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1.
Genetic capacity for green plant regeneration in anther culture were mapped in a population comprising 50 doubled haploid
lines from a cross between two wheat varieties ‘Ciano’ and ‘Walter’ with widely different capacity for green plant regeneration.
Bulked segregant analysis with AFLP markers and composite interval mapping detected four QTLs for green plant percentage on
chromosomes 2AL (QGpp.kvl-2A), 2BL (QGpp.kvl-2B.1 and QGpp.kvl-2B.2) and 5BL (QGpp.kvl-5B).The three QTLs detected on chromosome 2AL and 2BL all derived their alleles favouring green plant formation from the responsive
parent ‘Ciano’.The remaining QTL on chromosome 5BL had the allele favouring green plants from the low responding parent ‘Walter’.
In a multiple regression analysis the four QTLs could explain a total of 80% of the genotypic variation for green plant percentage.
None of the chromosomal regions with QTLs for green plant percentage showed significant influence on either embryo formation
or regeneration frequencies from the anther culture. The three major QTLs located on group two chromosomes were fixed in a
second DH population derived from two parents ‘Ciano’ and ‘Benoist’,both with high capacity to produce green plants. A QTL
explaining31.5% of the genetic variation for green plant formation were detected on chromosome 5BL in this cross as well.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Shigeki Moriya Hiroshi Iwanami Kazuma Okada Toshiya Yamamoto Kazuyuki Abe 《Euphytica》2011,177(1):135-150
Differentiation of cultivars with simple sequence repeat (SSR) markers is a very useful technique for the true-to-type characterization
of cultivars and clarification of parent-offspring relationships. We developed an SSR marker set for cultivar identification
comprising 15 markers that were screened from 46 previously published SSRs. This marker set could be used for apple varieties
including Malus × domestica and/or other Malus species. These SSRs successfully characterized 95 apples, including the leading and major founding cultivars used worldwide
for modern apple breeding. Therefore, this marker set could be applied to almost all apple cultivars. We also analyzed the
parent-offspring relationships of 69 cultivars by considering allele transmissions. This analysis revealed the true parentage
of the following seven cultivars: ‘Kizashi’, ‘Chinatsu’, ‘Honey Queen’, ‘Haruka’, ‘Seirin’, ‘Ozenokurenai’, and Morioka #48.
This analysis also revealed a parentage discrepancy for ‘Hacnine’. From the parent-offspring analysis, two microsatellite
mutation events at alleles inherited from pollen parents were observed. 相似文献
3.
Self and cross-incompatibility determination by means of fruit and seed set experiments or pollen tube growth observations
in the style has been frequently reported to be unclear in pear (Pyrus communis L.). Thus,in order to develop a reliable in vivo method to test pollen-pistil incompatibility in pear, pollen tube performance has been studied along the pistil following
self and cross-pollinations. Results show that, while pollen tube growth in the style may be an unclear test, ovule observation
at the microscope for the presence of pollen tube in the nucellus is a proper method to test incompatibility in this crop.
With this analysis we could identify S-alleles of ‘Williams’ (S1S2) and ‘Coscia’(S3S4), and three of the four possible S-genotypes resulting from the ‘Williams’ × ‘Coscia’ cross, as represented by ‘Butirra Precoz
Morettini’ (S1S3), ‘Santa Maria Morettini’ (S2S3)and ‘Tosca’ (S1S4). This result demonstrates that ‘Williams’ and ‘Coscia’ cultivars do not share any allele in common. We also established
two new inter-incompatibility groups in pear. Furthermore, the presence of a common allele between ‘Williams’ and ‘Agua de
Aranjuez’,and ‘Coscia’ and ‘Agua de Aranjuez’, three apparently unrelated old cultivars, may indicate a narrower genetic base
than expected for European pear. This finding together with the fact that 40% of new released cultivars have direct or indirect
parental relationship with the cultivars ‘Coscia’ and/or ‘Williams’, anticipates the possibility of new cases of cross-incompatibility
for this crop in the future. Both the method described and the determination of the S-genotypes will facilitate the characterisation
of self and cross-incompatibility relationships in this species.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
Summary
Valsa canker is the most serious wood rot disease of apple in Japan. Dormant, excised twig assay in vitro was used to determine
resistance to Valsa canker. ‘Fuji’, ‘Starking Delicious’, ‘M.26 EMLA’, and ‘MM.106’ were considered to be highly susceptible,
while Malus sieboldii showed moderate resistance. Several cultivars belonging toM. prunifolia, M. baccata, andM. × domestica showed comparative resistance. The phloridzin content in the bark ofMalus species was studied in relation toValsa canker resistance. Phloridzin content ofM. sieboldii was lower than inM. × domestica. Comparatively resistant cultivars had similar or higher phloridzin content compared to susceptible cultivars. No clear correlations
were found between resistance and phloridzin contents in the bark ofMalus species. 相似文献
5.
