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1.
Natural DNA variation at candidate loci is associated with potato chip color, tuber starch content, yield and starch yield 总被引:1,自引:0,他引:1
Li L Paulo MJ Strahwald J Lübeck J Hofferbert HR Tacke E Junghans H Wunder J Draffehn A van Eeuwijk F Gebhardt C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(8):1167-1181
Complex characters of plants such as starch and sugar content of seeds, fruits, tubers and roots are controlled by multiple
genetic and environmental factors. Understanding their molecular basis will facilitate diagnosis and combination of superior
alleles in crop improvement programs (“precision breeding”). Association genetics based on candidate genes is one approach
toward this goal. Tetraploid potato varieties and breeding clones related by descent were evaluated for 2 years for chip
quality before and after cold storage, tuber starch content, yield and starch yield. Chip quality is inversely correlated
with tuber sugar content. A total of 36 loci on 11 potato chromosomes were evaluated for natural DNA variation in 243 individuals.
These loci included microsatellites and genes coding for enzymes that function in carbohydrate metabolism or transport (candidate
loci). The markers were used to analyze population structure and were tested for association with the tuber quality traits.
Highly significant and robust associations of markers with 1–4 traits were identified. Most frequent were associations with
chip quality and tuber starch content. Alleles increasing tuber starch content improved chip quality and vice versa. With
two exceptions, the most significant and robust associations (q < 0.01) were observed with DNA variants in genes encoding enzymes that function in starch and sugar metabolism or transport.
Comparing linkage and linkage disequilibrium between loci provided evidence for the existence of large haplotype blocks in
the breeding materials analyzed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Li Li Eckhard Tacke Hans-Reinhardt Hofferbert Jens Lübeck Josef Strahwald Astrid M. Draffehn Birgit Walkemeier Christiane Gebhardt 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(4):1039-1052
Tuber yield, starch content, starch yield and chip color are complex traits that are important for industrial uses and food processing of potato. Chip color depends on the quantity of reducing sugars glucose and fructose in the tubers, which are generated by starch degradation. Reducing sugars accumulate when tubers are stored at low temperatures. Early and efficient selection of cultivars with superior yield, starch yield and chip color is hampered by the fact that reliable phenotypic selection requires multiple year and location trials. Application of DNA-based markers early in the breeding cycle, which are diagnostic for superior alleles of genes that control natural variation of tuber quality, will reduce the number of clones to be evaluated in field trials. Association mapping using genes functional in carbohydrate metabolism as markers has discovered alleles of invertases and starch phosphorylases that are associated with tuber quality traits. Here, we report on new DNA variants at loci encoding ADP-glucose pyrophosphorylase and the invertase Pain-1, which are associated with positive or negative effect with chip color, tuber starch content and starch yield. Marker-assisted selection (MAS) and marker validation were performed in tetraploid breeding populations, using various combinations of 11 allele-specific markers associated with tuber quality traits. To facilitate MAS, user-friendly PCR assays were developed for specific candidate gene alleles. In a multi-parental population of advanced breeding clones, genotypes were selected for having different combinations of five positive and the corresponding negative marker alleles. Genotypes combining five positive marker alleles performed on average better than genotypes with four negative alleles and one positive allele. When tested individually, seven of eight markers showed an effect on at least one quality trait. The direction of effect was as expected. Combinations of two to three marker alleles were identified that significantly improved average chip quality after cold storage and tuber starch content. In F1 progeny of a single-cross combination, MAS with six markers did not give the expected result. Reasons and implications for MAS in potato are discussed. 相似文献
3.
C. M. Kreike A. A. Kok-Westeneng J. H. Vinke W. J. Stiekema 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(3-4):463-470
A backcross population, derived from the cross (S. tuberosumxS. spegazzinii)xS. tuberosum was used to map QTLs involved in nematode resistance, tuber yield and root development. Complete linkage maps were available for the interspecific hybrid parent as well as the S. tuberosum parent, and interval mapping for all traits was performed for both. Additionally, the intra- and inter-locus interactions of the QTLs were examined. The Gro1.2 locus, involved in resistance to G. rostochiensis pathotype Ro1, that was previously mapped in the S. tuberosumxS. spegazzinii F1 population, was located more precisely on chromosome 10. A new resistance locus, Gro1.4, also conferring resistance to G. rostochiensis pathotype Ro1, was found on chromosome 3. Different alleles of this locus originating from both parents contributed to the resistant phenotype, indicating multiallelism at this locus. No interlocus interactions were observed between these two resistance loci. For resistance to G. pallida no QTLs were detected. One minor QTL involved in tuber yield was located on chromosome 4. Two QTLs involved in root development and having large effects were mapped on chromosomes 2 and 6 and an epistatic interaction was found between these two loci. 相似文献
4.
