Genome-wide association studies reveal QTL hotspots for grain brightness and black point traits in barley

Grain kernel discoloration(KD)in cereal crops leads to down-grading grain quality and substantial economic losses worldwide.Breeding KD tolerant varieties requires a clear understanding of the genetic basis underlying this trait.Here,we generated a high-density single nucleotide polymorphisms(SNPs)map for a diverse barley germplasm and collected trait data from two independent field trials for five KD related traits:grain brightness(TL),redness(Ta),yellowness(Tb),black point impact(Tbpi),and total black point in percentage(Tbpt).Although grain brightness and black point is genetically correlated,the grain brightness traits(TL,Ta,and Tb)have significantly higher heritability than that of the black point traits(Tbpt and Tbpi),suggesting black point traits may be more susceptible to environmental influence.Using genome-wide association studies(GWAS),we identified a total of 37 quantitative trait loci(QTL),including two major QTL hotspots on chromosomes 4H and 7H,respectively.The two QTL hotspots are associated with all five KD traits.Further genetic linkage and gene transcription analyses identified candidate genes for the grain KD,including several genes in the flavonoid pathway and plant peroxidase.Our study provides valuable insights into the genetic basis for the grain KD in barley and would greatly facilitate future breeding programs for improving grain KD resistance.

SNP-based identification of QTL for resistance to black point caused by Bipolaris sorokiniana in bread wheat

Black point disease caused by Bipolaris sorokiniana is a problem in wheat production worldwide.We aimed to identify major quantitative trait loci(QTL)for resistance to black point and develop molecular markers for marker-assisted selection(MAS).A recombinant inbred line(RIL)population derived from a cross between Wanyuanbai 1(susceptible)and SN4143(resistant)was evaluated for black point response at three locations during two years under artificial inoculation with B.sorokiniana,providing data for six environments.Thirty resistant and 30 susceptible RILs were selected to form resistant and susceptible bulks,respectively,that were genotyped by the wheat 660 K SNP array;685 singlenucleotide polymorphisms(SNPs)were identified,among which 385(56.2%)and 115(16.8%)were located on chromosomes 4 A and 2 B,respectively.Bulked segregant RNA-Seq analysis identified candidate regions on chromosomes 4 A(4.60–40.28 Mb)and 5 A(1.22–48.47 Mb).Genetic linkage maps were constructed for chromosomes 2 B,4 A,and 5 A using 59 polymorphic d CAPS and SSR markers.Finally,two QTL,designated QBB.hau-4 A and QBB.hau-5 A,were detected on chromosomes 4 A and 5 A,respectively.The resistance allele of QBB.hau-4 A was derived from SN4143,and that of QBB.hau-5 A came from Wanyuanbai 1.QBB.hau-4 A with a large and consistent effect(15.1%)is likely to be a new locus for black point resistance.The markers linked to QBB.hau-4 A and QBB.hau-5 A have potential application in MASbased breeding.

Efficacy of Plant Extracts on Morphology and Cultural Characteristics of Bipolaris sorokiniana, Causing Black Point Disease of Wheat in Bangladesh

Black point of wheat caused by Bipolaris sorokiniana (Bs) is very destructive disease of wheat in Bangladesh and all over the world. The symptoms of diseases caused by Bipolaris sorokiniana can vary depending on the host plant and environmental conditions. The conidia of Bs germinate from two poles, which differ physiologically as indicated by the rate, growth character, of length, breadth and number of septa on different media. The aim of this study was to evaluate the efficacy of selected plant extracts on the morphology and cultural characteristics of the fungus Bipolaris sorokiniana causing black point disease in wheat crops in Bangladesh. The efficacy of fifteen plant extracts on the growth and characteristics of Bs was conducted in vitro in 2019-2020. The treatments were: Untreated control, T1—Black berry Leaves, T2—Guava Leaves, T3—Lantena camera leaves, T4—Eucalyptus Leaves, T5— Turmeric Leaves, T6—Khoksha Leaves, T7—Papaya leaves, T8-Gurlic Bulb, T9—Chili dust, T10—Nigella seeds, T11—Turmeric dust, T12—Cloves, T13— Bohera fruits, T14—Black pepper and T15—Neem leaves. After 15 days of inoculation of Bipolaris sorokiniana, colony color and shapes were Gerrish blackish, greenish blackish, greyish blackish and shapes were round or irregular. In our study, conidia color was dark brown to light brown, conidiophore color was brown, dark brown, grayish brown, dark olivaceous, light brown and conidia shapes were elliptical, oblong or slightly curved. The septation of conidia was 2 - 5 and highest septation was seen in T4 and T14 treatments. The highest conidial length was 17.79 μm recorded in T2 treatment and lowest was 6.62 μm T9 treatment where conidial breath was 8.27 μm in control and lowest was 3.79 μm in T8 treatment. Mycelial growth rate of Bipolaris sorokiniana was different in different treatments in different days after inoculation (DAI) where at 7 DAI, % reduction of mycelial growth over control was highest in Bohera and Neem Leaves treatments respectively.

