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1.
海岛棉与澳洲棉、黄褐棉种间杂种F_1的细胞学研究   总被引:1,自引:1,他引:1  
本文研究了四倍体栽培种海岛棉与二倍体野生种澳洲棉、四倍体野生种黄褐棉种间杂种F1的主要形态特征及F1花粉母细胞减数分裂中期Ⅰ的粱色体行为。结果,(海岛棉416×澳洲棉)F1有的性状趋向澳洲棉,如茎、叶的茸毛、花冠颜色、花的开放形式;有的象海岛棉,如叶形、叶色、花药和花粉之颜色;有的则为中间型,如苞叶形状、铃形等。(海岛棉7124×黄褐棉)F1趋向父本黄褐棉的性状有:腺体较多,茎秆、叶片暗绿色,有茸毛,叶片掌状。短日照性强;表现中间型的性状有:花瓣黄色,有红心。两个组合F1的花粉母细胞减数分裂中期Ⅰ的配对构型分别为31.4Ⅰ+3.90Ⅱ+0.02Ⅲ+0.02Ⅳ和0.24Ⅰ+25.71Ⅱ+0.098tⅠ″+0.039Ⅳ,这一结果表明,海岛棉与澳洲棉的亲缘关系较远,与黄褐棉的亲缘关系较近,但海岛棉与黄褐棉的染色体间已有所分化,可能存在染色体结构上的差异。  相似文献   

2.
陆地棉与澳洲2个野生棉杂种细胞学研究   总被引:7,自引:2,他引:7  
本文首次报道了陆地棉×南岱华棉杂种F1的细胞学研究结果,并与陆地棉X斯特提棉的杂种进行了对比分析。供分析的细胞数均在700个以上,中期Ⅰ染色体构型种类占总PMC的百分率(构型率)均在7%以下,陆地棉与斯特提棉和南岱华棉杂种F1的染色体平均构型分别为21.97Ⅰ+7,97Ⅱ+0.35Ⅲ+0.01Ⅳ和20.62Ⅰ+8.37Ⅱ+0.52Ⅲ+0.02Ⅳ,单一细胞环状二价体、染色体桥和二价体交叉率分别是0.53与0.48、7.44与7.89和1.07及1.06。在2个杂种中均观察到八价体,但为数极少。中期Ⅰ时期二价体和多价体集中于细胞赤道面上,而单价体分散在周围。后期Ⅰ及以后,单价体分布完全随机,形成多个染色体块或片段。四分体形成时期,小孢子数目和大小及形状变异均较大。主要表现在小孢子不是规则的团体,体积大小相差可达2~4倍,单一PMC中的数目从l至13,但其四分体占多数,均在60%以上。且微核变幅较大,0~6个。经过比较分析,说明两个棉种亲缘关系很近,与陆地棉的种间关系差异也不大。  相似文献   

3.
黄绿苗浙12─12N与美国芽黄等突变体的芽黄性状差异明显、苗期真叶叶绿素含量也迥然不同,黄绿苗浙12─12N的子叶和苗期真叶均呈现淡黄色、叶绿素a+b、a、b的含量及a/b比值各为1.2355mg/g、0.7933mg/g、0.4422mg/g鲜叶和1.7991,分别比常绿苗的泗棉2号低33。32%、34.33%、31.44%和3.89%;较苗色浅黄至黄色的T582、V1、V2、V3高14.26%~58.24%、14.79%~65.59%、13.32%~45.05%和2.03%~59.26%。在棉铃吐絮前、黄绿苗浙12─12N的上部主茎叶及果枝新出叶仍然显现淡黄色、各叶位叶片叶绿素含量呈现由上而下递增趋势,主茎顶端完全展开叶、倒二叶的叶绿素含量极显著地低于泗棉2号、斯字棉701N,但倒五叶及其以下各叶的叶绿素含量反而较常绿色品种高。其各叶位叶片的净光合速率不同程度地高于泗棉2号,且水分利用率和无能利用率高。  相似文献   

4.
本文研究了原产澳大利亚的稀毛棉(G.pilosum)、皱壳棉(G.costulatum)、杨叶棉(G.populifolium)的核型。稀毛棉的核型公式为2n=2x=26=16m(4sat)+10sm,皱壳棉为2n=2x=26=16m(4sat)+10sm,杨叶棉为2n=2x=26=18m(4sat)+8sm。随体均有两对,一对位于第11对染色体的长臂上,另一对位于第13对染色体的短臂上。平均臂比和长度比分别为稀毛棉1.53和2.51、皱壳棉1.55和2.31、杨叶棉1.49和2.37,其核型均属于Stebbins的2B类型。对称系数稀毛棉为26.04,皱壳棉为27.93,杨叶棉为28.32。三者彼此之间的核型重合率均在90%以上。核型的同质性说明三者在起源上有很好的一致性  相似文献   

5.
冬小麦体细胞无性系种子蛋白质含量的遗传   总被引:3,自引:0,他引:3  
从同一单倍体的幼穗、成熟胚、继代花药愈伤组织和种子植株幼穗获得的无性系,其蛋白质含量的变幅很大,分别为12.14% ̄21.33%、13.98% ̄20.51%,13.82% ̄17.97%和16.62% ̄22.16%。无性系蛋白质含量的变异发生在早代。获得的高蛋白特性可以遗传。已从单倍体幼穗无性系获得5个蛋白质含量高(19%以上)的冬小麦新品系。  相似文献   

