,geographical indication trademarks,and geographical indications of agricultural products,this paper discussed the intellectual property protection of geographical indications of rape,rapeseed,and rapeseed oil in China.It analyzed the main problems such as the lag in the formulation of relevant standards for geographical indications and the low use of special signs for geographical indications,and finally came up with recommendations including building a public brand of geographical indications and expanding foreign exchanges of geographical indications.

National Protection Zone for Rapeseed Production and Industrial Cluster of Rape in Hubei Province

Hubei Province is the main winter rapeseed producing area in China,and has the national advantage and characteristic industrial cluster of rape.The protection zone for the production of important agricultural products of rapeseed in Hubei Province also ranks first as that in Hunan Province.This paper studied the winter rape industry,the important agricultural product production protection zone of rapeseed,the provincial double-low high-quality rape protection zone and the industrial cluster of rape in Jianghan Plain in Hubei Province,and analyzed the main problems existing in the development of rapeseed production protection zone and industrial cluster of rape.Finally,it came up with strategies including promoting national rape varieties,overcoming the problem of rape"agricultural chip",promoting the"rice+rape"rotation model,and strengthening the protection of intellectual property rights of brand marks.

Influence of the Number of Reserved Fruit on Fruit-bearing Branch of Early-maturing Citrus unshiu Marc. on Fruit Growth and Development

In order to provide theoretical references for early-maturing Citrus unshiu Marc. in terms of fruit thinning, timely fertilization and harvesting, as wel as for for-mulation of of Early-maturing Citrus unshiu Marc. Cultivation Technique Standards in Guizhou Province, the dynamic changes of fruit longitudinal diameter and trans-verse diameter of 11-year-old and 12-year-old early maturing Citrus unshiu Marc. were tested in two consecutive years and the effects of single-fruit bearing branch on fruit growth and development were compared. The results showed annual varia-tion of longitudinal and transverse diameter of the fruit in Guizhou grew faster at the beginning and then slowed down gradual y, maintaining a slow-growth period after October; the growth curve final y was flat in mature stage. General y, the growth and development stage of fruit showed four growth peaks, showing an in-creasing S-shape curve and fruit net increase also had four growth peaks with a double S-shape curve. Specifical y, longitudinal diameters growth alternated with transverse diameter growth and the former proved much stronger. In terms of ef-fects of single-fruit bearing branch on longitudinal and transverse diameter growth, the number of reserved fruits had direct effects on the growth, net increase of weight, time of growth peak, fluctuation and the number of growth peak. The growth and development, and quality of fruits in the treatments with two or three fruits re-served on single fruit-bearing branch proved better compared with the control with four left fruits. It suggested that early June and early July are the best time for fer-tilization of early-maturing Citrus unshiu Marc. in Guizhou Pprovince and would have better effect if combined with foliage spraying. The suitable harvest time is in the end of October. The preferred number of reserved fruit on single fruit-bearing branch is 2-3. In actual production, the implementation of flower and fruit thinning should also takes tree age, balance of tree vigor, strength of fruit bearing branch, alternate bearing phenomenon and other factors into consideration.

Biotechnology ofα-linolenic acid in oilseed rape(Brassica napus)using FAD2 and FAD3 from chia(Salvia hispanica)

α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.

An Artificial Approach for the Fractional Order Rape and Its Control Model

The current investigations provide the solutions of the nonlinear fractional order mathematical rape and its controlmodel using the strength of artificial neural networks(ANNs)along with the Levenberg-Marquardt backpropagation approach(LMBA),i.e.,artificial neural networks-Levenberg-Marquardt backpropagation approach(ANNs-LMBA).The fractional order investigations have been presented to find more realistic results of the mathematical form of the rape and its control model.The differential mathematical form of the nonlinear fractional order mathematical rape and its control model has six classes:susceptible native girls,infected immature girls,susceptible knowledgeable girls,infected knowledgeable girls,susceptible rapist population and infective rapist population.The rape and its control differential system using three different fractional order values is authenticated to perform the correctness of ANNs-LMBA.The data is used to present the rape and its control differential system is designated as 70%for training,14%for authorization and 16%for testing.The obtained performances of the ANNs-LMBA are compared with the dataset of the Adams-Bashforth-Moulton scheme.To substantiate the consistency,aptitude,validity,exactness,and capability of the LMBA neural networks,the obtained numerical values are provided using the state transitions(STs),correlation,regression,mean square error(MSE)and error histograms(EHs).

