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1.
The genetic basis of pear-shaped tomato fruit 总被引:1,自引:0,他引:1
H.-M. Ku S. Doganlar K.-Y. Chen S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(5):844-850
Molecular-marker analysis of a cross between yellow pear, a tomato variety bearing small, pear-shaped fruit, and the round-fruited,
wild species, Lycopersicon pimpinellifolium LA1589, revealed that pear-shaped fruit is determined largely by a major QTL on chromosome 2 and, to a lesser extent, a minor
QTL on chromosome 10. The locus on chromosome 2 was also detected in a cross between yellow pear and the round-fruited introgression
line (IL2–5) which carried the distal portion of chromosome 2 from the Lycopersicon pennellii genome. Based on its map position, we propose that the locus detected on chromosome 2 is the same as a locus referred to
as ovate in the early tomato literature (Linstrom 1926, 1927). The fruit-shape index (length/diameter) and neck constriction were
highly correlated in both populations suggesting that ovate exerts control over both traits or that the genes for these traits are tightly linked on chromosome 2. Using two-way ANOVA
test, the minor QTL on chromosome 10 showed no significant interaction with the ovate locus on chromosome 2 with respect to the fruit-shape index. For ovate round fruit was dominant to elongated fruit in the L. pimpinellifolium populations, but additive in the IL2–5 population. Thus far, no genes controlling fruit shape have been cloned. The molecular
mapping of the ovate locus may ultimately lead to its isolation via map-based cloning.
Received: 8 January 1999 / Accepted: 30 January 1999 相似文献
2.
Tör M Manning K King GJ Thompson AJ Jones GH Seymour GB Armstrong SJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):165-170
Cnr (Colourless non-ripening) is a dominant pleiotropic ripening mutation of tomato (Lycopersicon esculentum) which has previously been mapped to the proximal region of tomato chromosome 2. We describe the fine mapping of the Cnr locus using both linkage analysis and fluorescence in situ hybridisation (FISH). Restriction fragment length polymorphism
(RFLP)-, amplified restriction fragment polymorphism (AFLP)-, and cleaved amplified polymorphic sequence (CAPS)-based markers,
linked to the Cnr locus were mapped onto the long arm of chromosome 2. Detailed linkage analysis indicated that the Cnr locus was likely to lie further away from the top of the long arm than previously thought. This was confirmed by FISH, which
was applied to tomato pachytene chromosomes in order to gain an insight into the organisation of hetero- and euchromatin and
its relationship to the physical and genetic distances in the Cnr region. Three molecular markers linked to Cnr were unambiguously located by FISH to the long arm of chromosome 2 using individual BAC probes containing these single-copy
sequences. The physical order of the markers coincided with that established by genetic analysis. The two AFLP markers most-closely
linked to the Cnr locus were located in the euchromatic region 2.7-cM apart. The physical distance between these markers was measured on the
pachytene spreads and estimated to be approximately 900 kb, suggesting a bp:cM relationship in this region of chromosome 2
of about 330 kb/cM. This is less than half the average value of 750 kb/cM for the tomato genome. The relationship between
genetic and physical distances on chromosome 2 is discussed.
Received: 11 January 2001 / Accepted: 30 April 2001 相似文献
3.
S. Doganlar S. D. Tanksley M. A. Mutschler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(2):249-255
Using RAPD marker analysis, two quantitative trait loci (QTLs) associated with earliness due to reduced fruit-ripening time
(days from anthesis to ripening = DTR) were identified and mapped in an F2 population derived from a cross between Lycopersicon esculentum’E6203’ (normal ripening) and Lycopersicon esculentum’Early Cherry’ (early ripening). One QTL, on chromosome 5, was associated with a reduction in both ripening time (5 days)
and fruit weight (29.3%) and explained 15.8 and 13% of the total phenotypic variation for DTR and fruit weight, respectively.
The other QTL, on chromosome 12, was primarily associated with a reduction only in ripening time (7 days) and explained 12.3%
of the total phenotypic variation for DTR. The gene action at this QTL was found to be partially dominant (d/a=0.41). Together,
these two QTLs explained 25.1% of the total phenotypic variation for DTR. Additionally, two QTLs associated with fruit weight
were identified in the same F2 population and mapped to chromosomes 4 and 6, respectively. Together, these two QTLs explained 30.9% of the total phenotypc
variation for fruit weight. For all QTLs, the ’Early Cherry’ alleles caused reductions in both ripening time and fruit weight.