S. E. Ullrich H. Lee J. A. Clancy I. A. del Blanco V. A. Jitkov A. Kleinhofs F. Han D. Prada I. Romagosa J. L. Molina-Cano 《Euphytica》2009,168(3):331-345
Preharvest sprouting (PHS) and dormancy (DOR) can be problems in barley production and end use quality, especially for barley
used for seed and malting. Three crosses previously analyzed for DOR inheritance, were reanalyzed for PHS and DOR inheritance
using artificial rain to calculate sprout score (SSc) and measure alpha-amylase activity (AA). Germination percentage of untreated
grain for DOR was also measured. The crosses are ‘Steptoe’/’Morex’ (previously published), ‘Harrington’/TR306, and ‘Triumph’/Morex.
Among the three crosses, DOR QTLs were located to six and PHS QTLs to five chromosomes, respectively. Chromosome 6H was never
implicated. Previously identified DOR QTLs were confirmed in each cross, and most PHS QTLs coincided with DOR QTLs, but not
all. Unique PHS QTLs were identified on chromosomes 1H (AA), 2H (SSc, AA), 3H (SSc, AA), and 7H (SSc, AA) and unique DOR QTLs
on 1H, 2H, and 7H. Results indicate that PHS susceptibility and DOR are not always represented by opposite alleles at a locus.
Some QTL regions for a given trait are conserved across crosses and some are not. Several QTLs are suitable for marker-assisted
selection to balance PHS and DOR in breeding new cultivars. 相似文献
6.
Identification of QTLs controlling rice drought tolerance at seedling stage in hydroponic culture 总被引:1,自引:0,他引:1
‘Drought avoidance’ and ‘drought tolerance’ are two mechanisms by which plants adapt under water stress. These mechanisms
are difficult to evaluate separately in field experiments. Using hydroponic culture, we studied the genetic control of drought
tolerance in rice (Oryza sativa L.) without the effect of drought avoidance. A backcross inbred population of ‘Akihikari’ (lowland cultivar) × ‘IRAT109’
(upland cultivar) with 106 lines was cultured with (stressed condition) and without (non-stressed condition) polyethylene
glycol (PEG) at seedling stage. The relative growth rate (RGR), specific water use (SWU), and water use efficiency (WUE) showed
significant genotype × environment interactions with or without PEG, indicating that each line responded differently to water
stress. A quantitative trait locus (QTL) analysis revealed that these interactions were QTL specific. A total of three QTLs
on chromosomes 2, 4, and 7 were detected for RGR. The QTL on chromosome 7 had a constant effect across environments, while
the QTL on chromosome 4 had an effect only under non-stressed condition and that on chromosome 2 only under stressed condition.
The stress-specific QTL on chromosome 2 was not co-located with any QTLs for root system depth previously reported from the
same mapping population. However, this QTL was co-located with a stress-specific QTL for SWU, suggesting that the control
of transpiration was relevant to dry matter production under drought. We concluded that PEG-treated hydroponic culture is
very effective for use in genetic analyses of drought tolerance at seedling stage. 相似文献
7.
