共查询到20条相似文献,搜索用时 31 毫秒
1.
E. Barzen W. Mechelke E. Ritter J. F. Seitzer F. Salamini 《The Plant journal : for cell and molecular biology》1992,2(4):601-611
An RFLP linkage map for the nine chromosomes of sugar beet (Beta vulgaris L. ssp. vulgaris var. altissima Doell) was constructed by using a segregating population from a cross between two plants which were heterozygous for several agronomically interesting characters. One hundred and eleven RFLP loci have been mapped to nine linkage groups using 92 genomic markers. The current RFLP map covers a total length of 540 cM. Evidence for the existence of a major gene for rhizomania resistance (Rr1) is given, together with its map position on linkage group IV in the interval between loci GS44 and GS28a. The presence of an RFLP fragment at the GS3d locus is, until now, the best molecular marker for rhizomania-resistant genotypes in segregating populations of sugar beet; GS3d is linked to Rr1 with 6.7 cM. The gene MM, controlling the polygerm/monogerm seed type, has been mapped on linkage group IX in a distal position at 4.2 cM from the locus GS7. The gene R controlling the hypocotyl colour maps to linkage group VII and does not recombine with the RFLP locus GS42. The inheritance of a group of RFLP loci revealed the possible presence of a translocation in the population used to establish the map. The data presented are discussed in relation to the possibility of using RFLP markers in sugar beet breeding. 相似文献
2.
Schneider K Kulosa D Soerensen TR Möhring S Heine M Durstewitz G Polley A Weber E Jamsari Lein J Hohmann U Tahiro E Weisshaar B Schulz B Koch G Jung C Ganal M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(5):601-615
A panel of 13 sugar beet lines and one genotype each of the Beta vulgaris cultivars red beet and Swiss chard, and B. vulgaris ssp. maritima were used to identify polymorphisms in alignments of genomic DNA sequences derived from 315 EST- and 43 non-coding RFLP-derived
loci. In sugar beet lines, loci of expressed genes showed an average SNP frequency of 1/72 bp, 1 in 58 bp in non-coding sequences,
increasing to 1/47 bp upon the addition of the remaining genotypes. Within analysed DNA fragments, alleles at different SNP
positions displayed linkage disequilibrium indicative of haplotype structures. On average 2.7 haplotypes were found in sugar
beet lines, and haplotype conservation in expressed genes appeared to exceed 500 bp in length. Seven different genotyping
techniques including SNP detection by MALDI-TOF mass spectrometry, pyrosequencing and fluorescence scanning of labelled nucleotides
were employed to perform 712 segregation analyses for 538 markers in three F2 populations. Functions were predicted for 492 mapped sequences. Genetic maps comprised 305 loci covering 599.8 cM in population
K1, 241 loci distributed over 636.6 cM in population D2, and 166 loci over 507.1 cM in population K2, respectively. Based
on 156 markers common to more than one population an integrated map was constructed with 524 loci covering 664.3 cM. For 377
loci the genome positions of the most similar sequences from A. thaliana were identified, but little evidence for previously presented ancestral genome structures was found.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
V. Laporte D. Merdinoglu P. Saumitou-Laprade G. Butterlin P. Vernet J. Cuguen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(6-7):989-996
The present study shows that the recently described mitochondrial H haplotype is associated with cytoplasmic male-sterility
(CMS). This new source of CMS appears to be different from the mitotype E-associated CMS most frequently found in natural
populations. A mitotype H progeny with a sexual phenotype segregation was used to identify a gene restoring male fertility
(R1H ). Using bulk segregant analysis (BSA), nine RAPD markers linked to this restorer locus were detected and mapped. The comparison
with other Beta genetic maps shows that the closest RAPD marker, distant from R1H by 5.2 cM, belongs to the same linkage group as the monogermy locus. In order to determine the position of R1H more precisely, four RFLP loci within this linkage group were mapped in the segregating progeny. It thus became possible
to construct a linkage map of the region containing the RFLP, RAPD and R1H loci. The closest RFLP marker was located 1.7 cM away from R1H. However, a nuclear gene restoring the ‘Owen’ CMS which is currently used in sugar beet breeding is reportedly linked to
the monogermy locus, raising the question of a possible identity between the new CMS system and the ‘Owen’ CMS.
