抗茎腐病的玉米(Zea maysL．)自交系体细胞变异体选择

用玉米自交系综3、综31、5003、P9－10(Zea meys L)的幼胚所诱导的愈伤组织，在继代繁殖后一部分愈伤组织转移到含有玉米茎腐病的病原菌(F.graminearum)毒素的培养基中培养并进行变异体选择，现已获得了大量的抗毒素变异体再生植株，并有部分植株移栽成活。     

甜、糯玉米耐热性体细胞的筛选

以不同品种甜玉米和糯玉米幼胚为供试材料,研究了不同培养基对愈伤组织诱导、继代和分化的影响,并在高温条件下筛选玉米耐热性变异体。结果表明：采用含有低浓度2,4-D的N₆为玉米幼胚诱导培养基,可产生一定比例的变异,愈伤组织诱导率高,质量较好;MS培养基适于分化;温度渐变法可以保证幼胚能够在产生耐热变异的同时不至于死亡,并在最后进行了恢复培养,即温度恢复到适温,淘汰不稳定愈伤组织,得到相对稳定的耐热性变异体;通过测定愈伤组织游离脯氨酸浓度、再生植株叶片质膜相对透性和叶片相对失水率,确定玉米胚变异体的耐热程度。     

玉米幼胚愈伤组织诱导及再生

利用综3、87-1、郑58、昌7-2、137和K12等6个骨干自交系玉米幼胚进行愈伤组织诱导并建立再生体系。结果显示,2,4-D对玉米幼胚愈伤组织的诱导形成是必需的,浓度在2.0～2.5 mg/L;6-BA不利于愈伤组织的形成,但能促进幼胚直接长芽、长根,尤其以郑58最明显。材料综3、郑58、K12诱导愈伤组织比较容易,诱导率均≥85%;材料137和87-1表现中等,诱导率约在50%～60%;材料昌7-2表现最差,愈伤组织诱导率≤25%。     

对玉米幼胚愈伤组织再生能力的轮回选择

对玉米幼胚愈伤组织再生能力的轮回选择ＣａｒｌｏＲｏｓａｔｉ等谷类作物育种的组织培养技术的效率，往往由于难以建立具有高度植株再生能力的培养方法而受到限制。谷类作物愈伤组织培养的细胞全能性与胚状组织的表现有关。玉米幼胚产生的愈伤组织通常表现为Ⅰ型，白而紧...     

大麦胚性和非胚性愈伤组织的研究

利用幼胚培养诱导愈伤组织分化产生再生植株的方法,可产生大量的变异体,能克服花药培养染色体加倍而得到的二倍体的许多缺点,有倍体性稳定、出愈率高、分化率高、绿苗得率高和变异率高等优点,而且变异很容易被检出,为育种提供原始种质,能被育种     

玉米再生体系建立及其影响因素的研究

以玉米自交系辽7980、丹9818、340、5026为材料,对影响成熟胚愈伤组织诱导、继代培养及分化的因素进行了研究。结果表明,2,4-D对于玉米成熟胚愈伤组织的诱导是必要的,基因型对胚性愈伤诱导的影响显著。在培养基中添加L-脯氨酸对提高胚性愈伤组织有显著作用,但对愈伤组织生长率没有明显影响。适量的BA和AgNO₃对植株的再生有促进作用。     

小麦近缘野生种抗除草剂Dalapon变异体的筛选

为了发掘小麦近缘野生种抗除草剂资源,用在培养基中添加除草剂的方法对几个小麦近缘野生种细胞系进行了变异体筛选。结果表明,从黑麦草T ove中筛选到了抗4.32 mm ol.L-1D alapon的愈伤组织,该浓度下愈伤组织存活率为0.56%;从长穗偃麦草R 123中筛选到了抗2.88 mm ol.L-1D alapon的愈伤组织,存活率为0.59%;从黑麦草N apoleon和卵穗山羊草Y 100中均筛选到了抗1.44 mm ol.L-1D alapon的愈伤组织,存活率分别为0.49%和0.56%;方穗山羊草A e42的抗性水平最低,为0.72 mm ol.L-1,愈伤组织存活率为0.33%。对存活愈伤组织进行细胞水平上的鉴定表明,其仍然保持对D alapon的抗耐性;从不同浓度D alapon下筛选到的存活愈伤组织均得到了有抗性的再生植株。在种子水平上对纤毛鹅观草进行筛选,得到了0.195%的抗性植株。     

玉米自交系GS01愈伤组织的诱导及植株再生

实验用玉米自交系GS01的幼胚作为外植体,探讨不同培养基、不同蔗糖浓度和不同2,4-D浓度等对GS01愈伤组织诱导的影响,经过继代培养筛选出胚性愈伤组织,使之分化、生根和出苗,成长为完整的植株。实验表明:玉米自交系GS01在N6培养基、2,4-D浓度为1mg/L、蔗糖浓度为30g/L时的胚性愈伤组织诱导率最高。     