Background
Recombinant inbred (RI) strains are an important resource for mapping complex traits in many species. While large RI panels are available for Arabidopsis, maize, C. elegans, and Drosophila, mouse RI panels typically consist of fewer than 30 lines. This is a severe constraint on the power and precision of mapping efforts and greatly hampers analysis of epistatic interactions. 相似文献5.
J. C. Cervantes-Flores B. Sosinski K. V. Pecota R. O. M. Mwanga G. L. Catignani V. D. Truong R. H. Watkins M. R. Ulmer G. C. Yencho 《Molecular breeding : new strategies in plant improvement》2011,28(2):201-216
Development of orange-fleshed sweetpotatoes (OFSP) is desired for the improvement of the food supply and nutritional status
of millions of people in developing countries, particularly in sub-Saharan Africa. However, sweetpotato [Ipomoea batatas (L.) Lam] breeding is challenging due to its genetic complexity, and marker-assisted breeding tools are needed to facilitate
crop improvement. We identified quantitative trait loci (QTL) for dry-matter, starch, and β-carotene content in a hexaploid
sweetpotato mapping population derived from a cross between Tanzania, a white-fleshed, high dry-matter African landrace, and
Beauregard, an orange-fleshed, low dry-matter sweetpotato cultivar popular in the USA. Two parental maps were constructed
using a population of 240 clones. Strong correlations were observed between starch and dry-matter content (r > 0.8, P < 0.0001) in the storage roots, while moderate correlations (r = –0.6, P < 0.0001) were observed for β-carotene and starch content. In both parental maps, QTL analysis revealed the presence of 13
QTL for storage root dry-matter content, 12 QTL for starch content, and 8 QTL for β-carotene content. Multiple QTL regression
models developed for segregation of alleles in each parent explained 15–24% of the variation in dry-matter content, 17–30%
of the starch content, and 17–35% of β-carotene content. To the best of our knowledge, this research presents the only QTL
mapping study published to date for dry-matter, starch, and β-carotene content in sweetpotato. This work improves our understanding
of the inheritance of these important traits in sweetpotato, and represents a first step toward the long-term goal of developing
marker-assisted breeding tools to facilitate sweetpotato breeding efforts. 相似文献
6.
H. W. Raadsma E. Jonas M. R. Fleet K. Fullard J. Gongora C. R. Cavanagh I. Tammen P. C. Thomson 《Animal genetics》2013,44(5):547-559
The pursuits of white features and white fleeces free of pigmented fibre have been important selection objectives for many sheep breeds. The cause and inheritance of non‐white colour patterns in sheep has been studied since the early 19th century. Discovery of genetic causes, especially those which predispose pigmentation in white sheep, may lead to more accurate selection tools for improved apparel wool. This article describes an extended QTL study for 13 skin and fibre pigmentation traits in sheep. A total of 19 highly significant, 10 significant and seven suggestive QTL were identified in a QTL mapping experiment using an Awassi × Merino × Merino backcross sheep population. All QTL on chromosome 2 exceeded a LOD score of greater than 4 (range 4.4–30.1), giving very strong support for a major gene for pigmentation on this chromosome. Evidence of epistatic interactions was found for QTL for four traits on chromosomes 2 and 19. The ovine TYRP1 gene on OAR 2 was sequenced as a strong positional candidate gene. A highly significant association (P < 0.01) of grandparental haplotypes across nine segregating SNP/microsatellite markers including one non‐synonymous SNP with pigmentation traits could be shown. Up to 47% of the observed variation in pigmentation was accounted for by models using TYRP1 haplotypes and 83% for models with interactions between two QTL probabilities, offering scope for marker‐assisted selection for these traits. 相似文献
7.
