共查询到20条相似文献,搜索用时 15 毫秒
1.
Dongfang Cai Yingjie Xiao Wei Yang Wei Ye Bo Wang Muhammad Younas Jiangsheng Wu Kede Liu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(1):85-96
Yield is one of the most important traits for rapeseed (Brassica napus L.) breeding, but its genetic basis remains largely ambiguous. Association mapping has provided a robust approach to understand the genetic basis of complex agronomic traits in crops. In this study, a panel of 192 inbred lines of B. napus from all over the world was genotyped using 451 single-locus microsatellite markers and 740 amplified fragment length polymorphism markers. Six yield-related traits of these inbred lines were investigated in three consecutive years with three replications, and genome-wide association studies were conducted for these six traits. Using the model controlling both population structure and relative kinship (Q + K), a total of 43 associations (P < 0.001) were detected using the means of the six yield-related traits across 3 years, with two to fourteen markers associated with individual traits. Among these, 18 markers were repeatedly detected in at least 2 years, and 12 markers were located within or close to QTLs identified in previous studies. Six markers commonly associated with correlated traits. Conditional association analysis indicated that five of the associations between markers and correlated traits are caused by one QTL with pleiotropic effects, and the remaining association is caused by linked but independent QTLs. The combination of favorable alleles of multiple associated markers significantly enhances trait performance, illustrating a great potential of utilization of the associations in rapeseed breeding programs. 相似文献
2.
Guolan Liu Hanwei Mei Hongyan Liu Xinqiao Yu Guihua Zou Lijun Luo 《Molecular breeding : new strategies in plant improvement》2010,25(4):603-613
A lowland rice variety (Zhenshan97B) was crossed with an upland variety (IRAT109) to construct a set of recombinant inbred lines (RILs). The population was evaluated under both well-watered (control) and drought-stress (drought) conditions for 2 years. Panicle water potential (PWP), panicle length (PL), grain number per plant (GNP), primary branch number (PBN), second branch number (SBN), spikelet density (SPD), and dry grain weight per plant (DGW) were measured. Phenotypic correlation and path analysis were used to interpret the ranking of importance of other panicle traits to grain yield. Comparison of such rankings under control and drought conditions showed varied responses of panicle traits to drought stress. It was indicated that GNP was an important contributor to DGW under control, and even more important under drought. Thirty-two quantitative trait loci (QTLs) for panicle traits and dry grain weight were identified, with contribution rates ranging from 3.33% to 22.66%. Eleven epistatic QTLs were detected. Cases of collocated QTLs under control and drought were found for PL, SPD, GNP, PBN, and SBN, but not for DGW and PWP. The effectiveness of selection under normal and stressed conditions is discussed. 相似文献
3.
Touming Liu Shouwei Tang Siyuan Zhu Qingming Tang 《Molecular breeding : new strategies in plant improvement》2014,34(3):883-892
Ramie fiber extracted from stem bast is one of the most important natural fibers. The fiber yield of ramie is a valuable trait and is decided by several components, including stem number per plant (SN), the fiber yield per stem (FYPS), stem length (SL), stem diameter (SD), and bark thickness (BT). All of these fiber yield-related traits are inherited in a quantitative manner. The genetic basis for these traits is still uncharacterized, which has hindered the improvement of yield traits through selective ramie breeding. In this study, an F2 population derived from two ramie varieties, Zhongzhu 1 and Qingyezhuma, with striking differences in fiber yield-related traits, was used for cutting propagation and to develop an F2 agamous line (FAL) population. A genetic linkage map with 132 DNA loci spanning 2,265.1 cM was first constructed. The analysis of quantitative trait locus (QTL) for fiber yield-related traits was performed in ramie for the first time. Finally, a total of 6, 9, 5, 7, and 6 QTLs for FYPS, SL, SN, SD, and BT, respectively, were identified in the FAL population in two environments. Among these 33 QTLs, 9 QTLs were detected in both environments and 24 QTLs exhibited overdominance. The overdominance of these QTLs possibly contributed to the heterosis of these yield-related traits in ramie. Moreover, there were 7 QTL clusters identified. The identification of the QTLs for fiber yield-related traits will be helpful for improving the fiber yield in ramie breeding programs. 相似文献
4.
