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1.
Brian M. Leckie Darlene M. De Jong Martha A. Mutschler 《Molecular breeding : new strategies in plant improvement》2013,31(4):957-970
Acylsugars are broad-spectrum insect resistance sugar esters produced at very high levels by some accessions of the wild tomato, Solanum pennellii. Transferring acylsugar production from S. pennellii LA716 to cultivated tomato through traditional breeding developed the benchmark acylsugar breeding line CU071026. The base moiety of acylsugars (sucrose vs. glucose) can vary among S. pennellii accessions. Additionally the accession S. pennellii LA716 produces almost exclusively acylglucoses, but the breeding line CU071026 derived from S. pennellii LA716 produces exclusively acylsucroses. This study uses a BC1F1 and a BC1F2 population derived from the cross CU071026 × (CU071026 × S. pennellii LA716) to identify and confirm the action of three quantitative trait loci (QTL) on chromosomes 3, 4, and 11. The QTL on chromosomes 3 and 11 are both required for acylglucose production, while addition of the chromosome 4 QTL affects the level of acylglucose produced in the presence of the QTL on chromosomes 3 and 11. A three-way interaction between these acylglucose QTL was confirmed with a post hoc ANOVA. Identification of these three QTL provides a blueprint for breeding to shift acylsucrose production to acylglucose production in tomato breeding lines. The implications of these QTL and two additional QTL affecting total acylsugar level in the BC1F2 are discussed. 相似文献
2.
Brian M. Leckie Darlene M. De Jong Martha A. Mutschler 《Molecular breeding : new strategies in plant improvement》2012,30(4):1621-1634
Solanum pennellii LA716, a wild relative of tomato, produces acylsugars, an insect resistance compound with activity against many tomato insect pests. Breeding of cultivated tomato using S. pennellii LA716 as a donor parent has led to the development of the elite acylsugar-producing tomato breeding line CU071026. CU071026 contains five introgressed S. pennellii genomic regions, and produces acylsugars at moderate levels that are effective against insect pests. A BC1F1 population was created by crossing the F1 CU071026?×?S. pennellii LA716 with CU071026 as the recurrent parent; this BC1F1 population was used to identify additional regions of the S. pennellii genome important for further improvement of acylsugar production. This population was genotyped with 94 markers in the segregating regions and phenotyped for level of acylsugar production. Using QTLNetwork 2.1 for the detection of quantitative trait loci (QTL) and epistatic interactions, this study identified five QTL for total acylsugar level. Additionally, two epistatic interactions between QTL were found to control significant levels of total acylsugar production. Two of the QTL identified were further evaluated in silverleaf whitefly (Bemisia tabaci) field cage trials using acylsugar breeding lines that differ for the presence/absence of these QTL. While high levels of silverleaf whitefly resistance were observed in all acylsugar breeding lines, lines containing the additional QTL on either chromosomes 6 or 10 had increased levels of total acylsugar production and reduced incidence of whitefly. Acylsugar lines containing the chromosome 6 QTL also had increased density of the type IV glandular trichomes which produce and exude acylsugars. 相似文献
3.
John R. Smeda Anthony L. Schilmiller Andre Kessler Martha A. Mutschler 《Molecular breeding : new strategies in plant improvement》2017,37(8):104
The tomato breeding line, CU071026, was bred to accumulate high levels of the insect control compounds called acylsugars, which are exuded from glandular trichomes. The acylsugars of CU071026 exhibit a characteristic profile of acylsugar composition and constituent fatty acid acyl groups that is distinct from that of the progenitor wild tomato, Solanum pennellii LA716. A prior study reported the transfer of three QTL (FA2, FA7, and FA8), from S. pennellii LA716, that are associated with changes in acylsugar chemistry into CU071026 and demonstrated that the resulting lines, each of which possesses one of these QTL, displayed a unique acylsugar and fatty acid profile distinct from that characteristic of the acylsugars of CU071026 and each other. The current study utilized marker-assisted backcrossing to combine pairs of two of these QTL or all three of these QTL. This created a new set of lines, which allowed evaluation of the combinatory effects of FA2QTL, FA7QTL, and FA8QTL, on acylsugar level and acylsugar and fatty acid profile and diversity. Analysis of the new tomato lines revealed that these QTL interacted additively and epistatically to alter acylsugar level and chemistry, increasing the diversity of fatty acid constituents and/or acylsugar chemotypes present in the exudates of some of the lines. Extensive characterization of the lines for acylsugar level, through a spectrophotometric invertase assay, and acylsugar chemistry, through gas and liquid chromatography-mass spectrometry, allowed association of the QTL interactions with aspects of acylsugar chemotype. The evaluated fatty acids and acylsugars accumulated by the set of lines generally displayed high heritability and minimal environmental effect, which is discussed. The QTL interactions that govern a more diverse acylsugar and fatty acid profile provide valuable information for the generation of tomato lines with improved acylsugar efficacy against pests of tomato. 相似文献
4.
