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1.
为了扩增优质蛋白玉米育种新种质,用普通玉米种质转育创制优质蛋白玉米(QPM)近等基因系;利用SSR标记phi057进行辅助选择,以优质蛋白玉米种质为o2基因供体,转导、构建来自不同遗传背景普通玉米种质为受体的QPM近等基因系。结果表明：利用共显性SSR标记引物phi057在o2基因供体自交系与普通玉米受体自交系间表现多态性,能区分O2O2、O2o2和o2o2等3种基因型,来自不同遗传背景种质所构建获得的QPM近等基因系赖氨酸含量有不同程度提高,赖氨酸含量达到0.36%~0.42%,不同遗传背景受体自交系赖氨酸增加幅度9.1%~64.0%。普通玉米种质导入供体o2基因后能够提高种质赖氨酸含量。  相似文献   

2.
Vivek Maize Hybrid 9‐ a popular single‐cross hybrid developed by crossing CM 212 and CM 145 was released for commercial cultivation in India. The parental lines, being deficient in lysine and tryptophan, were selected for introgression of opaque‐2 allele using CML 180 and CML 170 as donor lines through marker‐assisted backcross breeding. The opaque‐2 homozygous recessive genotypes with >90% recovery of the recurrent parent genome were selected in BC2F2, and the seeds with <25% opaqueness in BC2F3 were forwarded for seed multiplication. Vivek Quality Protein Maize (QPM) 9, the improved QPM hybrid, showed 41% increase in tryptophan and 30% increase in lysine over the original hybrid. The grain yield of the improved hybrid was on par with the original hybrid. The newly improved QPM maize hybrid released in 2008 will help in reducing the protein malnutrition because its biological value is superior over the normal maize hybrids. This short duration QPM maize hybrid has been adopted in several hill states of North Western and North Eastern Himalayan regions.  相似文献   

3.
The number of drought and low-N tolerant hybrids with elevated levels of provitamin A (PVA) in sub-Saharan Africa could increase when PVA genes are optimized and validated for developed drought and low-N tolerant inbred lines. This study aimed to (a) determine the levels of drought and low-N tolerance, and PVA concentrations in early maturing PVA-quality protein maize (QPM) inbred lines, and (b) identify lines harbouring the crtRB1 and LcyE genes as sources of favourable alleles of PVA. Seventy early maturing PVA-QPM inbreds were evaluated under drought, low-N and optimal environments in Nigeria for two years. The inbreds were assayed for PVA levels and the presence of PVA genes using allele-specific PCR markers. Moderate range of PVA contents was observed for the inbreds. Nonetheless, TZEIORQ 55 combined high PVA concentration with drought and low-N tolerance. The crtRB1-3′TE primer and the KASP SNP (snpZM0015) consistently identified nine inbreds including TZEIORQ 55 harbouring the favourable alleles of the crtRB1 gene. These inbreds could serve as donor parents of the favourable crtRB1-3′TE allele for PVA breeding in maize.  相似文献   

4.
A collection of Portuguese maize accessions representing a valuable source of genes for introduction into modern cultivars is stored at the Portuguese Plant Germplasm Bank (Banco Português de Germoplasma Vegetal—BPGV). To assess genetic diversity among inbreds, microsatellite analysis was carried out for 54 inbred lines representing the diversity of Portuguese dent and flint maize germplasm. Fifty American and other European elite inbreds were also analysed for comparison. Fifteen microsatellite loci distributed throughout the maize genome were chosen based on their repeat unit and base composition. A total of 80 alleles were detected with an average allele number of 5.33 per locus. Polymorphism information content (PIC) values and observed genetic distances showed the existence of large variability among inbreds. Cluster analysis indicated that almost all of the inbreds could be distinguished from each other and Portuguese inbreds were present in all clusters formed. These associations were consistent with the known pedigree records of the inbreds, confirming a mixed origin of Portuguese materials. Comparative analysis of microsatellite diversity among groups was established according to important traits for both breeding and line identification. This revealed that, although most of the genetic diversity (>95%) was attributable to differences among inbreds of different groups, the existence of phenotypic differentiation in endosperm colour, kernel type and cob colour could be suggested for grouping. These findings support the joint use of molecular and morphological traits in management of the germplasm collection. In this study, SSR markers proved to be effective to characterise and identify maize inbred lines, and demonstrate associations among them. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

