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在1993～1998年间对采自中国浙江省的116批及菲律宾吕宋岛的129批稻种进行了假单胞杆菌及相关细菌多样性研究。分别从浙江省和吕宋岛分离出1200多个和2300多个有关菌株,并对它们进行了细菌学、致病性和数值分类(Biolog)法测定。结果显示,吕宋岛稻种上的荧光细菌数明显高于浙江省。鉴定出16个假单胞杆菌种或型及2个相关种,其中约一半的细菌种尚未有从稻种上分离出来的记录。503个菌株对水稻纹枯病菌、水稻叶鞘腐败病菌及水稻细菌性褐条病菌的拮抗性测定表明,在浙江省约占稻种细菌总数12%的菌对一个或多个水稻病原菌具拮抗性,而在吕宋岛约占17%左右。     

小麦中的1BL/1RS染色体易位

1BL／1RS易位在世界小麦品种中广泛分布,在世界小麦育种特别是在中国小麦育种中占有重要地位。通过种间特定的染色体易位和替换,黑麦（Secale cereale L．）染色体1R的短臂（1RS）已存在于大量普通小麦（Triticum aestivwm L）的染色体组中,许多对农艺性状具有重要作用的基因和抗性基因由此从黑麦转入小麦基因组中。1RS主要用于转移抗真菌病害的基因,尤其是抗锈病、白粉病的基因（Yr9、Lr26、Sr31、Pm8）,1BL／1RS能增加小麦根系的生物量,并可提高小麦籽粒产量和蛋白质含量。然而,由于1RS替换了1BS,造成了1BS上重要基因位点Glu-3、Gli-1的丢失和1RS上Sec-1位点的引入。Sec-1编码的γ-黑麦碱、w-黑麦碱不能补偿Glu-3、Gli-1编码的低分子量麦谷蛋白和γ-醇溶蛋白、w-醇溶蛋白的品质效应,引起小麦的麦谷蛋白聚合物结构的改变和数量的减少。因此,1BL／1RS易位小麦面粉的烘烤加工品质较差,从而降低了1RS易位系小麦的利用价值。另一方面1BL／1RS易位小麦面粉的可溶性纤维含量高于一般小麦,对人体有益,因此利用不含黑麦碱的改良1BL／1RS新易位采替换中国小麦品种中普遍存在的1BL／1RS易位＋既可保持1BL／1RS易位系的优点又能改善其烘烤加工品质,这为提高1BL／1RS易位小麦的品质提供了新的途径。1RS片段能与异源细胞质互作导致雄性不育,这可用于小麦的杂种优势利用。本文主要阐述1BL／IRS易位的特征、检测方法、地理分布、在小麦育种中的应用以及给小麦品质带来的影响,并探讨了解决其负面影响的策略。     

小麦1BL/1RS易位系1RS分子标记位点稳定性分析

为检测小麦1BL／1RS易位系1RS位点的稳定性,利用1RS上11个标记位点的PCR特异引物对21个小麦1BL／1RS易位系进行了分子检测。结果表明,21个1BL／1RS易位系中,66．7％的品种1RS的11个标记位点较为稳定,扩增出标记位点特异性带,但有33．3％的品种部分标记位点出现特异性带的丢失或添加,具有不同程度的位点变异,位点变异率最高达45．5％。对于1RS上的11种PCR特异引物,引物NOR-R1和APR1．3可稳定扩增出黑麦特异带,是在小麦遗传背景中鉴别黑麦1RS较为可靠的分子标记。     

GmHs1~(pro-1)多样性分析及蛋白互作预测

GmHs1~(pro-1)是Hs1~(pro-1)同源的抗线虫候选基因,通过使用不同的大豆品种克隆GmHs1~(pro-1)CDS区研究了其多样性、建立了进化树,并利用在线数据库分析预测了与其互作的蛋白。结果表明:在24种大豆品种中均克隆到长度约1 400bp的GmHs1~(pro-1)CDS区,同已有数据合并后该区段共有20个突变点,5个新突变点中的3个引起了编码氨基酸的变化。GmHs1~(pro-1)可能主要同glyma18g04770编码的蛋白互作,该蛋白受syringolide诱导。GmHs1~(pro-1)定位在胞浆内,具有1个吲哚化合物双加氧酶类似结构域,可能参与吲哚相关通路影响线虫发育。     