Jundae Lee Jee-Hwa Hong Jae Wahng Do Jae Bok Yoon 《Journal of Crop Science and Biotechnology》2010,13(4):227-233
Pepper (Capsicum spp.) anthracnose caused by Colletotrichum spp. is a serious disease damaging pepper production in Asian monsoon regions. For QTL mapping analyses of anthracnose resistance,
an introgression BC1F2 population was made by interspecific crosses between Capsicum annuum ‘SP26’ (susceptible recurrent parent) and Capsicum baccatum ‘PBC81’ (resistant donor). Both green and red fruits were inoculated with C. acutatum ‘KSCa-1’ and C. capsici ‘ThSCc-1’ isolates and the disease reactions were evaluated by disease incidence, true lesion diameter, and overall lesion
diameter. On the whole, distribution of anthracnose resistance was skewed toward the resistant parent. It might indicate that
one or two major QTLs are present. The introgression map consisting of 13 linkage groups with a total of 218 markers (197
AFLP and 21 SSR), covering a total length of 325 cM was constructed. Composite interval mapping analysis revealed four QTLs
for resistance to ‘KSCa-1’ and three QTLs for ‘ThSCc-1’ isolate, respectively. Interestingly, the major QTLs (CaR12.2 and CcR9) for resistance to C. acutatum and C. capsici, respectively, were differently positioned but there were close links between the minor QTL CcR12.2 for C. capsici and major QTL CaR12.2 as well as the minor QTL CaR9 for C. acutatum and major QTL CcR9. These results will be helpful for marker-assisted selection and pyramiding two different anthracnose-resistant genes in
commercial pepper breeding. 相似文献
8.
Uttam Kumar Arun K. Joshi Maya Kumari Rajneesh Paliwal Sundeep Kumar Marion S. Röder 《Euphytica》2010,174(3):437-445
Stay green or delayed senescence is considered to play a crucial role in grain development in wheat when assimilates are limited.
We identified three QTLs for stay green on the chromosomes 1AS, 3BS and 7DS using a recombinant inbred (RI) population developed
by making crosses between the stay green parent ‘Chirya 3’ and non-stay green ‘Sonalika’. The RI lines were evaluated in natural
field conditions for 2 years in replicated trial. The QTL on chromosome 1A was identified in both the years, while the QTLs
on 3BS and 7DS were identified only in 1st and 2nd year, respectively. The QTLs explained up to 38.7% of phenotypic variation
in a final simultaneous fit. The alleles for higher stay green values derived from the stay green parent ‘Chirya 3’. The QTLs
were named as QSg.bhu-1A, QSg.bhu-3B and QSg.bhu-7D. The QTL QSg.bhu-3B and QSg.bhu-7D were placed in the 3BS9-0.57-0.78 and 7DS5-0.36-0.61 deletion bins, respectively. 相似文献
9.
Takeshi Takasaki Kazuma Okada Carlos Castillo Yuki Moriya Toshihiro Saito Yutaka Sawamura Naoko Norioka Shigemi Norioka Tetsu Nakanishi 《Euphytica》2004,135(2):157-167
A new S
9-allele was discovered in 6 Japanese pear cultivars, ‘Shinkou’, ‘Shinsei’, ‘Niitaka’, ‘Amanogawa’, ‘Nangetsu’ and ‘Nansui’.
cDNA encoding S
9-RNase, a stylar product of S
9-allele, was cloned from pistils of ‘Shinkou’ and ‘Shinsei’ by 3' and 5' RACE. The S
9-RNase gene had an open reading frame of 684 nucleotides encoding 228 amino acid residues. S
9-RNase had a hypervariable (HV) region different from S
1- to S
8-RNase and shared higher similarity (95.2%) with apple S
3-RNase than with 8 Japanese pear S-RNases (from 61.0% to 70.7%). Genomic PCR with primers ‘FTQQYQ’ and ‘anti-(I/T) IWPNV’ provided S
1- to S
9-amplicon (product), but could not discriminate the S
2 from the S
9 of ca. 1.3 kb. The S
2 and S
9 were distinguished by digestion with AflII and BstBI, respectively. The digestion with nine S-allele-specific restriction endonucleases, SfcI, AflII, PpuMI, NdeI,AlwNI, HincII, AccII, NruI and BstBI, distinguished S
1 to S
9, establishing that this PCR-RFLP system is useful for S-genotype assignments in Japanese pear harboring S
1- to S
9-allele. ‘Shinkou’, ‘Shinsei’, ‘Nangetsu’ and ‘Nansui’ assigned as S
4
S
9 were determined to be cross incompatible.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
Characterization of segregation distortion on chromosome 3 induced in wide hybridization between indica and japonica type rice varieties 总被引:6,自引:0,他引:6