Conditional QTL mapping of oil content in rapeseed with respect to protein content and traits related to plant development and grain yield 总被引:21,自引:4,他引:17
Zhao J Becker HC Zhang D Zhang Y Ecke W 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(1):33-38
Oil content in rapeseed (Brassica napus L.) is generally regarded as a character with high heritability that is negatively correlated with protein content and influenced by plant developmental and yield related traits. To evaluate possible genetic interrelationships between these traits and oil content, QTL for oil content were mapped using data on oil content and on oil content conditioned on the putatively interrelated traits. Phenotypic data were evaluated in a segregating doubled haploid population of 282 lines derived from the F1 of a cross between the old German cultivar Sollux and the Chinese cultivar Gaoyou. The material was tested at four locations, two each in Germany and in China. QTLMapper version 1.0 was used for mapping unconditional and conditional QTL with additive (a) and locus pairs with additive × additive epistatic (aa) effects. Clear evidence was found for a strong genetic relationship between oil and protein content. Six QTL and nine epistatic locus pairs were found, which had pleiotropic effects on both traits. Nevertheless, two QTL were also identified, which control oil content independent from protein content and which could be used in practical breeding programs to increase oil content without affecting seed protein content. In addition, six additional QTL with small effects were only identified in the conditional mapping. Some evidence was apparent for a genetic interrelationship between oil content and the number of seeds per silique but no evidence was found for a genetic relationship between oil content and flowering time, grain filling period or single seed weight. The results indicate that for closely correlated traits conditional QTL mapping can be used to dissect the genetic interrelationship between two traits at the level of individual QTL. Furthermore, conditional QTL mapping can reveal additional QTL with small effects that are undetectable in unconditional mapping. 相似文献
8.
Connected populations for detecting quantitative trait loci and testing for epistasis: an application in maize 总被引:19,自引:0,他引:19
Blanc G Charcosset A Mangin B Gallais A Moreau L 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(2):206-224
Quantitative trait loci (QTL) detection experiments have often been restricted to large biallelic populations. Use of connected multiparental crosses has been proposed to increase the genetic variability addressed and to test for epistatic interactions between QTL and the genetic background. We present here the results of a QTL detection performed on six connected F2 populations of 150 F2:3 families each, derived from four maize inbreds and evaluated for three traits of agronomic interest. The QTL detection was carried out by composite interval mapping on each population separately, then on the global design either by taking into account the connections between populations or not. Epistatic interactions between loci and with the genetic background were tested. Taking into account the connections between populations increased the number of QTL detected and the accuracy of QTL position estimates. We detected many epistatic interactions, particularly for grain yield QTL (R
2 increase of 9.6%). Use of connections for the QTL detection also allowed a global ranking of alleles at each QTL. Allelic relationships and epistasis both contribute to the lack of consistency for QTL positions observed among populations, in addition to the limited power of the tests. The potential benefit of assembling favorable alleles by marker-assisted selection are discussed. 相似文献
9.
10.
11.
Sukumar Saha Jixiang Wu Johnie N. Jenkins Jack C. McCarty Russell Hayes David M. Stelly 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(6):1193-1205
We recently released a set of 17 chromosome substitution (CS-B) lines (2n = 52) that contain Gossypium barbadense L. doubled-haploid line ‘3-79’ germplasm systematically introgressed into the Upland inbred ‘TM-1’ of G. hirsutum (L.). TM-1 yields much more than 3-79, but cotton from the latter has superior fiber properties. To explore the use of these
quasi-isogenic lines in studying gene interactions, we created a partial diallel among six CS-B lines and the inbred TM-1,
and characterized their descendents for lint percentage, boll weight, seedcotton yield and lint yield across four environments.
Phenotypic data on the traits were analyzed according to the ADAA genetic model to detect significant additive, dominance,
and additive-by-additive epistasis effects at the chromosome and chromosome-by-chromosome levels of CS-B lines. For example,
line 3-79 had the lowest boll weight, seedcotton yield and lint yield, but CS-B22Lo homozygous dominance genetic effects on
seedcotton and lint yield were nearly four times those of TM-1, and its hybrids with TM-1 had the highest additive-by-additive
epistatic effects on seedcotton and lint yield. CS-B14sh, 17, 22Lo and 25 produced positive homozygous dominance effects on
lint yield, whereas doubly heterozygous combinations of CS-B14sh with CS-B17, 22Lo and 25 produced negative dominance effects,
suggesting that epistatic effects between genes in these chromosomes strongly affect lint yield. The results underscore the
opportunities to systematically identify genomic regions harboring genes that impart agronomically significant effects via
epistatic interactions. The chromosome-by-chromosome approach significantly complements other strategies to detect and quantify
epistatic interaction effects, and the quasi-isogenic nature of families and lines from CS-B intermatings will facilitate
high-resolution localization, development of markers for selection and map-assisted identification of genes involved in strong
epistatic effects. 相似文献
12.
