烟草抗PVY的EMS突变体pvyr1筛选与抗性遗传初步分析

为了从烟草EMS突变体库中筛选抗马铃薯Y病毒(Potato virus Y,PVY)突变体,采用苗期人工接种初筛M2抗病单株,对M3、M4和M5株系连续接种鉴定PVY抗性。采用e IF4E1基因特异分子标记检测和c DNA全长测序,分析突变体PVY抗性是否与e IF4E1突变有关。配制F1群体初步分析抗性遗传特性。苗期人工接种从1800份M2种子中筛选到1份抗PVY的烤烟突变体。冬季无加温措施塑料大棚内苗期人工接种PVY坏死株系MN分离物,接种后35 d未诱变对照品种发病率为100%,E9119-1Z/M3株系的发病率为56.3%,无症状单株ELISA检测PVY均为阴性,表明E9119-1Z/M3株系对PVY中抗。E9119-1Z的M4株系和M5株系在光照培养室内苗期人工接种对PVY坏死株系MN分离物和ZT-5分离物表现为中抗。E9119-1Z-R14-2/M5株系为抗性稳定的突变体,命名为pvyr1。pvyr1采用e IF4E1基因特异分子标记检测为阳性,c DNA测序表明e IF4E1基因无突变。pvyr1与未诱变对照品种(感PVY)、va位点抗PVY品种NC55的杂交F1代抗性鉴定结果初步表明,pvyr1突变体对PVY的抗性符合孟德尔隐性遗传,且与NC55的va位点不等位。表明pvyr1为一个与e IF4E1基因突变不同的抗PVY新资源。     

雪茄烟Beinhart1000-1对黑胫病0号生理小种的抗性遗传分析

以烟草黑胫病重要抗源Beinhart1000-1、优质烤烟品种小黄金1025和香料烟Samsun NN及其配置的2个抗、感杂交组合为试验材料,进行成株期黑胫病菌0号小种人工接种鉴定,选用四世代数量性状"主基因+多基因"的混合遗传模型对抗源Beinhart1000-1进行遗传分析。结果表明,Beinhart1000-1在与Samsun NN配置的杂交组合1中,最优遗传模型是两对加性-显性主基因+加性-显性多基因模型(E2),主基因遗传率为99.14%,多基因遗传率为0.48%;在与小黄金1025配置的杂交组合2中,最优遗传模型是两对加性-显性-上位性主基因模型(B1),主基因遗传率为99.52%。表明Beinhart1000-1黑胫病的抗性遗传以主基因效应为主,适合在早代进行选择。     

烟草品种GDSY-1的青枯病抗性与遗传分析

为比较广东地方晒烟品种GDSY-1和传统抗源DB101的青枯病抗性与遗传规律,于2011—2016年在温室和大田、苗期和成株期共7次对GDSY-1、DB101和长脖黄(感病品种)等3个品种的青枯病病情进行调查,并配制组合GDSY-1×长脖黄、DB101×长脖黄和GDSY-1×DB101,对其P1、P2、F1和F2代群体的青枯病发生情况进行比较,利用主基因+多基因混合遗传模型联合分析方法进行遗传分析。结果表明,GDSY-1的青枯病抗性优于DB101;DB101的抗性遗传以加性效应为主,符合2对加性主基因+加性-显性多基因模型(E-4),主基因遗传率低;GDSY-1的抗性遗传表现为部分显性,符合2对加性-显性-上位性主基因+加性-显性-上位性多基因模型(E-0),第1对主基因的加性效应值和显性效应值分别为-2.690 9和-2.690 9,抗病对感病完全显性,第2对主基因的加性效应值和显性效应值分别为-1.219 4和-0.230 7,抗病对感病呈部分显性,2对主基因存在互作效应,主基因遗传率高,为85.02%。GDSY-1的抗性遗传显性程度高、主基因遗传率高,具有较大的育种利用价值。     

