共查询到17条相似文献，搜索用时 593 毫秒
1.
半姊姐轮回选择对玉米群体改良效果研究 总被引：1，自引：0，他引：1
用半姊妹轮回选择法完成对中综２号三轮改良。结果表明：该法对群体产量和配合力均有显著的改良效果。经三轮选择后平均每周期获得量为７．４％；一般配合力从Ｃ０的－１０．０８１增长到Ｃ３的１５．９２４。二者每周期的获得量与选择轮数之间均呈显著的正相关。本研究第一轮的选择用遗传基础广泛的非亲缘综合种做测验种，二、三轮的选择用自交系做测验种，结果表明用自交系做测验对改良群体的一般配合力同样有效。 相似文献
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中国主要玉米改良群体杂种优势组合模式的初步评价 总被引：23，自引：1，他引：23
以13个玉米改良群体和4个标准测验种为材料,采用NCⅡ遗传设计,测定并分析了群体产量配合力、杂种优势、杂优模式和农艺性状。结果表明,WBM C4、豫综5号、辽旅综群、中群14 黄综群5个群体产量一般配合力较高。在群体与测验种的52个杂交组合中,12个组合产量与单交种对照相当,特殊配合力较高,其中掖478×黄综群、黄早4×中群14、丹340×黄综群、黄早4×豫综5号4个组合比对照增产,对照优势为2 29%～4 82%。研究结果既说明了中国玉米群体改良取得的研究进展,又为这些改良群体进一步改良、利用和杂优组合模式构建提供了依据。 相似文献
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半姊妹轮回选择对玉米群体改良效果研究 总被引：4，自引：0，他引：4
用半姊妹轮回选择法完成了对中综2号三轮改良,结果表明：该法对群体产量和配合力均有显著的改良效果。经三轮选择后平均每周期获得量为7.4;一般配合力从C0的-10
081增长到C3的15.924。二者每周期的获得量与选择轮数之间均呈显著的正相关。本研究第一轮的选择用遗传基础广泛的非亲缘综合种做测验种,二、三轮的选择用自交系 相似文献
4.
运轮1号玉米群体轮回选择改良效果 总被引：1，自引：1，他引：0
种质资源遗传基础狭窄是制约玉米育种的重要因素,而群体轮回选择是拓宽玉米资源遗传多样性的重要方法。以具有中国reid 血缘的8 个自交系组成的群体和美国坚秆种质群体BSSS 杂交后经过一轮混合授粉形成运轮1 号玉米群体。3 轮混合选择后,以昌7-2 为测验种分析了运轮1号群体的产量性状的配合力。结果表明,群体内单株间产量配合力差异显著,遗传变异较丰富。从138 个测交种中筛选出20 个较优良的对应自交单株作为新一轮轮回选择的亲本。预计新一轮合成群体产量配合力将提高11.6%,灌浆脱水速率较对照优越,其他农艺性状也得到相应改良。 相似文献
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玉米“黄金”群体产量等性状轮回选择改良效果评价研究 总被引：3，自引：0，他引：3
利用群体改良方法,充分挖掘地方优异种质的遗传潜力是玉米种质改良与创新的一个重要途径。本研究以黄金群5个轮次改良群体为材料,通过1年2点产量比较试验,分析了混合选择和相互半姊妹轮回选择方法对黄金群产量及穗部性状的改良效果。结果表明,两种选择方法对群体产量改良是有效的,随着改良轮次的增加,黄金群的单株产量逐轮提高,平均每轮提高3.78%,其中,混合选择改良的3轮群体平均每轮提高4.27%,相互半姊妹轮回选择的改良群体提高2.07%;虽然群体产量的变异系数从15.43%下降到12.80%,但群体内仍有较丰富的变异。通过改良群体穗部性状比较发现,穗长和行粒数改良效果显著,分别提高14.71%和17.62%,说明它们的提高是群体单株产量提高的主要因素。 相似文献
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对ZZ4完成了4轮MS1-HS和MS1选择.结果表明,经4轮选择的群体,两种方法均有效地保留了各主要性状的遗传方差.MS1-HS选择的群体遗传方差下降速率更慢,C4群体的单株籽粒产量的遗传方差仅减少3.7%.穗长、穗粗、粒行数、行粒数、出籽率、百粒重的遗传方差的变化与单株籽粒产量一致,MS1C4的遗传方差减少了8%～15%,MS1-HSC4的遗传方差仅减少了4%～15%.株高、穗位高、抽丝期、植株保绿度、抗倒性等相关选择性状的遗传方差的变化与产量性状基本一致.MS1-HS法对改良玉米群体籽粒产量与测验种间的特殊配合力十分有效,呈逐轮上升的趋势;改良群体与测验种综系140间的杂交后代产量平均每轮提高6%,杂种优势平均每轮提高6.9%.两种方法在改良群体产量性状一般配合力方面,均得到了良好的效果.同时,穗部性状及株高、穗位、抽丝期、散粉期、抗性等田间农艺性状的一般配合力也获得了同步改良.通过ZZ4改良群体与6个测验种间杂交组合产量及杂种优势的比较研究,得出ZZ4与黄早四类种质为杂种优势模式对. 相似文献
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改良S1后代轮回选择在玉米群体改良中应用的研究：I.直接响应与相关响应 总被引：2，自引：1，他引：2
以玉米群体中综３号为材料，研究改良Ｓ１后代轮回选择在玉米群体改良中的应用。通过对中综３号三轮改良Ｓ１后代选择群体的二年三点比较试验，研究改良Ｓ１后代轮回选择的直接响应与相关响应。结果表明：以籽粒产量为主要目标的改良Ｓ１选择，每轮群体自身产量可获得８％￣１０％的遗传增益，群体Ｓ１后代籽粒产量可获得近１４％的增益。单穗籽粒产量的提高，从穗部性状看，主要是穗长的增加和千粒重提高的结果。每行粒数有所增加， 相似文献
11.