Grit Haseneyer Silke Stracke Hans-Peter Piepho Sascha Sauer Hartwig H Geiger Andreas Graner 《BMC plant biology》2010,10(1):5
Background
Association mapping is receiving considerable attention in plant genetics for its potential to fine map quantitative trait loci (QTL), validate candidate genes, and identify alleles of interest. In the present study association mapping in barley (Hordeum vulgare L.) is investigated by associating DNA polymorphisms with variation in grain quality traits, plant height, and flowering time to gain further understanding of gene functions involved in the control of these traits. We focused on the four loci BLZ1, BLZ2, BPBF and HvGAMYB that play a role in the regulation of B-hordein expression, the major fraction of the barley storage protein. The association was tested in a collection of 224 spring barley accessions using a two-stage mixed model approach. 相似文献13.
Genetic diversity and population structure of a diverse set of rice germplasm for association mapping 总被引:4,自引:0,他引:4
Liang Jin Yan Lu Peng Xiao Mei Sun Harold Corke Jinsong Bao 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(3):475-487
Germplasm diversity is the mainstay for crop improvement and genetic dissection of complex traits. Understanding genetic diversity,
population structure, and the level and distribution of linkage disequilibrium (LD) in target populations is of great importance
and a prerequisite for association mapping. In this study, 100 genome-wide simple sequence repeat (SSR) markers were used
to assess genetic diversity, population structure, and LD of 416 rice accessions including landraces, cultivars and breeding
lines collected mostly in China. A model-based population structure analysis divided the rice materials into seven subpopulations.
63% of the SSR pairs in these accessions were in LD, which was mostly due to an overall population structure, since the number
of locus pairs in LD was reduced sharply within each subpopulation, with the SSR pairs in LD ranging from 5.9 to 22.9%. Among
those SSR pairs showing significant LD, the intrachromosomal LD had an average of 25–50 cM in different subpopulations. Analysis
of the phenotypic diversity of 25 traits showed that the population structure accounted for an average of 22.4% of phenotypic
variation. An example association mapping for starch quality traits using both the candidate gene mapping and genome-wide
mapping strategies based on the estimated population structure was conducted. Candidate gene mapping confirmed that the Wx and starch synthase IIa (SSIIa) genes could be identified as strongly associated with apparent amylose content (AAC) and pasting temperature (PT), respectively.
More importantly, we revealed that the Wx gene was also strongly associated with PT. In addition to the major genes, we found five and seven SSRs were associated with
AAC and PT, respectively, some of which have not been detected in previous linkage mapping studies. The results suggested
that the population may be useful for the genome-wide marker–trait association mapping. This new association population has
the potential to identify quantitative trait loci (QTL) with small effects, which will aid in dissecting complex traits and
in exploiting the rich diversity present in rice germplasm. 相似文献
14.
Effects of chlorocholine chloride (CCC) on phytohormones and photosynthetic characteristics of Zhongshu 3, a potato (Solanum tuberosum L.) variety widely cultivated in south China, were studied by foliar CCC application on 24 and 28 days after emergence, that
is, at the tuber initiation stage. It was found that on 42 days after emergence, that is, at the tuber bulking stage, spraying
CCC increased indolacetic-3-acid (IAA) and zeatin (Z) contents but decreased abscisic acid (ABA) content in leaves. The content
ratios of IAA/Z, IAA/ABA, Z/ABA, and (IAA + Z)/ABA in leaves treated with CCC were higher than those of the control. CCC plays
a prominent regulating role in the photosynthesis of Zhongshu 3. The net photosynthetic rate (P
n), stomatal conductance (G
s), intercellular CO2 concentration (C
i), and transpiration rate (T
r) of treated leaves were superior to those of controls at the tuber bulking stage. CCC markedly increased tuber yield and
quality. The contents of sucrose and starch in tubers treated with CCC increased at the end of the vegetation period, whereas
the contents of reducing sugars and solanine decreased. CCC at 2.0 g L−1 was found to be the most effective concentration. Collectively, the results of this research identify phytohomonal metabolism
and photosynthetic physiology of potato leaves as processes affected early after application of CCC resulting in significantly
improved increases in tuber yield and quality. 相似文献
15.