玉米再生植株后代质量性状和数量性状的变异

玉米植株的再生在1975年从品系 A188 和由该品系组配的杂交种的未成熟胚的圆锥形愈伤组织中首次获得成功(Green 等,1975)。在玉米组织培养中形成8种愈伤组织:形态发生型、胚胎发生型和无再生潜力型。通过异源愈伤组织中幼芽的形态发生可以获得数量有限的常常具有遗传学和细胞学多样性的植株。作物的形态发生潜力在很大程度上取决于基因型。玉米体细胞胚胎发生现象在1982年就曾有人描述过(Ly 等,1982)。从旺盛生长着的大量体细胞胚胎中获得的众多再生植株可以用于突变发生试验、繁殖有价值的基因型和遗传工     

裸燕麦胚性愈伤组织诱导及植株再生能力的研究

裸燕麦成熟胚在ＩＮ６培养基上诱导并继代所形成的是白色、瘤状、外软内硬、易分化植株的非松脆型愈伤组织．当在ＩＭ１—ＩＭ４培养基上进行循环式调控培养时，经７—８个月，初始愈伤组织状态转变为浅黄色、小颗粒状、生活力强的松脆型胚性愈伤组织，有效地减缓了愈伤组织经长期继代过程中生活力的衰退，并能稳定地维持胚性愈伤组织达９５％以上．对植株再生能力测定表明，调控的胚性愈伤组织具有较强的分化潜力，维持时间可达２年以上．     

56份人工合成六倍体小麦的遗传多样性分析

人工合成六倍体小麦具有丰富的遗传多样性。为给小麦遗传改良提供具有重要利用价值的基因资源,对引自国际玉米与小麦改良中心（CYMMIT）的56份人工合成六倍体小麦材料的主要农艺性状和白粉病田间抗性进行了检测和分析,对其高分子量谷蛋白亚基构成及基因组遗传多样性进行了初步研究。结果表明,供试材料具有繁茂性好、分蘖力强、成穗率高、穗粒数多等优良农艺性状特点,其中,Syn1、Syn2、Syn56等材料的单株成穗数在10穗以上,Syn46的单株穗数平均达到45.4穗;Syn19、Syn30等的穗粒数平均达到50粒以上;Syn52、Syn50、Syn54等材料的千粒重较高,达50~60 g。白粉病抗性鉴定结果显示,Syn4、Syn23、Syn24等80%以上的供试材料对白粉病具有良好的田间抗性。编码高分子量麦谷蛋白亚基的Glu-A1、Glu-B1和Glu-D1位点表现出丰富的多态性,共有35种HMW-GS等位变异;除含有多种优质亚基或亚基组合外,还含有新的亚基类型。利用SSR分子标记对供试人工合成小麦进行遗传多样性分析,发现相较于本地栽培品种,供试人工合成小麦材料具有更高的遗传多样性。     

THE AGRONOMIC EVALUATION OF SYN 1 TALL FESCUE IN THE WEST OF SCOTLAND

The agronomic value of Syn 1 tall fescue, a synthetic variety derived from North African parent material, was determined in three experiments. Herbage yield, sward purity and digestibility were measured under cutting treatments for incremental sward growth during autumn/winter, and for sward regrowths during autumn/winter, spring and a complete season. Similar data were obtained for sward regrowths during autumn/winter and spring under defoliation by grazing. Syn 1 was compared with several of the north-temperate region tall fescues, e.g. S170, Rozelle and Manade, also with S143 cocksfoot Syn 1 showed yield superiority in autumn/early winter when there were comparable populations of tall fescue. Under cutting management, Syn 1 swards thinned out rapidly because of lack of winter-hardiness and yields were depressed in the second season; the effects were worst under the winter foggage-type management. Under grazing, with probably less severe defoliation, Syn 1 swards maintained yields for an additional season, but thereafter failed to persist Syn 1 swards had low spring- and annual-yields. The yield advantage of Syn 1 in autumn/early winter was not sufficient to be of great agricultural value and with its shortcomings in winter-hardiness and annual yield, it was considered unsuitable for West of Scotiand conditions. The main value of plant material such as Syn 1 may lie in ccmferring autumn/winter growth potential to winter-hardy north-temperate tall fescues in a breeding programme.     

水稻体细胞突变体HX-3在细胞水平上对白叶枯病的抗性

对水稻抗白叶枯病体细胞突变体HX-3及其感病供体明恢63在细胞水平上与白叶枯病菌的互作进行了研究。结果表明,接种水稻白叶枯病菌浙173后,明恢63愈伤组织的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性均急剧大幅升高,O[sub]2[/sub]产生速率升高,而愈伤组织生长量减小,蛋白质含量下降。HX-3愈伤组织接菌后SOD、POD活性和O[sub]2[/sub]产生速率与未接菌愈伤组织相似,愈伤组织生长量减小不明显。说明HX-3与明恢63的细胞水平抗性存在较大差别,HX-3细胞水平抗性与植株水平抗性是一致的。     

Resistance to Bacterial Leaf Blight in a Somaclonal Rice Mutant HX-3 at Cellular Level

