共查询到17条相似文献，搜索用时 468 毫秒
1.
表型轮回选择和混合选择改良小麦群体效应的研究 总被引：6，自引：0，他引：6
在吴兆苏等(1984)创建的小麦基础群体中,采用不同的选择方案,对不育株和可育株分别进行两轮选择。结果表明两轮选择显著地降低了可育株和不育株群体的株高。可育株群体株高的下降速率大于不育株群体。单株产量和单株穗数没有得到显著的改良。相关性状穗长、千粒重等出现负向间接选择效应。轮回选择通过选株间的互交,维持了不 相似文献
2.
用小黑麦显性核雄性不育系与具有不同性状的小黑麦杂交和回交,建成群体进行轮回选择。经两轮轮选,发现利用轮选改进小黑麦籽粒饱满度(小黑麦育种中限制因素)比用常规系选快一倍。虽然在八倍体核不育系与六倍体小黑麦杂交群体中,随着世代的增加不育株在群体中所占比例逐渐减少,但也有少数后代仍保持1F:1S 的分离比例。说明利用 相似文献
3.
利用太谷核不育小麦轮回选择群体不育株与常规亲本杂交，通过系谱选择、混合选择、集团选择多种选育方法综合利用，培育出小麦新品种－豫麦３１号。 相似文献
4.
利用显性雄性不育基因进行小麦轮回选择育种的选择与交配问题 总被引：1，自引：0，他引：1
<正> 本文仅就利用显性雄性不育基因进行小麦轮回选择育种的选择与交配问题提出一些看法。众所周知,不育株只能由不育株经过异交而产生,因此,全部不育株都是 F_1代。在随机交配而又大量存在复等位基因的轮回选择群体内,不育株不可能获得较好的选择效应。人工安排的株行内姊妹交,也远不及可育株自交纯合速度快。此外,所 相似文献
5.
6.
矮败小麦及应用途径分析 总被引：13，自引：1，他引：13
矮败小麦是具有矮秆基因标记的显性核不育材料，非矮秆品种与之授粉，后代群体中的矮秆株是雄性不育的，而非矮秆株是雄性可育的。矮败小麦是太谷核不育小麦的第二代产品，多方面优于太谷核不育小麦，在常规育种、轮回选择和基础研究中有远大的应用前景。 相似文献
7.
谷子高度雄性不育基因在常规品种选育中的应用 总被引：3，自引：1，他引：3
采用携带有隐性核不育基因，不育率为１００％、不育度为９５％的谷子高度雄性不育系与优良恢复系品种测配，根据育种目标，选择优良的杂种Ｆ１继续种植，从Ｆ２育性分离的群体中选择优良不育株，利用其不育基因改谷子自花授粉为异花授粉，进行谷子品种间复合杂交及不同轮回选择群体育种，选育出６个品种和一批具有优异特性的不同世代材料。 相似文献
8.
利用太谷核不育小麦进行轮回选择的改良效应 总被引：2，自引：0，他引：2
由14个亲本的太谷核不育小麦不育株等量混合组成基础群体B_1,对其6个性状进行混合选择和单性状集团选择;由4个亲本的太谷核不育小麦不育株等量混合组成基础群体B_2,进行回交混合选择.结果表明,无论采取哪种方案,对单株籽粒蛋白质产量、穗粒数、百粒重和单株产量均具有较高的选择效率,三轮平均在5%以上.从单个性状的遗传进度看,集团选择效果最大;对群体的改良,以混合选择最优,其次是回交混合选择,二者均有利于群体方差的增大,而集团选择不利于群体方差的增大.就选择阶段而言,集团选择、混合选择和回交混合选择分别在第一、二、三轮选择效果最高.本文还对小麦轮回选择方法应用提出了新的看法. 相似文献
9.
小麦抗赤霉病基因库研究 总被引：5，自引：4，他引：1
利用太谷核不育小麦,进行多亲本杂交,按不同的方式组建基础群体,采用不同的选择方法和选择强度,分别进行轮回选择。对长期库GPO和近期库GPE、GPII、GPIII等4个不同轮选群体,于1989/1990和1990/1991年在南京进行了研究。群体平均抗赤霉病性GPIII较强,GPII较弱。各群体当选优良可育株平均病粒数（率）GPIII较低,但其后代 相似文献
10.