Received: 15 September 1997 / Accepted: 1 December 1997 相似文献
4.
Zhang W Lukaszewski AJ Kolmer J Soria MA Goyal S Dubcovsky J 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(3):573-582
Chromosome 7E from Lophopyrum ponticum carries a valuable leaf rust resistant gene designated Lr19. This gene has not been widely used in common wheat breeding because of linkage with the yellow pigment gene Y. This gene tints flour yellow, reducing its appeal in bread making. However, a high level of yellow pigment is desirable in durum wheat breeding. We produced 97 recombinant chromosomes between L. ponticum transfer 7D.7E#1 and its wheat homoeologues, using the ph1b mutation that promotes homoeologous pairing. We characterized a subset of 37 of these lines with 11 molecular markers and evaluated their resistance to leaf rust and the abundance of yellow pigment. The Lr19 gene was mapped between loci Xwg420 and Xmwg2062, whereas Y was mapped distal to Xpsr687, the most distal marker on the long arm of chromosome 7. A short terminal 7EL segment translocated to 7A, including Lr19 and Y (line 1-23), has been transferred to durum wheat by backcrossing. The presence of this alien segment significantly increased the abundance of yellow pigment. The Lr19 also conferred resistance to a new durum leaf rust race from California and Mexico that is virulent on most durum wheat cultivars. The new durum lines with the recombinant 7E segment will be useful parents to increase yellow pigment and leaf rust resistance in durum wheat breeding programs. For the common wheat breeding programs, we selected the recombinant line 1-96, which has an interstitial 7E segment carrying Lr19 but not Y. This recombinant line can be used to improve leaf rust resistance without affecting flour color. The 7EL/7DL 1-96 recombinant chromosome did not show the meiotic self-elimination previously reported for a 7EL/7BL translocation. 相似文献
5.
G. E. Truett H. J. Jacob J. Miller G. Drouin N. Bahary J. W. Smoller E. S. Lander R. L. Leibel 《Mammalian genome》1995,6(1):25-30
Thirteen loci, including the obesity gene fatty (fa), were incorporated into a linkage map of rat Chromosome (Chr) 5. These loci were mapped in obese (fa/fa) progeny of a cross between BN×13M-fa/+ F1 animals. Obese rats were scored for BN and 13M alleles at four loci (Ifna, D1S85h, C8b, and Lck1) by restriction fragment length polymorphisms and at eight additional loci (Glut1, Sv4j2, R251, R735, R980, R252, R371, and R1138) by simple sequence length polymorphisms (SSLP). The resulting map spans 67.3 cM of Chr 5, presenting nine previously unmapped loci and one locus (Lck1) previously assigned to Chr 5 by use of somatic cell hybrid lines. Seven of the eight SSLP loci are newly identified; the SSLP linkage group alone spans 56.8 cM. The order of the loci is Sv4j2-R251-R735-R980-R1138-Ifna-fa-D1S85h-C8b-(Glut1-R252-R371)-Lck1. One locus, D1S85h, was found to lie only 0.4 cM from fa, close enough to serve as a reliable marker for the prediction of phenotype from genotype, and will be useful also for studies on the development of obesity in the fatty rat. 相似文献
6.
Inheritance of resistance to beet necrotic yellow vein virus in Beta vulgaris conferred by a second gene for resistance 总被引:1,自引:0,他引:1
O. E. Scholten Th. S. M. De Bock R. M. Klein-Lankhorst W. Lange 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):740-746
Rhizomania is a serious disease of sugar beet, caused by beet necrotic yellow vein virus (BNYVV). The disease can only be
controlled by the use of resistant cultivars. The accession Holly contains a single dominant gene for resistance, called Rz. The identification of a locus for resistance that differs from Rz would provide possibilities to produce cultivars with multiple resistance to BNYVV. Inheritance of resistance to BNYVV was
studied by screening progenies of crosses between resistant plants of the accessions Beta vulgaris subsp. maritima WB42 and B. vulgaris subsp. vulgaris Holly-1–4 or R104. Observed and expected segregation ratios were compared to elucidate whether the resistance genes in the
three accessions are alleles or situated on different loci. STS markers, linked to the genes for resistance, were used to
study the segregation in more detail. The results demonstrated that the genes for resistance to BNYVV inHolly-1-4 and WB42
are closely linked. The gene for resistance in R104 is at the same locus as in Holly-1-4, and also closely linked to the gene
in WB42. As the Holly resistance gene has been named Rz, the name Rz2 is proposed to refer to the resistance gene in WB42. Consequently, the gene Rz should be referred to as Rz1.