The interaction between rice host and its pathogen Xanthomonas oryzae pv. oryzae (Xoo) at cellular level was studied by using a resistant somaclonal mutant HX-3 and its susceptable donor Minghui 63. After inoculation with Xoo strain Zhe 173 (Chinese pathotype |\ ). the activity of superoxide dismutase (SOD) and peroxidase (POD) in the callus of Minghui 63 was increased dramatically, and the active oxygen(O2^-) was produced at a higher rate; Meanwhile, the callus grew slowly with the reduction of protein content. Compared to the activity of SOD and POD. the production rate of O2^- and the fresh weight in HX-3 callus varied little after the inoculation. It could be proposed that there were great differences between the resistance of HX-3 and Mighui 63 at cellular level. There was no difference detected concerning resistance to bacterial leaf blight in HX-3 between the plant and the callus.     

利用基因枪法对玉米自交系501的转化研究

用基因枪法分别将带有潮霉素磷酸转移酶标记基因的pCI-Os07G0622000、pCI-AK072466两种克隆载体导入玉米自交系501,对自交系501幼胚和愈伤组织两种受体进行转化。结果表明,501的幼胚和愈伤组织的转化情况不同,平均再生频率分别为10.25%和0.85%;PCR分子检测表明,Os07G0622000和AK072466基因已整合到玉米基因组中,501幼胚和愈伤组织两种受体最终分别获得15株和2株转基因植株,平均转化率分别为1.67%和0.19%。在自交系501的两种受体中,幼胚更适合作基因枪转化的受体材料。     

Factors Affecting Agrobacterium-Mediated Transformation Efficiency in Rice

Several important factors affecting the efficiency of Agrobacterium-mediated rice transformation were studied with several predominant commercial indica and japonica rice cultivars. As far as indica rice callus was concerned, CC medium was the best and the quality of callus was improved with the addition of 1.0 to 2.0 mg/L ABA. It decreased the percentage of browning calli and improved the callus growing state by addition of a certain amount of sorbitol to the subculture medium. NB medium was the best for callus initiation of japonica rice, but the improvement in the quality of callus of japonica subspecies was not obvious by adding ABA. During the period of subculture, to a certain degree, increasing the sucrose concentration could improve the proportion of hygromycin resistant calli. Furthermore, the transformation efficiency would be higher by applying selection pressure in the selection stage, removing selection pressure during the plantlet differentiation period and applying selection pressure again during seedling hardening period. Besides, suitable combination of plant hormones was beneficial for callus differentiation. An efficient Agrobacterium-mediated rice transformation system had been established for several rice cultivars and a lot of transgenic rice plants had been obtained.     

Factors Affecting Agrobacterium-Mediated Transformation Efficiency in Rice

Several important factors affecting the efficiency of Agrobacterium-mediated rice transformation were studied with several predominant commercial indica and japonica rice cultivars. As far as indica rice callus was concerned, CC medium was the best and the quality of callus was improved with the addition of 1.0 to 2.0 mg/L ABA. It decreased the percentage of browning calli and improved the callus growing state by addition of a certain amount of sorbitol to the subculture medium. NB medium was the best for callus initiation of japonica rice, but the improvement in the quality of callus of japonica subspecies was not obvious by adding ABA. During the period of subculture, to a certain degree, increasing the sucrose concentration could improve the proportion of hygromycin resistant calli. Furthermore, the transformation efficiency would be higher by applying selection pressure in the selection stage, removing selection pressure during the plantlet differentiation period and applying selection pressure again during seedling hardening period. Besides, suitable combination of plant hormones was beneficial for callus differentiation. An efficient /Agrobacterium-mediated rice transformation system had been established for several rice cultivars and a lot of transgenic rice plants had been obtained.     

甘蔗黑穗病菌粗毒素对甘蔗愈伤组织的影响

甘蔗黑穗病菌(Ustiago Seitamimea Syd)的粗毒素处理三个甘蔗品种(新台糖10号、CP65／375和桂糖12号)的岔伤组织。接种粗毒素培养后，结果表明：甘蔗愈伤组织过氧化物酶活性的变化情况与品种的抗病性有关。     

农杆菌介导的小麦幼胚遗传转化体系的优化

为了优化农杆菌介导的小麦幼胚转化体系,通过对4个小麦品种河农827、石新828、河农825、良星99的幼胚组织培养及再生系统的研究表明,在改良培养基MSW1和MSW2中,小麦幼胚胚性愈伤组织诱导率与MSW0培养基相比分别提高了6.0%和5.4%,并且显著提高了植株再生能力。采用混合正交试验设计,对农杆菌遗传转化过程中小麦幼胚的诱导培养基、诱导时间、农杆菌侵染浓度、侵染时间进行了优化。结果表明,在诱导培养基MSW2,诱导培养6d,OD660=1,侵染时间3h时,愈伤GUS瞬时表达率及抗性愈伤成活率最高,对河农827成活的抗性再生植株进行PCR检测,获得了候选转基因植株。