Mateus Figueiredo Santos Tassiano Maxwell Marinho Câmara Gustavo Vitti Moro Emiliano Fernandes Nassau Costa Cláudio Lopes De Souza Jr 《Euphytica》2007,157(1-2):185-194
This research reports responses to selection and changes in general (GCA) and specific (SCA) combining abilities after three
cycles of a modified reciprocal recurrent selection procedure (MRRS) in EPB-4 and EPB-5 maize populations. In the MRRS procedure
a cycle can be completed in 1 or 2 years depending on the availability of winter breeding nurseries. The original and the
three selection cycles of the two populations per se (eight entries) and the partial diallel developed from the crosses between
them (16 entries) were evaluated in six environments. Realized response to selection on the population cross was 7.25% cycle−1 for grain yield, −13.63% cycle−1 for plant lodging, and 11.93% cyle−1 for prolificacy, whereas plant and ear heights remained unchanged. GCA estimates increased with selection cycles for both
populations for grain yield and prolificacy, and decreased for plant lodging, indicating that the frequency of favorable alleles
with additive effects for these traits increased with the MRRS cycles in both populations. SCA estimates increased for grain
yield and prolificacy indicating that the frequency of favorable complementary alleles at loci with non-additive effects in
the reciprocal populations increased with the MRRS cycles. For grain yield, SCA effects increased more than GCA effects with
selection cycles, indicating that MRRS exploited more the non-additive effects than the additive effects for the improvement
of this trait. The overall results showed that the MRRS procedure was highly effective in improving the population cross,
exploiting both GCA and SCA effects. 相似文献
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不同轮回选择方法对玉米窄基群体的改良效果 总被引：1，自引：0，他引：1
利用轮回选择进行群体改良,是玉米种质扩增与改良的有效方法,能为选育优良自交系提供基本素材,进而提高选育自交系及杂交种的效率。本研究以玉米窄基群体P4C0及其经过不同轮回选择方法改良的10个群体为材料,通过多点田间表型鉴定和配合力测定,研究不同轮回选择方法对玉米窄基群体的改良效果,利用SSR分子标记分析不同轮回选择方法对群体遗传多样性的影响。结果表明,几种轮回选择方法都能有效改良群体的主要性状及其一般配合力(GCA)。以时间计算,控制双亲混合选择(MS)对群体P4C0主要性状及其GCA改良效果优于半同胞-S2:3(HS-S2:3)轮回选择,但在株高和穗位高的改良上,HS-S2:3选择效果较好。以轮次计算,开放改良对群体P4HSC1主要性状及其GCA的改良效果优于MS,但开放改良后,群体株高和穗位高有较大幅度的增加。不同轮回选择方法对群体遗传多样性和遗传结构的影响不尽一致。P4C0经过5轮MS后,在群体改良的低代,群体遗传多样性得到了较好的保持,而多代的改良导致群体遗传多样性下降;P4C0经过1轮HS-S2:3选择后,遗传多样性比P4C0有较大幅度的下降。P4HSC1经过1轮开放改良后,遗传多样性有较大幅度的增加。P4HSC1经过3轮MS改良后,群体遗传多样性呈增大的趋势,但每轮增加的幅度均较小。 相似文献
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Combining ability is one of the most important information breeders use to identify superior inbred lines on the basis of their performance in hybrid combinations. The objectives of our study were (i) to quantify the importance of general combining ability (GCA) and specific combining ability (SCA) variances for seed yield, oil content and oil yield; and (ii) estimate GCA and SCA effects of seed yield, oil content and oil yield of inbred lines developed from advanced cycle pedigree breeding populations in sunflower. A total of 109 female S3 cytoplasmic male sterile (CMS) lines from four bi-parental populations in advanced cycle pedigree breeding were crossed with two testers to form 218 testcross hybrids (TCHs). The TCHs were then evaluated in three environments. Variance component analysis results showed predominance of σ2gca over σ2sca for seed yield and oil yield indicating that superior TCHs can be identified based on positive and significant GCA effects of the female lines. For oil content σ2sca was predominant over σ2gca indicating that selecting for TCHs with high oil content would be best among line × tester combinations and not among female S3CMS lines per se. The proportion of GCA and SCA effects in the best five TCHs in each breeding population also confirmed the predominance of GCA effects over SCA effects for seed yield and oil yield while for oil content both GCA and SCA effects appear to be important, with SCA effects having more influence than GCA. The best selection strategy would therefore be to capture the GCA in the early stages of inbreeding and then SCA for the few unique combinations when lines are almost fixed. 相似文献