S. Matsushita T. Iseki Y. Fukuta E. Araki S. Kobayashi M. Osaki M. Yamagishi 《Euphytica》2003,134(1):27-32
We previously surveyed chromosomal regions showing segregation distortion of RFLP markers in the F2 population from the cross between a japonica type variety ‘Nipponbare’ and an indica type variety ‘Milyang23’, and showed
that the most skewed segregation appeared on the short arm of chromosome 3. By comparison with the marker loci where distortion
factors were previously identified, this region was assumed to be a gametophytic selection-2 (ga2) gene region. To evaluate this region, two near isogenic lines (NILs) were developed. One NIL had the ‘Nipponbare’ segment
of this region on the genetic background of ‘Milyang23’ (NIL9-23), and the other NIL had the ‘Milyang23’ segment on the genetic
background of ‘Nipponbare’ (NIL33-18). NIL9-23 and ‘Milyang23’, NIL33-18 and
‘Nipponbare’, and ‘Nipponbare’ and ‘Milyang23’ were respectively crossed to produce F1 and F2 populations. The F1 plants of NIL9-23 × ‘Milyang23’ and NIL33-18 × ‘Nipponbare’ showed high seed fertility and the same pollen fertility as their
parental cultivars, indicating that ga2 does not reduce seed and pollen fertility. Segregation ratio of a molecular marker on the ga2 region in the three F2 populations was investigated to clarify whether segregation distortion occurred on the different genetic backgrounds. Segregation
distortion of the ga2 region appeared in the both F2 populations from the NIL9-23 and ‘Milyang23’ cross (background was
‘Milyang23’ homozygote) and the ‘Nipponbare’ and ‘Milyang23’ cross (background was heterozygote), but did notin the F2 population from the NIL33-18 and ‘Nipponbare’ cross (background was ‘Nipponbare’ homozygote). This result indicates that
ga2 interacts with a ‘Milyang23’ allele(s) on the different chromosomal region(s) to cause skewed segregation of the ga2 region. In addition, segregation ratio was the same between the F2 populations from NIL9-23 × ‘Milyang23’ and ‘Nipponbare’ × ‘Milyang23’ crosses, suggesting that the both genotypes, ‘Milyang23’
homozygote and heterozygote, of gene(s) located on the different chromosomal region(s) have the same effect on the segregation
distortion.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
Quantitative trait loci for resistance to Fusarium head blight in recombinant inbred wheat lines from the cross Huapei 57-2 / Patterson 总被引:3,自引:0,他引:3
Fusarium head blight (FHB), primarily caused by Fusarium graminearum in North America, often results in significant losses in yield and grain quality of wheat (Triticum aestivum L.). Evaluation of FHB resistance is laborious and can be affected by environmental conditions. The development of DNA markers
associated with FHB quantitative trait loci (QTL) and their use in breeding programs could greatly enhance selection. The
objective of this study was to identify the location and effect of QTLs for FHB resistance using simple sequence repeat (SSR)
markers. A population of wheat recombinant inbred lines derived from the cross ‘Huapei57-2’/‘Patterson’ was characterized
for type II resistance in one field experiment and two tests under controlled conditions in the greenhouse. Bulked segregant
analysis followed by QTL mapping was used to identify the major segregating QTLs. Results indicate that ‘Huapei 57-2’ may
have the same resistance allele as ‘Sumai3’ at a QTL located on the short arm of chromosome 3B. Other QTLs of lower effect
size were identified on the long arm of 3Band on chromosomes 3A and 5B. Our findings along with results from other studies
demonstrate that the effect of the QTL on3BS is large and consistent across a wide range of genetic backgrounds and environments.
Pyramiding this QTL with other FHB QTLs using marker-assisted selection should be effective in improving FHB resistance in
a wheat breeding program.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
12.
N. F. Weeden M. Hemmatt D. M. Lawson M. Lodhi R. L. Bell A. G. Manganaris B. I. Reischs S. K. Brown G. -N. Ye 《Euphytica》1994,77(1-2):71-75
Summary Extensive linkage maps, consisting primarily of molecular markers, are being developed for apple, pear, and grape varieties.