The polymorphic band for the most significant RAPD marker (OPAB-06), linked to the reduced ripening time QTL on chromosome
12, was converted to a cleaved amplified polymorphism (CAP) assay for marker-aided selection and further introgression of
early ripening time (DTR) into cultivated tomato.
Received: 15 March 1999 / Accepted: 29 April 1999 相似文献
4.
H-B. Zhang M. A. Budiman R. A. Wing 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(8):1183-1189
Abscission zones are specialized regions in plants, usually located at the base of most plant parts, such as flowers, fruit
and leaves, where organs are shed. Although a great deal of information is known about the physiological and biochemical events
that lead to organ shedding, very little is known of the molecular events that lead to the formation of the abscission zone
itself. In tomato, two recessive mutations have been discovered that completely suppress the formation of flower and fruit
pedicel abscission zones, i.e., jointless (j) and jointless-2 (j-2), both tentatively localized to chromosome 11 about 30 cM apart. Because the study of the control of abscission zone development
is important for both basic and applied research we are using a map-based cloning approach to identify the jointless genes.
The first step in any positional cloning experiment is to establish segregating mapping populations for the target gene and
identify closely linked molecular markers that flank the locus. In this study, bulked segregant analysis was used to identify
a RAPD marker associated with the j-2 locus, RPD140. To determine the chromosome location of RPD140, we converted it to an RFLP marker that was then mapped on
the Cornell reference tomato map in a marker-dense region of chromosome 12. To verify that the j-2 locus was located on tomato chromosome 12, we used nine chromosome 12 RFLP markers linked with RPD140 to map the j-2 gene in an interspecific F2 mapping population of 151 plants segregating for j-2. The j-2 gene was localized to a 3.0-cM interval between RPD140 and TG618 on tomato chromosome 12.
Received: 29 March 1999 / Accepted: 13 October 1999 相似文献
5.
High-resolution linkage analysis and physical characterization of the EIX-responding locus in tomato
M. Ron R. Kantety G. B. Martin N. Avidan Y. Eshed D. Zamir A. Avni 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(2):184-189
An ethylene-inducing xylanase (EIX) from Tricohoderma viride is a potent elicitor of ethylene biosynthesis, localized cell death and other defense responses in specific cultivars of
tobacco (Nicotiana
tabacum) and tomato (Lycopersicon esculentum). Wild species of tomato, such as Lycopersicon cheesmanii and Lycopersicon pennellii, do not respond to EIX treatment. The F1 progeny of a L. esculentum×L. cheesmanii and a L. esculentum×L. pennellii cross responded to EIX treatment with an increase in ethylene biosynthesis and the induction of localized cell death. The
F2 progeny of the above mentioned crosses segregated 3:1 (responding:non-responding). We mapped the EIX-responding locus (Eix) to the short arm of chromosome 7 using a population of introgression lines (ILs), containing small RFLP-defined chromosome
segments of L. pennellii introgressed into L. esculentum. RFLP analysis of 990 F2 plants that segregated for the introgressed segment mapped the Eix locus 0.1 cM and 0.9 cM from the flanking markers TG61 and TG131, respectively. Using the marker TG61 we isolated a yeast
artificial chromosome (YAC) clone that carries 300-kb DNA segments derived from the Eix region. By mapping the ends of this YAC clone we show that it spans the Eix locus. Thus, positional cloning of the Eix locus appears feasible.
Received: 20 March 1999 / Accepted: 30 April 1999 相似文献
6.