小麦-黑麦抗条锈病1BL/ 1RS易位系8-2-1的鉴定

利用农艺性状优良的普通小麦品系W770B(2n=6x=42,AABBDD)与墨西哥黑麦(Secale cereale L. 2n=2x=14,RR)杂交,秋水仙素处理染色体加倍,再经过多次与W770B回交,筛选出若干性状优良的衍生系。在大田用抖粉法人工接种条锈病混合菌种(CYR31,CYR32)对衍生系进行多次鉴定,筛选出对条锈病混合菌种(CYR31,CYR32)高抗的衍生系8-2-1。为了明确小麦新种质8-2-1的遗传基础,为该种质的应用提供参考,采用细胞学、原位杂交(genomic in situ hybridization,GISH)、分子标记(SCAR,SSR)、SDS-PAGE、近红外谷物分析仪和农艺性状调查对其进行鉴定分析。细胞学鉴定结果表明,8-2-1具有42条染色体(2n=42=21II);以黑麦DNA为探针的原位杂交(GISH)鉴定结果表明,8-2-1具有黑麦染色体信号;黑麦特异SCAR标记和1RS上的SCAR标记能够同时在黑麦和8-2-1中扩增出特异条带;小麦各个基因组SSR分子标记鉴定结果表明,只有小麦1BS上的SSR标记不能在8-2-1中扩增出目的条带,表明8-2-1为小麦-黑麦1BL/1RS易位系。SDS-PAGE 结果表明,8-2-1亚基组成为Null、7+8、2+12,与W770B(Null,7+16,2+12)在Glu-B1位点编码的HMW-GS存在差异。8-2-1粗蛋白含量（干基）、面筋含量（湿基）达到中筋小麦标准;Zeleny沉降值符合弱筋小麦标准。农艺性状调查发现,8-2-1具有早熟、大穗、大粒等优点。因此,8-2-1可为培育高产、抗病和优质小麦新品种提供重要的中间材料。     

非1B/1R和1B/1R类型K型小麦雄性不育系幼穗部分生理指标的变化

为了揭示非1B/1R及1B/1R类型K型小麦雄性不育系雄性败育的生化机制,在不同发育时期对K型非1B/1R小麦雄性不育系KTSP3314A及同型保持系TPS3314B与K型1B/1R小麦雄性不育系K3314A及同型保持系3314B幼穗中游离氨基酸总量、可溶性蛋白含量、可溶性糖和淀粉含量进行了测定.结果表明,非1B/1R类型的K型不育系幼穗的这些生理指标与1B/1R类型K型小麦雄性不育系的变化不同.1B/1R类型不育系除可溶性糖含量在整个发育时期与其同型保持系差别不明显外,其它物质的含量在单核小孢子时期均差异明显;非1B/1R类型不育系这四种物质含量在二核小孢子时期均差异较大.由此说明,这两类K型不育系的雄性败育进程有所不同,非1B/1R类型K型不育系的雄性败育时间晚于1B/1R类型K型不育系,并在雄性败育的过程中伴随着部分生理指标的变化.     

非1B/1R和1B/1R 类型小麦K型雄性不育系穗长和小穗数性状的遗传分析

为明确非1B/1R和1B/1R 类型小麦K 型雄性不育系穗长和小穗数的遗传规律,利用非1B/1R类型KTSP732A和1B/1R类型K3314A 两种K型不育系材料,采用主基因+多基因混合遗传模型分析法,对穗长和小穗数两类性状进行单世代和多世代混合分离分析.结果显示,非1B/1R类型KTSP732A和1B/1R类型K3314A穗长性状均符合加性-显性-上位性多基因模型(C-0),无主基因存在;非1B/1R类型KTSP732A的小穗数性状符合两对等显性主基因+加性-显性多基因混合模型(E-6),主基因遗传率为40.7%;而1B/1R类型K3314A的控制小穗数性状基因类型与非1B/1R不同,该类型无主基因存在,也符合加性-显性-上位性多基因模型(C-0).     

Sec-1位点缺失对1BL/1RS易位系籽粒品质的影响

为了解 Sec-1位点缺失对1BL/1RS易位系品质的影响,用 Sec-1位点缺失突变体与郑麦7698多次回交,系谱法辅助分子标记多代选择后得到 Sec-1位点缺失的1BL/1RS易位系（简称 Sec-1位点缺失易位系）和正常1BL/1RS易位系（简称正常易位系）,并进行品质性状、抗病性及农艺性状鉴定。结果表明,蛋白质含量、湿面筋含量、干面筋含量和中峰值高度在 Sec-1位点缺失易位系和正常易位系之间差异不显著,而 Sec-1位点缺失易位系的面筋指数、面团形成时间、稳定时间、粉质质量指数、和面时间、中峰值宽度和8 min尾宽显著高于正常易位系。正常易位系的吸水率和衰落角显著大于 Sec-1位点缺失易位系。 Sec-1位点缺失易位系的条锈病抗性和白粉病抗性均低于正常易位系,但二者之间条锈病的病情指数差异不显著,而白粉病的病情指数差异达显著水平。正常易位系与 Sec-1位点缺失易位系间的千粒重、穗粒数、产量水平差异均不显著。综上所述, Sec-1位点缺失对小麦籽粒品质的正向调控作用显著,而对农艺性状的负面效应不显著, Sec-1位点缺失突变体是研究和改良小麦籽粒品质的优良遗传材料。     

