杂交油菜制种保纯措施

1影响杂交油菜种子纯度的因子 1．1种子变异 杂交油菜种子生产采用的是三系配套法,在三系种子生产过程中,不育系、保持系、恢复系都可产生变异,造成亲本种子不纯,用不合格的亲本种子制种,直接影响了杂交F1代的纯度。     

河西走廊Ogura CMS三系杂交油菜制种优势和技术流程

河西走廊由于具有天然的自然环境和地理优势,被称为是"天然的种子生产车间"和"天然的种子仓库",其是甘蓝型冬油菜制、繁种的良地。从Ogura CMS三系杂交油菜种的自身特点以及河西走廊地理、气候特点,讨论了Ogura CMS三系杂交油菜在春播区的制种优势和制种技术。     

两系杂交油菜种子全程质量管理技术

对于种子企业而言,生产合格的油菜种子来规避质量风险,不仅是油菜制种工作的重点和难点．更是油菜品种产量潜力能否得到充分发挥的前提和保证。两系杂交油菜制种因其母本特有的育性分离．增加了制种工作的难度和强度。要确保两系杂交油菜制种的质量,不仅仅需要种子企业员工统一思想认识．更需要制定出严格的质量管理规程。明确各方面的职责．充分调动各方面尤其是制种基地干部群众参与质量管理工作的积极性和主动性．认真做好油菜种子全程质量管理．     

两系杂交油菜高产制种技术研究

两系杂交油菜制种的主要缺点是细胞核雄性不育系用兄妹交繁殖后，不育株率只能保持在50％左右，制种时必须在开花前拔除占母本群体50％的可育株，投入的人力和物力较大，生产成本较高。但两系法在彻底清除可育株和严格的隔离条件下，制种的纯度可达99％以上，能保证杂交种的质量。因此，两系杂交油菜制种仍然是目前大面积生产上常用的杂交油菜种子生产方法。本文研究在保证两系制种纯度和种子质量的前提下，如何提高大面积两系杂交油菜制种产量，为农民增产增收提供理论依据。     

浅议杂交水稻制种技术的创新与发展

杂交水稻种子需要年年制种生产,以确保子一代的杂种优势。当前,我国已建立了成熟的种子生产技术体系,但是基于劳力密集型的种子生产技术操作程序繁杂、劳动强度大,滞后于现代农业,迫切需要创新制种技术。应发展新型轻简的全程机械化制种技术,以及父母本混播混种和杂种优势固定(第三代杂交水稻和一系法杂交稻)的种子生产技术,以助推杂交水稻种业的发展。     

提高杂交油菜制种质量和产量的措施

杂交油菜制种技术较复杂 ,中间环节多 ,易受外界环境的影响 ,因而对制种环境、媒介和亲本都有严格要求。下面分别谈谈影响杂交油菜制种质量和产量的因素 ,及其可采取的相应措施。1　影响杂交油菜制种质量的因素1.1　亲本配合力 :杂交油菜制种需要不育系、保持系、恢复系三系共同作用才能完成 ,若亲本选择不严格或越代使用 ,使亲本间配合力降低 ,则会导致所制得的杂交种子纯度降低 ;若保持系的保持能力不够 ,则会使用于制种的不育系的不育率和不育度都较差 ,出现大量的半不育株和正常花株 ;若恢复系的恢复能力较差 ,则会使所制得的杂交种子中…     

化学杀雄剂对油菜三系杂交制种母本微粉控制试验简报

三系杂交油菜制种母本微粉的产生是影响F1代种子纯度的关键因素。秋播油菜三系制种通过“旱、薄、迟、密”等农艺措施很难消除母本微粉的产生。微粉的产生量与油菜花期天气的好坏有着极为密切的关系。笔者通过近5年系统试验，明确了化学杀雄剂对陕2A微粉控制效果；选配了复配型化学杀雄剂在现蕾期处理母本、控制微粉效果均在80％以上；F1代种子纯度较ck均能提高10个百分点以上；种子纯度均在83％以上。从而探讨了一条三系杂交油菜制种微粉的控制由“天控”向“人控”的转变途径。     

