西洋梨二倍体及其人工诱导同源四倍体遗传差异的SSR分析

以西洋梨‘丰产’二倍体及其10个同源四倍体株系为材料,通过微卫星(SSR)分子标记技术对西洋梨二倍体与同源四倍体之间的遗传差异性进行了研究。应用10对SSR引物对11份材料进行扩增,共扩增出23条谱带,其中有8条呈多态性,多态性比例为34.78%;10对引物中有3对引物为多态性引物。聚类分析显示,不同同源四倍体株系与二倍体的遗传差异大小亦不同;在10个同源四倍体株系中有3个株系扩增的条带与二倍体完全相同,7个同源四倍体株系与二倍体相比产生了差异性条带。研究结果表明,西洋梨二倍体与其同源四倍体之间以及10个同源四倍体株系之间在DNA水平上表现出了一定的多态性。本研究能够为进一步进行西洋梨多倍体的育种实践提供理论指导。     

Mutation breeding of autotetraploid Achimenes cultivars

Summary Colchicine-induced autotetraploids of three Achimenes cultivars were irradiated with X-rays or fast neutrons. The results were compared, in one cultivar, with those of the irradiated diploid form. The mutation frequency after irradiation of the autotetraploid was 20–40 times higher than for the corresponding diploid. These results may open new possibilities for mutation breeding, though they are hard to explain. Several promising mutants were selected.     

涪陵胭脂萝卜多倍体诱导研究

以不同浓度秋水仙素溶液处理胭脂萝卜幼苗茎尖生长点,通过苗期和成株期对诱变植株和正常二倍体植株进行形态学和细胞学鉴定,探讨四倍体胭脂萝卜的诱导方法与途径.结果表明,5种浓度秋水仙素都能诱变出四倍体胭脂萝卜,其中2 g/L秋水仙素诱变率最大,为33.3％.四倍体胭脂萝卜平均叶片厚度、叶长、株高、叶宽和开展度较二倍体分别增加32.4％、39.6％、39.8％、24％和31.7％,四倍体胭脂萝卜叶片单位视野内的气孔数目少于二倍体72.2％,但气孔的横径和纵径分别较二倍体大40.8％和30.7％.说明叶片厚度、叶长、株高、叶宽、开展度、气孔数目、气孔的横径和纵径等性状可以作为四倍体鉴定的重要特征,特别是气孔数目、气孔的横径和纵径可以作为快速鉴定四倍体与二倍体胭脂萝卜的重要指标.利用秋水仙素诱导是获得四倍体胭脂萝卜的有效途径之一.     

High embryo sac fertility and diversity of abnormal embryo sacs detected in autotetraploid indica/japonica hybrids in rice by whole‐mount eosin B‐staining confocal laser scanning microscopy

An eosin B staining procedure for use with confocal microscopy (WE‐CLSM) was used to examine the mature embryo sacs in 24 typical autotetraploid (2n = 4x = 48) indica/japonica hybrids and to compare with their original diploid (2n = 2x = 24) indica/japonica hybrids in rice. Four of the 24 hybrids showed >80% embryo sac fertility, and 13 hybrids over 70%. The average embryo sac fertility of the 24 autotetraploid indica/japonica hybrids was 68.08%, which was 17.33% higher than that in diploid hybrids. When compared with the diploid hybrids, 79.17% of the autotetraploid hybrids had higher embryo sac fertility. A diversity of abnormal embryo sacs occurred in autotetraploid indica/japonica hybrids. Embryo sac abnormalities were similar for both autotetraploid and diploid hybrid, but their frequencies were different. Some novel abnormal types were found in autotetraploid hybrids, such as enlarged egg apparatus. The embryo sac fertilities and frequencies of various abnormalities in autotetraploid hybrids varied with parental genotype and environment. The average seed set of the autotetraploid hybrids were higher than their diploid hybrids in different growing seasons.     

Generation and characterisation of colchicine-induced autotetraploid Lavandula angustifolia

Lavandula angustifolia (lavender) is a small woody perennial grown for essential oil, which is steam distilled from flowers. To potentially improve size of flowers and oil yield we produced and characterised autotetraploid plants. L. angustifolia seed germinated in the presence of the mitotic spindle inhibitor colchicine at concentrations of 125 mg l⁻¹ or less resulted in plants carrying sports with larger flowers. Propagation of two sports gave rise to putative polyploid cultivars C3/2 and C6/24. Direct chromosome counts in root tip cells of seedlings from four common cultivars of L. angustifolia and the seed lot from which C3/2 and C6/24 were derived was 50 whereas C3/2 and C6/24 had greater than 90 chromosomes indicating they were autotetraploid. Ploidy level assessed by flow cytometry (FCM) of nuclei showed that 12 cultivars of L. angustifolia had similar nuclear DNA content whereas C3/2 and C6/24 had double the amount of DNA confirming autotetraploidy. The genome size (1C-value) of a diploid L. angustifolia cultivar was estimated by FCM to be 0.90 (±0.07) pg. Morphological characteristics were measured in autotetraploid and control plants. Autotetraploids had thicker peduncles, larger flowers and larger seeds than diploids. Scanning electron microscopy revealed peltate glandular trichomes were larger in the tetraploids relative to diploids. Both tetraploid and diploid cultivars had complex non-glandular trichomes on leaves and sepals and two different types of capitate glandular trichomes were identified on leaves. Autotetraploid lavenders represent useful germplasm both for commercial oil production and future breeding.     