John R. Smeda Anthony L. Schilmiller Taylor Anderson Sulley Ben-Mahmoud Diane E. Ullman Thomas M. Chappell Andre Kessler Martha A. Mutschler 《Molecular breeding : new strategies in plant improvement》2018,38(1):3
Acylsugars are important insect defense compounds produced at high levels by glandular trichomes of the wild tomato, Solanum pennellii. Marker-assisted selection was used to select for plants containing the three AGQTL named AG3QTL, AG4QTL, and AG11QTL from self-pollinated populations derived from an interspecific backcross population of CU071026 x (CU071026 x S. pennellii LA716). High acylglucose-accumulating lines were selected from these populations that possess these three AGQTL and the fewest number of extraneous S. pennellii LA716 introgressions. Incorporation of these three acylglucose QTL in the presence of the five standard S. pennellii introgressions of CU071026 altered acylsugar level and sugar moiety, demonstrating epistatic interactions between the acylglucose QTL on both of these traits. Comparison of the lines generated from the two breeding techniques indicated the three acylglucose QTL are essential but not necessarily sufficient for the production of elevated levels of acylglucose acylsugars. Fine-mapping of AG3QTL, AG4QTL, and AG11QTL resulted in less than 1 Mbp intervals for the locations of AG4QTL and AG11QTL; proposals of the causal genes underlying these acylglucose QTL are discussed. Characterization of the fatty acid profile of lines selected out of the interspecific backcross populations revealed an increase in the proportion of acylsugar n-C10 fatty acid acyl chains, possibly governed by one or more of the three acylglucose QTL. Characterization of the acylsugar profile of acylglucose lines selected from the interspecific backcross populations also demonstrated interactions among the acylglucose QTL to further modulate the diversity of acylsugars accumulated. Evaluation of an acylglucose line and controls against the tomato insect pest Frankliniella occidentalis demonstrated that levels of resistance differed among these lines and that the acylsugars accumulated by the acylglucose line were effective at reducing both F. occidentalis oviposition and incidence of Tomato spotted wilt orthotospovirus. However, of some of the acylglucose lines and hybrids tested against Spodoptera exigua did not indicate differences for larval weight gain and survival. 相似文献
5.
Acylsugars are important insect defense compounds produced at high levels by glandular trichomes of the wild tomato, Solanum pennellii. The ability to produce acylsugars at elevated levels was bred into the tomato line CU071026. This study utilized a marker-assisted backcross approach to individually introgress into CU071026 and to fine map the three quantitative trait loci (QTL) fatty acid 5 (FA5QTL), fatty acid 7 (FA7QTL), and fatty acid 8 (FA8QTL), which were previously associated with changes in acylsugar chemistry. Additional breeding with and fine mapping the previously introgressed QTL, fatty acid 2 (FA2QTL), was also conducted. The effect of these four QTL on acylsugar quality and quantity in the presence of the five introgressions of CU071026 was evaluated. Incorporation of the QTL altered acylsugar chemotype by modulating the length, orientation, and/or relative proportion of fatty acid acyl groups. The resulting quantities of acylsugar produced in most of the new lines were similar to that of CU071026; however, introgression of FA5QTL reduced acylsugar levels. The acylsugar lines containing each QTL were characterized for acylsugar level, trichome abundance, and acylsugar chemistry through gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. The novel acylsugar chemotype lines created can contribute to elucidation of the mechanism of insect resistance mediated by acylsugars and help with identification of yet-unknown genes contributing to acylsugar synthesis and diversity. 相似文献
6.
S. L. Blauth G. A. Churchill M. A. Mutschler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(3-4):458-467
Lycopersicon pennellii LA716, a wild relative of tomato, is resistant to a number of insect pests due to the accumulation of acylsugars exuded from
type IV trichomes. These acylsugars are a class of compounds including both acylglucoses and acylsucroses. Intraspecific populations
between L. pennellii LA716 and L. pennellii LA1912, the latter an accession that assorts for low-level acylsugar accumulation, were created to study the inheritance
of type IV trichome density, acylsugar accumulation levels, percentage of acylsugars that are acylglucoses, and leaf area.