B. S. Stamova R. T. Chetelat 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(4):527-537
Cucumber mosaic virus (CMV) infects a wide variety of crop plants and in tomato (Lycopersicon esculentum Mill.) causes significant economic losses in many growing regions, particularly the Mediterranean. The objective of the present
study was to identify the number and map locations of genes controlling resistance to CMV in breeding lines (BC1–inbreds) derived from the related wild species L. chilense. These lines also carried the gene Tm-2
a
for resistance to ToMV, which facilitated the interpretation of disease symptoms. The segregation for CMV resistance in the
BC2F1 and BC2F2 generations, following mechanical inoculation with subgroup-I isolates, was consistent with expectations for a single dominant
gene, for which the symbol Cmr (cucumber mosaic resistance) was given. Resistant and susceptible BC1-inbreds were analyzed with RFLP and isozyme markers to identify genomic regions introgressed from L. chilense. The only L. chilense-specific markers found were on chromosome 12; some resistant lines contained a single introgression comprising the entire
short arm and part of the long arm of this chromosome, while others contained a recombinant derivative of this introgression.
The chromosome 12 markers were significantly associated with CMV resistance in both qualitative and quantitative models of
inheritance. The qualitative analysis, however, demonstrated that CMV resistance was not expressed as a reliable monogenic
character, suggesting a lack of penetrance, significant environmental effects, or the existence of additional (undetected)
resistance factors. In the quantitative analysis, the marker interval TG68 – CT79 showed the most significant association
with CMV resistance. No association between CMV resistance and the Tm-2
a
gene was observed. These breeding lines are potentially useful sources of CMV resistance for tomato improvement, in which
context knowledge of the map location of Cmr should accelerate introgression by marker-assisted selection.
Received: 9 August 1999 / Accepted: 22 December 1999 相似文献
7.
I. Levin N. Gilboa E. Yeselson S. Shen A. A. Schaffer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(2):256-262
A genetic trait determining the ratio of fructose to glucose in mature tomato fruits is described. A backcross breeding program
based on the interspecific cross of Lycopersicon
hirsutum and L. esculentum yielded stable genotypes with a high ratio of fructose to glucose (>1.5:1) compared with the approximately equimolar ratios
found in L. esculentum. Two inter-simple- sequence repeat (ISSR) DNA sequences, highly associated (20 <LOD score <21) with the trait, were identified.
The markers were found to be less associated with either glucose or fructose levels individually (2 <LOD score <3) and were
statistically unlinked to total sugars and total soluble solids (TSS). These two ISSR bands segregated in a dominant fashion
and were found to be allelic to each other, one associated in coupling and the other in repulsion with the trait of high fructose
to glucose ratio. Both ISSR markers were mapped to the centromeric region of tomato chromosome 4. Quantitative analysis of
the identified locus, based on data from segregating F2, BC and F3 populations from the cross between genotypes having high and low fructose to glucose ratios, suggested that the L. hirsutum-derived allele (Fgr
H), which increases the fructose to glucose ratio, is partially dominant. Fgr
H leads to an increase in fructose levels and a subsequent decrease in glucose levels, with no effect on total hexose levels.
Accordingly, we conclude that the Fgr locus modulates the partitioning of hexose sugars between fructose and glucose, with no effect on total sugars or TSS.
Received: 8 March 1999 / Accepted: 12 May 1999 相似文献
8.
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
9.
The use of semi-automated fluorescent microsatellite analysis for tomato cultivar identification 总被引:5,自引:0,他引:5
G. M. M. Bredemeijer P. Arens D. Wouters D. Visser B. Vosman 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(4):584-590
The objectives of this study were to evaluate the usefulness of a fluorescent-analysis method for genotyping PCR-based tomato
microsatellite markers (or STMSs) and to establish the value of these markers to generate unique DNA profiles of tomato cultivars.
The analyses were performed using forward primers labelled with a fluorochrom and using an ALF express DNA sequencer. In general,
analysis of the tomato STMSs revealed distinct allelic peaks. PCR artefacts like stuttering and differential amplification
were observed for several tomato STMS markers, but in most cases these artefacts did not seriously hamper allele designation.
Comparison of fluorescent and silver-stained allelic profiles revealed a similar distribution of alleles among the test cultivars.
Sixteen tomato cultivars were DNA-typed for 20 selected STMS markers using the fluorescent approach. Length polymorphism among
the PCR products was detected with 18 of these markers, yielding gene diversity values from 0.06 to 0.74. The number of alleles
per microsatellite locus ranged from 2 to 8. As few as four STMSs were sufficient to differentiate between all 16 cultivars,
indicating that these markers are especially suitable for a species like tomato which has low levels of variation as detected
by other types of markers.
Received: 5 February 1998 / Accepted: 7 April 1998 相似文献
10.
