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1.
普×爆自交高代选系的配合力及利用价值研究   总被引：3，自引：3，他引：3  
以24个普×爆自交高代选系和7个爆裂玉米骨干自交系按NCⅡ遗传交配设计组配成的168个单交组合为材料,对3个膨爆特性指标和12个主要农艺性状进行了配合力分析。结果表明,BP02,BP03,BP04,BP12,BP14等选系主要性状的GCA较高,应进一步利用这些选系与爆裂玉米自交系广泛测交组配利用;BP20,BP21与N03,BP02与F2,BP11与N16穗粒重和膨化倍数的SCA效应均为较大极显著正值,应进一步利用这些选系分别与其父本的同类群近缘系进一步测配,从中筛选优良组合;24个选系的聚类结果与其亲本和系谱来源不存在必然联系;所有测交组合的综合性状较对照豫爆2号无明显优势,作为普通型爆裂玉米杂交种在生产上的利用价值不大。  相似文献   

2.
以改良Reid群内7个自交系（8112、478、5003、掖107、7922、97039、B73）组配测交种的自交后代为试验材料，获得68个测交组合，进行配合力测定，结果表明：玉米自交中代各性状的狭义遗传力都较低．其中狭义遗传力相对较高的性状有株高、穗住、穗粗、穗行数、穗重和穗粒重；根据测配结果，选出综合性状优良的自交中代有Al—3—2、B3—10—3、B3—9—1，从而淘汰中代姊妹系间分离出的低配合力自交系，使高配合力个体在下代出现的机率增大，有利于集中选择，减少工作量，选择效果更强。  相似文献   

3.
甜玉米二环系选育的早代判别法研究   总被引：2，自引：0，他引：2  
戴惠学  陆作楣 《种子》2006,25(5):30-34
本文设计了二环系选育的早代判别法,尝试在二环系选育的早代进行农艺性状选择的同时进行配合力选择,提高组合早代筛选效率。试验利用2个优良甜玉米品种苏甜8号(35×33)和晶甜3号(403×452)的4个亲本配制4个新单交组合;同时利用35和33两个自交系进行测交,得到403/35//33、403/33//35、452/35//33和452/33//35四个测交组合,比较分析了测交组合的农艺性状,淘汰劣势组合,将选留的2个优势组合按常规育种的方法分别得到5个和6个选系,分别与相应的测交自交系35和33进行测配,得到11个验证组合并进行比较分析,结果表明:3-5和4-6是能显著增产且综合性状优良的二环系。试验表明:从早代筛选出的优势组合中选育出优良二环系的概率是比较大的,但要注重自交后代不同单穗选系之间的比较筛选。  相似文献   

4.
利用113对SSR多态性引物研究了来源比较广泛的56个爆裂玉米自交系的遗传多样性，并初步进行了杂种优势群划分。结果表明：供试自交系问存在较丰富的SSR多态性；56个爆裂玉米自交系可划分为6个杂种优势群，其中Ⅰ，Ⅴ，Ⅵ类群以国内种质选系为主，Ⅱ，Ⅲ，Ⅳ类群主要为外引杂交种选系，第1类群又可分为3个亚群。该分群结果与杂交组合的组配效果相吻合，高优势组合的亲本均属于不同的优势类群(亚群)，而在类群(亚群)内未组配出优良组合。SSR标记可以用于研究爆裂玉米自交系的种质基础。  相似文献   

5.
利用适当的温带种质对外引种质进行改良,可进一步丰富温带玉米遗传基础。以来自CI-MMYT的Pob101群体和我国主要种质的代表系为试验材料,研究不同温带种质比例的Pob101×掖478半外来群体选系与旅大红骨群和Lancaster群的杂种优势,为这些半外来群体的进一步改良和利用提供依据。结果表明,理论上含有75%温带血缘的Pob101×掖478半外来群体选系与旅大红骨群和Lancaster群的杂种优势均值均大于含有25%温带血缘的掖478×Pob101半外来群体选系与旅大红骨群和Lancaster群的杂种优势均值,在高产育种中有较大的利用潜力。  相似文献   