基于YOLO v5的直播油菜激光间苗系统设计与试验

间苗是保证直播油菜增产的一项关键技术措施,为解决人工间苗劳动强度大、机械间苗不精确的问题,采用机器视觉的方式,基于深度学习算法YOLO v5平台,设计并搭建自动间苗装置。机器视觉系统评估幼苗种群的合理密植情况,间苗算法以间距和幼苗叶展为评估标准,实现控制幼苗间距和筛选优质苗的功能。选用遗传算法对间苗行进路径进行规划,相较于未规划路径可缩短最低为50%的行进距离,最终采用激光器高温烧除的方式完成间苗作业。选取油菜苗作为试验材料,间苗阈值α是划定幼苗最小间距的参数,设置不同的间苗阈值α进行试验。结果表明,间除苗的数量随着间苗阈值α的增加而增加,幼苗平均密度下降的同时种群分布趋于均匀,对间除苗的叶展长度分类统计,α为0~75 mm时,间除苗叶展长度全部在0~20 mm范围;α为75~200 mm时,间除苗叶展长度为0~40 mm,其中叶展长度为20~40 mm的最高占比约为76%;α为200~350 mm时,间除苗叶展长度在40 mm以上的幼苗开始增加,最高占比约为14%,间除苗叶展长度梯次分布证明了间苗算法具备筛选优质苗的性能。间苗执行阶段耗时占据间苗作业总耗时的90%以上,以激光走线参数L、激光器功率P、间苗距离阈值为试验因素,三因素三水平正交试验结果表明:选择合适的激光走线参数L能有效提高间苗死亡率、降低间苗误伤率和减少间苗耗时,在参数L为30 mm、P为7.5 W、α为250 mm下开展土槽台架性能验证试验,激光间苗平均死亡率为93.29%,平均误伤率为5.19%,平均总耗时为15.19 min,为开发基于机器视觉的激光自动间苗机提供了理论基础和技术支撑。

四川盆区油菜花期低温阴雨灾损评估及风险区划

花期低温阴雨是四川盆区油菜生产的主要气象灾害之一。本研究利用四川盆区1961-2020年101个气象站的逐日气象资料,1983-2000年油菜产量资料和干旱、低温冷害、连阴雨、大风、冰雹灾情资料,筛选花期低温阴雨灾害年份,采用数理统计方法获取花期低温阴雨产量灾损率和致灾因子,通过相关性分析确定油菜花期低温阴雨致灾指标,并利用2001-2020年灾情资料进行检验;基于筛选出的低温、连阴雨关键致灾因子,采用回归分析法建立油菜花期低温阴雨灾害损失评估模型,并进行回代和预测检验,分析灾害风险区划和变化趋势。结果表明:(1)日平均气温≤7℃、过程持续天数≥1d是四川盆区油菜花期低温致灾指标,日平均气温≤7℃的负积温和≥3d过程持续降水量共同组成低温阴雨灾害的关键致灾因子;选用2001-2020年油菜花期低温冷害发生情况对指标进行检验,与实际情况相符。(2)选用1983-2000年的气象、产量、灾情数据建立四川盆区油菜花期低温阴雨灾损评估模型,模型对轻度、中度灾害损失评估等级与实际等级相同或相差1级的评估准确率在96%以上;重度、特重评估等级与实际等级相同的准确率为0,与实际等级相差1级的准确率为75%和0。选用2001-2020年油菜花期低温阴雨灾害发生情况对模型检验,与实际情况基本相符。(3)1961-2020年四川盆区油菜花期低温阴雨灾害风险偏高区域主要分布于盆区西南部、南部及东北部,以中-高风险为主;灾害风险偏低的区域集中于盆区西北部及中部,以低-次低风险为主。(4)气候变暖背景下,四川盆区油菜花期低温阴雨灾害高风险区域呈减少趋势,低风险区域呈增加趋势。综上分析,四川盆区油菜花期低温冷害指标结果可靠,低温阴雨灾损评估模型能够较好地评估灾害损失,可应用于农业气象业务服务;灾害风险区划结果可为四川油菜生产布局提供参考依据。

Maternal-Fetal Pregnancy Complications of in Minors Raped with or without Physical Restraint in Eastern Democratic Republic of Congo