利用太谷核显性核不育基因，开展小麦株粒重、株穗数和株高三个性状的轮回选择，研究群体改良的效果。经四轮选择看出：（1）株粒重增加8.25g，平均每轮增加2.06g；株穗数增加5.25个，平均每轮增加1.31个；株高降低8.82cm，平均每轮降低2.21cm。三个性状态参数的论间差异显著。（2）随轮选次数的递增，群体平均值朝着附合育种 相似文献
11.
By crossing Aegilops mutica with Triticum dicoccum as a bridge species and backcrossing with common wheat as a recurrent pollen
parent, male sterile alloplasmic line(s) were produced. In progeny of the crosses, a self fertile plant with 42 chromosomes
was selected and named R 20. From this plant several lines that possessed Rf (fertility restoring) genes and/or powdery mildew
resistant genes were obtained. Apparently, the system of sterility-fertility of pollen can be applied for hybrid wheat production.
In addition, the disease resistance may be used in breeding. The male fertile lines possessed one or more Ae. mutica sat-chromosome(s),
which show the ability to suppress the nucleolar organizing regions of chromosomes 1B and 6B of common wheat. The relation
between the sat-chromosomes and male fertility restoration is not yet clear.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
分子标记辅助选择聚合棉花Rf1育性恢复基因和抗虫Bt基因 总被引：19，自引：0，他引：19
胞质雄性不育恢复系0-613-2R与转Bt基因抗虫棉R019(轮回亲本)杂交、回交产生BC2群体。利用CMS恢复基因Rfl紧密连锁的3个SSR标记和Bt基因的PCR标记开展分子标记辅助选择培育聚合有Rfl和Bt的转基因抗虫棉恢复系。在分析的59个BC2单株中55株存在恢复基因标记，54株存在Bt基因；综合标记分析结果，共获得54个同时具Rfl与Bt基因的聚合单株；这些聚合单株自交后，通过标记辅助选择，获得10株含Bt基因且Rfl纯合的单株。为棉花优良恢复系的快速培育提供了重要基础。 相似文献
13.
Four cycles of recurrent selection for FHB resistance were conducted in an intermating wheat breeding population using the
dominant male-sterile gene ms
2 during 1987–1991.Five cycles of phenotypic mass selection for male-sterile plants were evaluated using the soil-surface inoculation
method in Experiment I. Experiment II evaluated changes in FHB scores during five cycles of progeny selection for fertile
plants using the single-floret inoculation method. In Experiment I, the average level of FHB response increased to MR level
in C4, compared to MS level in C0. The numbers of infected spikelets and diseased kernels decreased 0.32 and 2.68 per cycle, respectively. In Experiment II,
the average level of FHB response increased to R level in C4F1. The numbers of infected spikelets and diseased kernels decreased 0.93 and 4.58 per cycle, respectively. In both experiments,
the largest selection gains were realized in the first cycle. The frequencies of R and MR individuals were increased significantly.
The frequencies of individuals with FHB response equal and/or superior to Sumai 3 were increased to 5–8% in C4 and 25% in C4F1after the fourth cycle. Agronomic traits tended to be slightly improved in selected populations. Compared to 2% in C0, about 34% of lines superior in both FHB resistance and agronomic traits in C4F1 were selected to enter the conventional breeding program for further evaluation. Sixty three semidwarf lines superior in
both FHB resistance and yield potential were selected from the F5 generations derived from C1F1 to C4F1. From them, two resistant cultivars with high-yielding potential were developed and commercialized in the Lower Yangtze Valley.
Recurrent selection appears to be highly effective and feasible in shifting the average FHB response of the intermating population
in the desirable direction, thereby enhancing the frequency of resistant individuals.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
太谷显性核不育基因用于抗逆性育种的效应 总被引：1，自引：0，他引：1
利用太谷核不育小麦，采用改良半姐妹和混合轮选及隔代回交轮选三种方法进行抗逆性育种。结果表明，改良半姐妹和混合轮选对群体主穗粒数、单株粒重、百粒重等主要产量性状和抗干热风能力均有显著改良效果。改良半姐妹比混合轮选改进幅度大，且对降低群体株高有极显著效果；而混合轮选对降低株高效果不明显；两群体各主要经济性状有向选择目标集中，变异度下降的趋势。用隔代回交轮选法改造丰抗２号效果显著，升选系抗干热风，抗寒性 相似文献
15.