Received: 29 October 1998 / Accepted: 12 March 1999 相似文献
7.
R. Heller J. Schondelmaier G. Steinrücken C. Jung 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(8):991-997
Sugar beet (Beta vulgaris L.) is highly susceptible to the beet cyst nematode (Heterodera schachtii Schm.). Three resistance genes originating from the wild beets B. procumbens (Hs1
pro-1) and B. webbiana (Hs1
web-1, Hs2
web-7) have been transferred to sugar beet via species hybridization. We describe the genetic localization of the nematode resistance genes in four different sugar beet lines using segregating F2 populations and RFLP markers from our current sugar beet linkage map. The mapping studies yielded a surprising result. Although the four parental lines carrying the wild beet translocations were not related to each other, the four genes mapped to the same locus in sugar beet independent of the original translocation event. Close linkage (0–4.6 cM) was found with marker loci at one end of linkage group IV. In two populations, RFLP loci showed segregation distortion due to gametic selection. For the first time, the non-randomness of the translocation process promoting gene transfer from the wild beet to the sugar beet is demonstrated. The data suggest that the resistance genes were incorporated into the sugar beet chromosomes by non-allelic homologous recombination. The finding that the different resistance genes are allelic will have major implications on future attempts to breed sugar beet combining the different resistance genes. 相似文献
8.
Mukhlesur Rahman Genyi Li Dana Schroeder Peter B. E. McVetty 《Molecular breeding : new strategies in plant improvement》2010,26(3):439-453
Seed coat color inheritance in Brassica napus was studied in F1, F2, F3 and backcross progenies from crosses of five black seeded varieties/lines to three pure breeding yellow seeded lines. Maternal
inheritance was observed for seed coat color in B. napus, but a pollen effect was also found when yellow seeded lines were used as the female parent. Seed coat color segregated from
black to dark brown, light brown, dark yellow, light yellow, and yellow. Seed coat color was found to be controlled by three
genes, the first two genes were responsible for black/brown seed coat color and the third gene was responsible for dark/light
yellow seed coat color in B. napus. All three seed coat color alleles were dominant over yellow color alleles at all three loci. Sequence related amplified polymorphism
(SRAP) was used for the development of molecular markers co-segregating with the seed coat color genes. A SRAP marker (SA12BG18388) tightly linked to one of the black/brown seed coat color genes was identified in the F2 and backcross populations. This marker was found to be anchored on linkage group A9/N9 of the A-genome of B. napus. This SRAP marker was converted into sequence-characterized amplification region (SCAR) markers using chromosome-walking technology.
A second SRAP marker (SA7BG29245), very close to another black/brown seed coat color gene, was identified from a high density
genetic map developed in our laboratory using primer walking from an anchoring marker. The marker was located on linkage group
C3/N13 of the C-genome of B. napus. This marker also co-segregated with the black/brown seed coat color gene in B. rapa. Based on the sequence information of the flanking sequences, 24 single nucleotide polymorphisms (SNPs) were identified between
the yellow seeded and black/brown seeded lines. SNP detection and genotyping clearly differentiated the black/brown seeded
plants from dark/light/yellow-seeded plants and also differentiated between homozygous (Y2Y2) and heterozygous (Y2y2) black/brown
seeded plants. A total of 768 SRAP primer pair combinations were screened in dark/light yellow seed coat color plants and
a close marker (DC1GA27197) linked to the dark/light yellow seed coat color gene was developed. These three markers linked
to the three different yellow seed coat color genes in B. napus can be used to screen for yellow seeded lines in canola/rapeseed breeding programs. 相似文献
9.