5.
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   

6.
Modifier loci in QPM play a vital role in achieving acceptable degree of kernel hardness and accumulation of lysine and tryptophan. This study was undertaken to characterize a set of diverse QPM inbreds using SSRs linked to endosperm and amino acids modifier loci for their effective utilization in the breeding programme. Significant variation was observed for endosperm modification (25–100% opaqueness), tryptophan (0.056–0.111%) and lysine (0.223–0.444%). Generally, inbreds with soft endosperm possessed more tryptophan and lysine than inbreds with higher vitreousness. SSRs generated 341 alleles with two to seven alleles per locus. The frequency of unique and rare alleles was more for amino acid modifications, compared to endosperm modifications. Phylogenetic analyses grouped the inbreds into three major clusters, and the study identified suitable crosses for accumulation of endosperm and amino acids modifiers. QPM inbreds with desirable modifications identified here would serve as suitable donor for both opaque2 and modifier loci in the marker‐assisted backcross breeding. Further, contrasting inbreds can be used for generating mapping populations to identify new modifier loci underlying both endosperm and amino acids modifications.  相似文献   

7.
SSR标记对宁单11种子纯度的鉴定   总被引：3，自引：0，他引：3  
采用SSR分子标记方法,选用24对引物,以杂交玉米宁单11杂交种子及其父母本为实验材料,对宁单11种子纯度进行鉴定。通过带型分析,筛选出在杂交种中呈现清晰且双亲互补带型的特异性引物,并依据特异性引物的筛选标记结果对抽样批次的宁单11种子样本进行纯度鉴定。结果表明:phi034、phi080、umc1638、bnlg439、bnlg1792五对SSR引物可用于玉米杂交种宁单11种子纯度鉴定。  相似文献   

8.
利用SSR标记鉴定‘苏玉30’杂交种遗传纯度研究   总被引：2，自引：0，他引：2  
为了快速鉴定高产优质玉米杂交种‘苏玉30’的遗传纯度,以‘苏玉30’及‘YJ7’和‘HL40’2个亲本、‘苏玉10’、‘苏玉22’、‘苏玉29’、‘苏玉32’、‘郑单958’、‘登海9’号为供试材料,进行SSR标记分析。结果发现,从40个SSR标记中筛选出在‘苏玉30’及双亲之间扩增带型稳定、多态性明显的5个SSR标记（phi053k2、bnlg2291k4、bnlg2305k4、bnlg161k8、umc2084w2）,可用于‘苏玉30’的鉴定,此外,利用其中的单个标记（bnlg2291k4或bnlg2305k）或2-3个标记组合（phi053k2与bnlg161k8组合、umc2084w2与bnlg161k8组合、phi053k2与umc2084w2组合）可将‘苏玉30’与另外6个杂交种区分开。筛选出的5对SSR标记对‘苏玉30’的鉴定结果与田间鉴定结果高度一致。因此,利用SSR标记鉴定玉米杂交种遗传纯度具有快速、准确、实用性强等优点,为生产上快速鉴定‘苏玉30’遗传纯度提供了参考依据。  相似文献   

9.
A.K. Joshi  R. Chand  B. Arun 《Euphytica》2002,123(2):221-228
A total of 1,407 spring wheat (T. aestivum) lines of Indian and CIMMYT (International Maize and Wheat Improvement Centre, Mexico) origin were evaluated for plant height, days to maturity and resistance to spot blotch (caused by Bipolaris sorokiniana) during the 1994–95, 1995–96 and 1996–97 crop seasons. The frequency distribution of genotypes, based on disease score ignoring the growth stages, differed from the distribution in which disease score was assessed on a similar growth stage. Two crosses each,between `tall resistant × dwarf susceptible' and `late resistant × early susceptible' genotypes, were made. The evaluation of homozygous resistant lines in the F3, F4 and F5 generations of both crosses showed a wide range of plant height and days to maturity. These lines showed significant differences for plant height and days to maturity but did not show a significant difference for AUDPC values of spot blotch. The correlation coefficients for AUDPC versus plant height or days to maturity were weak, i.e., – 0.336 and 0.061, respectively. Results indicated that resistance to spot blotch severity was independent of plant height and days to maturity in progenies from these crosses.  相似文献   