Analysis of Low Melting Point Fat Constituents of Black Soybeans by HS-SPME-GC-MS

[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between different kinds of black soybeans. [Methods] Using HS-SPME-GC-MS,the qualitative analysis was performed on the low melting point fat constituents of black soybeans; using peak area normalization method,the relative content of constituents was calculated. [Results]A total of 42 peaks were identified from the low melting point fat constituents of the black soybeans with yellow heart,and 18 kinds of chemical constituents were identified,accounting for 81.39% of total relative content of low melting point fat constituents; a total of 37 peaks were identified from the low melting point fat constituents of the black soybeans with green heart,and 15 kinds of chemical constituents were identified,accounting for 83.24% of total relative content of low melting point fat constituents. There were 9 kinds of common chemical constituents for the two kinds of black soybeans,and 5-allylguaiacol had the highest relative content,followed by hexanol. [Conclusions] There was no significant difference in the low melting point fat constituents between two kinds of black soybeans.

The Gravitational Radiation Emitted by a System Consisting of a Point Particle in Close Orbit around a Schwarzschild Black Hole

We analytically model a relativistic problem consisting of a point-particle with mass m in close orbit around a stationary Schwarzschild black hole with mass M = 1 using the null-cone formalism when l = 2. We use the -function to model the matter density of the particle. To model the whole problem, we apply the second order differential equation obtained elsewhere for a dynamic thin matter shell around a Schwarzschild black hole. The only thing that changes on the equation is the quasi-normal mode parameter which now represent the orbital frequency of the particle. We compare our results with that of the standard 5.5 PN formalism and found that there is a direct proportionality factor that relates the two results, i.e. the two formalisms.

On the Final State of Black Holes

The final state of a black hole and its force balance is considered, in the limit where all available energy is radiated away and all matter remains in the lowest form of Zero Point Energy (ZPE). In conventional theory without the concept of ZPE, the gravitational contraction would transfer the system into a mass point, being questionable from the theoretical point of view. But the inclusion of ZPE makes a force balance possible, resulting in a finite characteristic radius of a black hole mass distribution. This radius is of the same order as that of the so-called Schwarzschild radius, but is not related to the physics of the latter, which is due to particle trapping in the gravitational field.

The Spatial Patterns of Road Traffic Crash Black Spots and Emergency Facilities in Federal Capital City

This study aimed at determining the spatial patterns of Road Traffic Crash (RTC) black spots, Federal Road Safety Commission (FRSC) zebra points and emergency health care facilities in Federal Capital City (FCC). The aim was to provide stakeholders with information that will aid their understanding of accident prone locations and accessible rescue possibilities for accident victims on the roads in FCT. GPS Map 76S Mark (GARMIN) was used to locate and pick coordinates of data in the study area. A total of 16 possible emergency health care facilities, seventy (70) RTC black spots and Five Zebra point locations were obtained from FRSC. ArcGIS 10.0 was used to compute the data by plotting the coordinates to produce maps of the spatial relationship and to carry out Nearest Neighbour Analysis (NNA). The result was further used to determine the spatial patterns of RTC black spots as well as patterns of the emergency facilities. Generally, the result shows that the spatial trend is turning towards dispersion. However, there is less than 1% likelihood that the dispersed patterns could be the result of random chance. It was recommended that, the Federal Road Safety Commission should be staffed with trained professionals that can be responsible for accident data surveillance and analysis using geospatial techniques.