不同倍性栝楼生长发育及果实糖酸含量的研究

摘要：以天然二倍体和人工诱变成的四倍体栝楼为材料,对其生长发育和果实中总糖和总酸含量的测定研究表明：四倍体栝楼的长势快于二倍体;叶片中叶绿素含量明显高于二倍体;四倍体栝楼果实大小、重量、结实率和百粒重明显小于二倍体;果实中总糖和总酸的含量四倍体明显高于二倍体。由DPS软件分析可知：在0.05水平下,四倍体和二倍体栝楼总糖和总酸的含量有显著的差异;在0.01水平下,总糖和总酸的含量有极显著的差异。     

山西花生地方品种芽期耐寒性鉴定及SSR遗传多样性

低温寒害是引起花生产量和品质下降的主要因素之一, 培育和种植高产稳产耐寒性强的品种是降低低温寒害的理想途径。然而高耐寒性种质的缺乏和耐寒性鉴定的困难, 是限制耐寒性育种取得突破的主要原因。本研究对72份山西花生地方品种进行芽期耐寒性鉴定, 以其相对发芽率和相对发芽指数作为耐寒性评价指标, 初步将其分为高耐寒、耐寒、中感、敏感、高感5级。为了解山西花生地方品种耐寒性遗传多样性, 合理、高效利用耐寒型花生资源, 用多态性好的90对SSR引物评价了不同耐寒性花生品种, 结果显示, 参试品种遗传多样性存在较大差异, 在遗传距离为0.4时, 被聚类为三大类群。3份高耐寒品种和7份耐寒品种分别聚类到不同的3个类群中, 说明耐寒性花生遗传多样性丰富。     

Glycine max and Glycine soja are capable of cold acclimation

Soybean has been considered a cold intolerant species; based largely upon seed germination and soil emergent evaluations. This study reports a distinct acquisition of cold tolerance, in seedlings, following short acclimation periods. Diversity in cold responses was assessed in eight cultivars of Glycine max and six accessions of G. soja. All varieties of soybean significantly increased in freezing tolerance following acclimation. This study indicates soybean seedlings are indeed capable of sensing cold and acquiring cold tolerance. Germination rates after cold imbibition were negatively correlated with maturity group, but positively correlated with cold acclimation potential in G. soja. Seed fatty acid composition was varied between the species, with Glycine soja accessions containing about 2‐times more linolenic acid (18:3) than G. max. Furthermore, high levels of linoleic acid (18:2) in seeds were positively correlated with germination rates following cold imbibition in G. soja only. We suggest that domestication has not impacted the overall ability of soybean to cold acclimate at the seedling stage and that there is little variation within the domesticated species for ability to cold acclimate. Thus, this brief comparative study reduces the enthusiasm for the “wild” species as an additional source of genetic diversity for cold tolerance.     

Inheritance of salt tolerance in rice

Summary The genetic behavior of salt tolerance was studied in artificially salinized conditions at the International Rice Research Institute.Divergent selection, carried out at a salinity level where the ECe was 15.2 mmhos/cm at 25 C in F₃ lines from two crosses confirmed the effects of salt tolerance on F₄ progeny with realized heritability values of 0.39 and 0.62, respectively.In a cross between two tolerant cultivars there was clear over-dominance for tolerance, despite the high environmental fluctuation which resulted in a low genetic response as indicated by a low but significant repeatability of 0.20–0.25, and many progeny lines more tolerant than the parents were recovered. The superior tolerance of these progenies compared to the parents was confirmed subsequently at 3 different salt levels. In the same experiment a cross between tolerant and susceptible cultivars produced some progeny of comparable tolerance with tolerant sources.In a 6×6 diallel cross experiment with two tolerant, moderate, and susceptible varieties each, both general and specific combining ability were significant.The findings indicate the possibility of breeding rices more tolerant than existing tolerant cultivars through cumulative crosses of tolerant cultivars. Further improvement can be attained by crossing highly tolerant lines with donors of good agronomic traits and pest and disease resistance.     