6.
河南主要优良玉米自交系利用潜力分析   总被引：4，自引：2，他引：2  
选择9个河南省当前玉米育种的主要优良自交系按Griffing方法4设计组配36个杂交组合,对单株产量等15个性状的配合力及不同性状配合力之间的相关性进行了分析,结果表明： 除了出籽率外,各自交系其余14个性状的配合力之间存在着显著或极显著差异;自交系单株产量GCA与籽粒长、穗位高GCA之间显著相关;昌7－2、洛06、济533、郑22利用潜力较高,豫8701、中72、868利用潜力中等,洛1544、郑58利用潜力较低;自交系总配合力效应（TCAˊ=gi+ssi.）能够直观地反映自交系利用价值的大小,是较好的的配合力综合评价指标。根据以上研究结果,作者对这些自交系的特点进行了分析,并对这些自交系的改良和利用提出了自己的看法。  相似文献   

7.
以最新选育的20个玉米自交系为被测系，以5个分别来自Suwan、Reid和非Reid三个杂种优势类群的自交系为测验种，采用NC-Ⅱ遗传交配设计，共配制100个杂交组合，在云南省宣威市、嵩明县2个不同生态条件下进行田间鉴定，分析研究新选自交系的配合力。结果表明，YML12、YML11、YML20、YML05、YML07为综合性状配合力比较优良的自交系，较易组配出优良杂交组合，具有较高的育种利用潜力。杂交组合YML05×T1、YML12×T1、YML07×T1具有较高的产量对照优势，可进一步研究其丰产性、稳产性和适应性。采用单倍体诱导育种选系时先自交1～2代再诱导，可淘汰一些不利基因，有利于获得更多的优良DH系，但不同育种材料间差异较大。  相似文献   

8.
利用phi116和umc1044标记选育抗纹枯病玉米品系   总被引：4，自引：0，他引：4  
玉米纹枯病已成为我国玉米产区的主要病害之一,为解决玉米纹枯病抗病育种工作中人工接种鉴定困难、选择效率低等问题,利用第7和第1染色体上与抗病QTL紧密连锁的两个标记phi116和umc1044对(CML270×478)×CML270回交后代13份BCF6:7选系进行了抗性分子标记辅助选择。结果发现,2份选系与478具有1条相同带型,1份与478具有2条相同的带新型;另10份选系与CML270具有相同带型。人工接种鉴定结果表明,依据标记推断为不抗病的3份材料表现为感到高感纹枯病,而其余10份表现从感到高抗,带谱与病性指数相关系数达极显著水平,相关系数r=0.6625>r0.01=0.64,从中获得高抗玉米纹枯病选系478C4-2-2、478C4-2-3、478C4-2-4。配合力分析表明,478C4-2-2具有较高的一般配合力和特殊配合力,所配组合渝单24在2006年已通过重庆市审定。研究表明,标记鉴定和表型鉴定相结合,选择玉米纹枯病抗病自交系是完全有效的。  相似文献   

9.
7个玉米合成群体选系的杂优类群分析   总被引：3，自引：0，他引：3  
以7个玉米人工合成群体的21个新选自交系和西南地区常用的6个骨干玉米自交系以及代表我国玉米核心种质的S37、黄早四、丹598和478四个标准测验种为材料,利用SSR标记,进行了杂优类群划分,以21个新选系和6个常用骨干系按不完全双列杂交组配的126个杂交组合为材料,通过单株产量测定、杂种优势估算,分析了杂优模式。结果表明:31个自交系间遗传相似系数变幅为0.520～0.808,以相似系数0.655为阈值,可将31个自交系划分为5个大类群,其中第Ⅲ类群又可分为3个亚群;7个玉米人工合成群体的21个新选系有6个划入热带种质,2个划入Lancaster群,3个划入四平头群,1个划入Reid群,9个划入其他类群;在各类群组配中,热带种质群分别与Reid群、Lancaster群和旅大红骨群组配可产生较强的杂种优势;部份群体选系聚类出现交叉的原因可能是由于具有相同的遗传背景所致。  相似文献   