Analysis of the genetic architecture of maize kernel size traits by combined linkage and association mapping 总被引:1,自引:0,他引:1
Min Liu Xiaolong Tan Yan Yang Peng Liu Xiaoxiang Zhang Yinchao Zhang Lei Wang Yu Hu Langlang Ma Zhaoling Li Yanling Zhang Chaoying Zou Haijian Lin Shibin Gao Michael Lee Thomas Lübberstedt Guangtang Pan Yaou Shen 《Plant biotechnology journal》2020,18(1):207-221
Kernel size‐related traits are the most direct traits correlating with grain yield. The genetic basis of three kernel traits of maize, kernel length (KL), kernel width (KW) and kernel thickness (KT), was investigated in an association panel and a biparental population. A total of 21 single nucleotide polymorphisms (SNPs) were detected to be most significantly (P < 2.25 × 10?6) associated with these three traits in the association panel under four environments. Furthermore, 50 quantitative trait loci (QTL) controlling these traits were detected in seven environments in the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population, of which eight were repetitively identified in at least three environments. Combining the two mapping populations revealed that 56 SNPs (P < 1 × 10?3) fell within 18 of the QTL confidence intervals. According to the top significant SNPs, stable‐effect SNPs and the co‐localized SNPs by association analysis and linkage mapping, a total of 73 candidate genes were identified, regulating seed development. Additionally, seven miRNAs were found to situate within the linkage disequilibrium (LD) regions of the co‐localized SNPs, of which zma‐miR164e was demonstrated to cleave the mRNAs of Arabidopsis CUC1, CUC2 and NAC6 in vitro. Overexpression of zma‐miR164e resulted in the down‐regulation of these genes above and the failure of seed formation in Arabidopsis pods, with the increased branch number. These findings provide insights into the mechanism of seed development and the improvement of molecular marker‐assisted selection (MAS) for high‐yield breeding in maize. 相似文献
16.
Peng Wang Yongzhong Xing Zhikang Li Sibin Yu 《Molecular breeding : new strategies in plant improvement》2012,29(4):903-913
To facilitate marker-assisted transfer of desirable genes for improvement of yield traits, we used a set of backcross recombinant
inbred lines (BRIL) derived from two elite parental lines, ‘Zhenshan97’ and ‘93-11’, to resolve a quantitative trait loci
(QTL) cluster for heading date and yield-related traits in rice. Four main-effect QTL (qHD6.1, qHD6.2, qHD7, and qHD8) and four epistatic QTL affecting heading date in the BRIL were detected in two experimental trials. The major QTL (qHD8) was confirmed in three heterogeneous inbred families (HIF) that segregated for this target region, and narrowed down to
a 20-kb segment in a large HIF-derived population. qHD8 was found to interact with qHD7 and had a pleiotropic effect responsible for heading date and yield components. To test usability of the identified QTL in
rice improvement, we further developed near-isogenic lines (NIL) containing one or more target genes by marker-assisted transfer
of ‘93-11’ alleles at qHD8, qHD7, and qHD6.1, and the GS3 gene for grain size into ‘Zhenshan97’. The pyramid line NIL(qHD8 + GS3) had higher yield potential, longer grains, and a more suitable heading date than ‘Zhenshan97’. Comparison of the NIL showed
existence of epistasis between alleles at different loci and background effect on qHD8, which are very important for pyramiding of desirable alleles at the target QTL. These results will be particularly useful
not only to understand the genetic basis of yield-related traits but also to improve the efficiency of marker-assisted selection
for favorable loci in rice breeding programs. 相似文献
17.