H.-M. Ku S. Grandillo S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(5-6):873-878
fs8.1 is a major fruit-shape QTL differentiating fresh-market and processing tomatoes. Mature fruits from plants with the wild-type
fresh-market alleles are round, whereas those with alleles from processing variety E6203 are elongated (sometimes referred
to as blocky or square tomatoes). Fine mapping was undertaken to determine whether the effect is due to a single gene or several
tightly linked genes. RAPD and RFLP linkage analysis, and substitution mapping of nearly isogenic lines (NILs) segregating
for the 22.8 cM-TG176-CT92 interval at the top of chromosome 8 in tomato were used for high-resolution mapping. For the 1212
gametes screened in F2 and F3 families, it was determined that fs8.1 maps as a single locus near the centromere of chromosome 8. A comparative developmental study of fs8.1 NILs revealed that fs8.1 alleles exert their effects on fruit shape early in carpel development at least 6 days before anthesis. Field evaluations
of the NILs indicate that fs8.1 affects not only fruit shape, fruit length, and fruit weight but also the number of flowers and fruits per inflorescence,
and the harvest index. The date of first flower and fruit diameter were not significantly affected.
Received: 19 July 1999 / Accepted: 16 December 1999 相似文献
11.
Growth of mycorrhizal tomato and mineral acquisition under salt stress 总被引:19,自引:0,他引:19
G. N. Al-Karaki 《Mycorrhiza》2000,10(2):51-54
High salt levels in soil and water can limit agricultural production and land development in arid and semiarid regions. Arbuscular
mycorrhizal fungi (AMF) have been shown to decrease plant yield losses in saline soils. The objective of this study was to
examine the growth and mineral acquisition responses of greenhouse-grown tomato to colonization by the AMF Glomus mosseae [(Nicol. And Gerd.) Gerd. and Trappe] under varied levels of salt. NaCl was added to soil in the irrigation water to give
an ECe of 1.4 (control), 4.7 (medium) and 7.4 dS m–1 (high salt stress). Plants were grown in a sterilized, low P (silty clay) soil-sand mix. Mycorrhizal colonization was higher
in the control than in saline soil conditions. Shoot and root dry matter yields and leaf area were higher in mycorrhizal than
in nonmycorrhizal plants. Total accumulation of P, Zn, Cu, and Fe was higher in mycorrhizal than in nonmycorrhizal plants
under both control and medium salt stress conditions. Shoot Na concentrations were lower in mycorrhizal than in nonmycorrhizal
plants grown under saline soil conditions. The improved growth and nutrient acquisition in tomato demonstrate the potential
of AMF colonization for protecting plants against salt stress in arid and semiarid areas.
Accepted: 21 February 2000 相似文献
12.
Comparative analysis of polymorphism and chromosomal location of tomato microsatellite markers isolated from different sources 总被引:33,自引:0,他引:33
Areshchenkova T Ganal MW 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):229-235
Previously isolated tomato (Lycopersicon esculentum) microsatellite markers were mainly clustered in the centromeric heterochromatin and not located in euchromatic regions.
To achieve a more-uniform distribution of microsatellite markers for genome mapping purposes, a set of tomato microsatellite
markers containing dinucleotide simple sequence repeats were developed by screening genomic libraries enriched for single-copy
sequences, and screening the tomato EST database. The tomato microsatellites isolated in these ways were characterized by
combinations of different types of repeated motifs and they were polymorphic in a set of L. esculentum varieties detecting up to four alleles. A total of 20 markers were placed on the genetic map of tomato. Interestingly, all
markers isolated from genomic libraries enriched for single-copy sequences by PstI-pre-digestion mapped into the centromeric regions. The majority of markers derived from EST sequences contained predominantly
AT microsatellites and were located in euchromatic regions.
Received: 22 December 2000 / Accepted: 4 May 2001 相似文献
13.