Introduction: Pregnancy resulting from rape is a public health and sexual and reproductive health issue, especially among minors. Rape can be perpetrated with or without physical restraint. The objective of the present study is to highlight the prevalence of physical coercion leading to pregnancy and the associated maternal-fetal complications. Methodology: This was a comparative descriptive and analytical cross-sectional study of complications associated with post-rape pregnancy by physical restraint among minors who were treated at the General Reference Hospital of Panzi over a two-year period from June 2020 to June 2022. A total of 140 minor survivors of violence with pregnancy were included in the study. Data were collected using a questionnaire, coded and analyzed in Excel and XLSTAT version 2014. Results: The prevalence of physical constraints was 65%. After mulltivariate analyses, denial of pregnancy (ORa: 9.64 95% CI: 1.1 - 81.2;p-value: 0.0370), attempted abortion (ORa: 56.1 95% CI: 1.5 - 2027.6;p-value: 0.0278) and agitation during delivery (ORa: 88.7 95% CI: 4.5 - 1715;p-value: 0.0030) were the complications associated with pregnancy in minors who experienced physical restraint rape. In addition, BMI was a factor in reducing the risk of physical restraint rape at the ORa of 0.5054 [0.3;0.8];p 0.006). Conclusion: Pregnancy among minors is a reality and occurs in a situation of physical coercion in the eastern Democratic Republic of Congo. These pregnancies are often associated with complications that require an intensive management system since they can jeopardize the maternal-fetal prognosis of minors.

强制、同意与性别平等:强奸罪入罪模式及其改革

我国刑法规定的强奸罪确立了以“强制手段”为核心要素的规范结构,可概括为强制模式。在强制手段或被害人反抗不明显的情形中,行为人违反被害人意愿实施性行为却难以受到刑法的制裁,从而使个人性自主权的保护存在重大漏洞。强制不是强奸罪不法的核心,违背他人意志才是强奸罪的本质。以同意替代强制是强奸罪法律规范发展的必然趋势。强奸罪立法的主要任务是为个体之间的性互动确立一个相对客观的、符合社会规范和性别平等价值的沟通规则。根据性互动的沟通结构及其特点,结合性互动行为的实践和不同模式的适用效果,我国宜采取修正的否定同意模式,即一般情形下适用否定同意模式,对虽然具有同意能力但其认知能力和防卫能力存在减损的脆弱人群应适用积极同意模式。

油菜角果叶绿素含量传感检测技术在农业信息化中的应用研究

该文研究油菜叶绿素含量传感检测技术在农业信息化中的应用,探讨其在作物生长监测、营养管理与施肥优化、病虫害预测与防控等方面的重要性。通过分析突出该技术在提高农业生产效率、实现资源精细管理方面的广泛应用。最后,该文也讨论该技术面临的测量误差与精度问题、传感器的稳定性与耐久性等挑战,期望通过不断深化研究,该技术能够更好地服务于现代农业的可持续发展与智能化管理。

面向夹持采收的油菜薹夹段茎秆离散元参数标定与优化

为提高离散元法对指导油菜薹有序采收装备设计与优化的准确性和可靠性,该研究以双行垄作移栽的“农大1号”双低甘蓝型油菜机械化适收期油菜薹夹段茎秆为对象,测定其本征参数、表面接触参数以及破碎力学参数,利用EDEM仿真软件Hertz-Mindlin无滑移模型和Hertz-Mindlin with bonding粘结模型建立夹段茎秆堆积仿真标定模型和破碎仿真标定模型。采用逐步调整仿真参数使仿真试验值与物理试验值逼近的方法,利用夹段茎秆堆积仿真标定模型,以休止角仿真试验值与实际物理试验值的相对误差为目标,完成夹段茎秆表面接触参数的标定与优化;利用破碎仿真标定模型,以轴向压缩和弯曲仿真试验与实际物理试验的最大轴向压缩力和最大弯曲力的相对误差为目标,利用标定后的表面接触参数完成夹段茎秆粘结参数的标定与优化。最后,利用夹段茎秆的径向压缩与剪切、内芯与表皮拉伸的破碎仿真力学试验和有序采收EDEM-Recurdyn耦合仿真试验验证标定后的表面接触参数和粘结参数。结果表明,仿真与实测试验的破碎力学参数相对误差在5%以内,且仿真与实测的“时间-载荷”曲线变化趋势一致,低速、中速和高速档的有序采收仿真试验结果与实际物理试验结果相对误差在7.0%以内。研究结果表明,采用离散元仿真方法研究油菜薹采收过程具有可行性,标定结果可用于指导油菜薹机械化生产。