Amukelani Lacrecia Shiringani Matthias Frisch Wolfgang Friedt 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(2):323-336
The productivity of sorghum is mainly determined by quantitative traits such as grain yield and stem sugar-related characteristics. Substantial crop improvement has been achieved by breeding in the last decades. Today, genetic mapping and characterization of quantitative trait loci (QTLs) is considered a valuable tool for trait enhancement. We have investigated QTL associated with the sugar components (Brix, glucose, sucrose, and total sugar content) and sugar-related agronomic traits (flowering date, plant height, stem diameter, tiller number per plant, fresh panicle weight, and estimated juice weight) in four different environments (two locations) using a population of 188 recombinant inbred lines (RILs) from a cross between grain (M71) and sweet sorghum (SS79). A genetic map with 157 AFLP, SSR, and EST-SSR markers was constructed, and several QTLs were detected using composite interval mapping (CIM). Further, additive × additive interaction and QTL × environmental interaction were estimated. CIM identified more than five additive QTLs in most traits explaining a range of 6.0–26.1% of the phenotypic variation. A total of 24 digenic epistatic locus pairs were identified in seven traits, supporting the hypothesis that QTL analysis without considering epistasis can result in biased estimates. QTLs showing multiple effects were identified, where the major QTL on SBI-06 was significantly associated with most of the traits, i.e., flowering date, plant height, Brix, sucrose, and sugar content. Four out of ten traits studied showed a significant QTL × environmental interaction. Our results are an important step toward marker-assisted selection for sugar-related traits and biofuel yield in sorghum. 相似文献
5.
Honghao Lv Qingbiao Wang Yangyong Zhang Limei Yang Zhiyuan Fang Xiaowu Wang Yumei Liu Mu Zhuang Yan Lin Hailong Yu Bo Liu 《Molecular breeding : new strategies in plant improvement》2014,34(1):87-98
Cabbage heading traits are important quantitative traits that greatly affect both quality and yield of cabbage. However, the genetic control of these traits remains unclear. To detect quantitative trait loci (QTLs) associated with heading traits, a double haploid (DH) population with 196 lines was created from a cabbage hybrid 01–20 × 96–100. A genetic map with insertion–deletion and simple sequence repeat markers was constructed based on the DH population, with a total length of 934.06 cM and average interval length of 2.3 cM between adjacent markers. Field experiments in three seasons were carried out to evaluate the heading traits, including head mature period (Hm), head weight (Hw), core length (Cl), head vertical diameter (Hvd), and the ratio of Cl to Hvd (Cl/Hvd). Using the map and the trait data, 13 reliable QTLs in total were identified and 5 were found in more than one season based on the adjusted means of three seasons. Major QTLs were identified for Hm (R 2 = 40.4, LOD = 14.84), Hw (R 2 = 28.6, LOD = 9.83), Cl (R 2 = 38.8, LOD = 15.73), Hvd (R 2 = 19.2, LOD = 9.26), and Cl/Hvd (R 2 = 38.8, LOD = 12.75). The most significant QTLs were Hm3.1, Cl3.1, and Cl/Hvd3.1, which were detected in three seasons with the maximum contribution rate of almost 40 %. Six active regions that harbored more than one QTL were identified on five chromosomes, and one of them contained major QTLs associated with five traits. The QTLs obtained in this study should be useful for marker-assisted selection in cabbage breeding and for understanding the genetic control of these traits. 相似文献
6.
Gowda SJ Radhika P Mhase LB Jamadagni BM Gupta VS Kadoo NY 《Journal of applied genetics》2011,52(1):9-21
Chickpea is one of the most important leguminous cool season food crops, cultivated prevalently in South Asia and Middle East.
The main objective of this study was to identify quantitative trait loci (QTLs) associated with seven agronomic and yield
traits in two recombinant inbred line populations of chickpea derived from the crosses JG62 × Vijay (JV population) and Vijay × ICC4958
(VI population) from at least three environments. Single locus QTL analysis involved composite interval mapping (CIM) for
individual traits and multiple-trait composite interval mapping (MCIM) for correlated traits to detect pleiotropic QTLs. Two-locus
analysis was conducted to identify the main effect QTLs (M-QTLs), epistatic QTLs (E-QTLs) and QTL × environment interactions.