S. Fukuoka H. Namai K. Okuno 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(3):446-449
Complementary recessive genes hwd1 and hwd2 controlling hybrid breakdown (weakness of F2 and later generations) were mapped in rice using RFLP markers. These genes produce a plant that is shorter and has fewer
tillers than normal plants when the two loci have only one or no dominant allele at both loci. A cultivar with two dominant
alleles at the hwd1 locus and a cultivar with two dominant alleles at the hwd2 locus were crossed with a double recessive tester line. Linkage analysis was carried out for each gene independently in two
F2 populations derived from these crosses. hwd1 was mapped on the distal region of rice genetic linkage map for chromosome 10, flanked by RFLP markers C701 and R2309 at
a distance of 0.9 centiMorgans (cM) and 0.6 cM, respectively. hwd2 was mapped in the central region of rice genetic linkage map for chromosome 7, tightly linked with 4 RFLP markers without
detectable recombination. The usefulness of RFLP mapping and map information for the genes controlling reproductive barriers
are discussed in the context of breeding using diverse rice germplasm, especially gene introduction by marker-aided selection. 相似文献
10.
Yun‐Po Zhao Mu‐Wang Li An‐Ying Xu Cheng‐Xiang Hou Ming‐Hui Li Qiu‐Hong Guo Yong‐Ping Huang Xi‐Jie Guo 《Insect Science》2008,15(5):399-404
The yellow color of the cocoon of the silkworm Bombyx mori is controlled by three genes, Y (Yellow haemolymph), I (Yellow inhibitor) and C (Outer‐layer yellow cocoon), which are located on linkage groups 2, 9 and 12, respectively. Taking advantage of a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progeny were used for linkage analysis and mapping of the C gene using silkworm strains C108 and KY, which spin white and yellow cocoons, respectively. DNA was extracted from individual pupae and analyzed for simple sequence repeat (SSR) markers. The C gene was found to be linked to seven SSR markers. All the yellow cocoon individuals from a female heterozygous backcross (BC1 F) showed a heterozygous profile for SSR markers on linkage group 12, whereas individuals with light yellow cocoons showed the homozygous profile of the strain C108. Using a reciprocal heterozygous male backcross (BC1 M), we constructed a linkage map of 36.4 cM with the C gene located at the distal end, and the closest SSR marker at a distance of 13.9 cM. 相似文献
11.
A. Kaga T. Ishii K. Tsukimoto E. Tokoro O. Kamijima 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(2):207-213
A genetic linkage map was developed with 86 F2 plants derived from an interspecific cross between azuki bean (Vigna angularis, 2n=2x=22) and rice bean (V. umbellata, 2n=2x=22). In total, 14 linkage groups, each containing more than 4 markers, were constructed with one phenotypic, 114 RFLP
and 74 RAPD markers. The total map size was 1702 cM, and the average distance between markers was 9.7 cM. The loci showing
significant deviation from the expected ratio clustered in several linkage groups. Most of the skewed loci were due to the
predominance of rice bean alleles. The azuki-rice bean linkage map was compared with other available maps of Vigna species in subgenus Ceratotropis. Based on the lineage of the common mapped markers, 7 and 16 conserved linkage blocks were found in the interspecific map
of azuki bean ×V. nakashimae and mungbean map, respectively. Although the present map is not fully saturated, it may facilitate gene tagging, QTL mapping
and further useful gene transfer for azuki bean breeding.
Received: 20 March 1999 / Accepted: 29 April 1999 相似文献
12.
RAD‐seq linkage mapping and patterns of segregation distortion in sedges: meiosis as a driver of karyotypic evolution in organisms with holocentric chromosomes
下载免费PDF全文
![点击此处可从《Journal of evolutionary biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Meiotic drive, the class of meiotic mechanisms that drive unequal segregation of alleles among gametes, may be an important force in karyotype evolution. Its role in holocentric organisms, whose chromosomes lack localized centromeres, is poorly understood. We crossed two individuals of Carex scoparia (Cyperaceae) with different chromosome numbers (2n = 33II = 66 × 2n = 32II = 64) to obtain F1 individuals, which we then self‐pollinated to obtain second‐generation (F2) crosses. RAD‐seq was performed for 191 individuals (including the parents, five F1 individuals and 184 F2 individuals). Our F2 linkage map based on stringent editing of the RAD‐seq data set yielded 32 linkage groups. In the final map, 865 loci were located on a linkage map of 3966.99 cM (linkage groups ranged from 24.39 to 193.31 cM in length and contained 5–51 loci each). Three linkage groups exhibit more loci under segregation distortion than expected by chance; within linkage groups, loci exhibiting segregation distortion are clustered. This finding implicates meiotic drive in the segregation of chromosome variants, suggesting that selection of chromosome variants in meiosis may contribute to the establishment and fixation of chromosome variants in Carex, which is renowned for high chromosomal and species diversity. This is an important finding as previous studies demonstrate that chromosome divergence may play a key role in differentiation and speciation in Carex. 相似文献
13.