M. J. Truco L. B. Randall A. J. Bloom D. A. St. Clair 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(7):1082-1092
The genetic basis for shoot wilting and root ammonium uptake under chilling temperatures was examined in an interspecific
backcross (BC1) population derived from Lycopersicon esculentum Mill. cv T5 and wild Lycopersicon hirsutum f. typicum accession LA1778. The chilling sensitivity of shoot wilting and ammonium uptake was evaluated in four replicated cuttings
from each of 196 BC1 plants. Wilting was evaluated at two different times: 2 hours (wilting 2 h) and 6 hours (wilting 6 h recovery) after root
exposure to 4°C. The BC1 plants were genotyped with 89 polymorphic RFLP markers, and composite interval mapping was used to detect quantitative trait
loci (QTLs). Three QTLs, one each on chromosomes 5, 6 and 9, were detected for wilting 2 h. The presence of a L. hirsutum (H) allele at the QTL on chromosomes 5 and 9 decreased wilting, while the H allele at the QTL on chromosome 6 increased wilting.
To analyze plant recovery from wilting at 6 h, subsets of the BC1 population were selected, based on phenotype and genotype, because not all plants wilted at 2 h. The phenotype subset (wilting
6 h-PS) included plants that wilted to a greater degree at 2 h, and the genotype subsets included plants carrying specific
allelic compositions at the QTL for wilting 2 h on chromosomes 5 (wilting 6 h-GS-ch5), 6 (wilting 6 h-GS-ch6), and 9 (wilting
6 h-GS-ch9). On chromosome 6, a QTL was located that was associated with three subsets (wilting 6 h-PS, wilting 6 h-GS-ch5
and wilting 6 h-GS-ch9), while on chromosome 7 a QTL was detected with two subsets (wilting 6 h-PS and wilting 6 h-GS-ch5).
Three additional QTLs were detected within a single subset: chromosome 1 (wilting 6 h-GS-ch6), chromosome 11 (wilting 6 h-GS-ch5)
and chromosome 12 (wilting 6 h-GS-ch9). The presence of the H allele at the QTL on chromosomes 7 and 12 had a positive effect,
enhancing recovery from wilting, while the H allele at the other QTL had a negative effect. Three traits were used to evaluate
the chilling sensitivity of root ammonium uptake: ammonium uptake before a chilling episode, ammonium uptake after the chilling
episode, and the relative inhibition of uptake (difference in uptake rates before and after chilling divided by the rate before
chilling). One QTL was detected on chromosome 3 for the rate before chilling and one on chromosome 6 for the relative inhibition
of ammonium uptake. Our results demonstrate that shoot wilting and ammonium uptake under chilling are controlled by multiple
QTLs.
Received: 10 August 1999 / Accepted: 25 March 2000 相似文献
14.
Identifying the loci responsible for natural variation in fruit size and shape in tomato 总被引:18,自引:0,他引:18
S. Grandillo H. M. Ku S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(6):978-987
Fruit size and shape are two major factors determining yield, quality and consumer acceptability for many crops. Like most
traits important to agriculture, both are quantitatively inherited. Despite their economic importance none of the genes controlling
either of these traits have been cloned, and little is known about the control of the size and shape of domesticated fruit.
Tomato represents a model fruit-bearing domesticated species characterized by a wide morphological diversity of fruits. The
many genetic and genomic tools available for this crop can be used to unraveal the molecular bases of the developmental stages
which presumably influence fruit architecture, size and shape. The goal of this review is to summarize data from the tomato
QTL studies conducted over the past 15 years, which together allow the identification of the major QTLs responsible for fruit
domestication in tomato. These results provide the starting point for the isolation of the genes involved in fruit-size/shape
determination in tomato and potentially other fruit-bearing plants.
Received: 21 January 1999 / Accepted: 12 March 1999 相似文献
15.