The F2 population was subsequently used to determine genomic regions associated with these traits. The relative proportion of acylglucoses
and acylsucroses was found to be largely controlled by a single locus near TG549 on chromosome 3. One locus on chromosome
10 showed significant associations with acylsugar levels. In addition, 1 locus on chromosome 4 showed significant associations
with leaf area. Ten additional loci showed modest associations with one or more of the traits examined, 5 of which have been
previously reported.
Received: 13 March 1997 / Accepted: 19 September 1997 相似文献
7.
QTL analysis of pest resistance in the wild tomato Lycopersicon pennellii: QTLs controlling acylsugar level and composition 总被引:2,自引:0,他引:2
M. A. Mutschler R. W. Doerge S. C. Liu J. P. Kuai B. E. Liedl J. A. Shapiro 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(6):709-718
Some accessions of Lycopersicon pennellii, a wild relative of the tomato Lycopersicon esculentum, are resistant to a number of important pests of cultivated tomato due to the accumulation of acylsugars, which constitute 90% of the exudate of type-IV trichomes in L. pennellii LA716. An interspecific F2 population, created by the cross L. esculentum x L. pennellii LA 716, was surveyed for acylsugar accumulation and subjected to RFLP/QTL analysis to determine the genomic regions associated with the accumulation of acylglucoses, acylsucroses, and total acylsugars, as well as with acylglucoses as a percentage of total acylsugars (mole percent acylglucoses). Data were analyzed using MAPMAKER/QTL with and without a log10 transformation. A threshold value of 2.4 (default value for MAPMAKER/QTL) was used, as well as 95% empirically derived threshold values. Five genomic regions, two on chromosome 2 and one each on chromosomes 3, 4 and 11, were detected as being associated with one or more aspects of acylsugar production. The L. esculentum allele is partially dominant to the L. pennellii allele in the regions on chromosomes 2 and 11, but the L. pennellii allele is dominant in the region on chromosome 3. Throughout this study, we report the comparative effects of analytical methodology on the identification of acylsugar QTLs. Similarities between our results and published results for the genus Solanum are also discussed.R. W. Doerge · S.-C. Liu · J. P. Kuai contributed equally to the paper, and we ordered randomly 相似文献
8.
Brian M. Leckie Damon A. D'Ambrosio Thomas M. Chappell Rayko Halitschke Darlene M. De Jong André Kessler George G. Kennedy Martha A. Mutschler 《PloS one》2016,11(4)
Acylsugars are secondary metabolites exuded from type IV glandular trichomes that provide broad-spectrum insect suppression for Solanum pennellii Correll, a wild relative of cultivated tomato. Acylsugars produced by different S. pennellii accessions vary by sugar moieties (glucose or sucrose) and fatty acid side chains (lengths and branching patterns). Our objective was to determine which acylsugar compositions more effectively suppressed oviposition of the whitefly Bemisia tabaci (Gennadius) (Middle East—Asia Minor 1 Group), tobacco thrips, Frankliniella fusca (Hinds), and western flower thrips, Frankliniella occidentalis (Pergande). We extracted and characterized acylsugars from four S. pennellii accessions with different compositions, as well as from an acylsugar-producing tomato breeding line. We also fractionated the acylsugars of one S. pennellii accession to examine the effects of its components. Effects of acylsugars on oviposition were evaluated by administering a range of doses to oviposition sites of adult whiteflies and thrips in non-choice and choice bioassays, respectively. The acylsugars from S. pennellii accessions and the tomato breeding line demonstrated differential functionality in their ability to alter the distribution of whitefly oviposition and suppress oviposition on acylsugar treated substrates. Tobacco thrips were sensitive to all compositions while western flower thrips and whiteflies were more sensitive to acylsugars from a subset of S. pennellii accessions. It follows that acylsugars could thus mediate plant-enemy interactions in such a way as to affect evolution of host specialization, resistance specificity, and potentially host differentiation or local adaptation. The acylsugars from S. pennellii LA1376 were separated by polarity into two fractions that differed sharply for their sugar moieties and fatty acid side chains. These fractions had different efficacies, with neither having activity approaching that of the original exudate. When these two fractions were recombined, the effect on both whiteflies and thrips exceeded the sum of the two fractions’ effects, and was similar to that of the original exudate. These results suggest that increasing diversity of components within a mixture may increase suppression through synergistic interactions. This study demonstrates the potential for composition-specific deployment of acylsugars for herbivore oviposition suppression, either through in planta production by tomato lines, or as biocides applied by a foliar spray. 相似文献
9.