Through CIM analysis, a total of 106 significant QTLs (41 in JV and 65 in VI populations) were identified for the seven traits,
of which one QTL each for plant height and days to maturity was common in both the populations. Six pleiotropic QTLs that
were consistent over the environments were also identified. LG2 in JV and LG1a in VI contained at least one QTL for each trait.
Hence, concentrating on these LGs in molecular breeding programs is most likely to bring simultaneous improvement in these
traits. 相似文献
7.
Elsayed Mansour Ana M. Casas M. Pilar Gracia José Luis Molina-Cano Marian Moralejo Luigi Cattivelli William T. B. Thomas Ernesto Igartua 《Molecular breeding : new strategies in plant improvement》2014,33(2):249-265
Advances in plant breeding through marker-assisted selection (MAS) are only possible when genes or quantitative trait loci (QTLs) can contribute to the improvement of elite germplasm. A population of recombinant inbred lines (RILs) was developed for one of the best crosses of the Spanish National Barley Breeding Program, between two six-row winter barley cultivars Orria and Plaisant. The objective of this study was to identify favourable QTLs for agronomic traits in this population, which may help to optimise breeding strategies for these and other elite materials for the Mediterranean region. A genetic linkage map was developed for 217 RILs, using 382 single nucleotide polymorphism markers, selected from the barley oligonucleotide pool assay BOPA1 and two genes. A subset of 112 RILs was evaluated for several agronomic traits over a period of 2 years at three locations, Lleida and Zaragoza (Spain) and Fiorenzuola d’Arda (Italy), for a total of five field trials. An important segregation distortion occurred during population development in the region surrounding the VrnH1 locus. A QTL for grain yield and length of growth cycle was also found at this locus, apparently linked to a differential response of the VrnH1 alleles to temperature. A total of 33 QTLs was detected, most of them for important breeding targets such as plant height and thousand-grain weight. QTL × environment interactions were prevalent for most of the QTLs detected, although most interactions were of a quantitative nature. Therefore, QTLs suitable for MAS for most traits were identified. 相似文献
8.
S. G. Atienza R. de la Rosa L. León A. Martín A. Belaj 《Molecular breeding : new strategies in plant improvement》2014,34(2):725-737
Development of methodologies for early selection is one of the most important goals of olive breeding programs at present. In this context, the identification of molecular markers associated with beneficial alleles could allow the development of marker-assisted selection (MAS) strategies in olive breeding programs. Fruit-related and plant vigor traits, which are of key importance for olive selection and breeding, were analyzed during two seasons in a progeny derived from the cross ‘Picual’ × ‘Arbequina.’ Quantitative trait loci (QTL) analyses were performed using MapQTL 4.0. A total of 22 putative QTLs were identified in the map of ‘Arbequina.’ QTLs clustered in linkage groups (LG) 1, 10 and 17. QTLs for oil-related traits located in LG 1 and 10 explained around 20–30 % of the phenotypic variability depending on the season and the trait. QTL for moisture-related traits were detected in LG 1, 10 and 17, and QTLs for the ratio pulp to stone were identified in LG 10 and 17 explaining around 15–20 %. Interaction between QTLs for the same trait was investigated. The significance of these results was discussed considering the co-localization of QTLs and Pearson correlations among traits. Five additional QTLs were detected in the map of ‘Picual.’ Four of them clustered in LG 17 indicating the presence of a QTL for fruit weight explaining around 12.7–15.2 % of the variability. Additionally, a QTL for trunk diameter was detected in LG 14 explaining 16 % of the variation. These results represent an important step toward the application of MAS in olive breeding programs. 相似文献
9.