不同的部分保持系可能存在不同的微效恢复基因,通过有性杂交,产生基因重组,能够获得完全保持系类型,但只有在不育细胞质中才能观察得到微效恢复基因是否存在以及它们的作用大小.反向杂交法以不育细胞质为选择背景,在杂交后代植株中直接观察到微效恢复基因的表达,获得的完全不育株,在一定程度上排除微效恢复基因,不育株再通过高温处理转换为可育后自交,来自不育株的微效恢复基因可以进一步排除掉,从而产生出没有(或很少)微效恢复基因的"亲本",利用该"亲本"高温处理后仍可转换为可育的特性,作为父本进行杂交或回交育种,在其后代中获得没有微效恢复基因的完全保持系.该研究为Cp 26不育细胞质源创造出了完全保持系.如果在田间鉴定出优异的完全不育株,对其进行单倍体育种(诱导孤雌生殖或花培),选择到没有(或很少)微效恢复基因的纯合不育株.再对其进行花培,筛选可育的突变体;或者利用纯合不育株的原生质体与一个已破坏细胞核的可育系原生质体融合,都可能得到具有纯合不育株细胞核和可育细胞质的保持系,而能够完善和改进反向杂交法.反向杂交法不但能够为所谓不能保持的不育细胞质源创造出保持系,而且有利于加强新不育系选育的目标性和预见性,提高不育系配合力和培育不同类型优异不育系. 相似文献
16.
Maksimir 3 Synthetic (M3S) maize population was developed at the Faculty of Agriculture University of Zagreb by intercrossing
inbred lines, whose origins trace back to several open-pollinated varieties and local populations from different regions of
the former Yugoslavia. The population was subjected to two cycles of selfed progeny recurrent selection for grain yield. The
objectives of this study were: (i) to determine genetic distances among the parental inbred lines of the M3S population (M3S
progenitors), the M3S population before and after two cycles of recurrent selection, and elite inbred lines representing the
BSSS and Lancaster heterotic group; and (ii) to examine the effect of two cycles of recurrent selection on allele frequency
changes in the population. Nine M3S progenitors, three BSSS lines, and three Lancaster lines were genotyped at 24 SSR loci,
out of which nine randomly chosen loci were used for genotyping 96 individuals from both C0 (the M3S population before selection)
and from C2 (M3S population after two cycles of selection). A total of 101 alleles were detected across 24 loci in the 15
lines, whereas 83 alleles were found in the nine M3S progenitors. Among the latter 83 alleles 31 were unique, i.e. found only
in one of the progenitors. Mean genetic distance among nine M3S progenitors was 0.61 indicating a broad genetic base of the
M3S population. High mean genetic distance was found between M3S progenitors and BSSS lines (0.69) and M3S progenitors and
Lancaster lines (0.71). This indicates that the M3S population represents a germplasm source unrelated to both the BSSS and
Lancaster germplasm. Mean genetic distance between the M3S population and BSSS as well as Lancaster lines decreased slightly
after two cycles of recurrent selection suggesting the need to introduce testers from both groups in future selection in the
M3S population in order to maintain heterotic complementarity of the M3S population to these groups. A test of selective neutrality
identified several non-neutral loci in the population whose allele frequency changes from the C0 to the C2 cannot be explained
by genetic drift. The majority of non-neutral alleles, whose frequency increased after two cycles of selection, were present
in at least one line from the BSSS or Lancaster heterotic group. 相似文献
17.
‘Ogura radish’, a cytoplasmic genetic male sterile line, was crossed with four local and three Japanese cultivars to identify
maintainer lines. Out of seven F1 families, one cross involving a local cultivar, Aushi, produced 100% male sterile (MS) progeny. The crosses involving the
other two local cultivars, Tangail Local and Kuni, produced about 90% MS progeny, indicating the presence of maintainer gene(s)
for male sterility. The fourth local cultivar, Tasaki, produced 100% male fertile (MF) progeny. All three exotic cultivars
appeared to possess the chromosomal gene(s) for controlling the male sterility. In BC1, BC2 and BC3 generations, segregation of MS plants were more frequent when ‘Aushi’ was used as recurrent parent. The expression of male
sterility was not affected by seasonal influences. Thus the local cultivar ‘Aushi’ may be used as maintainer line for ‘Ogura
radish’. To produce hybrid seed, ‘Tasaki’ can be used as pollinator line as it exhibit high heterosis with ‘Aushi’.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献