S. L. Blauth J. C. Steffens G. A. Churchill M. A. Mutschler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):373-381
Acylsugars exuded by type IV glandular trichomes are responsible for insect resistances found in many Lycopersicon pennellii accessions. Acylsugars are complex mixtures composed of polyacylated sugars (glucose or sucrose) esterified to branched and
straight-chain 4 : 0 to 12 : 0 fatty acids. The biogeneses of these unusual fatty acid constituents have their origins in
branched-chain amino acid pathways. However, the mechanism of fatty acid elongation in these systems and the genetic control
of carbon flux from amino acid to fatty acid pathways remain unclear. In this study, we used an intraspecific F2 population derived from the cross between L. pennellii LA716 and L. pennellii LA1912 to examine the genetic basis of acylsugar fatty acid composition. Six QTLs were detected which, combined, explain
23–60% of the variance observed for each of the nine segregating fatty acid constituents. Both correlation data and QTL analysis
data indicate that branched medium-chain fatty acids are synthesized through elongation of short-chain precursors in two-carbon
increments. The proportion of iso-branched acylsugar fatty acids that have an even-carbon chain length was found to be primarily determined by a single locus
that maps to a location 5.5 cM above TG117 on chromosome 8. QTL function in several cases can be inferred from discrete patterns
of fatty acid composition; in other cases, control of acylsugar fatty acid composition appears to be complex.
Received: 7 April 1998 / Accepted: 28 December 1998 相似文献
10.
Anthony L. Schilmiller Gaurav D. Moghe Pengxiang Fan Banibrata Ghosh Jing Ning A. Daniel Jones Robert L. Last 《The Plant cell》2015,27(4):1002-1017
Glandular trichomes from tomato (Solanum lycopersicum) and other species in the Solanaceae produce and secrete a mixture of O-acylsugars (aliphatic esters of sucrose and glucose) that contribute to insect defense. Despite their phylogenetic distribution and diversity, relatively little is known about how these specialized metabolites are synthesized. Mass spectrometric profiling of acylsugars in the S. lycopersicum x Solanum pennellii introgression lines identified a chromosome 11 locus containing a cluster of BAHD acyltransferases with one gene (named Sl-ASAT3) expressed in tip cells of type I trichomes where acylsugars are made. Sl-ASAT3 was shown to encode an acyl-CoA-dependent acyltransferase that catalyzes the transfer of short (four to five carbons) branched acyl chains to the furanose ring of di-acylsucrose acceptors to produce tri-acylsucroses, which can be further acetylated by Sl-ASAT4 (previously Sl-AT2). Among the wild tomatoes, diversity in furanose ring acyl chains on acylsucroses was most striking in Solanum habrochaites. S. habrochaites accessions from Ecuador and northern Peru produced acylsucroses with short (≤C5) or no acyl chains on the furanose ring. Accessions from central and southern Peru had the ability to add short or long (up to C12) acyl chains to the furanose ring. Multiple ASAT3-like sequences were found in most accessions, and their in vitro activities correlated with observed geographical diversity in acylsugar profiles. 相似文献
11.
The growth and ion content of salt sensitive Lycopersicon esculentum Mill. cv. M82 and salt tolerant L. pennellii Correll accession LA716 were examined under both control and stress conditions (150 mM NaCl). L. esculentum grew more vigorously than L. pennellii under optimal conditions, however, L. pennellii was able to maintain its growth better than cultivated tomato when the plants were exposed to salinity. Sodium content of
both L. esculentum and L. pennellii increased as a result of NaCl stress. In addition, both species showed reduced potassium and calcium content due to salinity.
The physiological traits were also measured in a population of 52 L. pennellii introgression lines grown under both normal and stress conditions. A total of 311 quantitative trait loci (QTL) were identified
for the studied traits: plant height, stem diameter, leaf number, leaf and root fresh and dry mass, and sodium, potassium
and calcium contents. Some of the loci (124) were identified under both control and stress conditions while 86 QTL were identified
only under non-stress conditions and 101 loci were identified only under NaCl stress. 相似文献
12.