The intrinsically high heterozygosity of outcrossing perennial species is utilized to produce segregating populations directly
from a cross between varieties. Nearly complete linkage maps have been generated for the apple varieties ‘Rome Beauty’ and
‘White Angel’. The map for ‘Rome Beauty’ contains 161 molecular markers, while that for ‘White Angel’ has 251 markers. Maps
for the pear varieties, ‘Bartlett’ and NY10353, also are being developed. Linkages conserved between the pear and apple genomes
have been identified. In grapes, maps for four varieties are available, the most extensive being those for ‘Cayuga White’
and ‘Aurore’. The apple maps have been used to investigate the genetic basis of morphological and physiological characters.
A gene controlling the presence of anthocyanins in the skin of the fruit is located on linkage group 3. Genes controlling
early bud break, branching habit, and production of root suckers have also been identified and mapped. 相似文献
13.
Summary
C. annuum L. ‘Serrano Criollo de Morelos-334’ (SCM-334) is a well-known source of resistance against pepper diseases, including Potato Virus Y (PVY). In this work, inheritance studies involving ‘SCM-334’ and related to PVY resistance were described. For this purpose, ‘SCM-334’ derived lines were used, and plant material from the cross between ‘SCM-334’ and ‘Yolo Wonder’ (YW) was employed as well. Five PVY isolates were used for the inoculations. The first resistance described is a monogenic and recessive gene, controlling a specific-isolate resistance, and provisionally named as pvr1
4. The second one is related to the inheritance of systemic necrotic symptoms after PVY inoculation. In this case a codominant gene is proposed and expressed only when the Pvr4 gene is not present. 相似文献
14.
To understand the genetic background of panicle characteristics in temperate japonica rice (Oryza sativa L.), we genetically analyzed DH lines derived from a cross between two temperate japonica rice cultivars, ‘Akihikari’ and
‘Koshihikari’,in 1996 and 1997. Four traits of panicle characteristics, number of primary branches per panicle (NPB), number
of secondary branches per panicle (NSB), average number of spikelets on one primary branch (NSP)and average number of spikelets
on one secondary branch (NSS), in 212 DH lines were measured, and the interval mapping of QTLs for these traits was carried
out using169 DNA markers with an LOD threshold of2.5. Five, three and one putative QTLs for NPB, NSB and NSS were identified,respectively,
and no QTLs relating to NSP appeared. The percentages in total phenotypic variation explained by all putative QTLs for NPB
were 35.5%: and43.8% in 1996 and 1997, respectively. All putative QTLs for NSB accounted for 35.5%and 27.5% of total phenotypic
variation in1996 and 1997, respectively. The QTLs identified in this study will be useful intemperate japonica rice breeding
for improved spikelet yield.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
Polish apple cvs: ‘Ligol’, ‘Odra’ and ‘Primula’ served for studies of self-incompatibility. Basing on available sequence data,
a new set of primers upstream and downstream of the hypervariable (HV) region of apple S-RNases were designed. Using the RT-PCR method, cDNA was amplified on RNA isolated from styles. PCR products were cloned and
sequenced. A new trans-generic S-RNase allele, designated as Skb (GenBank accession no. EU443101), was discovered in cvs ‘Odra’ and ‘Primula’. Nucleotide sequence alignment revealed that
Skb-RNase shows 98% identity to SaucS19-RNase from Sorbus aucuparia and 97% identity to CmonS17-RNase from Crataegus monogyna. The occurrence of extensive intergeneric hybridization among extant Pyrinae is considered since the deduced amino acid sequence of Skb-RNase from M. × domestica showed higher similarity to CmonS17 from C. monogyna, SaucS19-RNase from S. aucuparia, St from Malus transitoria, S5-RNase and S3-RNase from Pyrus pyrifolia, and S40-RNase from P. ussuriensis than to S-alleles from Malus × domestica and all of them are grouped in the same cluster of phylogenetic tree. In respect to extremely high similarities between aforementioned
S-RNases it could be possible that these alleles existed before the separation of Malus, Pyrus, Sorbus and Crataegus genera. Within Malus, the Skb-RNase from M. × domestica and St-RNase from M. transitoria show 100% identity of the HV region at the deduced amino acid level, suggesting that these S-RNases diverged more recently than the other Malus S-RNases. In ‘Ligol’, the agronomically most important cultivar in Poland, the S2 and S9 were identified. 相似文献
16.