F. Garriga-Calderé D. J. Huigen A. Angrisano E. Jacobsen M. S. Ramanna 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(2):155-163
By backcrossing three BC1 genotypes of potato (+) tomato fusion hybrids to different tetraploid potato pollinators, BC2 populations were produced. A combined total of 97 BC2 plants from three BC2 populations were analysed with chromosome-specific probes through restriction fragment length polymorphism (RFLP) for the
presence of alien tomato chromosomes. The number of different alien tomato chromosomes transmitted through the female BC1 parent ranged from 0 to 6, and the average number of different alien chromosomes transmitted per BC2 plant varied between 1.7 and 3.4 in the different populations. This variation corresponded to the chromosome constitution
of the individual BC1 parents: parent 6739, which possessed 11 different alien chromosomes in a single condition, gave rise to progeny with a lower
average number of alien chromosomes per plant than the BC1 parent 2003 that possessed 2 of the 12 alien chromosomes in a disomic condition. In the latter case, the higher transmission
rate was attributed to the more regular distribution of the two alien chromosomes in the disomic condition because of regular
bivalent formation during meiosis as revealed by genomic in situ hybridisation (GISH) and fluorescent in situ hybridisation
(FISH). The transmission frequencies of individual alien chromosomes were subjected to statistical analysis to test whether
the maternal genotypes had an effect on alien-chromosome transmission. Among the BC2 plants, a total of 27 single additions were detected for as many as seven different chromosomes (1, 2, 4, 6, 8, 10 and 12)
out of the 12 possible types.
Received: 4 March 1997 / Accepted: 28 August 1997 相似文献
16.
Heredity and genetic mapping of domestication-related traits in a temperate japonica weedy rice 总被引:10,自引:0,他引:10
C. Bres-Patry M. Lorieux G. Clément M. Bangratz A. Ghesquière 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(1):118-126
Rice is often found as various weedy forms in temperate or newly cultivated rice growing regions throughout the world. The
emergence of these forms in the absence of true wild rice remains unclear. A genetic analysis of domestication-related traits
(weed syndrome) has been conducted to better understand the appearance of these plants in rice fields. A doubled haploid (DH)
population was derived from a cross between a japonica variety and a weedy plant collected in Camargue (France) to set up a genetic linkage map consisting of 68 SSR and 31 AFLP
loci. Five qualitative traits related to pigmentation of different organs and 15 developmental and morphological quantitative
traits were scored for genes and QTLs mapping. Despite a good reactivity in anther culture and a high fertility of the DH
lines, segregation distortions were observed on chromosomal segments bearing gametophytic and sterility genes and corresponded
to various QTLs evidenced in indica×japonica distant crosses. Mapping of the coloration genes was found to be in agreement with the presence of several genes previously
identified and according to the genetic model governing the synthesis and distribution of anthocyan pigment in the plant.
In addition, the main specific traits of weedy forms revealed the same genes/QTLs as progeny derived from a cross between
Oryza sativa and its wild progenitor O. rufipogon. A large variation for most characters was found in the DH population, including transgressive variation. Significant correlations
were observed between morphology and traits related to weeds and corresponded to a distinct colocalization of most of the
QTLs on a limited number of chromosomal regions. The significance of these results on the origin of weedy forms and the de-domestication
process is discussed.
Received: 25 February 2000 / Accepted: 14 April 2000 相似文献
17.
H. van Oss Y. Aron G. Ladizinsky 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(3-4):452-457
Chloroplast DNA (cpDNA) restriction site diversity was assessed by 21 enzyme/probe combinations in 30 accessions of six Lens species, including the recently recognized L. lamottei and L. tomentosus. A total of 118 fragments were scored and 26 restriction site mutations were identified. The cpDNA restriction pattern supports
circumscribing L. lamottei and L. tomentosus as independent species. The value of the data for reconstructing phylogeny in the genus is discussed. The cpDNA of all 13
accessions of the lentil’s wild progenitor, L. culinaris subsp. orientalis, differed from that of the single lentil cultivars used in this study. This diversity indicates that other populations of
this subspecies from Turkey and Syria examined by Mayer and Soltis (1994) are potentially the founder members of lentil. Examination
of L. lamottei×L. nigricans hybrids between accessions having different restriction patterns showed paternal plastid inheritance in L. nigricans.
Received: 2 July 1996 / Accepted: 19 July 1996 相似文献
18.