6.
河北省棉花黄萎病菌致病性的研究   总被引:20,自引:9,他引:20  
在棉花苗期采用塑料营养钵底部定量注菌液法接种,于昼温25~26℃,夜温20~22℃的人工培养室中测定了自河北省重点植棉县分离的40个棉花黄萎病菌单孢菌系和外地5个菌系的致病性。以中棉石系亚、海岛棉海7124、陆地棉93抗12、辽棉5号、冀棉11号、农大3656个品种为鉴别寄主,以病情指数作为划分抗、感类型的标准,根据在鉴别寄主上的反应,45个供试菌系可被划分为致病力强的Ⅰ型、致病力中等的Ⅱ型和致病力弱的Ⅲ型,分别占53.5%、28.9%、17.8%。Ⅰ型菌系除使中棉表现抗(耐)病外,海岛棉和陆地棉均表现感病。该类菌系遍布冀中南棉区,其中有7个菌系可使部分品种表现落叶,证明河北省已有落叶型菌系存在。试验还表明,海7124、93抗12、冀棉11号和农大3654个棉花品种对黄萎病鉴别力较强,可作为鉴别寄主加以应用  相似文献   

7.
麦套夏播转Bt基因棉田主要害虫及其天敌的发生规律   总被引:68,自引:6,他引:68  
1997年在田间系统研究了转Bt基因棉品种中棉所30(R93-6)在麦套种植方式下,对棉田主要害虫及其天敌种群的影响。结果表明,转基因棉对棉铃虫(Heliothisarmigera)和棉造桥虫(Anomisflava)有良好的抗性,发生高峰期百株幼虫数量均显著低于对照品种中棉所16(早熟品种),但转基因棉田仍需防治三、四代棉铃虫;和常规棉相比,转基因棉自然控制田和转基因棉综合防治田的棉蚜(Aphisgosypi)分别增加33.1%和减少25.1%、红蜘蛛(Tetranychuscinnabarinus)分别增加138.9%和减少18.5%、棉蓟马(Thripstabaci)分别增加346.0%和315.3%、白粉虱(Trialeurodesvaporariorum)分别增加63.8%和29.0%、棉盲蝽(Lyguslucorum)分别增加57.1%和减少18.9%、棉叶蝉(Empoascabigutula)分别增11.5%和14.2%、龟纹瓢虫(Propylaeajaponica)分别增加11.8%和45.5%、草间小黑蛛(Erigonidiumgraminicola)分别减少3.6%和3.6%、草蛉(Ch  相似文献   

8.
用比色法测定了甲哌啶在棉子和土壤中的残留及其在棉叶和土壤中的消解动态。棉子、棉叶和土壤的方法添加回收率71.5%~74.8%、72.8%~81.7%和83.3%~92.2%,变异系数4.98%~9.84%、4.79%~7.15%和5.16%~7.13%,最小检出浓度0.28、0.19和0.29mg·kg-1。测定结果表明,按照甲哌啶推荐用量处理棉花,棉子中未检出甲哌啶。甲哌啶在棉叶和土壤中的半衰期为9.41~9.44天和8.2天。  相似文献   

9.
研究结果表明:(1)病害烂铃在棉株上的水平、垂直和外扩三方向上的分布模型均呈y=axb(b<0),以棉株基部1~3台果枝和2.6个圆锥体围层上的烂铃为主,分别占烂铃总数的89.22%和97.84%。(2)棉铃虫蛀害烂铃在棉株上的水平方向分布模型:3~10台呆枝上呈y=ax2+bx+c(a<0),另2~3果节上虫蛀烂铃最多;11~18台果枝上为y=axb(b<0),第1~2果节上虫蛀烂铃最多。垂直方向分布模型为y=ax2+bx+c(a<0),第11台果枝上虫蛀烂铃最多;虫蛀烂铃以11~15台果枝上的另1~2天节上分布为核心,占虫蛀烂铃总数的54.76%。(3)上述结果对指导棉花烂铃防治具有重要的科学意义。  相似文献   

10.
三个棉属种间杂种花粉母细胞减数分裂观察   总被引:2,自引:0,他引:2  
对棉属3个种间杂种TM-1×石系亚1号、TM-1×辣根棉和TM-1×瑟伯氏棉花粉母细胞的减数分裂进行了观察。结果表明,3个杂种多数花粉母细胞中期Ⅰ的染色体构型为13Ⅱ+13Ⅰ。二价体联会成环状、棒状或V型。TM-1×辣根棉杂种的二价体联会较紧密。杂种除正常的染色体组AA和DD联会外,还发生AD联会及出现多价体。中期Ⅰ单价体大部分分散于赤道板两侧,并较早移向两级。个别二价体也不排列在赤道板上。二价体向两极移动时常形成染色体"桥",使这些染色体移动速度减慢,导致细胞分裂不同步。此外,在第一次分裂和第二次分裂中都能看到落后染色体、远离大多数染色体的零星染色体、孤立的染色体群等现象。后期Ⅱ的花粉母细胞可形成较多的核仁。在四分孢子期,3个种间杂种既产生四分体,也形成二、三、五、六乃至十分体。TM-1×石系亚1号、×辣根棉、×瑟伯氏棉杂种的四分体数分别为70.2%、63.1%和35.1%。  相似文献   

11.
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.  相似文献   

12.
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.  相似文献   

13.
G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.  相似文献   

14.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.  相似文献   

15.
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...  相似文献   

16.
Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.  相似文献   

17.
P. A. York  R. Cook 《Euphytica》1989,43(1-2):135-141
Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.  相似文献   

18.
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.  相似文献   

19.
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.  相似文献   

20.
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...  相似文献   

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