Y. Du E. F. Remmers H. Zha E. A. Goldmuntz J. Szpirer C. Szpirer R. L. Wilder 《Mammalian genome》1995,6(4):295-298
Nine microsatellite loci were mapped to rat Chromosome (Chr) 7 by genetic linkage and somatic cell hybrid analysis. These loci include the gene encoding a member of the IID sub-family of cytochrome P450 (Cyp2d), a gene with repetitive sequences expressed during myotube formation (D7Arb1e), four anonymous loci, D7Arb81, D7Arb208, D7Arb569, D7Arb609a, and three DNA loci defined by MapPairTM markers R245, R513, and R1071. The nine loci were all identified by PCR-based microsatellite polymorphism analysis and were characterized in 40 F2 intercross progeny of Fischer (F344/N) and Lewis (LEW/N) rats for segregation analysis. These markers formed a single linkage group spanning 76.8 cM with the following order and distances: D7Arb569-11.4 cM-D7Arb81-9.7 cM-R513-2.6 cM-Cyp2d-0.0 cM-R245-1.3 cM-D7Arb1e-10.4 cM-R1071-15.9 cM-D7Arb609a-15.4 cM-D7Arb208. Physical mapping of Cyp2d by somatic cell hybrid analysis allowed us to assign this linkage group to rat Chr 7. For each marker, two to six alleles were detected in a panel of 16 inbred rat strains (ACI/N, BN/SsN, BUF/N, DA/Bkl, F344/N, LER/N, LEW/N, LOU/MN, MNR/N, MR/N, SHR/N, SR/Jr, SS/Jr, WBB1/N, WBB2/N, WKY/N). 相似文献
14.
蛋用鹌鹑伴性羽色基因互作与连锁的关系 总被引:15,自引:1,他引:14
本研究首次发现了鹌鹑伴性羽基因的基因互作关系并进行了遗传验证.试验证明,鹌鹑的栗羽、黄羽和白羽是Z染色体上两个有连锁关系的基因座B/b和Y/y相互作用的结果.B和b为一对等位基因,不控制任何性状,只与色素的合成有关,B为有色基因,b为白化基因,B对b为显性;Y和y为另一对等位基因,分别控制栗羽和黄羽,Y对y为显性.栗羽和黄羽的表现取决于有色基因B的存在,B与Y相互作用产生栗羽,B与y相互作用产生黄羽,白羽是白化基因b对Y和y上位作用的结果.B/b和Y/y两基因座在雄性表现出一定的互换率,在雌性为完全连锁.这一研究补充和发展了以前人们对鹌鹑羽色伴性遗传的研究,为人们利用鹌鹑羽色进行自别雌雄配套系生产提供了重要的遗传学基础。
Abstract:The interaction of sex-linked gene for plumage color in quails was first discovered and identified by genetictest.It was proved that the phenotypic expressions of the maroon feather,the yellow feather and the white feather result from the interaction between B/b and Y/y loci in the Z-chromosome.The allele B and b have something to do with the composition of pigment in plumage and nothing to do with any relative characters,the coloured gene B is dominant to its albino allele b.The maroon and yellow feather constituted a pair of relative characters determined by a couple of alleles Y and y,the maroon feather was caused by a dominant allele Y,and the yellow feather caused by a recessive allele y.But the phenotypic expression of maroon and yellow was decided by the present of the coloured gene B in Z-chromosome,the maroon feather was the result of interaction between gene B and Y,the yellow feather was result of interaction between gene B and y.The white was caused by a recessive albino gene b which epistasis to gene Y and y.The incomplete linkage was present between B/b and Y/y in Z-chromosome in male and complete linkage in female.This research enriches and delelops the earlier studies of the sex-linked inheritance of plumage color.It provides an important genetic basis for the quail autosexing system production by means of plumage color. 相似文献
15.