烤烟不同黄瓜花叶病毒病(CMV)抗源的抗性遗传分析

为深入认识烤烟不同抗源对黄瓜花叶病毒病(Cucumber mosaic virus,CMV)的抗性遗传规律,以3份CMV高抗材料(抗88、台烟8号和FC8)为父本分别与感病材料C151杂交构建了3个F2群体,采用摩擦接种的方法进行了苗期抗病性鉴定。利用主基因+多基因混合遗传模型分析方法分别对3个组合4个世代的病情调查结果进行了分析。结果表明:抗88和台烟8号的最优模型是E1模型,即抗性受2对加性-显性-上位性主基因+加性-显性多基因控制,主基因的遗传率分别为91.91%和68.50%。FC8的抗性由2对加性-显性-上位性主基因控制(B1模型),主基因的遗传率为76.43%。3个抗源的抗性都主要由遗传因素控制,主基因遗传率较高,说明抗病性状可以在早期进行选择。抗88和台烟8号主基因间的上位性效应以及多基因的加性和显性效应都有助于提高抗性,在育种中可以加以利用;FC8的2个主基因显性效应明显,适合杂种优势利用。     

两个烟草赤星病抗源的遗传分析

以高抗赤星病烟草品种净叶黄(JYH)、Beinhart1000-1(Beinhart)和感病品种NC82为材料分别构建了2个杂交组合的P₁、P₂、F₁、F₂四世代群体,成熟期赤星病菌人工接种鉴定后,采用主基因+多基因混合遗传模型对JYH和Beinhart两个材料进行抗性分析,结果表明,两者的赤星病抗性均受两对加性-完全显性主基因+加性-显性多基因控制。组合1的加性效应以第1对主基因为主,且多基因的加性效应大于显性效应;组合2的两对主基因负向加性效应相等,且多基因的显性效应大于加性效应;2个组合F₂群体主基因遗传率分别为64.72%和63.88%,表明赤星病的抗性遗传以主基因效应为主,并且受环境影响较大。     

烟草青枯病抗性突变体486-K和117-K的遗传分析

烟草青枯病是一种典型的维管束细菌性病害,严重影响我国烟叶生产。为了解烟草青枯病抗性突变体的遗传规律和开发抗性相关分子标记,本研究选用EMS诱变烤烟品种翠碧一号获得的烟草青枯病抗性突变体486-K和117-K为研究对象,以翠碧一号和2个突变体为亲本,构建了两个不同的杂交组合,采用卡方检验和植物数量性状"主基因+多基因"混合遗传模型分析方法,进行群体遗传效应分析。结果表明,卡方检验显示突变体486-K和117-K的F2代各病级株数呈正态分布,存在一定性状分离。"主基因+多基因"混合模型分析发现突变体117-K的最优抗性遗传模型为2MG-A,即2对主基因为加性效应控制遗传,无显性效应和上位性效应,主基因的遗传效率为78.57%;突变体486-K的最优抗性遗传模型为2MG-ADI,即2对加性-显性-上位性主基因模型,上位性效应中以显性×显性互作和显性×加性互作效应较大,主基因遗传效率为88.34%。表明烟草青枯病抗性突变体的遗传方式以主基因效应为主,受环境影响较小。     

烟草青枯病抗性遗传效应分析

烟草青枯病是由青枯菌引起的烟草细菌性病害,是危害我国烟草生产的主要病害之一,解析烟草青枯病的抗性遗传效应对指导抗病育种具有重要意义。本研究采用主基因+多基因混合遗传模型的多世代联合分析方法,以多个抗病/感病样本为亲本,构建了两个不同的杂交组合,进行群体遗传效应分析。结果表明,岩烟97的青枯病抗性由2对加性、显性、上位性主基因以及加性、显性、上位性多基因控制;反帝三号-丙的青枯病抗性受1对加性-显性基因+加性-显性-上位性多基因控制。烟草青枯病抗性以加性效应为主,兼有显性效应,有利于等位基因聚合育种及早代选择。     