10.
In order to identify quantitative trait loci (QTL) for the eating quality of waxy corn and sweet corn (Zea mays L.), QTL analysis was conducted on an F2 population derived from a cross between a waxy corn inbred line and a sweet corn inbred line. Ten QTLs for pericarp thickness (PER), amylose content (AMY), dextrose content (DEX) and sucrose content (SUC) were found in the 158 F2 families. Among them, four QTLs, qAMY4 (10.43%), qAMY9 (19.33%), qDEX4 (21.31%) and qSUC4 (30.71%), may be considered as major QTLs. Three of these, qAMY4, qDEX4 and qSUC4, were found to be located within a region flanked by two adjacent SSR markers on chromosome 4 (umc1088 and bnlg1265), making this SSR marker pair a useful selection tool for screening the eating quality traits of AMY, DEX and SUC. The QTL for amylose content was found to be located between markers phi027 and umc1634, raising the possibility of its identity being the Wx1 gene, which encodes a granule-bound amylose synthase. The new QTLs identified by the present study could serve as useful molecular markers for selecting important eating quality traits in subsequent waxy corn breeding studies.  相似文献   

11.
opaque-2玉米近等基因系的构建与赖氨酸含量快速检测   总被引：2，自引：0，他引：2  
我国高赖氨酸玉米种质资源狭窄,opaque-2(o2)突变基因能大幅提高玉米赖氨酸含量,通过分子标记辅助选择构建o2玉米近等基因系并检测其赖氨酸含量具有重要意义。其中,要解决的两个关键问题是如何准确地将不同供体的o2突变基因导入受体系和如何快速地检测导入系的赖氨酸含量。本研究利用O2基因内紧密连锁的SSR共显性标记引物phi057检测玉米供体和受体自交系的多态性,利用其特异性和共显性构建o2近等基因系;参考已有研究,改进染料结合(DBL)法,测定18组构建成功的o2近等基因系的赖氨酸含量。结果表明,不仅在不同供体(CA339和山东2548)之间存在多态性,而且在不同受体系间也存在多态性,利用phi057能够成功地将不同供体的o2突变基因导入受体系,构建o2近等基因系;改进的DBL法分析表明,不同受体系赖氨酸含量变化较大,不同背景的受体系导入o2突变基因后赖氨酸含量增加的幅度差异也较大;普通玉米自交系间赖氨酸含量为0.223%~0.368%,构建成功的不同o2近等基因系间,赖氨酸含量为0.373%~0.527%,与受体亲本相比,赖氨酸增加幅度最低为13%,最高为74%。分析表明,phi057能准确筛选导入o2突变基因的受体系,结合改进的DBL法能快速地选择赖氨酸含量高的玉米。  相似文献   

12.
There is a need to develop the next generation of healthier crop products for an improved human and animal nutrition. Maize (Zea mays L.) cultivars with improved amino acid profiles are essential to diets focused on this crop. Breeders have added crop value with the development of quality protein maize (QPM). However, QPM cultivars have never been an option to farmer and ranchers in short-season environments. The objectives of this research were: (1) to adapt QPM genotypes to the northern U.S. through the North Dakota (ND) EarlyQPM Program, and (2) to develop new early generation SS and non-SS short-season QPM lines and populations for breeding purposes. Fifty-three inbred lines, including 47 QPM donor lines, five experimental North Dakota State University (NDSU) lines, and one ex-PVP line from industry, were selected to produce 94 early-QPM backcross populations. Considering earliness, protein content, and amino acid levels, 218 early generation lines were selected for producing testcrosses with industry testers. Experiments evaluating testcrosses were arranged in 10 × 10 and 12 × 12 partially balanced lattice designs across three ND locations in 2013 and 2014. A total of 48 lines were selected for further development, 17 representing the Stiff Stalk (SS) heterotic group and 31 representing the non-SS group. Selected lines showed, in hybrid combinations, not only above average grain yield, rate of dry down, and total protein content but also high levels of lysine, tryptophan, and methionine essential amino acids for feedstock nutrition. The results of this research show, for the first time, the successful adaptation of QPM genotypes to short-season environments. As a result, new ND EarlyQPM germplasms and lines have been developed for potential release.  相似文献   