不同施氮水平对冬油菜根际微生物群落特征的影响

【目的】探究冬油菜根际微生物群落特征对不同施肥的响应,确定油菜氮肥适宜用量,为土壤培肥和调控土壤生态功能提供理论依据【方法】田间试验在油菜种植区(武穴)开展,在秸秆还田条件下设置5个处理:不施氮肥(SN0)、N 120 kg/hm^(2)(SN120)、N 180 kg/hm^(2)(SN180)、N 240 kg/hm^(2)(SN240)和N 300 kg/hm^(2)(SN300),采用16S rRNA和ITS高通量测序方法,分析根际土壤细菌和真菌群落结构及其功能变化,同时测定土壤理化性质和作物产量。【结果】1)与不施氮处理(SN0)相比,施氮处理降低了根际土壤有效磷含量(24.63%~35.10%)和速效钾含量(39.67%~59.77%),提高了全氮(6.18%~14.60%)和碱解氮含量(7.18%~34.99%)。SN180处理提升土壤全氮和碱解氮含量的幅度最小,SN300处理提升幅度最大。随着氮肥的增加,有机碳含量呈增长趋势,pH呈下降趋势,油菜产量先增加后减少,SN180产量最高。2)随着施氮量的递增,细菌的Chao1指数呈递增趋势;与SN0处理相比,SN180处理提高了真菌Shannon指数7.20%。施氮肥改变了细菌和真菌群落结构。与SN0处理相比,SN180处理提高了子囊菌门、担子菌门和拟杆菌门相对丰度,降低了被孢霉门和酸杆菌门相对丰度,减缓了鞘氨醇单胞菌和芽孢杆菌属的减少趋势,富集了红假单胞菌属(Rhodopseudomonas)和线黑粉酵母属(Filobasidium)。与SN0处理相比,施氮处理均降低了化学异养、固氮、芳香化合物降解和几丁质分解功能菌群的丰度,同时降低undefined saprotroph丰度。3)环境因子与群落关联网络分析和RDA分析显示,土壤有机碳(SOC)、碱解氮(AN)、全氮(TN)和有效磷(AP)含量是影响真菌群落的主要环境因子,SOC和AP含量是细菌群落的主要影响因子。无色穗孢属(Achroiostachys)与SOC含量呈负相关,与AN呈正相关。Emericellopsis与AN和TN含量呈显著负相关,与pH呈显著正相关。SOC与类诺卡氏属(Nocardioides)显著正相关,与厌氧粘细菌属(Anaeromyxobacter)显著负相关。【结论】从产量、群落多样性及富集有益微生物角度综合分析,冬油菜施用N 180 kg/hm^(2)是较合理的氮肥用量。

广西不同绿肥油菜品种的养分累积差异及富硒品种筛选

【目的】探明不同绿肥油菜品种的养分差异及对土壤硒富集效应,为丰富绿肥油菜品种及广西富硒土壤资源应用提供理论依据。【方法】以川油36(CY36)、丰油823(FY823)和沣油919(FY919)等19个绿肥油菜品种为研究对象,采用盆栽试验,研究不同品种生物量,氮、磷、钾和钙养分累积差异及对土壤硒吸收、富集的响应。【结果】不同绿肥油菜品种之间的地上部生物量、地下部生物量和总生物量均存在一定差异。地上部干生物量为4.49~6.62 g/盆,地下部为0.14~0.84 g/盆;总干生物量为4.82~7.14 g/盆。总生物量前3位的中双9号、沣油958和南油12显著高于生物量最低的3个品种(花油8号、川油36和华湘油12号);地上部氮、磷、钾和钙养分含量分别为8.86~19.64 g/kg、 0.69~2.24 g/kg、 13.07~37.68 g/kg和11.82~34.23 g/kg。浙油51号和花油6号地上部和地下部的养分含量均较高。氮、磷、钾和钙含量综合评分排序前3位的油菜品种为浙油51、中双10号和花油6号。硒含量地上部为0.095~0.369 mg/kg,地下部为0.160~0.579 mg/kg;全株硒含量为0.111~0.382 mg/kg;沣油919、绵油88和圣光86的地上部、地下部和全株硒含量较高,均显著高于其他油菜品种;硒总累积量在0.552~2.286μg/盆,沣油919和绵油88显著高于其他油菜品种。【结论】综合各品种的养分累积量和硒素吸收特性,沣油919、绵油88和圣光86的富硒能力较强,可作为广西富硒土壤资源高效利用的绿肥油菜品种。