黑寡妇算法与P&O相结合的光伏MPPT研究

目的 在局部遮阴条件下,传统最大功率点追踪(MPPT)算法通常会跟踪到局部最优值,单个群智能优化算法在多极值的情况下能有效跟踪最大功率点,但追踪时间相对较长,为此,提出一种基于黑寡妇(BWOA)与扰动观察法相结合的MPPT算法。方法 将boost电路中开关管的占空比定义为算法中的个体位置,通过对输出占空比的调整实现MPPT控制。结果 相比于原BWOA算法和PSO算法,基于BWOA与P&O结合算法的MPPT能够更加快速地跟踪到最大功率点。结论 与扰动观察法的结合可以有效加快BWOA算法收敛速度,并提高算法收敛精度。

小麦种子黑胚对发芽的影响及病原菌鉴定的研究

对6个小麦品种种子的黑胚进行了研究。结果表明:1.不同品种种子黑胚率不同,同一品种成熟期间因大气湿度提高黑胚率显著增加;2.黑胚严重的品种一般易穗发芽,同品种黑胚种子穗发芽率高于白胚种子,已经穗发芽的种子仍具有再发芽能力,但其发芽率明显低于正常的未穗发芽种子;3.同品种黑胚种子的千粒重明显高于白胚种子,这与两类种子于同株不同穗和同穗不同小穗中的分布密切有关;4.小麦种子黑胚经鉴定证明是一种真菌性病害,主要是链格孢菌(Alternaria alternata)所致,且多于小麦成熟期(开花后25—30天)侵染种子。

小麦黑胚病药剂防治研究

为了有效防治小麦黑胚病,室内测定了8种不同杀菌剂对小麦黑胚病菌(A lternaria a lternata)的抑菌效果。试验结果表明,敌力脱对小麦黑胚病菌菌丝生长抑菌活性最强,EC50为3.38 m g/kg;烯唑醇、世高抑菌效果也较好,EC50分别为6.61和6.89 m g/kg。代森锰锌对病菌孢子萌发抑菌活性最强,EC50为0.25 m g/kg;麦叶净、福美双、烯唑醇抑制效果也较好,EC50分别为0.30、0.80和1.76 m g/kg。通过两年田间试验发现,22%麦叶净W P 600倍液喷雾对小麦黑胚病防效最好,平均防效达80.59%;其次为25%敌力脱EC 1 000倍喷雾,两年平均防效为74.97%;22%麦叶净W P 800倍和12.5%烯唑醇1 500倍液喷雾也有较好的防效,两年平均防效均超过60%。从防治时期和次数试验结果来看,扬花后5 d喷药防治效果最好,随着施药时间延迟,防治效果也随之下降;两次施药效果明显优于一次施药。

小麦品种(系)的黑胚病抗性评价

为利用抗病品种有效防治黑胚病，从2003年至2005年，采用田间自然病圃法对生产上大面积种植和新近选育的小麦品种（系）的抗性黑胚病进行了鉴定和评价。结果发现，供试材料中无免疫品种，但品种（系）间抗性差异明显。其中，豫优1号、陕229等6个品种（系）平均籽粒黑胚率小于5％，为抗病类型，占供试材料的13.64％；漯麦4号、豫农9901等6个品种（系）平均籽粒黑胚率超过30％，达到高感水平，占13．64％；豫展9705、豫麦49等15个品种（系）的平均籽粒黑胚率在5．0％～14．9％之间，为轻感类型，占34．09％；新原958、中育6号等17个品种（系）平均籽粒黑胚率在15．0％～29.9％之间，为中感类型，占38．64％。同时．调查发现同一品种在不同年份问的抗性表现有一定差异。对滤纸保湿培养法和直接观察法评价小麦品种对黑胚病抗性进行了比较，发现两种方法评价结果趋势基本一致，但保湿培养法籽柱黑胚率普遍高于直接观察法。

