苏联球茎大麦有利基因引入普通小麦的研究

本研究从1979年开始,用抗病性较强的苏联球茎大麦(4x)为父本,普通小麦品种中国春(6x)为母本进行属间杂交,经离体培养杂种幼胚,获得了属间杂种(F_1)。杂种自交不育,用秋水仙素加倍亦不成功,而以中国春5B单体与之回交,获得回交一代(BC_1F_1)。杂种F_1形态为两亲的中间型,其花粉母细胞染色体数在24—30条之间。BC_1F_1代杂种的形态与F_1相似,染色体数在45—49条之间(其中大多数细胞终变期有20—21个二价体和3—7个单价体)。BC_1F_1代自交或回交均有部分结实。以后各代继续自交分离;于1985—1986年,分离出6个异源二体附加系(2n=22Ⅱ)和异源八倍体(2n=28Ⅱ)以及若干个与母本形态有明显差异的整倍体杂种后代(2n=21Ⅱ)。这些整倍体和非整倍体后代中,有2个附加系的蛋白质含量较高(22.30％和20.37％);在整倍体后代中有两个株系与其父本一样对小麦黄花叶病(WYMV)具有抗性,而其母本与浙江省当前推广的小麦品种均不抗病,说明球茎大麦抗黄花叶病基因可能已导入母本中国春小麦。     

外源DNA导入春麦引起蛋白质性状变异的研究

应用外源DNA导入春麦改良主裁品种的某些性状,结果表明:利用花粉管通道进行外源DNA直接导入是改良春麦品种的有效技术.导入D_2代在表现型及基因型均发生变异,变异具有随机性,不受亲缘关系的影响,获得一批优良性状的变异株(系),特别是高蛋白质含量的变异株系,比原品种蛋白质含量提高2—4%.     

中国春双端二体中端体的配对研究

21个中国春双端二体与中国春品种杂交,观察了杂种F_1减数分裂中期Ⅰ端体与相应染色体的配对。结果表明:14个组合的中期Ⅰ具有1个异形三价体的PMC的百分数超过90%;有3个组合(6A、5B和6D)分别为89.87%、83.56%和85.71%;2个组合(4A和1B)低于80%。在4A、1B和5B的3个组合中,具有1个异形二价体和1个单价端体的PMC超过15%。在4A、1B和4D的组合中,还有一定频率的PMC具有2个单价端体。用21个组合中端体配对频率计算的二价体频率与中国春品种中期Ⅰ构型频率基本一致。这些结果表明,染色体臂作为端体时和它作为双臂染色体的一部分时,是以同样的方便程度配对的。     

phlb基因诱导小麦ABD染色体组部分同源染色体配对的研究

通过花药培养首次获得了“中国春”phlb突变体单倍体,同时也获得了“中国春”单倍体。对其细胞学观察表明,前者花粉母细胞减数分裂中期Ⅰ每个细胞染色体交叉为5.08个,后者为1.30个。证明了phlb基因在单倍体状态下具有强的诱导ABD染色体组部分同源染色体间的配对作用。     

河南鲁山五大温泉水细菌多样性分析

【背景】位于河南中部的平顶山市含有丰富的温泉资源,对温泉水中的微生物多样性和群落结构进行研究有助于更好地开发利用温泉资源。【目的】探究河南鲁山五大温泉水中(上汤、中汤、下汤、温汤和神汤)细菌多样性。【方法】采用Illumina Hi Seq2500 PE250技术对鲁山五大温泉水细菌的16S r RNA基因V3-V4变异区序列进行测序,应用UPARSE、Mothur、Silva、MUSCLE和QIIME等软件整理和统计样品序列数目和操作分类单元(Operational taxonomic unit,OTU)数量,最后分析五大温泉水中细菌的丰度和多样性。【结果】上汤、中汤、下汤、温汤和神汤分别获得56 017、68 319、65 247、59 340、68 825条有效Tags,聚类为670、287、337、598、381个OTU。细菌分类分析表明,五大温泉水的细菌超过40个门,变形菌门(Proteobacteria)占84.12%,是优势菌;在属分类阶元上,五大温泉水的细菌超过239个属,上汤的优势菌是不动杆菌属(Acinetobacter),中汤的优势菌是Tepidimonas,下汤的优势菌是Vogesella和不动杆菌属(Acinetobacter),温汤的优势菌是Sphingopyxis和新鞘脂菌属(Novosphingobium),神汤的优势菌是Aquabacterium。【结论】鲁山五大温泉水中含有丰富的微生物资源,为后续五大温泉水中的微生物资源开发奠定了基础。     

Origin and diversity of North American hard spring wheats

Genetic diversity is an important safeguard against crop vulnerability to biotic and abiotic stresses. Coefficient-of-parentage (COP) values of 248 North American hard spring wheat (Triticum aestivum L. em. Thell) cultivars released from 1901 to 1991 were used to estimate the genetic similarity of cultivars. COP values were used: to (1) quantify germ plasm sources and their contributions to the North American hard spring wheat gene pool; (2) measure changes in genetic diversity through time; and (3) identify major groupings of related cultivars. Landraces and local cultivars that contributed to the formation of the gene pool were: spring wheat (64%), winter wheat (16%), T. turgidum var. durum L. (10%), and T. turgidum var. emmer L. (8%). Fife, Hard Red Calcutta, and Turkey Red accounted for 18%, 13%, and 8%, respectively, of the hard spring wheat origins. Era and Butte in the US, and Neepawa and HY 320 in Canada, were the most commonly used named parents of cultivars released from 1981 to 1991. Both Canada and US had the greatest level of similarity among new cultivar releases in the 1930s (Canada: r=0.39, US: r=0.34). Genetic similarity in the US declined to r=0.14 in the 1940s and remained relatively constant thereafter. Similarity among released Canadian cultivars remained relatively high until the 1970s when the introduction of new market classes resulted in a 50% reduction in genetic similarity to approximately the same level of similarity found in the US. Cluster analysis was used to group cultivars released after 1941 into 13 clusters of similar genotypes. The cultivar clusters may have value for the stratified sampling of spring wheat germ plasm or in identifying diverse germ plasm for intermating.Contribution of the Idaho Agric. Exp. Stn. publication no. 95731. Missouri Pub. No. 12338     