In vitro shoots of six pear (Pyrus communis L.) cultivars, ‘Conference’, ‘Doyennéd'Hiver’, ‘Passe Crassane’, ‘Bartlett’, ‘AbbéFetel’ and ‘Butirra Precoce Morettini’
were irradiated with gamma rays (3.5 Gy). After three subcultures, microcuttings from the irradiated shoots and from additional
non-irradiated microcuttings were rooted to establish plants for survey orchards. All trees were individually observed for
variation in fruit traits and for productivity. Trees were selected for improved characters related to production such as
early bearing and consistent productivity. Variations observed in fruit appearance concerned degree of russeting, fruit shape
and size. The frequencies of the observed variations in fruit traits depended on the cultivar, ranging from 0.81% in ‘Doyennéd'Hiver’
to 3.64% in ‘Passe Crassane’. Of the 97 variants selected, only two showed chimeral behavior.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
T. Miedaner F. Wilde V. Korzun E. Ebmeyer M. Schmolke L. Hartl C. C. Schön 《Euphytica》2009,166(2):219-227
Fusarium head blight (FHB) infects all cereals including maize and is considered a major wheat disease, causing yield losses and mycotoxin
contamination. This study aimed to compare the realized selection gain from marker and phenotypic selection in European winter
wheat. A double cross (DC) combined three FHB resistance donor-QTL alleles (Qfhs.lfl-6AL and Qfhs.lfl-7BS from ‘Dream’, and one QTL on chromosome 2BL from ‘G16-92’) with two high yielding, susceptible winter wheats, ‘Brando’ and
‘LP235.1’. The base population of 600 DC derived F1 lines was on one hand selected for the respective QTLs by SSR markers (marker-selected cycle, CM), resulting in 35 progeny
possessing different combinations of beneficial donor-QTL alleles. On the other hand it was selected phenotypically, only
by FHB rating, and the best 20 lines were recombined and selfed (phenotypically selected cycle, CP). The variants CP, CM,
and an unselected variant (C0) were tested at four locations by inoculation of Fusarium culmorum. Resistance was measured as the mean of multiple FHB ratings (0–100%). FHB severity was reduced through both phenotypic and
marker selection by 6.2 vs. 5.0%, respectively. On a per-year basis, marker selection by 2.5% was slightly superior to phenotypic
selection with 2.1%, because the first variant saved 1 year. Marker-selected lines were on average 8.6 cm taller than phenotypically
selected lines. A high genetic variation within the marker-selected variant for FHB resistance and the high effect of a resistance-QTL
allele on straw length indicate that additional phenotypic selection will further enhance selection gain. 相似文献
18.
Sreedhar Alwala Collins A. Kimbeng John C. Veremis Kenneth A. Gravois 《Euphytica》2009,167(1):127-142
The cultivated sugarcane (Saccharum spp. hybrids, 2n = 100–130) is one crop for which interspecific hybridization involving wild germplasm has provided a major breakthrough in
its improvement. Few clones were used in the initial hybridization event leading to a narrow genetic base for continued cultivar
development. Molecular breeding would facilitate the identification and introgression of novel alleles/genes from the wild
germplasm into cultivated sugarcane. We report the identification of molecular markers associated with sugar-related traits
using an F1 population derived from a cross between S. officinarum ‘Louisiana Striped’ × S. spontaneum ‘SES 147B’, the two major progenitor species of cultivated sugarcane. Genetic linkage maps of the S. officinarum and S. spontaneum parents were produced using the AFLP, SRAP and TRAP molecular marker techniques. The mapping population was evaluated for
sugar-related traits namely, Brix (B) and pol (P) at the early (E) and late (L) plant growing season in the plant cane (04)
and first ratoon (05) crops (04EB, 04LB, 04LP, 05EB and 05EP). For S. officinarum, combined across all the traits, a total of 30 putative QTLs was observed with LOD scores ranging from 2.51 to 7.48. The
phenotypic variation (adj. R2) explained by all QTLs per trait ranged from 22.1% (04LP) to 48.4% (04EB). For S. spontaneum, a total of 11 putative QTLs was observed with LOD scores ranging from 2.62 to 4.70 and adj. R2 ranging from 9.3% (04LP) to 43.0% (04LB). Nine digenic interactions (iQTL) were observed in S. officinarum whereas only three were observed in S. spontaneum. About half of the QTLs contributed by both progenitor species were associated with effects on the trait that was contrary
to expectations based on the phenotype of the parent contributing the allele. Quantitative trait loci and their associated
effects were consistent across crop-years and growing seasons with very few QTLs being unique to the early season. When the
data were reanalyzed using the non-parametric discriminant analysis (DA) approach, significant marker-trait associations were
detected for markers that were either identical to or in the vicinity of markers previously identified using the traditional
QTL approach. Discriminant analysis also pointed to previously unidentified markers some of which remained unlinked on the
map. These preliminary results suggest that DA could be used as a complementary approach to traditional QTL analysis in a
crop like sugarcane for which saturated linkage maps are unavailable or difficult to obtain. 相似文献
19.