新疆小麦黑胚病的病原、致病性及侵染的研究

通过对小麦黑胚病病原分离、病原的鉴定及致病性研究结果表明,新疆的小麦黑胚病是由多种的病原侵染所组成,确立了Alternaria consortiale（Thüm.）Hughes,Alternaria alternate（Fr.） Keissler与Bipolaris sorokiniana（Sacc et Sorokin） Shoems是引发新疆小麦黑胚病的病原,前二者是本病主要病原成分,第三个虽然也可引起与前者同样症状的黑胚病,分离率却很低,仅占病原总分离率的7.0%～8.1%.A.consortiale可侵染小麦种粒且成为新疆小麦黑胚病的优势病原菌.3种病原对麦粒的致病性表现有差异,A.consortiale与A.alternate对小麦苗期的致病力不显著,以B.sorokiniana最强;但进入小麦接穗期后却表现相反：B.sorokiniana对麦粒的致病力表现较弱,且其侵染期仅局限在小麦的抽穗期至乳熟期,而A.consortiale与A.alternate却明显地较强,其侵染致病期均出现在小麦的乳熟期至黄熟期.小麦黑胚病病原的侵染机制,表现在穗轴各部位首先发病,然后由病变处的菌丝体穿透过小穗的基部再过渡到胚尖,才使得小麦的胚也感染变黑.大田环境高温多湿,是引致小麦黑胚病高发的首要成因.

2010年郑州地区小麦黑胚率及黑胚粒发芽特性

对2010年郑州地区收获的257份小麦品种（系）进行了黑胚率统计,并以发病较重的周麦18和漯麦4-168两个品种为材料,分析了黑胚病对种子发芽势、发芽率、发芽指数等发芽特性以及苗高、根长、单株质量等幼苗生长指标的影响。试验结果表明：257份小麦品种（系）的黑胚率介于0~54%,其中豫麦35号、百泉41等77个品种的黑胚率低于1%,济程2号的黑胚率最高,达到54%。70%的品种（系）黑胚率低于5%,80%的品种（系）病粒级别较低（0-2级）,与往年比较,2010年郑州小麦黑胚率降低。周麦18黑胚率为18.0%,黑胚粒发芽势、发芽率、发芽指数、根长、苗高与单株质量均降低,其中0-1级与2-3级种子间差异极显著;漯麦4-168黑胚率为25.7%,病粒的发芽与幼苗生长指标也降低,但不同病级间的差异不显著。

不同小麦品种(系)黑胚病发生及其对子粒危害的影响

为了解河南省目前推广及新近选育的小麦品种(系)黑胚病的田间发生及其对子粒危害的影响,并在室内对田间收获的各小麦品种(系)的黑胚率、千粒重、发芽率及幼芽鲜重进行检测.结果表明,不同小麦品种(系)的黑胚率存在显著差异,陕229和豫优1号发病最轻,黑胚率为2.0%和2.1%;漯麦4号发病最重.小偃803等43个品种黑胚子粒的千粒重是增加的,病、健子粒千粒重差值为0.71~6.96 g;仅有豫麦49号等5个品种黑胚子粒千粒重是降低的,病、健子粒千粒重差值为-0.08^-5.2 g.豫麦68号等35个品种的健康子粒发芽率高于病子粒,病、健子粒发芽率差值为-3.33^-20.0;新麦18等4个品种的黑胚子粒发芽率高于健康子粒,病、健子粒发芽率差值为3.33~10.0;山东95519等9个品种黑胚子粒和健康子粒的发芽率是一致的.豫麦70号等13个品种黑胚子粒萌发后的幼芽重是增加的,病、健子粒幼芽鲜重差值为0.000 6~0.004 4 g;郑麦9023等35个品种的黑胚子粒萌发后幼芽鲜重比健康子粒萌发后的幼芽鲜重减轻,病、健子粒幼芽鲜重差值为-0.000 2^-0.016 4 g.不同小麦品种的黑胚率与病、健子粒千粒重、发芽率和幼芽鲜重的差值之间没有相关性.

PERC背钝化工艺卡点位置缺陷导致EL不良研究

以二合一管式PECVD背钝化镀膜工艺过程中出现的石墨舟空心卡点EL发黑品质异常为研究对象,分析讨论二合一管式PECVD背钝化工艺中射频功率、工艺温度、氧化铝沉积厚度等对晶硅太阳电池空心卡点EL发黑品质异常的影响。结果表明,在二合一管式PECVD背钝化工艺时采用12~16 nm厚度的氧化铝薄膜、350~370℃的预淀积工艺温度,能有效解决镀膜空心卡点EL发黑品质异常,显著提升晶硅太阳电池在二合一管式PECVD的镀膜品质。