利用AhMITE1转座子分子标记鉴定花生F1代杂种

对杂交后代进行杂种的真实性鉴定是杂交育种成功的前提。AhMITE1转座子标记是一类基于PCR的分子标记,其在花生中扩增的产物片段差异大,多态性强,采用琼脂糖凝胶电泳即可区分。本研究用7对多态性转座子引物对6个花生组合的166个F1单株进行了真实性鉴定。根据杂种植株含有父母本带型为依据共鉴定出了77个单株为真杂种,真杂种植株数占植株总数的比率为44.86%;收获时根据田间表型鉴定出了79个单株为真杂种,真杂种比率为47.59%。     

小麦Wx-A1和Wx-D1位点的PCR分子标记

为了获得筛选低直链淀粉含量的分子标记,根据已知小麦Waxy基因序列设计PCR引物,通过在基因水平和蛋白质水平进行分离群体验证,建立分别专一检测Wx-A1位点和Wx-D1位点的PCR标记MAG264和MAG269。在分离群体中,MAG264标记能清楚地区分Wx-A1位点的三种不同基因型,呈共显性遗传。MAG269标记引物在野生型中扩增片段为1 400 bp,在突变型(Wx-D1bWx-D1b)中的扩增片段为800bp。但在分离群体中没有出现杂合体带型,从而使本应该表现为共显性的标记表现为显性遗传。MAG264和MAG269引物对DNA的扩增稳定性、重复性好。这些结果表明,本研究获得的Waxy基因分子标记可以用于小麦Waxy基因缺失类型的鉴定和糯质专用小麦的分子标记辅助选育。     

Maize cryptochromes 1a1 and 1a2 promote seedling photomorphogenesis and shade resistance in Zea mays and Arabidopsis

Maize growth and development are regulated by light quality, intensity and photoperiod. Cryptochromes are blue/ultraviolet-A light receptors involved in stem elongation, shade avoidance, and photoperiodic flowering. To investigate the function of cryptochrome 1(CRY1) in maize, where it is encoded by Zm CRY1, we obtained two Zm CRY1a genes(Zm CRY1a1 and Zm CRY1a2), both of which share the highest similarity with other gramineous plants, in particular rice CRY1a by phylogenetic analysis. In Arabid...     

Differentiation of Wheat-Rye Translocation Lines using Antibody Probes forGli-B1andSec-1

In order to develop both a general screen for wheat-rye chromosome 1 translocation lines and a specific assay for 1BL.1RS lines, separate monoclonal antibodies (mAbs) were isolated that recognisedM_r40 000 γ-secalins (808/10) and gliadins encoded on chromosome 1B (218/17), respectively. Using aqueous propan-2-ol extracts of half grain, flour or meal and a direct enzyme linked immunosorbent assay (ELISA) format, mAb 808/10 gave a positive response with lines containing 1RS translocated onto either chromosome 1A, 1B or 1D, while non-translocation wheats displayed very low reactivity. Similar results were obtained with dilute saline extracts of flour or meal. The binding of mAb 808/10 to secalins was dependent on the proteins retaining some tertiary structure since the antibody response was abolished if the proteins were reduced. MAb 218/17 displayed little reaction with aqueous propan-2-ol extracts of 1BL.1RS translocation lines, but gave a positive colour response with all other wheats tested. Therefore detection of 1BL.1RS translocation lines can be achieved by a positive response to mAb 808/10 or a negative response to mAb 218/17. Alternatively, both ELISAs can be performed on a single aqueous propan-2-ol sample extract to differentiate three groups: 1BL.1RS translocation lines, cultivars carrying 1RS on wheat chromosomes 1A (or less commonly 1D), and non-translocation wheats. The methods were assessed with sets of non-1RS and 1RS translocations in American and Australian backgrounds. These ELISAs have several advantages over other immunoassays forGli-B1gliadins orSec-1secalins. They include reduced assay time because of fewer steps, enabling greater throughput of samples, and adaptability to meal, flour or half-grain samples.     