‘Conrad’, a soybean cultivar tolerant to Phytophthora root rot (PRR), and ‘OX760-6-1’, a breeding line with low tolerance
to PRR, were crossed. F2 derived recombinant inbred lines were advanced to F6 to generate a population through single-seed descent. This population was used to identify quantitative trait loci (QTLs)
influencing PRR tolerance in ‘Conrad’. A total of 99 simple sequence repeat (SSR), or microsatellite, markers that were polymorphic
and clearly segregated in the F6 mapping population were used for QTL detection. Based on the data of PRR in the field at two planting locations, Woodslee
and Weaver, for the years 2000 and 2001, one putative QTL, designated as Qsatt414-596, was detected using MapMaker/QTL. Qsatt414-596
was flanked by two SSR markers from the linkage group MLG J, Satt414 and Satt596. Satt414 and Satt596 were also detected to
be significantly (P < 0.005) associated with PRR using the SAS GLM procedure and were estimated to explain 13.7% and 21.5% of the total phenotypic
variance, respectively. 相似文献
20.
Morphological and molecular characterization of melon accessions resistant to Fusarium wilts 总被引:1,自引:1,他引:0
Fusarium wilt incited by Fusarium oxysporum f. sp. melonis (F.o.m) is one of the most widespread and devastating melon diseases. While resistance to physiological races 0, 1, and 2
is relatively frequent in different botanical varieties, sources of resistance to race 1,2 are restricted to a few Far-Eastern
accessions. In this work, the results of a screening for resistance to F.o.m. race 1,2 among 32 accessions are presented.
Three Japanese accessions (‘Kogane Nashi Makuwa’, ‘C-211’, and ‘C-40’) showed the highest resistance levels, but useful levels
of resistance were also detected in one Russian ‘C-160’ and two Spanish (‘C-300’ and ‘Mollerusa-7’) accessions. These resistant
materials, together with other accessions previously described as resistant to F.o.m. races 0, 1, and/or 2 have been morphologically
and molecularly characterized. Based on cluster analysis, these accessions have been grouped according to the botanical subspecies
they belong to. Assessment of genetic diversity indicated that the resistant accessions to races 0, 1 and 2, are scattered
along the established clusters. On the other hand, high levels of resistance to the race 1,2 could be found only among accessions
belonging to Cucumis melo subsp. agrestis, nevertheless, a certain degree of resistance to this race could also be found within some accessions belonging to subsp.
melo. As far as we know, this is the first report of resistance to F.o.m race 1,2 found out from the Far-Eastern melon material.
Based on fruits characteristics, it appears that several inodurus and cantalupensis accessions could be exploited in breeding programs as resistance sources to F.o.m races 0, 1 and/or 2 for the improvement
of these melon types. The accessions with the highest levels of resistance to the race 1,2 appeared to be very distant both
molecularly and morphologically from the commercial types. Nevertheless ‘C-160’, ‘C-300’, and ‘Mollerusa-7’ classified as
var. inodorus are morphologically very similar to the Spanish commercial types and might be used as resistant sources in breeding these
melon types. 相似文献