Seed maturity is a critical process of seed vigor establishment. In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed vigor, including the germination potential (GP), germination rate (GR), germination index (GI), and time for 50 % of germination (T50), at 4, 5, and 6 weeks after heading in 2 years. Significant differences of seed vigor were observed among two parents and RIL population; the heritability of four traits was more than 90 % at three maturity stages. A total of 19 additive and 2 epistatic quantitative trait loci (QTL) for seed vigor were identified using QTL Cartographer and QTLNetwork program, respectively, in 2012, while 16 simple sequence repeat (SSR) markers associated with seed vigor were detected using bulked segregant analysis (BSA) in 2013. The phenotypic variation explained by each additive, epistatic QTL, and QTL × seed maturity interaction ranged from 9.19 to 22.94 %, 7.23 to 7.75 %, and 0.05 to 0.63 %, respectively. Ten additive QTLs were stably expressed in 2 years which might play important roles in establishment of seed vigor in different environments. By comparing chromosomal positions of ten stably expressed additive QTLs with those previously identified, they might be true QTLs for seed vigor; the regions of QTLs for seed vigor are likely to coincide with QTLs for seed dormancy, seed reserve mobilization, low-temperature germinability, and seedling growth. Using four selected RILs, three cross-combinations were predicted to improve seed vigor; 9 to 10 elite alleles could be pyramided by each combination. The selected RILs and the identified QTLs might be applicable for the improvement of seed vigor by marker-assisted selection (MAS) in rice. 相似文献
10.
Mapping QTLs for yield and nitrogen-related traits in wheat: influence of nitrogen and phosphorus fertilization on QTL expression 总被引:7,自引:0,他引:7
Yunfeng Xu Ruifang Wang Yiping Tong Huatian Zhao Qingen Xie Dongcheng Liu Aimin Zhang Bin Li Hongxing Xu Diaoguo An 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(1):59-72
Key message
The present study identified some new important genomic regions and demonstrated the availability of conditional analysis in dissecting QTLs induced by environmental factors.Abstract
The high input and low use efficiency of nutrient fertilizers require knowledge of the genetic control of crop reaction to nutrient supplements. In this study, 14 morphological and 8 physiological traits of a set of 182 wheat (Triticum aestivum L.) recombinant inbred lines (Xiaoyan 54 × Jing 411) were investigated in six environments to map quantitative trait loci (QTLs). The influence of nitrogen (N) and phosphorus (P) fertilization on QTL expression was studied by unconditional and conditional analysis. A total of 117 and 30 QTLs were detected by unconditional and conditional analysis, respectively, among which 21 were common for both methods. Thirty-four QTL clusters were identified. Eighteen conserved QTLs (15.4 % of the 117 QTLs) between years, but within nutritional treatment were found. The three major QTLs on chromosomes 2D, 4B and 6A were coincident with Rht8, Rht-B1b and TaGW2, respectively. The other two important intervals on chromosomes 4B and 7A for yield component traits were newly detected QTLs that warrant further study. By conditional analysis, spikelet number per spike was found to be induced by P fertilization mostly, whereas N fertilization had more effects on the expression of the QTLs for nitrogen concentration and utilization efficiency traits. QTLs that respond to N and P interactions were also detected. The results are helpful for understanding the genetic basis of N utilization efficiency in wheat under different N and P supplement environments and provide evidence for the availability of conditional analysis in dissecting QTLs induced by environmental factors. 相似文献11.
Lixia Ku Zhenzhen Ren Xiao Chen Yong Shi Jianshuang Qi Huihui Su Zhiyong Wang Guohui Li Xiaobo Wang Yuguang Zhu Jinlong Zhou Xin Zhang Yanhui Chen 《Molecular breeding : new strategies in plant improvement》2016,36(5):63
Maize yield increase has been strongly linked to plant population densities over time with changes in plant architecture, but the genetic basis for the plant architecture response to plant density is unknown, as is its stability across environments. To elucidate the genetic basis of the plant architecture response to density in maize, we mapped quantitative trait loci (QTLs) for leaf morphology-related traits in four sets of recombinant inbred line (RIL) populations under two plant density conditions. Forty-five QTLs for six traits were detected in both high and low plant density conditions. Thirty-seven QTLs were only detected when grown under high plant density, and 34 QTLs were only detected when grown under low plant density. Twenty-two meta-QTLs (mQTLs) were identified by meta-analysis, and mQTL1-1, mQTL3-2 and mQTL8 were identified when grown under high and low plant densities, with R 2 of some initial QTLs > 10 %, suggesting the mQTLs might be hot spots of the important QTLs for the related traits under planting density stress conditions. The results presented here provide useful information for further research and the marker-assisted selection of varieties targeting increased plant density and will help to reveal the molecular mechanisms related to leaf morphology in response to density. 相似文献
12.