烟草品种“大叶密合”青枯病抗性遗传分析

选用大叶密合和5个对青枯病具有不同抗性水平的烟草品种,按完全双列杂交设计,采用Griffi ng方法 I及Hayman方法进行遗传分析,并应用植物数量性状主基因+多基因混合遗传模型对大叶密合(抗病品种)×长脖黄(感病品种)组合P1、P2、F1和F2等4个世代群体的青枯病抗性进行了联合分析。结果表明:参试品种的青枯病抗性为细胞核遗传;大叶密合×长脖黄组合的青枯病抗性遗传符合2对加性-显性-上位性主基因+加性-显性多基因遗传模型(E-1),主基因的加性和显性效应值分别为0.5013、-0.3023和1.6439、0.8401,多基因的加性和显性效应值分别为-1.3989和-1.7798,主基因遗传率63.95%,利用大叶密合进行抗病育种,适宜在分离晚世代进行选择并加大后代筛选群体。大叶密合与NC95的抗性遗传存在差异,后者的抗性表现为加性遗传。     

一个与净叶黄抗赤星病基因紧密连锁的SSR标记

为了在分子水平上弄清烟草赤星病抗性的遗传规律,并进行遗传定位,以抗赤星病品种净叶黄和感赤星病品种NC82为亲本,构建了F₁、F₂、BC₁ 代群体。通过对该群体进行赤星病接种鉴定和抗性遗传分析,发现净叶黄对赤星病的抗性由显性多基因控制。通过分子标记群体扩增,在第M号连锁群上,筛选到一个与净叶黄的赤星病抗性基因紧密连锁的SSR标记,它与抗性基因间的遗传距离为4 cM。该标记可用于抗赤星病育种的辅助选择。     

香料烟青枯病抗性基因的遗传分析

本研究以香料烟青枯病抗病品种Xanthi、感病品种Samsun、F1以及F2群体为研究材料,采用青枯病圃进行抗性鉴定,利用主基因+多基因混合遗传模型对各群体单株的病情指数进行分析,结果表明:香料烟青枯病抗性基因是受2对加性-显性-上位主基因+加性-显性多基因(E-1模型)控制遗传;主基因的遗传率为49.63%。     

转几丁质酶基因烟草遗传稳定性研究

从转几丁质酶基因烟草株系(NPTII基因是选择标记基因)对卡那霉素的抗性,及外源几丁质酶基因表达蛋白的活性(Western Blot检测)两个方面对转基因株系的遗传稳定性进行了分析研究。在卡那霉素抗性检测试验中,检测了13个T₂转基因株系,其中9个株系被检测种子100%对卡那霉素(100 mg/L)具有抗性;T₃和T₄转基因株系各检测了10个,100%被检测种子在含卡那霉素100 mg/L的MS培养基上长成了烟苗。Western Blot检测了11个T₂株系,检测结果表明,6个株系被检测植株100%含有外源几丁质酶蛋白,2个株系被检测植株80%含有外源几丁质酶蛋白,2个株系被检测植株50%含有外源几丁质酶蛋白,1个株系被检测植株19.05%含有外源几丁质酶蛋白。在温室内将转基因烟草与未转基因烟草密植在一起,种植2代,烟株开花期模仿自然风力对烟株吹风,进行了转基因烟草是否可以通过花粉进行基因漂移的研究。研究结果表明,在自然风媒条件下未发现转基因烟草可进行基因漂移。      

引进美国烤烟新品种(系)的抗性检测与评价

为选育和利用抗病品种、有效防治烟草病害,采用人工诱发抗性鉴定方法对引进的13个美国烤烟品种(系)进行了烟草黑胫病、烟草普通花叶病(TMV)和赤星病的抗性测定,并采用分子标记方法对黑胫病和TMV进行了辅助检测。结果表明:NCT5、NCT6、NCT7、NCT8、NCT9、NCT10和NCT13抗黑胫病,NCT1、NCT4、NCT11和NCT12中抗黑胫病,抗病分子标记辅助检测中仅有4个烤烟品种NCT6、NCT9、NCT12和NCT13检测出Ph基因,其余品种未检出含有Ph基因。NCT1、NCT8、NCT11和NCT4中感赤星病,NCT12、NCT10、NCT2、NCT13、NCT9、NCT3、NCT7、NCT6和NCT5中抗赤星病。NCT13、NCT10、NCT9、NCT12、NCT6、NCT4、NCT1、NCT2、NCT11、NCT7和NCT8感TMV,NCT5和NCT3中感TMV。PCR分析表明,所有供试品种(系)均不含N基因,与抗性鉴定结果中13个供试品种(系)对TMV均表现感病和中感的结果相吻合。      