Anne Frary Deniz Göl Davut Keleş Bilal Ökmen Hasan Pınar Hasan Ö Şığva Ahmet Yemenicioğlu Sami Doğanlar 《BMC plant biology》2010,10(1):58
Background
Excessive soil salinity is an important problem for agriculture, however, salt tolerance is a complex trait that is not easily bred into plants. Exposure of cultivated tomato to salt stress has been reported to result in increased antioxidant content and activity. Salt tolerance of the related wild species, Solanum pennellii, has also been associated with similar changes in antioxidants. In this work, S. lycopersicum M82, S. pennellii LA716 and a S. pennellii introgression line (IL) population were evaluated for growth and their levels of antioxidant activity (total water-soluble antioxidant activity), major antioxidant compounds (phenolic and flavonoid contents) and antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase) under both control and salt stress (150 mM NaCl) conditions. These data were then used to identify quantitative trait loci (QTL) responsible for controlling the antioxidant parameters under both stress and nonstress conditions. 相似文献13.
Lawson Darlene M. Lunde China F. Mutschler Martha A. 《Molecular breeding : new strategies in plant improvement》1997,3(4):307-317
Acylsugars exuded from type IV trichomes mediate the multiple pest resistance found in the wild tomato species, Lycopersicon pennellii. A marker-assisted selection breeding program was used to attempt the transfer of the ability to accumulate acylsugars to cultivated tomato. RFLP and PCR-based markers were used through three backcross generations to select plants containing 5 target regions associated by QTL analysis with acylsugar accumulation. The BC1F1 plant selected possessed all 5 target regions and accumulated acylsugars at a moderate level similar to that of the interspecific F1 control. The BC2F1 and BC3F1 selections contained complementary subsets of the 5 target regions and did not accumulate acylsugars. BC3F1 plants with complementary subsets of the 5 target regions were intermated to produce populations segregating for the 5 target regions. From 1000 BC3F1-intermated plants, three plants were found which accumulated acylsugars at low levels and contained 3 to 5 of the target regions. The recovery of acylsugar accumulation in progeny of the intermated BC3F1 plants supports the involvement of at least some of the 5 target regions in acylsugar biosynthesis. However, since the levels of acylsugars accumulated by these plants were lower than that of the interspecific F1, it is likely that another, as of yet unidentified, region is necessary for accumulation of higher levels of acylsugars. 相似文献
14.
Molly Sharlach Douglas Dahlbeck Lily Liu Joshua Chiu José M. Jiménez-Gómez Seisuke Kimura Daniel Koenig Julin N. Maloof Neelima Sinha Gerald V. Minsavage Jeffrey B. Jones Robert E. Stall Brian J. Staskawicz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(3):601-609
The RXopJ4 resistance locus from the wild accession Solanum pennellii (Sp) LA716 confers resistance to bacterial spot disease of tomato (S. lycopersicum, Sl) caused by Xanthomonas perforans (Xp). RXopJ4 resistance depends on recognition of the pathogen type III effector protein XopJ4. We used a collection of Sp introgression lines (ILs) to narrow the RXopJ4 locus to a 4.2-Mb segment on the long arm of chromosome 6, encompassed by the ILs 6-2 and 6-2-2. We then adapted or developed a collection of 14 molecular markers to map on a segregating F2 population from a cross between the susceptible parent Sl FL8000 and the resistant parent RXopJ4 8000 OC7. In the F2 population, a 190-kb segment between the markers J350 and J352 cosegregated with resistance. This fine mapping will enable both the identification of candidate genes and the detection of resistant plants using cosegregating markers. The RXopJ4 resistance gene(s), in combination with other recently characterized genes and a quantitative trait locus (QTL) for bacterial spot disease resistance, will likely be an effective tool for the development of durable resistance in cultivated tomato. 相似文献
15.
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17.
Frary A Fulton TM Zamir D Tanksley SD 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(3):485-496
In this study, the advanced backcross QTL (AB-QTL) mapping strategy was used to identify loci for yield, processing and fruit quality traits in a population derived from the interspecific cross Lycopersicon esculentum E6203 × Lycopersicon pennellii accession LA1657. A total of 175 BC2 plants were genotyped with 150 molecular markers and BC2F1 plots were grown and phenotyped for 25 traits in three locations in Israel and California, U.S.A. A total of 84 different QTLs were identified, 45% of which have been possibly identified in other wild-species-derived populations of tomato. Moreover, three fruit-weight/size and shape QTLs (fsz2b.1, fw3.1/fsz3.1 and fs8.1) appear to have putative orthologs in the related solanaceous species, pepper and eggplant. For the 23 traits for which allelic effects could be deemed as favorable or unfavorable, 26% of the identified loci had L. pennellii alleles that enhanced the performance of the elite parent. Alleles that could be targeted for further introgression into cultivated tomato were also identified.Communicated by G. Wenzel 相似文献
18.