The identification of quantitative trait loci (QTLs) based on anchor markers, especially candidate genes that control a trait of interest, has been noted to increase the power of QTL detection. Since these markers can be scored as co-dominant data, they are also valuable for comparing and integrating the QTL linkage maps from diverse mapping populations. To estimate the position and effects of QTLs linked to oil yield traits in African oil palm, co-dominant microsatellites (SSR) and candidate gene-based sequence polymorphisms were applied to construct a linkage map for a progeny showing large differences in oil yield components. The progeny was genotyped for 97 SSR markers, 93 gene-linked markers, and 12 non-gene-linked SNP markers. From these, 190 segregating loci could be arranged into 31 linkage groups while 12 markers remained unmapped. Using the single marker linkage, interval mapping and multiple QTL methods, 16 putative QTLs on seven linkage groups affecting important oil yield related traits such as fresh fruit bunch yield (FFB), ratio of oil per fruit (OF), oil per bunch (OB), fruit per bunch (FB) and wet mesocarp per fruit (WMF) could be identified in the segregating population with estimated values for explained variance ranging from 12.4 % to 54.5 %. Markers designed from some candidate genes involved in lipid biosynthesis were found to be mapped near significant QTLs for various economic yield traits. Associations between QTLs and potential candidate genes are discussed. 相似文献
13.
D. Socquet-Juglard D. Christen G. Devènes C. Gessler B. Duffy A. Patocchi 《Plant Molecular Biology Reporter》2013,31(2):387-397
The F1 population “Harostar”?×?“Rouge de Mauves” was used to perform a quantitative trait loci (QTL) mapping for tree architecture traits (i.e., tree diameter, total branch number, tree shape); time to initial reproductive bud break; and fruit quality traits (i.e., ground color, fruit form, soluble solid content) using data collected from 2010 to 2012. For architectural traits, interval mapping detected QTLs only in “Rouge de Mauves” on linkage group 1 for trunk diameter in 2010, on LG6 for total branch number in 2010, and on LG1 and LG5 for tree shape for both years 2010 and 2011 combined. QTLs were detected only in “Harostar” for time to initial reproductive bud break on LG1 and LG4 in 2011. For fruit quality traits, data were collected in 2011 and 2012. QTLs were identified on LG1 in 2011 and on LG4 in 2012 for soluble solid content, on LG3 for ground color in both years, on LG7 only in 2011, and on LG3 for fruit form in both years. The QTLs that we identified were compared to those previously identified in other Prunus spp. 相似文献
14.
G. Srinivas K. Satish R. Madhusudhana R. Nagaraja Reddy S. Murali Mohan N. Seetharama 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(8):1439-1454
The identification of quantitative trait loci (QTLs) affecting agronomically important traits enable to understand their underlying
genetic mechanisms and genetic basis of their complex interactions. The aim of the present study was to detect QTLs for 12
agronomic traits related to staygreen, plant early development, grain yield and its components, and some growth characters
by analyzing replicated phenotypic datasets from three crop seasons, using the population of 168 F7 RILs of the cross 296B × IS18551. In addition, we report mapping of a subset of genic-microsatellite markers. A linkage map
was constructed with 152 marker loci comprising 149 microsatellites (100 genomic- and 49 genic-microsatellites) and three
morphological markers. QTL analysis was performed by using MQM approach. Forty-nine QTLs were detected, across environments
or in individual environments, with 1–9 QTLs for each trait. Individual QTL accounted for 5.2–50.4% of phenotypic variance.
Several genomic regions affected multiple traits, suggesting the phenomenon of pleiotropy or tight linkage. Stable QTLs were
identified for studied traits across different environments, and genetic backgrounds by comparing the QTLs in the study with
previously reported QTLs in sorghum. Of the 49 mapped genic-markers, 18 were detected associating either closely or exactly
as the QTL positions of agronomic traits. EST marker Dsenhsbm19, coding for a key regulator (EIL-1) of ethylene biosynthesis,
was identified co-located with the QTLs for plant early development and staygreen trait, a probable candidate gene for these
traits. Similarly, such exact co-locations between EST markers and QTLs were observed in four other instances. Collectively,
the QTLs/markers identified in the study are likely candidates for improving the sorghum performance through MAS and map-based
gene isolations. 相似文献
15.