甘蓝型油菜角果的抗裂角特性及其相关分析

应用改良拉裂法,对286份甘蓝型油菜品种（系）进行裂角力测定.结果表明,抗裂角性状在现有甘蓝型油菜品种（系）中存在广泛变异.在146份甘蓝型杂交油菜品种（组合）中,裂角力变异范围0.82～ 2.87N（牛顿）,平均裂角力1.83N,变异系数22.11％;裂角力小于1N的有3份（占2.05％）,1～2N之间的96份（占65.75％）,在2～3N之间的47份（占32.19％）,没有检测到裂角力大于3N的品种或组合.在140份甘蓝型常规油菜品种（系）中,裂角力变异范围0.58 ～ 3.47N,平均裂角力1.94N,变异系数31.55％,均高于杂交油菜,其中裂角力小于1N的6份（占4.29％）,在1～2N之间的76份（占54.29％）,在2～3N之间的49份（占35％）,大于3N的9份（占6.42％）.与角果和籽粒性状的相关分析表明,油菜角果的裂角力值与单角壳重、单位面积壳重、千粒重达极显著正相关,与每角粒数和角果宽度达到显著正相关.分析杂种与亲本恢复系之间的关系,发现杂种裂角力与恢复系的角果宽度、单角壳重、单位面积壳重、千粒重等性状呈极显著正相关,与粒壳比呈极显著负相关.说明角果大小显著影响油菜的抗裂角特性,角果大、果壳厚、千粒重高等可以作为筛选抗裂角油菜的形态指标.在杂交油菜育种中选用大角大粒恢复系亲本能有效提高杂交油菜的抗耐裂角性.     

Detection and identification of transgenic virus resistant papaya and squash by multiplex PCR

Two separate multiplex PCR assays were developed for the detection of transgenic papaya and transgenic squash. Papaya line 55-1 contains a genetic insertion consisting of the coat protein gene of Papaya ringspot virus strain p and is resistant to infection by this virus. A multiplex PCR was developed to specifically amplify the papaya ringspot virus coat protein transgene construct and an endogenous papaya gene sequence. A third primer set was designed to amplify the -glucuronidase gene construct, which can distinguish between the commercial and noncommercial papaya lines 55-1 and 63-1. Squash line ZW-20 contains genetic insertions of the coat protein genes from Watermelon mosaic virus II and Zucchini yellow mosaic virus and is resistant to these two viruses. Squash line CZW-3 is similar to ZW-20 but additionally confers resistance to Cucumber mosaic virus. A second multiplex assay was developed to detect and differentiate squash lines ZW-20 and CZW-3 in a single reaction.     

Phenotyping and genotyping of antibiotic-resistant Escherichia coli isolated from a natural river basin

Scientists have become increasingly concerned about the occurrence of antibacterial resistance in the environment. In this study, Escherichia coli resistant to one or more antibiotics among nine antibiotics was screened from Wenyu River Basin in Beijing, China, with mean frequency of 48.7 +/- 8.7% of 388 isolates in summer and 47 +/- 6% of 236 isolates in winter. The mean multiantibiotic resistance (MAR) index in summer was 0.11 +/- 0.03, slightly lower than that (0.14 +/- 0.04) in winter. Most frequent resistance appeared for sulfonamides, tetracycline, and ampicillin. The distribution of 20 tetracycline, three sulfonamide, and three beta-lactam resistance genes was assessed in the resistant isolates. While 97% of the ampicillin (AMP) resistant mechanism could be explained by the resistance gene TEM, 90% of the tetracycline (TC) and 96% of the sulfonamide (SXT) resistances could be explained by tet(A), tet(B), tet(M), and their combinations and sul(I), sul(II), sul(III), and their combinations, respectively. tet(M), a tetracycline-resistant gene originally detected in Gram-positive bacteria, and its combinations with tet(A) or tet(B) were first detected in E. coli isolated from a natural river basin, suggesting that tet(M) in E. coli might have been transferred from other bacterial species through horizontal gene transfer, which was supported by the fact that no tet(M) was detected in the isolates of human and chicken sources, except for only one isolate from swine. The source of sulfonamide-resistant E. coli in the river was supposed to be mainly from humans, based on a comparison of the sulfonamide resistance genotypes in animals and humans.     