小麦黑胚病对种子发芽和出苗等生长因子的影响

为了解小麦黑胚病对种子发芽及出苗的影响,室内测定了2006年黑胚病发生严重的小麦品种漯麦4号的健康籽粒和发病籽粒的发芽势、发芽率、幼芽鲜重、出苗率以及三叶期的苗长、苗鲜重、根长、根鲜重。结果表明,小麦发生黑胚病后,病粒导致发芽势、发芽率、幼芽鲜重、出苗率、苗高、苗鲜重、根长、根鲜重降低,尤其是发芽势、发芽率明显降低,各病级处理间差异显著,种子病级与上述生长因子呈负相关。小麦黑胚病对小麦种质有较大的影响,尤其是重病粒。

3种杀菌剂对小麦黑胚病菌的毒力测定及病害防治作用

采用分生孢子萌发率和菌落直径比较了3种杀菌剂对小麦黑胚病主要致病菌小麦根腐离蠕孢(B ip olaris sorok injana)和链格孢霉(A lternaria a lterna ta)的毒力作用,并在温室盆载和田间小区试验条件下进行了防治效果研究。结果表明,不同杀菌剂、同种杀菌剂不同浓度之间存在明显毒力差异。从分生孢子萌发率看,敌力脱浓度为0.250μL/mL时对小麦黑胚病2种病原菌分生孢子萌发抑制率高达99%以上,代森锰锌浓度为350μg/mL时的抑制率达94.5%以上,而多菌灵浓度为500μg/mL时的抑制率不到40%,远远低于以上两种药剂。从菌落直径看,敌力脱的致死中浓度(EC50)值最小,对小麦黑胚病菌菌丝生长的抑制作用最强。在小麦灌浆初期对温室盆栽和田间小区种植的感病品种丰舞981于人工接种前2 d和接种后4 d分别喷施3种杀菌剂,小麦黑胚率调查结果与室内抑菌实验结果相似,敌力脱和代森猛锌对小麦黑胚率有较好的控制作用,而多菌灵效果较差。接种病原菌后4 d喷药处理的防病效果明显优于接种前2 d的喷药处理。

小麦黑胚病籽粒黑变机制研究进展

综述了小麦黑胚病病因及其黑变机制研究进展。目前的研究结果表明,环境因素与病菌侵染引起酶促褐变,导致小麦黑胚病症状产生,而褐变是小麦籽粒中酚类物质发生氧化形成褐色物质导致的。筛选不同的生理型与病理型感病材料是研究小麦黑胚病黑变机制的前提,采用基因组学、转录组学、蛋白质组学、代谢组学等组学研究方法能够进一步揭示小麦黑胚病的黑变机制。

小麦种子黑胚病发病规律研究

链格孢Alternaria alternata(Fr.)Kiessler是小麦种子黑胚病的主要致病菌。1987～1988年在鲁麦8号小麦抽穗、开花及籽粒发育各阶段自穗部进行分离,结果表明:小麦籽粒乳熟后期(花后20天)病菌开始侵染胚部,引起黑胚,随着籽粒成熟黑胚率相应增加。在此期间遇雨或田间相对湿度高(90%以上),易结露,则黑胚病加重。室温26～27℃下接种,病害潜育期为3～4天。大气中的链格孢菌是小麦种子黑胚病的侵染源。小花上残留的花药是病菌进入花内的途径之一。小麦黑胚病普遍发生,不同品种(品系)有差异。高肥水地种子黑胚率高于旱地,雨后收获的种子黑胚病亦较雨前收获的重。黑胚粒的粒重大于非黑胚粒。

黑胚对小麦幼芽某些生理生化代谢的影响

比较研究了三个不同程度抗感黑胚病的小麦品种病粒和健粒的幼根和胚芽鞘中 SOD、POD、PPO和 PAL活性及幼根中总酚与类黄酮含量的变化。结果表明 ,抗病品种豫麦 2号黑胚种子的幼根和胚芽鞘中SOD和 POD活性显著升高 ;高感品种豫麦 4 0号的 SOD和 POD活性变化不大。抗病品种幼根中 PPO和 PAL活性显著升高 ,胚芽鞘中 PPO和 PAL活性显著降低 ;高感品种幼根和胚芽鞘 PPO活性升高 ,PAL活性下降。抗病品种总酚和类黄酮含量增加幅度最大。