10.
多抗优质玉米自交系‘早48’的选育与应用研究   总被引：1，自引：1，他引：0  
针对玉米育种和生产上种质遗传基础狭窄,缺乏抗病优质自交系的问题,以国内自交系‘掖478’与含有热带血缘的外引杂交种后代选系‘P249’杂交、回交及多代自交,培育出具有温-热带种质的多抗优质自交系‘早48’。该自交系抗茎腐病、矮花叶病、小斑病、大斑病、穗腐病等多种病害;籽粒粗蛋白、粗淀粉含量高,品质优良;株型紧凑,秆矮抗倒,配合力高,适应性广。利用‘早48’自交系组配育成的‘强盛31’、‘晋单44’、‘忻玉110’、‘咏丰1号’、‘晋阳2号’、‘晋单70’等6个杂交种通过国家或省级审定。这些新品种已在中国东华北早熟区、黄淮海夏播区大面积推广应用,取得较大的社会经济效益。  相似文献   

11.
Preharvest aflatoxin (AF) contamination by Aspergillus flavus Link:Fr is one of the main limitations for maize (Zea mays, L.) production in the southern USA, causing enormous economic losses and posing a risk to animal and human health. The objectives of this study were (1) to estimate aflatoxin accumulation and expression of associated traits in quality protein maize (QPM) inbreds and their testcrosses, (2) to compute their repeatabilities and correlations, and (3) to study the relationship between inbred lines and their testcrosses for aflatoxin accumulation. Forty-eight inbreds and their testcrosses plus checks were grown in one and three locations in south and central Texas, respectively. Aflatoxin concentration was evaluated in the plants following inoculation with A. flavus. Average aflatoxin concentration overall for inbreds was 286.3 ng g−1, and for testcrosses 596.5 ng g−1 at Corpus Christi, TX, 325.1 ng g−1 at Weslaco, TX, and 105.1 ng g−1 at College Station, TX. Flinty orange inbreds developed from CIMMYT Population 69 were the least susceptible to aflatoxin accumulation in both inbreds and testcrosses at all locations. Repeatability for aflatoxin was 0.67 in inbreds at Weslaco, TX and 0.54 in testcrosses across locations. Aflatoxin in testcrosses was positively correlated both phenotycally and genotypically with endosperm texture and kernel integrity, and negatively correlated with grain yield and silking date. Less aflatoxin accumulation was associated with flinty endosperm texture, better kernel integrity, and later maturities. Association between the expression of traits in inbreds and aflatoxin in testcrosses was relatively high for endosperm texture (R 2 = 0.62), silking date (R 2 = 0.44), kernel integrity (R 2 = 0.39), and aflatoxin (R 2 = 0.60 for log ng g−1). It seems plausible to select for associated traits having high heritabilities and strong correlation with aflatoxin, in addition to low aflatoxin accumulation in inbreds and hybrids to reduce the risk of aflatoxin contamination.  相似文献   

12.
Breeding efforts in West and Central Africa (WCA) have focused on the development of Low-N-tolerant (LNT) maize inbreds and their classification into heterotic groups. This study was conducted to classify LNT maize lines into heterotic groups using testcross performance, morphological and SNP markers and to compare the consistency of groupings by the three methods. Thirty-six LNT inbreds were crossed to two contrasting inbred testers to generate 72 testcrosses that were evaluated under low-N conditions in Nigeria in 2014. Also, the 36 inbreds and the two testers were evaluated for per se performance under similar conditions as the testcrosses in 2014 and genotyped in 2015 using 1,123,196 SNP markers. Based on testcross performance, 33 of the 36 LNT inbreds were grouped by the two testers. Morphological characterization from per se performance and genetic relationship by SNP markers classified the inbreds into four groups that were inconsistent with their pedigree. Correlation analysis showed non-concurrence of the three grouping methods. However, information from these groupings would assist in reducing the number of crosses to be made and evaluated.  相似文献   