同源四倍体水稻花粉母细胞减数分裂期间微管骨架组织和结构变化

应用间接免疫荧光标记-激光扫描共聚焦显微术,观察了同源四倍体水稻花粉母细胞减数分裂过程的微管骨架和染色体行为变化。结果表明:同源四倍体水稻花粉母细胞微管组织形态变化与二倍体水稻的基本一致,但出现一些不同,如核周微管较长,纺锤体微管数量较多;并呈现许多异常现象。前期I细线期,微管数量少,分布不均匀;偶线期,呈现不规则网络状结构,未见明显的极性分布;粗线期,核仁解体,呈现混乱的网络状结构;双线期,微管提早解聚,不形成环绕状微管;终变期,微管数量稀少,核周未见明显的微管聚集;中期I纺锤体形态出现多种异常现象;末期I成膜体形状异常,出现点状微管;末期II-四分体时期,二分体细胞两端不分开;出现三分体细胞,其内微管混乱。以上各时期的染色体行为也出现不同程度的异常。综合认为,微管组织的异常可能与染色体的行为异常存在一定的关联,两者共同作用影响花粉发育,导致育性偏低。     

Growth and Development of Six Barley (Hordeum vulgare ssp. vulgare L.) Cultivars in Response to a Model Weed (Sinapis alba L.)

The aim was to study the growth and development of six spring barley (Hordeum vulgare ssp. vulgare L.) cultivars as a response to a model weed population of Sinapis alba L. The development of light interception profiles over time was characterized for each cultivar in weed‐free stands. The cultivars were chosen such that they represent a range of weed‐suppressive abilities based on previously performed trials. One field experiment each was conducted in 1996 and 1997 at a site SE of Uppsala, Sweden. The two cultivars with low competitive ability against weeds, Etna and Blenheim, allowed the highest weed biomass and the lowest crop biomass in competition with the weeds. These two cultivars transmitted more photosynthetic active radiation through the canopy down to 20 and 40 cm height than did the other cultivars. Although the biomass of cv. Etna was low, the grain yield was higher than that of the other cultivars when grown in competition with weeds. In 1997, cv. Svani with good competitive ability against weeds transmitted least light and had greater grain yield than most other cultivars. The absence of a relationship between high grain yield and low weed suppressive ability in the present study indicates that it should be possible for plant breeders to combine high grain yielding capacity with approved weed‐competitive ability.     

二倍体及四倍体枳橙DNA甲基化变异的MSAP分析

为探讨染色体加倍对四倍体枳橙(Citrus sinensis (L.) Osb.×Poncirus trifoliate (L.) Raf.)叶片基因组DNA甲基化修饰的影响,明确四倍体枳橙基因组DNA甲基化水平及模式的变化特征。本研究以枳橙二倍体为对照,利用MSAP分子标记技术对同源四倍体枳橙叶片基因组DNA甲基化水平及模式变化进行分析。结果表明,10对选择性扩增引物共扩增出775条条带,二倍体和同源四倍体枳橙扩增带数分别为391条和384条,对应的总甲基化率分别为31.97%(含全甲基化率16.37%,半甲基化率15.6%)和31.25%(含全甲基化率18.49%,半甲基化率12.76%);MSAP扩增条带统计表明,同源四倍体的总甲基化率变化较小,全甲基化率高于二倍体,半甲基化率较二倍体均有所降低,相比二倍体对照,四倍体枳橙叶片基因组DNA主要发生了甲基化模式的变化。     

Involvement of Chromosomes 5A and 5D in Cold-Induced Abscisic Acid Accumulation in and Frost Tolerance of Wheat Calli

The relationship between frost tolerance and abscisic acid (ABA) accumulation was studied in callus cultures of three wheat cultivars differing in the level of frost-tolerance, and of the 5A and 5D chromosome substitution lines from the frost-tolerant variety ‘Cheyenne’ into frost-sensitive ‘Chinese Spring’. Following cold hardening, the increase in ABA level in the calli of the two frost tolerant cultivars was significantly higher than in those of the frost-susceptible cultivar. Similarly, in 5A and 5D substitution lines, significantly higher ABA levels were detected than in the recipient ‘Chinese Spring’. One week-long ABA treatment at 26 °C induced a significantly higher level of frost tolerance than that achieved by cold hardening, irrespective of the frost sensitivity of the examined genotypes.     