The frequencies of sister chromatid exchanges (SCEs) were examined in phytohaemagglutinin-stimulated blood lymphocytes of a normal individual, a Bloom's syndrome heterozygote (bl/+), and two Bloom's syndrome homozygotes (bl/bl). To determine the baseline SCE frequencies, lymphocytes were cultured with various concentrations of 5-bromodeoxyuridine (BrdUrd) for two cell cycles. The incidence of SCEs per two cell cycles inbl/bl lymphocytes levelled off at BrdUrd concentrations below 10 g/ml while that in normal andbl/+ lymphocytes stayed constant below 7.5 g/ml. The baseline SCE frequency in bl/bl cells was ten times higher than that in normal andbl/+ cells. At BrdUrd concentrations above 15 g/ml, SCEs inbl/bl cells were induced more frequently than in normal andbl/+ cells. These results indicate that at low concentrations BrdUrd has a minimal effect on the induction of SCEs in all individuals, while at higher concentrations the BrdUrd incorporated inbl/bl cells has a larger effect than that in normal andbl/+ cells. To elucidate the effect of BrdUrd incorporated into the daughter and parental DNA strands on SCE induction, SCEs occurring during each cell cycle were examined separately in three-way or two-way differentially stained, third-cycle metaphases. The incidence of SCEs detected in each cell cycle at 5 g/ml BrdUrd was constant in all individuals and the rates of SCEs in each cell cycle inbl/bl cells were remarkably higher than those observed in normal andbl/+ cells. These findings strongly indicate that most of the abnormally increased SCEs in thebl/bl cells used in our study occurred independently of any effect of BrdUrd incorporated into both the daughter and parental DNA strands. In addition, an abnormal response ofbl/bl cells to BrdUrd was not found for cell cycle progression or chromosomal aberration induction. Thus, the bl/bl cells did not exhibit an abnormal hypersensitivity to BrdUrd. From these results, it seems quite probable that the abnormally increased SCEs in thebl/bl lymphocytes used here were spontaneous. 相似文献
16.
B. S. Vivek P. W. Simon 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):58-64
A 109-point linkage map consisting of three phenotypic loci (P
1, Y
2, and Rs), six restriction fragment length polymorphisms (RFLPs), two random amplified polymorphic DNAs (RAPDs), 96 amplified fragment
length polymorphisms (AFLPs), and two selective amplification of microsatellite polymorphic loci (SAMPL) was constructed for
carrot (Daucus carota L. ssp. sativus; 2n=2x=18). The incidence of polymorphism was 36% for RFLP probes, 20% for RAPD primers, and 42% for AFLP primers. The overall incidence
of disturbed segregation was 18%. Linkage relationships at a LOD score of 4.0 and θ=0.25 indicated 11 linkage groups. The
total map length was 534.4 cM and the map was clearly unsaturated with markers spaced at 4.9 cM. AFLP P6B15 was 1.7 cM from
P
1, AFLP P1B34 was 2.2 cM from Y
2, and AFLP P3B30XA was 8.1 cM from Rs.
Received: 2 September 1998 / Accepted: 28 November 1998 相似文献
17.
Brian J. Just Carlos A. F. Santos Brian S. Yandell Philipp W. Simon 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(7):1155-1169
We performed QTL analyses for pigment content on a carotenoid biosynthesis function map based on progeny of a wild white carrot
(QAL) which accumulates no pigments × domesticated orange carrot (B493), one of the richest sources of carotenoid pigments—mainly
provitamin A α- and β- carotenes. Two major interacting loci, Y and Y
2
on linkage groups 2 and 5, respectively, control much variation for carotenoid accumulation in carrot roots. They are associated
with carotenoid biosynthetic genes zeaxanthin epoxidase and carotene hydroxylase and carotenoid dioxygenase gene family members
as positional candidate genes. Dominant Y allele inhibits carotenoid accumulation. When Y is homozygous recessive, carotenoids that accumulate are either only xanthophylls in Y
2
__ plants, or both carotenes and xanthophylls, in y
2
y
2
plants. These two genes played a major role in carrot domestication and account for the significant role that modern carrot
plays in vitamin A nutrition. 相似文献
18.