大豆资源抗疫霉根腐病基因分析

采取下胚轴创伤接种法鉴定156份大豆资源对13个不同毒力基因型大豆疫霉菌株的抗性。结果表明,125份资源分别抗1～13个菌株,占鉴定资源总数的80.13%。125份抗性大豆资源与13个大豆疫霉菌株共产生90种反应型。通过与13个鉴别寄主的反应型比较发现,有9份大豆资源产生的5种反应型与含有已知抗病基因的大豆资源的反应型相同;12份大豆资源产生的5种反应型与已知2个抗病基因组合的反应型一致,另外,还有至少抗1个菌株的104份大豆资源产生的80种反应型,既不同于已知单个抗病基因的反应型,也不同于2个已知抗病基因组合的反应型,推测可能含有新的抗病基因或基因组合。     

烟草野生种eIF4E1-S同源基因的多样性与马铃薯Y病毒抗性分析

  背景和目的  在栽培烟草中,真核生物翻译起始因子（Eukaryotic translation initiation factor 4E1,eIF4E1-S）的缺失或突变能够抗马铃薯Y病毒（Potato virus Y,PVY）侵染。为了解烟草野生种eIF4E1-S同源基因的多样性和PVY抗性状况,预测野生种含有抗PVY新基因（即不同于eIF4E1-S基因缺失或突变的基因）的可能性。  方法  本文设计了普通烟草eIF4E1-S和其同源基因eIF4E1H-T（非感病基因）的特异引物,扩增测定了34个烟草野生种的同源基因cDNA序列,分析了野生种PVY抗性与感马铃薯Y病毒属病毒eIF4E蛋白关键结构域序列（loop1和loop2）的相关性。  结果  在eIF4E1-S同源基因的系统进化树上,绒毛烟草组（Tomentosae）的4个抗PVY野生种Nicotiana otophora、N.setchelli、 N.tomentosa、 N.tomentosiformis聚成一组,loop1和loop2的氨基酸序列与eIF4E1H-T一致,这4个野生种对PVY的抗性可能与eIF4E1进化为eIF4E1H-T有关、包含抗PVY新基因的可能性较低。圆锥烟草组（Paniculatae）的4个抗PVY野生种N.benavidesii、N.raimondii、 N.cordifolia、N.knightiana聚成一组,同源基因氨基酸序列与eIF4E1-S一致率高于eIF4E1H-T,但loop1和loop2氨基酸序列相互之间差异较大,这4个野生种包含抗PVY新基因的可能性中等。与eIF4E1-S聚成一个小分支的N.glauca、N.noctiflore、N.africana高抗5个PVY分离物（包含可克服va抗性的PVY分离物）,其中N.glauca、N.noctiflore的同源基因loop1氨基酸序列与eIF4E1-S相同,loop2与eIF4E1-S之间只有1-2个氨基酸差异,N.africana同源基因loop1与eIF4E1-S和eIF4E1H-T差异较大、loop2与eIF4E1-S之间只有1个氨基酸差异（V97M）。推测这3个野生种的PVY抗性与eIF4E1的突变无关且含有新的抗PVY基因可能性高,可作为重点抗源研究利用。  结论  根据PVY侵染栽培烟草所利用的寄主因子eIF4E1-S基因的同源基因的多样性,抗PVY烟草野生种存在抗PVY新基因的可能性划分为高、中和低三档。N.glauca、N.noctiflore、N.africana含有新的抗PVY基因可能性高于其他供试野生种。      