小麦Wx-A1和Wx-B1亚基的生化与分子标记检测

为了解小麦品种(系)Wx亚基的缺失类型,为品质育种提供依据,利用SDS-PAGE和STS分子标记技术对99份国内外小麦品种(系)Wx-A1和Wx-B1亚基的缺失型进行检测.结果表明,供试小麦品种(系)中Wx-B1亚基缺失的有19份,未检测出Wx-A1亚基缺失材料.STS标记结果中,Wx-7A位点的显性标记引物在野生型中扩增出一条1 172 bp的特异带,即Wx-A1a基因出现;Wx-7A位点的共显性标记引物在野生型中扩增出一条593 bp的特异带,在缺失类型中扩增出一条574 bp的特异带.Wx-4A位点的显性标记引物在野生型中扩增出一条425 bp的特异带,即Wx-B1a亚基出现,而在缺失该亚基的突变材料中没有扩增出该特异带.     

小麦-黑麦1BL/1RS易位系中的染色体结构变异

用黑麦(Secale cereale L.)自交系Kustro与普通小麦(Triticum aestivum L.)品种绵阳11杂交,获得了八倍体小黑麦MK,再用绵阳11与MK回交,用基因组原位杂交(GISH)和荧光原位杂交(FISH)的方法从回交后代中筛选到含1条1BL/1RS易位染色体的植株13FT-100。为了筛选含有变异染色体的姊妹1BL/1RS易位系,用FISH方法对植株13FT-100的自交后代进行了分析。结果表明,在1个后代植株中,1条6B染色体在核仁组织区断裂,造成6BS端部缺失;而在另1个后代植株中,1条1BL/1RS易位染色体的1BL端部Oligo-p Sc119.2-1信号缺失。变异6B染色体可以用来研究6BS臂从核仁组织区到端部区段的功能,变异1BL/1RS易位染色体可以用来研究1BL的变异对1BL/1RS易位染色体发挥功能的影响。本研究结果提示,对于小麦远缘杂交后代,应多留意小麦染色体结构的变化,获得具有新型结构的小麦染色体或易位染色体可能对小麦育种研究更具重要意义。     

Mixing properties and dough functionality of transgenic lines of a commercial wheat cultivar expressing the 1Ax1, 1Dx5 and 1Dy10 HMW glutenin subunit genes

In this work we report the effects of the HMW-GS 1Ax1, 1Dx5 and 1Dy10 on the breadmaking quality of the bread wheat cultivar Anza that contains the HMW-GS pairs 1Dx2 + 1Dy12 and 1Bx7* + 1By8, and is null for the Glu-A1 locus. This allows the characterization of individual subunits 1Dx5 and 1Dy10 in the absence of subunit 1Dx5, and the interactions between these subunits and subunits 1Dx2 and 1Dy12 to be determined. Three transgenic lines termed T580, T581 and T590, containing, respectively, the HMW-GS 1Ax1, 1Dx5 and 1Dy10 were characterized over 3 years using a range of widely-used grain and dough testing methods. The transgenic subunits 1Ax1, 1Dx5 and 1Dy10 accounted for 25.2%, 20.3% and 17.9%, respectively, of the total HMW-GS in the three transgenic lines. Although lines T581 and T590 expressed similar levels of subunits 1Dx5 and 1Dy10 they had different effects on other aspects of protein composition, including changes in the ratios of glutenin/gliadin, of HMW/LMW-GS, the 1Dx2/1Dy12, the x-type/y-type HMW-GS and the proportions of high molecular mass glutenin polymers. In contrast, lines transformed to express subunits 1Ax1 and 1Dx5 showed similar changes in protein composition, with higher protein contents and decreased ratios of glutenin/gliadin and 1Dx2/1Dy12. In addition, both transgenic lines showed similar increases in the ratio of x-type/y-type subunits compared to the control line. The transgenic lines were analysed using Farinograph, Mixograph and Alveograph. This confirmed that the expression of all three subunits resulted in increased dough strength (and hence breadmaking quality) of the cultivar Anza. A beneficial effect of subunit 1Dx5 has not been reported previously, transgenic wheat lines expressing this subunit giving overstrong dough unsuitable for breadmaking. However, the expression of subunit 1Dy10 had a greater effect on breadmaking quality than subunits 1Ax1 and 1Dx5. The Farinograph parameters such as dough stability and peak time were increased by 9.2-fold and 2.4-fold, respectively, in line T590 (expressing 1Dy10) with respect to the control line. Similarly, the Mixograph mixing time was increased by four-fold and the resistance breakdown decreased by two-fold in line T590 compared with the control line. The Alveograph W value was also increased by 2.7-fold in line T590 compared to the control line. These transgenic lines are of value for studying the contribution of specific HMW-GS to wheat flour functional properties.