提高甘蓝型三系杂交油菜制种种子纯度和产量的措施

甘蓝型油菜制种不育系对低温、水分较为敏感,尤其对秋播制种油菜在春季初花期易产生微粉自交结实,影响种子纯度。勉县是陕西省杂交油菜生产基地之一,多年来一直研究解决制约杂交油菜制种高产和确保种子纯度这一矛盾,在总结1996年杂交油菜秦油二号制种纯度下降、转商损失300万元这一严重教训的基础上,从1997年秋播开始,做了以下试验工作,收到了十分明显的效果,现总结如下。1采用旱地、迟播、密植、控肥技术,搭好制种油菜丰产苗架1.1改平坝水田油菜制种为丘陵旱地制种由于平坝油菜制种多为水田,土壤湿度大,含水分高,油菜长势旺,难以控制水肥,…     

杂交水稻种子生产教学重点探讨——种子生产学授课体会

文章从杂交水稻种子生产的特点,两类雄性不育系的遗传特点及在种子生产中可能遇到的问题,杂交稻亲本几种原种生产方法的特点和应用,杂交水稻制种的共性技术,三系、两系制种及籼稻、粳稻制种的差异等5个方面,介绍了《种子生产学》有关杂交水稻种子生产部分的授课体会。     

杂交油菜湘杂油3号制种技术

湘杂油 3号是常德市农科所和湖南亚华种业科学研究院利用秦油 2号不育胞质选育而成的甘蓝型油菜三系杂交种。在常德市油菜区试和湖南省油菜区试中分别比对照中油 82 1增产 31.8%、17.13% (均达到极显著水平 ) ,2 0 0 1年通过湖南省品种审定委员会审定。由于湖南地处长江中游以南 ,春季气温不稳定与胞质不育系遇低温产生微量花粉这一矛盾成为杂交制种的主要难点 ,制约了本地区杂交油菜种子生产和推广。为此 ,我们经过多年试验探讨 ,以延迟初花期控制不育系微粉为重点 ,以规范其它配套措施为保证 ,在制种产量和质量上取得了较好的效果。技术要…     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

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.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

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

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.     

Genetic variation for disease and nematode resistances and forage quality in perennial diploid and tetraploid lucerne populations (Medicago sativa L.)

Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.     

Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System

In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...     

Effects of Pb on Rhizosphere Soil Enzyme Activity and Chemical Constituents of Achyranthes bidentata Blume

[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.     

Isozyme variation between diploid and tetraploid cytotypes of Glycine tabacina (Labill.) Benth.

Summary Glycine tabacina (Labill.) Benth. is a wild perennial species related to the cultivated soybean, G. max (L.) Merr. It is composed of diploid (2n=40) and tetraploid (2n=80) cytotypes. Currently, to differentiate the cytotypes, plants are grown out in the greenhouse and chromosome counts made on pollen mother cells. It is a laborious and time consuming process. The objective of this study was to determine whether electrophoretic techniques could be utilized to separate the cytotypes. Electrophoretic examination of seven isozyme systems from seed of 67 G. tabacina accessions revealed banding patterns that could be used to differentiate between diploid and tetraploid cytotypes in the species. Among the tetraploid accessions, the number of bands observed were always greater than the diploids. Some tetraploid banding patterns consisted of bands similar to the diploid tabacina and/or additional bands previously identified in other Glycine species. The patterns of isozyme multiplicity and variation in the tetraploid tabacinas suggests more than one mode of origin for the tetraploids.     

Some physiological and photosynthetic characters of rice × sorghum and rice × wheat hybrids

Summary Some photosynthetic characters as-leaf anatomy, leaf photosynthetic rate and CO₂ compensation pointdistinguishing C₃ and C₄ plants and physiological characters as leaf area ratio, nitrogen content, leaf stem ratio and total shoot-to-root and deep root-to-shoot ratios have been studied in rice × sorghum and rice × wheat hybrids. Rice × sorghum 1. has lower values of photosynthetic rate, leaf nitrogen, total root and deep root-to-shoot ratio and CO₂ compensation point as of rice parent where as, rice × sorghym 2. is superior in all these characters. Both hybrids lack kranz anatomy. Though both rice × sorghum hybrids show characters of C₃ rice plant but rice × sorghum 2. has improved drought tolerance and leaf characters in relation to yield. Rice × wheat hybrid have higher assimilatory area and higher total root-to-shoot ratio. Grains of rice × wheat hybrids are identical to rice grain. However, as grains of rice × wheat hybrid does not contain seed coat, it could be exploited as novel rice germplasm after improvement.Abbreviations T CO₂ compensation point - T21 CO₂ compensation point at 21% O₂ - T2 CO₂ compensation point at 2% O₂ - dR/sR deep Root-to-shoot Ratio - LAR Leaf Area Ratio - CER photosynthetic rate - TR/SR Total Root-to-Shoot Ratio