Resende JT Maluf WR Cardoso Md Nelson DL Faria MV 《Genetics and molecular research : GMR》2002,1(2):106-116
Acylsugars present in Lycopersicon pennellii are responsible for the high levels of pest resistance often found in this wild tomato taxon. We investigated the inheritance of acylsugar contents in segregating populations of the interspecific tomato cross L. esculentum x L. pennellii and estimated correlations between leaflet acylsugar contents and the levels of mite repellence. Acylsugar contents were quantified with the Sommogy-Nelson colorimetric method in the acessions L. esculentum 'TOM-584' (P(1), low acylsugars), L. pennellii 'LA-716' (P(2), high acylsugars), in the interspecific F(1) (P(1) x P(2)) and in the F(2 )(P(1) x P(2)) generations. Mite resistance was assessed by a repellence test. Broad-sense heritability of acylsugar contents was moderately high (h(2)(b) = 0.476). Frequency distributions in the P(1), P(2), F(1) and F(2) can be explained by the action of a single major locus, with near-complete dominance of the L. esculentum allele for low-acylsugar content over the L. pennellii allele for high content. Indirect selection for high levels of acylsugars in leaflets led to correlated increases in the levels of mite repellency, indicating that acylsugars may be the main factor involved in mite resistance. 相似文献
19.
Hamid Ashrafi Matthew P. Kinkade Heather L. Merk Majid R. Foolad 《Molecular breeding : new strategies in plant improvement》2012,30(1):549-567
Epidemiological and clinical studies indicate that a steady dietary intake of bioavailable lycopene, a C40 carotenoid and potent natural antioxidant, may be associated with a decreased incidence of prostate cancer in humans. Since fresh tomatoes and processed tomato products represent approximately 85% of the average human??s dietary lycopene intake, the identification of novel genetic factors which regulate high fruit lycopene content in tomato is imperative for the improvement of nutritional quality in this commercially valuable specialty crop. To understand the genetic control of the extraordinarily high fruit lycopene content in an accession (LA2093) of the tomato wild species Solanum pimpinellifolium, a quantitative trait locus (QTL) mapping study was conducted using a recombinant inbred line (RIL) population of a cross between LA2093 and a cultivated tomato (S. lycopersicum) breeding line, NCEBR-1. The parental lines, F1 progeny, and F7-F10 RIL populations were grown in replicated field trials in four successive years and evaluated for lycopene content as well as several other traits, including fruit fresh weight, soluble solids content, pH of puree, and plant maturity. The lycopene content of ripe fruit was estimated using three methods: high-performance liquid chromatography (HPLC), spectrophotometry, and colorimetric assays. Based on these measurements, QTL were identified and compared across generations. Among the QTL identified for lycopene, two QTL, located on chromosomes 7 and 12, had very large effects and were consistent across generations. The genomic intervals in which these two QTL reside do not correspond to known map positions of carotenoid biosynthetic genes, indicating that these QTL may represent novel alleles with potentially important implications for tomato breeding as well as increased understanding of carotenoid accumulation in tomato. Several QTL were also identified for fruit weight, soluble solids content and plant maturity. The potential implications of these results for tomato crop improvement are discussed. 相似文献
20.
A. B. Bonnema J. M. Melzer M. A. O'Connell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(3):339-348
Summary Cybrids have been regenerated following protoplast fusion of iodoacetamide-treated leaf mesophyll cells of Lycopersion esculentum cv UC82 and gamma-irradiated cell suspensions of L. pennellii, LA716. The cybrids were recovered in the regenerant population at a frequency of 19%, no selection pressure was applied for the persistence of the donor cytoplasm. The nuclear genotype of ten cybrids was characterized extensively using isozyme markers, cDNA-based restriction fragment length polymorphisms (RFLPs), and the morphology of the plants. No nuclear genetic information from L. pennellii was detected in the cybrids. The organellar genotype of the cybrids was determined using cloned probes and species-specific RFLPs. All the cybrids had inherited the tomato chloroplast genome and had varying amounts of L. pennellii mitochondrial DNA. The cybrids all had a diploid chromosome number of 24, produced pollen, and set seed. 相似文献