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Long-term selection experiments provide germplasm to study the effects of selection in a closed population. Recurrent selection
to enhance grain yield in oat has been ongoing at the University of Minnesota since 1968. The objectives of this study were:
(i) estimate the GCA and SCA effects for three agronomic traits in the seventh cycle of selection, (ii) assess the effect
of the current methods of selection on parental contribution and unselected traits, and (iii) determine the direct and indirect
responses to seven cycles of recurrent selection for grain yield. Progeny of the Cycle 6 parents and parents for Cycles 0
through 7 were grown in two separate tests. Grain yield, heading date and plant height were evaluated in each test. Grain
yield was increased by 21.7% after seven cycles of selection. Evaluation of Cycle 6 progeny showed that GCA effects were significant
for all three traits studied, and SCA effects were significant only for grain yield. Four Cycle 6 parents did not have any
progeny selected as Cycle 7 parents. Results from this study indicate that long term recurrent selection has continued to
increase grain yield. Alternative selection strategies may be necessary to maintain the genetic variability in this population,
particularly when improvement of secondary traits is required.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Matheus Costa Dos Reis Fernando Lisboa Guedes Guilherme Barbosa Abreu João Cândido de Souza 《Euphytica》2013,191(2):217-222
The objective of the research was to evaluate recurrent selection strategies in maize (Zea mays L.) by determining the expected and realized responses to selection, as well as the alterations in heterosis, of hybrids from the cross between the original populations (C0) and the third cycle (C3). The genetic variances and covariances were obtained for intrapopulational (P11 and P22) and interpopulational (P12 and P21) half-sib progenies from populations 1 and 2 in cycles C0 and C3. One-hundred progenies of each type were evaluated [husked ear weight (g plant?1)] at two separate locations by conducting 10 × 10 triple lattice design experiments contiguous for each cycle. Four different recurrent selection strategies were investigated: reciprocal recurrent selection (RRS), interpopulation testcross half-sib selection (THS 1 and THS 2) and intrapopulational half-sib recurrent selection (HSS). THS 1, which employed population 1 (with the lowest frequency of favorable alleles) as tester, was most efficient in the simultaneous improvement of the hybrid and the two populations per se. RRS showed the highest efficiency in improving the interpopulational hybrid but not in the parental populations. In order to estimate heterosis and realized responses to RRS, representative samples of seed from intra and inter-populational half-sib progenies from C0 and C3 were employed in randomized block design experiments with 10 repetitions carried out at two separate locations. RRS increased heterosis in the interpopulational hybrid from 12.3 % (C0) to 24.9 % (C3), and the productivity gain [husked ear weight (t ha?1)] was 13.5 % over the three cycles. 相似文献
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中国南瓜β-胡萝卜素含量配合力的研究 总被引：1，自引：0，他引：1
以16个具有代表性的中国南瓜自交系及其按Griffing双列杂交方法Ⅳ组配成的120个杂交组合为材料,对中国南瓜β-胡萝卜素含量的配合力进行了系统的研究,旨在了解不同南瓜自交系β-胡萝卜素含量的配合力特点。结果表明：在16个南瓜自交系中,从上海黄狼南瓜中选出的自交系‘百泉10’的一般配合力最大,其次是,‘百泉5’（来源于广东）,‘百泉4’（来源于黑龙江）。最小的是‘百泉2’（来源于北京）。在120个杂交组合中,特殊配合力最大的是‘百泉9’（来源于河南）ב百泉10’（来源于上海）,其次是‘百泉7’（来源于河南）ב百泉15’（来源于北京）、‘百泉4’（来源于黑龙江）ב百泉12’（来源于海南）,最低的是‘百泉1’（来源于湖南）ב百泉11’（来源于江西）。因此不同来源的南瓜自交系间一般配合力差异很大。自交系间地理差异越大,其间的特殊配合力往往越高。 相似文献
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2个玉米人工合成群体S2主要性状的配合力分析 总被引：8，自引：1，他引：8
以48-2,9636,RP125为测验种,采用不完全双列杂交设计,对2个玉米人工合成群体S260个单株的配合力进行研究,以分析不同群体自交后代间、群体内S2株系间、株系内个体间配合力差异。结果表明,除株高、穗位高、行粒数外,其余性状GP-5 S2GCA优于GP-4 S2,多数性状群体内S2株系间GCA具有较大差异,株系内个体间经济性状GCA的差异远远大于农艺性状;不同性状及同一性状不同群体自交后代所配组合SCA效应值达显著或极显著差异的数目均有一定差异,且GCA与SCA无明显相关关系。55,57,89,93,105,107株系多数性状具有较高的GCA,可能有较大利用潜势。 相似文献