Response of two tomato cultivars differing in salt tolerance to inoculation with mycorrhizal fungi under salt stress 总被引:19,自引:0,他引:19
Effects of arbuscular mycorrhizal fungi (AMF) and salt stress on nutrient acquisition and growth of two tomato cultivars exhibiting
differences in salt tolerance were investigated. Plants were grown in a sterilized, low-P (silty clay) soil-sand mix. Salt
was applied at saturation extract (ECe) values of 1.4 (control), 4.9 (medium) and 7.1 dS m–1 (high salt stress). Mycorrhizal colonization occurred irrespective of salt stress in both cultivars, but AMF colonization
was higher under control than under saline soil conditions. The salt-tolerant cultivar Pello showed higher mycorrhizal colonization
than the salt-sensitive cultivar Marriha. Shoot dry matter (DM) yield and leaf area were higher in mycorrhizal than nonmycorrhizal
plants of both cultivars. Shoot DM and leaf area but not root DM were higher in Pello than Marriha. The enhancement in shoot
DM due to AMF inoculation was 22% and 21% under control, 31% and 58% under medium, and 18% and 59% under high salinity for
Pello and Marriha, respectively. For both cultivars, the contents of P, K, Zn, Cu, and Fe were higher in mycorrhizal than
nonmycorrhizal plants under control and medium saline soil conditions. The enhancement in P, K, Zn, Cu, and Fe acquisition
due to AMF inoculation was more pronounced in Marriha than in the Pello cultivar under saline conditions. The results suggest
that Marriha benefited more from AMF colonization than Pello under saline soil conditions, despite the fact that Pello roots
were highly infected with the AMF. Thus, it appears that Marriha is more dependent on AMF symbiosis than Pello.
Accepted: 22 January 2001 相似文献
19.
A. J. Monforte E. Friedman D. Zamir S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(4):572-590
Quantitative Trait Locus (QTL) allelic variation was studied by analyzing near-isogenic lines (NILs) carrying homologous introgressions
on chromosome 4 from three green-fruited wild tomato species. The NILs affect agronomic (yield, brix, fruit weight) and fruit (fruit shape,
color, epidermal reticulation) traits in a similar manner. However, significant differences were detected in the magnitudes
of the effects, the dominance deviations and epistatic interactions, indicating that those species carry different alleles
for the QTL. As the QTL did not show any interaction across environments, gene-tic backgrounds or other QTLs, it can be used
to introduce novel genetic variation into a broad range of cultivars. Analysis of new recombinant NILs showed that fruit traits
are controlled by several linked genetic loci, whereas multiple genetic loci control the agronomic traits within the original
introgression. The hypothesis that QTLs may be composed of multiple linked genes can not be rejected prior to implement projects
for QTL isolation and cloning. Loci involved in color enhancement could not be related to any known gene involved in the carotenoid
biosynthesis pathway, therefore it is hypothesized that the function of those loci must be related to the genetic regulation
of the carotenoid biosynthetic pathway.
Received: 14 April 2000 / Accepted: 12 May 2000 相似文献
20.
J. P. W. Haanstra F. Meijer-Dekens R. Laugé D. C. Seetanah M. H. A. J. Joosten P.J.G.M. de Wit P. Lindhout 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(4):661-668
In the past, numerous Lycopersicon accessions have been described that harbor resistance genes to Cladosporium fulvum (Cf genes). Several Cf genes have been isolated, like Cf-4, Cf-4A and Cf-9, which are present on the short arm of Chromosome 1, and Cf-2 and Cf-5, which reside on Chromosome 6. To identify Cf genes linked to the Hcr9 cluster ”Milky Way” on the short arm of Chromosome 1, we test-crossed 66 resistant Lycopersicon accessions to the near-isogenic line Moneymaker-Cf4, and the F1s were crossed to the susceptible tomato cultivar Moneymaker. Putative linkage between an unknown Cf gene and Cf-4 was concluded based on small-scale allelic tests from an under-representation of susceptible genotypes in the progenies of
24 plants after inoculation with race 0 of C. fulvum. In this way, of the 21 resistant lines tested, 10 harbored a Cf gene that was linked to the Hcr9 Milky Way cluster. Moreover, one of the lines harboring a Cf gene closely linked to Cf-4 specifically recognizes the extracellular protein ECP5 of C. fulvum and was designated Cf-ECP5. Using a testcross population of 338 plants, we mapped Cf-ECP5 more accurately at 4 cM proximal to the Hcr9 Milky Way locus. This report shows that the method of small-scale allelic tests provides a useful tool to rapidly screen
for Cf genes on the short arm of Chromosome 1. Further analysis of these Cf genes will elucidate the complex genetic organization of Cf genes on Chromosome 1 of tomato.
Received: 23 August 1999 / Accepted: 12 January 2000 相似文献