Qingzhang Du Xiaohui Yang Jianbo Xie Mingyang Quan Liang Xiao Wenjie Lu Jiaxing Tian Chenrui Gong Jinhui Chen Bailian Li Deqiang Zhang 《Plant biotechnology journal》2019,17(3):608-624
In perennial woody plants, the coordinated increase of stem height and diameter during juvenile growth improves competitiveness (i.e. access to light); however, the factors underlying variation in stem growth remain unknown in trees. Here, we used linkage‐linkage disequilibrium (linkage‐LD) mapping to decipher the genetic architecture underlying three growth traits during juvenile stem growth. We used two Populus populations: a linkage mapping population comprising a full‐sib family of 1,200 progeny and an association mapping panel comprising 435 unrelated individuals from nearly the entire natural range of Populus tomentosa. We mapped 311 quantitative trait loci (QTL) for three growth traits at 12 timepoints to 42 regions in 17 linkage groups. Of these, 28 regions encompassing 233 QTL were annotated as 27 segmental homology regions (SHRs). Using SNPs identified by whole‐genome re‐sequencing of the 435‐member association mapping panel, we identified significant SNPs (P ≤ 9.4 × 10?7) within 27 SHRs that affect stem growth at nine timepoints with diverse additive and dominance patterns, and these SNPs exhibited complex allelic epistasis over the juvenile growth period. Nineteen genes linked to potential causative alleles that have time‐specific or pleiotropic effects, and mostly overlapped with significant signatures of selection within SHRs between climatic regions represented by the association mapping panel. Five genes with potential time‐specific effects showed species‐specific temporal expression profiles during the juvenile stages of stem growth in five representative Populus species. Our observations revealed the importance of considering temporal genetic basis of complex traits, which will facilitate the molecular design of tree ideotypes. 相似文献
18.
Association mapping for Fusarium head blight resistance in European soft winter wheat 总被引:1,自引:0,他引:1
Thomas Miedaner Tobias Würschum Hans P. Maurer Viktor Korzun Erhard Ebmeyer Jochen C. Reif 《Molecular breeding : new strategies in plant improvement》2011,28(4):647-655
Resistance to Fusarium head blight (FHB) is of great importance in wheat breeding programs in the northern hemisphere. In
Europe, breeders prefer adapted germplasm as resistance donor because of high grain yield and quality demands. Our objective
was to identify chromosomal regions affecting FHB resistance among 455 European soft winter wheat (Triticum aestivum L.) lines using a genome-wide association mapping approach and to analyze the importance of epistatic interactions. All entries
were evaluated for FHB resistance by inoculation in two environments and several ratings. Wheat was genotyped by 115 simple
sequence repeat markers randomly distributed across the genome and two allele-specific markers for Rht-B1 and Rht-D1 genes. The genome-wide scan revealed nine significant (P < 0.05) marker–phenotype associations on seven chromosomes including dwarfing gene Rht-D1. Using a Bonferroni–Holm correction, three significant associations remained on chromosomes 1B, 1D, and 2D. The proportion
of the genotypic variance explained simultaneously by individual markers was 36% and increased to 50% when two digenic epistatic
interactions were considered, one of them associated with Rht-B1. In conclusion, new genomic regions on chromosomes 1D and 3A could be found for FHB resistance in European wheat and the
effect of epistatic interactions was substantial. 相似文献
19.
20.
Genetic control of yield related stalk traits in sugarcane 总被引:1,自引:0,他引:1
Aitken KS Hermann S Karno K Bonnett GD McIntyre LC Jackson PA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(7):1191-1203
A major focus of sugarcane variety improvement programs is to increase sugar yield, which can be accomplished by either increasing
the sugar content of the cane or by increasing cane yield, as the correlation between these traits is low. We used a cross
between an Australian sugarcane variety Q165, and a Saccharum officinarum accession, IJ76-514, to dissect the inheritance of yield-related traits in the complex polyploid sugarcane. A population
of 227 individuals was grown in a replicated field trial and evaluated over 3 years for stalk weight, stalk diameter, stalk
number, stalk length and total biomass. Over 1,000 AFLP and SSR markers were scored across the population and used to identify
quantitative trait loci (QTL). In total, 27 regions were found that were significant at the 5% threshold using permutation
tests with at least one trait; individually, they explained from 4 to 10% of the phenotypic variation and up to 46% were consistent
across years. With the inclusion of digeneic interactions, from 28 to 60% of the variation was explained for these traits.
The 27 genomic regions were located on 22 linkage groups (LGs) in six of the eight homology groups (HGs) indicating that a
number of alleles or quantitative trait alleles (QTA) at each QTL contribute to the trait; from one to three alleles had an
effect on the traits for each QTL identified. Alleles of a candidate gene, TEOSINTE BRANCHED 1 (TB1), the major gene controlling branching in maize, were mapped in this population using either an SSR or SNP markers. Two alleles
showed some association with stalk number, but unlike maize, TB1 is not a major gene controlling branching in sugarcane but only has a minor and variable effect. 相似文献