高粱同源四倍体与二倍体受精前后生殖特性的比较研究

观察四倍体与二倍体的胚囊、花粉特性和受精过程，结果表明，四倍体胚囊发育完整，与二倍体相似，但四倍体花粉育性及萌发和在花柱中的生长情况与二倍体存在显著差异，因此，认为这是影响四倍体结实率的主要因素。同时，不同品系诱导的四倍体结实率和生殖特性存在显著差异。     

马铃薯高效染色体加倍方法建立与抗寒资源创制

In this work, different treatment combinations including colchicine concentrations and treatment methods as well as different time points was used to investigate the survival rate and chromosome doubling efficiency of potato tissue culture plantlets. The potato chromosome doubling by using colchicine had been successfully optimized. The potato plantlet stems treated with 0.1% colchicine for three days shaking at 120 r min^-1 showed the highest doubling efficiency due to its better contact to the colchicine solution. Compared with other potato chromosome doubling techniques, this method has much higher chromosome doubling rate, shorter time treatment and easier to operate, so that it could provide a higher efficient method for potato ploidy operation. In the meantime, compared with the diploid, the tetraploid interspecific hybrids showed differences in the morphological characteristic, which had higher plants, thicker stem, bigger petals and pollen grain. In addition, no significant difference was found between diploid and tetraploid interspecific hybrids in terms of cold resistance, but both significantly enhanced cold resistance compared with the common potato cultivar. Taken together, the doubled interspecific hybrids could sever for improving cold resistance of potato cultivars.     

The accumulation of glycinebetaine during cold acclimation in early and late cultivars of barley

Summary Barley plants are able to accumulate glycinebetaine (betaine) at high levels in their leaves in response not only to water and salt stress but also to cold stress. Such accumulation of betaine during acclimation to cold is associated to some extent with freezing tolerance in leaves of barley plants, as previously demonstrated with near-isogenic lines that differed only in a single gene for the spring type of growth habit (Plant, Cell and Enyironment 17: 89–95, 1994). We now present evidence that the levels of betaine accumulated during cold acclimation might be associated with the earliness or lateness of the maturity of cultivars, namely, that late cultivars accumulate more betaine than early cultivars. Moreover, the grade of the vermalization requirement of the cultivars seemed unlikely to be associated with the level of betaine acumulated during cold acclimation. However, the trait that controlled accumulation of betaine during cold acclimation was not linked with the earliness or lateness of the maturity of cultivars. The higher levels of betaine in the late cultivars might have resulted from co-selection for lateness of maturity and freezing tolerance, which is generally a requirement in the areas of Japan where such late cultivars were originally cultivated.     

同源四倍体高粱不育系和保持系的生物学及生理特性研究

以二倍体高粱不育系及其保持系和由它们诱变成的同源四倍体选系为材料, 研究 了同源四倍体不育系和保持系的生物学特征及生理特性, 结果发现, 四倍体的株高一般为 二倍体的80.6％～90.1％, 单株总叶片数减少1～2片; 保持系加倍后, 顶部三叶面 积增 加4.6％～9.4％; 不育系的花药由二倍体时的白色变为四倍体的淡黄色,     

同源四倍体水稻与假稻杂交结籽的胚胎学机理研究

利用激光扫描共聚焦显微技术对同源四倍体水稻与假稻杂交结籽的特殊生殖现象进行了研究.研究结果表明,假稻的花粉粒不能在二倍体水稻的柱头上萌发,因而二倍体水稻与假稻的生殖隔离很严格.然而,假稻的花粉粒在同源四倍体水稻的柱头上能萌发,前者的花粉管能在后者的花柱中伸长并能将雄配子送入胚囊内.在同源四倍体水稻与假稻的     

Genetic variation of germination cold tolerance in Japanese rice germplasm

Low temperatures at the initial stages of rice development prevent fast germination and seedling establishment and may cause significant productivity losses. In order to develop rice cultivars exhibiting cold tolerance, it is necessary to investigate genetic resources, providing basic knowledge to allow the introduction of genes involved in low temperature germination ability from accessions into elite cultivars. Japanese rice accessions were evaluated at the germination under two conditions: 13°C for 28 days (cold stress) and 28°C for seven days (optimal temperature). The traits studied were coleoptile and radicle length under optimal temperature, coleoptile and radicle length under cold and percentage of the reduction in coleptile and radicle length due to low temperature. Among the accessions studied, genetic variation for traits related to germination under low temperatures was observed and accessions exhibiting adequate performance for all investigated traits were identified. The use of multivariate analysis allowed the identification of the genotypes displaying cold tolerance by smaller reductions in coleoptile and radicle lenght in the presence of cold and high vigour, by higher coleoptile and radicle growth under cold.     

同源四倍体和二倍体水稻香味的遗传分析

本研究用1.7%KOH 溶液浸泡叶片法分析了同源四倍体水稻和二倍体水稻的香味遗传。采用的香稻品种:香籽、香芒糯、京香1号和早香17。包含1个香稻品种的各种杂交组合的 F_1植株均无香味。在 F_2代,4个四倍体杂交组合无香味与有香味植株的分离比例符合35∶1,5个二倍体杂交组合的分离比例符合3∶1,而且正反交的分离比例没有差别。