Xianzhi Wang Guo-Liang Jiang Marci Green Roy A. Scott Qijian Song David L. Hyten Perry B. Cregan 《Molecular genetics and genomics : MGG》2014,289(5):935-949
Soybean seeds contain high levels of oil and protein, and are the important sources of vegetable oil and plant protein for human consumption and livestock feed. Increased seed yield, oil and protein contents are the main objectives of soybean breeding. The objectives of this study were to identify and validate quantitative trait loci (QTLs) associated with seed yield, oil and protein contents in two recombinant inbred line populations, and to evaluate the consistency of QTLs across different environments, studies and genetic backgrounds. Both the mapping population (SD02-4-59 × A02-381100) and validation population (SD02-911 × SD00-1501) were phenotyped for the three traits in multiple environments. Genetic analysis indicated that oil and protein contents showed high heritabilities while yield exhibited a lower heritability in both populations. Based on a linkage map constructed previously with the mapping population and using composite interval mapping and/or interval mapping analysis, 12 QTLs for seed yield, 16 QTLs for oil content and 11 QTLs for protein content were consistently detected in multiple environments and/or the average data over all environments. Of the QTLs detected in the mapping population, five QTLs for seed yield, eight QTLs for oil content and five QTLs for protein content were confirmed in the validation population by single marker analysis in at least one environment and the average data and by ANOVA over all environments. Eight of these validated QTLs were newly identified. Compared with the other studies, seven QTLs for seed yield, eight QTLs for oil content and nine QTLs for protein content further verified the previously reported QTLs. These QTLs will be useful for breeding higher yield and better quality cultivars, and help effectively and efficiently improve yield potential and nutritional quality in soybean. 相似文献
16.
Genetic Mapping and QTL Analysis of Growth Traits in the Large Yellow Croaker Larimichthys crocea 总被引:1,自引:0,他引:1
Hua Ye Yang Liu Xiande Liu Xiaoqing Wang Zhiyong Wang 《Marine biotechnology (New York, N.Y.)》2014,16(6):729-738
Large yellow croaker (Larimichthys crocea) is an important maricultured species in China. A genetic linkage map of the large yellow croaker was constructed using type II microsatellites and expressed sequence tag (EST)-derived microsatellites in two half-sib families (two females and one male). A total of 289 microsatellite markers (contained 93 EST-SSRs) were integrated into 24 linkage groups, which agreed with the haploid chromosome number. The map spanned a length of 1,430.8 cm with an average interval of 5.4 cm, covering 83.9 % of the estimated genome size (1,704.8 cm). A total of seven quantitative trait locis (QTLs) were detected for growth traits on five linkage groups, including two 1 % and five 5 % chromosome-wide significant QTLs, and explained from 2.33 to 5.31 % of the trait variation. The identified QTLs can be applied in marker-assisted selection programs to improve the growth traits. 相似文献
17.
Juan Alfonso Salazar David Ruiz José Antonio Campoy Stefano Tartarini Luca Dondini Pedro Martínez-Gómez 《Tree Genetics & Genomes》2016,12(4):71
Reproductive phenological traits of great agronomical interest in apricot species, including flowering date, ripening date and fruit development period, were studied during 3 years in two F1 progenies derived from the crosses ‘Bergeron’ × ‘Currot’ (B × C) and ‘Goldrich’ × ‘Currot’ (G × C). Results showed great variability and segregation in each population, confirming the polygenic nature and quantitative inheritance of all the studied traits. Genetic linkage maps were constructed combining SSR and SNP markers, using 87 markers in the ‘B × C’ population and 89 markers in ‘G × C’. The genetic linkage maps in both progenies show the eight linkage groups (LGs) of apricot, covering a distance of 394.9 cM in ‘Bergeron’ and of 414.3 cM in ‘Currot’. The ‘Goldrich’ and ‘Currot’ maps were of 353.5 and 422.3 cM, respectively. The average distance obtained between markers was thus 7.59 cM in ‘Bergeron’ and 7.53 cM in ‘Currot’, whereas the ‘Goldrich’ and ‘Currot’ averages were 5.6 and 7.5 cM, respectively. According to the polygenic nature of the studied phenology traits, QTLs linked to flowering date, ripening date and the fruit development period were identified during the 3 years of the study in all LGs except for LG 8. Among the QTLs identified, major QTLs for flowering and ripening date and the fruit development period were identified in LG 4, especially important in the ‘G × C’ population. 相似文献
18.