13.
Maize (Zea mays L.) is an important source of carbohydrates and protein in the diet in sub-Saharan Africa. The objectives of this study were to (i) estimate general (GCA) and specific combining abilities (SCA) of 13 new quality protein maize (QPM) lines in a diallel under stress and non-stress conditions, (ii) compare observed and predicted performance of QPM hybrids, (iii) characterize genetic diversity among the 13 QPM lines using single nucleotide polymorphism (SNP) markers and assess the relationship between genetic distance and hybrid performance, and (iv) assess diversity and population structure in 116 new QPM inbred lines as compared to eight older tropical QPM lines and 15 non-QPM lines. The GCA and SCA effects were significant for most traits under optimal conditions, indicating that both additive and non-additive genetic effects were important for inheritance of the traits. Additive genetic effects appeared to govern inheritance of most traits under optimal conditions and across environments. Non-additive genetic effects were more important for inheritance of grain yield but additive effects controlled most agronomic traits under drought stress conditions. Inbred lines CKL08056, CKL07292, and CKL07001 had desirable GCA effects for grain yield across drought stress and non-stress conditions. Prediction efficiency for grain yield was highest under optimal conditions. The classification of 139 inbred lines with 95 SNPs generated six clusters, four of which contained 10 or fewer lines, and 16 lines of mixed co-ancestry. There was good agreement between Neighbor Joining dendrogram and Structure classification. The QPM lines used in the diallel were nearly uniformly spread throughout the dendrogram. There was no relationship between genetic distance and grain yield in either the optimal or stressed environments in this study. The genetic diversity in mid-altitude maize germplasm is ample, and the addition of the QPM germplasm did not increase it measurably.  相似文献   

14.
优质蛋白玉米（QPM）是过去植物育种领域中取得最意想不到的成就之一，它的赖氨酸和色氨酸含量比普通玉米高，从而改善玉米蛋白质品质，因此其营养价值优于普通玉米。文章回顾了优质蛋白玉米的发展历史以及中国优质蛋白玉米研究的发展历程，提出政府支持，重视科技投入，加强研究力度，实施多学科合作尤其是现代生物技术的引进利用，加强种质资源创新与利用研究，把普通玉米自交系和杂种优势群转育为优质蛋白玉米资源，挖掘新的种质源，探索新的检测方法和应用领域，形成科研——种植——加工业——养殖业产业链联合开发是中国优质蛋白玉米研究的发展方向。  相似文献   

15.
Genetic diversity of four new yellow single crosses, five new yellow three-way crosses, and five yellow inbred lines of maize (Zea mays L.) was studied using different molecular (SSR, ISSR, and RAPD) and biochemical markers (seed storage protein content). All markers were able to clearly separate the inbred lines in one cluster from the different types of hybrids. The correlation among the different types of molecular markers was moderately high according to the Mantel’s test (e.g. 0.67 between SSR and ISSR, 0.42 between SSR and RAPD, and 0.65 between ISSR and RAPD), indicating that the three techniques are efficient for evaluating genetic diversity in the maize genotypes. The correlation of biochemical markers (seed storage protein SDS-PAGE) with SSR, ISSR, and RAPD markers was 0.61, 0.74, and 0.48, respectively. It can be concluded that both molecular and biochemical markers are efficient to study the genetic diversity in maize. Among the different types of molecular markers, SSR is a more accurate marker-type because of its co-dominance and stability of results. It can also be said that biochemical and molecular markers are positively correlated and the correlation ranged between moderate to high. This could suggest using both marker types, separately or together, for genetic diversity studies in maize.  相似文献   