James W. Borrone J. Steven Brown Cecile L. Tondo Margarita Mauro-Herrera David N. Kuhn Helen A. Violi Robert T. Sautter Raymond J. Schnell 《Tree Genetics & Genomes》2009,5(4):553-560
Recent enhancement of the pool of known molecular markers for avocado has allowed the construction of the first moderately
dense genetic map for this species. Over 300 SSR markers have been characterized and 163 of these were used to construct a
map from the reciprocal cross of two Florida cultivars 'Simmonds' and 'Tonnage'. One hundred thirty-five primer pairs amplified
163 usable loci with 20 primer pairs amplifying more than one locus. 'Tonnage' was heterozygous for 152 (93%) loci, whereas
'Simmonds' was heterozygous for 64 (39%). Null alleles were identified at several loci. Linkage maps were produced for both
reciprocal crosses and combined to generate a composite linkage map for the F1 population of 715 individuals. The composite map contains 12 linkage groups. Linkage groups ranged in size from 157.3 cM
(LG2) to 2.4 cM (LG12) and the number of loci mapped per group ranged from 29 (LG1) to two (LG12). The total map length was
1,087.4 cM. Only seven markers were observed to have segregation distortion (α ≤ 0.05) across both sub-composite (reciprocal) maps. Phenotypic data from traits of horticultural interest are currently
being collected on this population with the ultimate goal of identifying useful quantitative trait loci and the development
of a marker-assisted selection program. 相似文献
19.
Selvaraj Michael Gomez N. Manikanda Boopathi S. Satheesh Kumar T. Ramasubramanian Zhu Chengsong P. Jeyaprakash A. Senthil R. Chandra Babu 《Acta Physiologiae Plantarum》2010,32(2):355-364
Drought is a major limitation for rice production in rainfed ecosystems. Identifying quantitative trait loci (QTLs) linked
to drought resistance provides opportunity to breed high yielding rice varieties suitable for drought-prone areas. Although
considerable efforts were made in mapping QTLs associated with drought-resistance traits in rice, most of the studies involved
indica × japonica crosses and hence, the drought-resistance alleles were contributed mostly by japonica ecotypes. It is desirable to look for genetic variation within indica ecotypes adapted to target environment (TE) as the alleles from japonica ecotype may not be expressed under lowland conditions. A subset of 250 recombinant inbred lines (RILs) of F8 generation derived from two indica rice lines (IR20 and Nootripathu) with contrasting drought-resistance traits were used to map the QTLs for morpho-physiological
and plant production traits under drought stress in the field in TE. A genetic linkage map was constructed using 101 polymorphic
PCR-based markers distributed over the 12 chromosomes covering a total length of 1,529 cM in 17 linkage groups with an average
distance of 15.1 cM. Composite interval mapping analysis identified 22 QTLs, which individually explained 4.8–32.2% of the
phenotypic variation. Consistent QTLs for drought-resistance traits were detected using locally adapted indica ecotypes, which may be useful for rainfed rice improvement. 相似文献
20.
K. A. Eagen I. L. Goldman 《Molecular breeding : new strategies in plant improvement》1996,2(2):107-115
In the past twenty years, betalain pigments found in red beet (Beta vulgaris L.) have been adopted for use as natural red food colorings. Utility and extractability of these compounds is dependent upon native concentrations of both pigment and total dissolved solids. In an effort to develop red beet populations with elevated levels of betalain pigment, recurrent half-sib family selection for high pigment and both high and low solids was practiced for seven cycles. This scheme resulted in the development of a high pigment/high solids and a high pigment/low solids population. A total of 200 randomly chosen oligonucleotide decamer primers were used to amplify genomic DNA of individual plants in the selection scheme for repeatability and clarity of amplification products. Thirty-one primers were chosen on this basis and used to assess random-amplified polymorphic DNA (RAPD) marker frequencies on genomic DNA samples isolated from 47 randomly-chosen individual plants in each of cycles 1, 3, and 6 in both high pigment/high solids and high pigment/low solids. Number of scorable Polymerase Chain Reaction products ranged from 1–10, resulting in a total of 161 RAPD markers. Chi-square and regression analyses were performed to determine the presence/absence of a linear trend in marker frequencies during the selection scheme. Comparisons were made among cycles within high pigment/high solids and high pigment/low solids populations. Significant linear trends were detected in both cases for certain RAPD markers. Formulae were used to test whether observed linear marker frequency trends were due to the effects of selection or random genetic drift. Chi-square tests revealed a subset of markers which exhibited significant frequency changes across cycles changed due to selection. These data demonstrate changes in RAPD marker frequencies with recurrent selection and suggest linkage of RAPD markers to genes controlling pigment in red beet. 相似文献