Breeding for fruit quality traits is complex due to the polygenic (quantitative) nature of the genetic control of these traits.
Therefore, to improve the speed and efficiency of genotype selection, attention in recent years has focused on the identification
of quantitative trait loci (QTLs) and molecular markers associated with these QTLs. However, despite the huge potential of
molecular markers in breeding programmes, their implementation in practice has been limited by the lack of information on
the stability of QTLs across different environments and within different genetic backgrounds. Here, we present the results
from a comprehensive analysis of the inheritance of fruit quality traits within a population derived from a cross between
the apple cultivars ‘Telamon’ and ‘Braeburn’ over two successive seasons. A total of 74 different QTLs were identified for
all the major fruit physiological traits including fruit height, diameter, weight and stiffness, flesh firmness, rate of flesh
browning, acidity, the oBrix content and harvest date. Seventeen of these QTLs were ‘major’ QTLs, accounting for over 20%
of the observed population variance of the trait. However, only one third (26) of the identified QTLs were stable over both
harvest years, and of these year-stable QTLs only one was a major QTL. A direct comparison with published QTL results obtained
using other populations (King et al., Theor Appl Genet 102:1227–1235, 2001; Liebhard et al., Plant Mol Biol 52:511–526, 2003)
is difficult because the linkage maps do not share a sufficient number of common markers and due to differences in the trait
evaluation protocols. Nonetheless, our results suggest that for the six fruit quality traits which were measured in all populations,
nine out of a total of 45 QTLs were common or stable across all population × environments combinations. These results are
discussed in the framework of the development and application of molecular markers for fruit quality trait improvement. 相似文献
19.
M. R. García M. J. Asíns E. A. Carbonell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(3):487-493
Amount, regularity and low seed content of the crop are important properties of scion citrus cultivars. The genetic control
of these traits was studied in a progeny derived from the cross Citrus volkameriana×Poncirus trifoliata using molecular marker analysis. Since the traits were not normally distributed, the Kruskal-Wallis non-parametric test was
used for quantitative trait loci (QTLs) detection. Most of the QTLs detected correspond to the trait ”number of fruits per
tree”, in agreement with its known physiological complexity. Related traits (fruit number, fruit size and seed number) are
controlled by QTLs some of which are located in the same genomic regions, suggesting that undesired associations could be
broken to some degree by recombination. QTL analysis over years revealed important effects of genotype-by-environment interaction
on QTL detection. This result agrees with the differences found for the trait means among years, which was found to be related,
among other causes, to the alternate bearing of some genotypes and the amount of rain before harvest.
Received: 1 October 1999 / Accepted: 2 December 1999 相似文献
20.
Suvendu Mondal Ashok B. Hadapad Poonam A. Hande Anand M. Badigannavar 《Molecular breeding : new strategies in plant improvement》2014,33(4):961-973
Groundnut bruchid (Caryedon serratus Olivier) is a major storage insect pest that significantly lowers the quality and market acceptance of the produce. Screening for resistance against groundnut bruchid in field conditions is difficult due to the variation in environmental factors and possible occurrence of biotypes. Hence, identification of tightly linked markers or quantitative trait loci (QTLs) is needed for selection and pyramiding of resistance genes for durable resistance. A population of recombinant inbred lines derived from a cross between VG 9514 (resistant) and TAG 24 (susceptible) was screened for five component traits of bruchid resistance in 2 years. The same population was genotyped with 221 polymorphic marker loci. A genetic linkage map covering 1,796.7 cM map distance was constructed with 190 marker loci in cultivated groundnut. QTL analysis detected thirteen main QTLs for four components of bruchid resistance in nine linkage groups and 31 epistatic QTLs for total developmental period (TDP). Screening in 2 years for bruchid resistance identified two common main QTLs. The common QTL for TDP, qTDP-b08, explained 57–82 % of phenotypic variation, while the other common QTL for adult emergence, qAE2010/11-a02, explained 13–21 % of phenotypic variation. Additionally, three QTLs for TDP, adult emergence and number of holes and one QTL for pod weight loss were identified which explained 14–39 % of phenotypic variation. This is the first report on identification of multiple main and epistatic loci for bruchid resistance in groundnut. 相似文献