白芥和甘蓝型油菜属间杂种后代菌核病抗性鉴定

通过对24个白芥和甘蓝型油菜属间杂种回交后代株系叶片菌核病菌丝接种鉴定,发现有11个株系与抗病品种中双9号抗性差异不显著,有4个株系抗性极显著强于中双9号。茎秆接种也验证了这个结果。结果表明,白芥和甘蓝型油菜属间杂种后代部分株系抗菌核病能力得到明显提高,对创造抗菌核病油菜新种质具有重要意义。     

Chemical and structural quality traits during postharvest ripening regulated by chromosome segments from a wild relative of tomato Solanum pennellii IL4-2 and IL5-1

Tomato is usually harvested at an early ripening stage with high firmness suitable for storage and transportation but lacks many quality parameters such as sugars, organic acids, and phenolics. In a recent study, we have selected introgression lines (ILs) IL4-2 and IL5-1, developed from a cross between the Solanum pennellii and the Solanum lycopersicum M82, that exhibit differentiated postharvest shelf-life characteristics in the fruit compared to M82 and the rest of the ILs. Here, we first structurally and biochemically characterized IL4-2, IL5-1, and their parent M82 to decipher the cell wall mechanistic difference between soft (IL4-2) and firm (IL5-1) lines at two postharvest ripening periods. Generally, IL4-2 had more active cell wall modifications in terms of ripening-related gene expression, water-soluble pectin, and cell wall structure under the microscope, which probably makes this line softer than IL5-1. We also evaluated these lines based on commercial quality parameters, sugars, phenolics, organic, and amino acids to gain insight into their commercial and functional quality and reveal noticeable differences. In summary, the contribution of the S. pennellii IL5-1 and IL4-2 to the shelf life of the tomato was structurally characterized, and the component differences meeting the quality criteria were revealed.     

Atmospheric chemistry of perfluoroalkanesulfonamides: kinetic and product studies of the OH radical and Cl atom initiated oxidation of N-ethyl perfluorobutanesulfonamide

Perfluorooctanesulfonamides [C8F17SO2N(R1)(R2)] are present in the atmosphere and may, via atmospheric transport and oxidation, contribute to perfluorocarboxylates (PFCA) and perfluorooctanesulfonate (PFOS) pollution in remote locations. Smog chamber experiments with the perfluorobutanesulfonyl analogue N-ethyl perfluorobutanesulfonamide [NEtFBSA; C4F9SO2N(H)CH2CH3] were performed to assess this possibility. By use of relative rate methods, rate constants for reactions of NEtFBSA with chlorine atoms (296 K) and OH radicals (301 K) were determined to be kCL) = (8.37 +/- 1.44) x 10(-12) and kOH = (3.74 +/- 0.77) x 10(-13) cm3 molecule(-1) s(-1), indicating OH reactions will be dominant in the troposphere. Simple modeling exercises suggestthat reaction with OH radicals will dominate removal of perfluoroalkanesulfonamides from the gas phase (wet and dry deposition will not be important) and that the atmospheric lifetime of NEtFBSA in the gas phase will be 20-50 days, thus allowing substantial long-range atmospheric transport. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis showed that the primary products of chlorine atom initiated oxidation were the ketone C4F9SO2N(H)COCH3; aldehyde 1, C4F9SO2N(H)CH2CHO; and a product identified as C4F9SO2N(C2H5O)- by high-resolution MS but whose structure remains tentative. Another reaction product, aldehyde 2, C4F9SO2N(H)CHO, was also observed and was presumed to be a secondary oxidation product of aldehyde 1. Perfluorobutanesulfonate was not detected above the level of the blank in any sample; however, three perfluoroalkanecarboxylates (C3F7CO2-, C2F5CO2-, and CF3CO2-) were detected in all samples. Taken together, results suggest a plausible route by which perfluorooctanesulfonamides may serve as atmospheric sources of PFCAs, including perfluorooctanoic acid.