黄土高原半干旱区春小麦农田有限灌溉对策初探

２年的大田试验研究表明,在黄土高原半干旱区,春小麦农田有限灌溉的时期为３叶期到孕穗期之间,但由于该地区降水变率很高,不同降水年型有限灌溉的关键时期和增产效果有很大差异,实际的需水关键期和作物生理的需水关键期往往不相吻合,对半干旱地区的有限浇灌琢作物的耗水过程和产量形成过程进行了讨论。     

臭氧胁迫下春小麦叶片胁迫乙烯产生与多胺含量的变化与调控

应用开顶式熏气装置,研究了０．７９６ ｍ ｇ／ｍ ３ Ｏ３ 浓度下,四叶期春小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍＬ．）叶片内胁迫乙烯产生和多胺含量的变化及其调控。结果表明：Ｏ３ 使胁迫乙烯的产生呈现先升后降的变化。ＣｏＣｌ２ 能强烈抑制胁迫乙烯产生。胁迫初期,精氨酸脱羧酶（ＡＤＣ）活性增强,当叶片伤害加重后,ＡＤＣ活性下降。对氯汞苯甲酸（ＰＣＭＢ）能抑制ＡＤＣ活性,并使腐胺（Ｐｕｔ）含量减少,而亚精胺（Ｓｐｄ）和精胺（Ｓｐｍ ）含量稍有增加。ＣｏＣｌ２ 对叶片ＡＤＣ活性影响不大,未见Ｐｕｔ的积累,Ｓｐｄ 和Ｓｐｍ 含量急剧增加,且一直保持较高水平,叶片所表现的伤害也较轻。较高浓度的Ｓｐｄ 和Ｓｐｍ 能抑制Ｏ３ 对植株的伤害,Ｓｐｄ 和Ｓｐｍ 的抑制作用大于Ｐｕｔ。由此认为,多胺含量变化是植物体对Ｏ３ 胁迫适应的调节机制之一     

A validated UPLC–MS/MS method for the surveillance of ten aquatic biotoxins in European brackish and freshwater systems

Over the past few decades, there has been an increased frequency and duration of cyanobacterial Harmful Algal Blooms (HABs) in freshwater systems globally. These can produce secondary metabolites called cyanotoxins, many of which are hepatotoxins, raising concerns about repeated exposure through ingestion of contaminated drinking water or food or through recreational activities such as bathing/swimming. An ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) multi-toxin method has been developed and validated for freshwater cyanotoxins; microcystins-LR, -YR, -RR, -LA, -LY and -LF, nodularin, cylindrospermopsin, anatoxin-a and the marine diatom toxin domoic acid. Separation was achieved in around 9 min and dual SPE was incorporated providing detection limits of between 0.3 and 5.6 ng/L of original sample. Intra- and inter-day precision analysis showed relative standard deviations (RSD) of 1.2–9.6% and 1.3–12.0% respectively. The method was applied to the analysis of aquatic samples (n = 206) from six European countries. The main class detected were the hepatotoxins; microcystin-YR (n = 22), cylindrospermopsin (n = 25), microcystin-RR (n = 17), microcystin-LR (n = 12), microcystin-LY (n = 1), microcystin-LF (n = 1) and nodularin (n = 5). For microcystins, the levels detected ranged from 0.001 to 1.51 μg/L, with two samples showing combined levels above the guideline set by the WHO of 1 μg/L for microcystin-LR. Several samples presented with multiple toxins indicating the potential for synergistic effects and possibly enhanced toxicity. This is the first published pan European survey of freshwater bodies for multiple biotoxins, including two identified for the first time; cylindrospermopsin in Ireland and nodularin in Germany, presenting further incentives for improved monitoring and development of strategies to mitigate human exposure.     

Cross prediction studies on spring barley

Summary The genetical and environmental control of three height characters, two maturity characters and neck length in five barley pair crosses was studied using both F₂ triple test cross and model fitting analysis.Significant additive and dominance effects were found for all six characters with some evidence of epistasis for each character. Generally, dominance was incomplete for the height characters but was significantly directional for increased height in those crosses where dwarfing genes were segregating. Variable dominance effects were found for both the maturity characters. Complete dominance was found in three cases, otherwise incomplete dominance was found. Significant directional dominance for earliness was found for both maturity characters in one cross but this was attributed to the presence of a daylength insensitivity factor in one of the parents. Most of the genetic variation for neck length was additive, though some evidence of dominance was found.Broad sense and narrow sense heritability estimates generally were found to be high for the height and maturity characters but low for neck length. It was concluded that early generation selection for height at ear emergence, for final height and for awn emergence was worthwhile. Early generation selection for neck length was not recommended from the results of this study.