13.
Leaf rust is the most frequent leaf disease of winter rye in Germany. All widely grown population and hybrid varieties are susceptible. This study was undertaken to estimate quantitative‐genetic parameters of leaf‐rust resistance in self‐fertile breeding materials with introgressed foreign leaf‐rust resistances and to analyze the relative importance of seedling and adult‐plant resistance. Forty‐four inbred lines and their corresponding testcrosses with a highly susceptible tester line were grown in a field in four different environments (location‐year combinations) with artificial inoculation. Plots were separated by a nonhost to promote autoinfections and minimize interplot interference. Leaf‐rust severity was rated on three leaf insertions at three dates. The testcrosses showed a considerably higher disease severity than the lines. High correlations (r ? 0.9, P = 0.01) existed among the leaf insertions and the rating dates. Large genotypic variation for resistance was found in both the inbred and testcross populations. Genotype‐environment interaction and error variances were of minor importance, thus high entry‐mean heritabilities were achieved. A tight correlation between the inbreds and their corresponding testcrosses was found (r = 0.88, P = 0.01). Heterosis for resistance was significant (P = 0.05), but not very important. In a seedling test with 20—30 single‐pustule isolates, 34 out of 44 inbreds reacted race‐specifically. From the remaining inbred lines, three were medium and seven highly susceptible. In a further greenhouse test with 16 inbreds, seven were susceptible and five were resistant in both seedling and adult‐plant stages. The remaining four lines had adult‐plant resistance. In conclusion, race‐specific leaf‐rust resistance can be selected among inbred lines per se. Lines should also be tested in the adult‐plant stage.  相似文献   

14.
Aflatoxin accumulation in maize (Zea mays L.) kernels is a serious economic and health problem that reduces grain quality and nutritional values and causes death to livestock and humans. Understanding the genetic parameters and heterotic responses of exotic maize inbred lines can facilitate their use for developing aflatoxin resistant parents of hybrids in Africa. This study was designed to (1) determine the heterotic affinities of aflatoxin resistant exotic lines, (2) identify exotic inbreds with good combining ability, and (3) determine the mode of inheritance of resistance to aflatoxin contamination in these lines. A line?×?tester mating design was used to determine combining ability of 12 yellow and 13 white inbreds and classify them into heterotic groups. The inbreds were crossed to two adapted testers representing two African heterotic groups and the resulting testcrosses along with hybrid checks were evaluated in separate trials at two locations for 2 years in Nigeria. General combining ability (GCA) effects were more important than specific combining ability effects for aflatoxin and grain yield. Among 15 exotic inbred lines having negative GCA effects for aflatoxin and 13 with positive GCA effects for grain yield, six combined the two desired traits. Five white and six yellow endosperm testcrosses were found to be good specific combiners for the two desired traits. The exotic lines with negative GCA effects for aflatoxin accumulation will be used as donor parents to develop backcross populations for generating new inbred lines with much higher levels of resistance to aflatoxin accumulation.  相似文献   

15.
The European com borer (ECB) Ostrinia nubilalis H. is a major pest in World maize Zea mays L. production. Objectives of this study were to (1) investigate the genotypic variance and covariance in testcrosses of European flint and dent inbreds for ECB resistance and agronomic traits, and (2) estimate the correlation between line per se and testcross performance for ECB resistance traits. A total of 16 flint and 24 dent inbreds and their testcrosses with two testers from the opposite germplasm pool were evaluated in four and three German environments, respectively. Using artificial infestation with ECB larvae, resistance was assessed by damage rating of stalks, tunnel length in dissected stalks, and relative yield of infested plots compared with protected plots. Yield losses due to ECB damage in testcross hybrids amounted to 40%. Significant genotypic variances between flint and dent lines and high heritabilities were found for damage rating of stalks for both line per se and testcross performance. Heritabilities were low or intermediate for tunnel length and relative grain yield. Correlations between line per se and testcross performance were tight for the damage rating of stalks and moderate for tunnel length and relative yield in both flint and dent germplasm. For damage rating of stalks, per se performance of lines tested in a few environments can be used to predict their testcross performance. In contrast, assessment of testcross performance for tunnel length and relative yield requires evaluating testcrosses with several testers in multi-environment trials.  相似文献   