16.
The comparison of different methods of estimating genetic diversity could define their usefulness in plant breeding and genetic improvement programs. This study evaluates and compares the genetic diversity of 70 spring wheat accessions representing a broad genetic pool based on molecular markers and parentage relationships. The sample was composed of 32 accessions from the International Maize and Wheat Improvement Center (CIMMYT) and 38 from other breeding programs worldwide. Eight AFLP-primer combinations and 37 pairs of SSR primers were used to characterize the accessions and the Coefficients of Parentage (COP) were calculated from registered pedigrees. The average genealogical (COP) similarity (0.09 with a range of 0.0–1.0) was low in comparison to similarity calculated using SSR markers (0.41 with a range of 0.15–0.88) and AFLP markers (0.70 with a range of 0.33–0.98). Correlation between the genealogical similarity matrix (excluding accessions with COPs = 0) and the matrices of genetic similarity based on molecular markers was 0.34≤r≤0.46 (p <0.05). It is concluded that AFLP and SSR markers are generally in agreement with estimates of diversity measured using COPs, especially when complete pedigree data are available. However, markers may provide a more correct estimate due to some unrealistic assumptions made when calculating COPs, such as absence of selection. Furthermore, both COP and marker distances indicate that CIMMYT accessions are different from the worldwide group of accessions. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

17.
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18.
Maize is an important food and feed crop worldwide. Phytic acid (PA), in maize kernel, is an antinutritional factor. PA chelates mineral cations and causes mineral deficiency in humans and phosphorous deficiency in animals. The undigested PA excreted by monogastric animals causes phosphorous eutrophication. Therefore, development of low‐phytate maize is indispensable. The low‐phytate locus (lpa2 allele) has been transferred from low‐phytate mutant line ‘EC 659418’ into an elite inbred UMI 395 through marker‐assisted backcross breeding (MABB). The MABB involved three backcrosses followed by two selfing steps, including ‘foreground selection’, that is, selecting lines with lpa2 allele with the help of a codominant SSR marker ‘umc2230’ and ‘background selection’, that is, selecting plants having genetic background similar to that of the recurrent parent using 50 codominant SSR markers. Two low‐phytate lpa2 lines with genome similar (>90% similarity) to that of recurrent parent have been identified. These lines can be used as parent in future hybridization programmes for obtaining low‐phytate high‐yielding maize hybrids.  相似文献   

19.
Root lodging is an important problem in corn fields. Fungi recovered from roots include seedling blight and stalk rot pathogens. The objective of this work was to study the inheritance of maize seedling resistance to pathogens causing maize lodging. The Fusarium graminearum strain, 241 Fr1, was isolated from maize lodged plants and identified as the most pathogenic isolate for root rotting. Nine inbred lines of maize and their diallel F1 crosses plus control genotypes were studied. Seedlings were inoculated at the stage of four-leaves. Disease severity was measured as percentage of the root rotted area. Highly significant differences between inoculated and non-inoculated genotypes were found. Four genetic models and two statistical approaches—the mixed model for the best linear unbiased prediction (BLUP) and the general linear model (GLM)—were used for the analysis. Favorable heterosis of resistance of hybrids over inbreds was the most important effect detected. The general combining ability (GCA) effects were significant for all genetic models and statistical methods studied, and a good agreement existed among the GCA estimates by the different methods. The type of gene action, either additive or dominance, showed a large variation among the parental inbreds and hybrids. Selection of additive effects based exclusively on inbred lines is not sufficient to confer resistance to hybrids, additional selection should be practiced on hybrids to look for favorable dominance effects. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

20.
Simple sequence repeat (SSR) or microsatellite markers are a valuable tool for several purposes such as evaluation of genetic diversity, fingerprinting, marker‐assisted selection and breeding. In this study, a SSR genomic enriched library was developed in Lathyrus sativus (grass pea) by affinity capture of restriction fragments to biotinylated microsatellite oligonucleotides. About 400 randomly selected clones were sequenced, and SSRs were present in approximately 30% of them. Clones contained 75%, 9% and 16% of simple, interrupted and compound SSRs, respectively. Of the 10 SSRs tested, 7 primer pairs produced clearly distinguishable DNA banding patterns. Successively, SSR primer pairs were successfully tested to reveal polymorphism in a set of four different grass pea germplasm accessions. The transferability of SSR markers was high among three related species of Lathyrus, namely Lathyrus cicera, Lathyrus ochrus and Lathyrus tingitanus, and the legume crop, Pisum sativum. These results indicate that the novel SSR markers are informative and will be useful and convenient for genetic analysis in grass pea and related species.  相似文献   

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