16.
Grain yield (GY) is a direct function of its components and these traits to being less complex and highly correlated with yield. The objectives of this study were to map Quantitative Trait Loci (QTL) for GY and its components in maize lines and GY in their testcrosses, to verify its congruence and the possibility to select testcrosses from the predict means of the lines by using markers information. Two hundred and fifty-six S1 lines derived from the cross L-08-05F × L-14-04B of tropical germplasm and the testcrosses of these lines with two testers were evaluated in six environments. The traits analysed in the lines were GY, prolificacy, ear height and diameter, number of rows per ear and kernels per row, kernel depth, grain weight, and GY in the testcrosses. QTL were mapped in the lines and in testcrosses and the predicted means of the lines were computed based on QTL effects and in all markers of the genome. Few QTL detected for GY and its components in the lines were coincident with the QTL for yield in testcrosses. The correlations between the predicted means of the lines and the phenotypic means of the testcrosses were not significant or low for most of the components. The coincidence of the selected lines and testcrosses was very low for all traits and the results were similar for both testcrosses and intensity. It is not possible to select testcrosses by using GY or its components information from the lines, even with the aid of molecular markers.  相似文献   

17.
Drought stress is thought to promote epicuticular wax accumulation on maize leaves, which reduces plant water loss. We evaluated 62 maize inbred lines and their hybrid testcross progeny for epicuticular wax accumulation on flag leaves at flowering under full and limited irrigation regimes. Extracted wax was measured as a percentage of wax weight to leaf weight (WLW) and leaf area (WLA). Eleven genotypes had above average WLW as both inbred lines and hybrid testcrosses. Thirteen genotypes had above average WLA as either inbred lines or hybrid testcrosses. The drought treatment did not significantly alter WLW or WLA. Heritability of WLW was 0.17 (inbred lines) and 0.58 (hybrid testcrosses). Heritability of WLA was 0.41 (inbred lines) and 0.59 (hybrid testcrosses), suggesting it is a better trait than WLW for epicuticular wax screening. Correlations (r) between inbred lines and their testcross progeny were 0.44 and 0.18, for WLW and WLA, respectively. Heritability of grain weight per ear and plot yield was highest in hybrid testcrosses, with no correlation between inbred and hybrid germplasm. It is not warranted to evaluate epicuticular wax accumulation as the sole drought tolerance mechanism. However, it may be a good secondary trait to observe in relation to grain yield production in hybrids tested under water‐limiting conditions.  相似文献   

18.
8个热带、亚热带玉米群体的配合力和 杂种优势分析   总被引：1，自引：0，他引：1  
【研究目的】对8个热带、亚热带玉米群体Pob45、Pob46、Pob501、Pob502、Pool33、Pool34、Pob25、Suwan1进行配合力及杂种优势分析。【方法】试验以自交系昌7-2、郑22、掖478、齐319、Mo17为测验种,采用NCⅡ遗传设计。【结果】Pob25和Pob502的产量一般配合力（GCA）较高,综合产量的一般配合力（GCA）、特殊配合力（SCA）和配合力总效应。【结论】得出塘四平头（昌7-2）×Pob501,塘四平头（昌7-2）×Pob25,Reid（掖478）×Pob25,塘四平头（昌7-2）×Suwan1,旅大红骨（郑22）×Pob502为5大杂优模式。  相似文献   

19.
Plant breeders have been trying to predict the performance of hybrids based on their parental performance. One application of molecular markers is its use in selection. The objectives were to map quantitative trait loci (QTL) and verify its congruence in maize lines and in their testcrosses and verify the possibility to select testcrosses from the predicted means of the lines by using information from markers. Two-hundred and fifty six lines and the testcrosses of these lines with two testers were evaluated in six environments, considering grain yield, plant lodging, days to anthesis and silking, anthesis-silking interval, plant and ear height and ear placement. QTL were mapped in the lines and in testcrosses and the predicted means of the lines were computed based on QTL effects and in all markers of the genome. The congruence of QTL detected in the lines and testcrosses were small for all traits. The correlations between the predicted means of the lines and the phenotypic means of the testcrosses ranged from low for grain yield to moderate for cycle and stature traits. The highest coincidences of the lines and selected testcrosses were observed for cycle and stature traits and the lowest for grain yield. Even by using molecular markers information, it is only possible to predict the testcrosses performance from the lines information to less complex traits and with reduced dominance effect. For complex traits and with pronounced dominance effect, information of markers must be obtained directly in the testcrosses, so they can be used for selection.  相似文献   

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