Gametophytic selection in a winter × spring barley cross

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 918-922 ◽  
Author(s):  
C. C. Schön ◽  
P. M. Hayes ◽  
T. K. Blake ◽  
S. J. Knapp
Keyword(s):  
Segregation Distortion ◽  
Doubled Haploid ◽  
Doubled Haploids ◽  
Spring Barley ◽  
Population Based ◽  
Doubled Haploid Population ◽  
Dh Population ◽  
Gametophytic Selection ◽  
Segregation Ratios ◽  
Haploid Population

Segregation distortion and the consequences of gametophytic selection were assessed in a winter × spring barley cross by comparing segregation of enzyme, storage protein, DNA, and morphological markers in three populations derived from the same cross: a control F2 (F2C), a doubled-haploid (DH) population, and an F2 derived from F1 plants self-pollinated at 10 °C (F2T). Segregation distortion was present in the F2T and the doubled-haploid population. Based on a comparison of the F2C and the F2T, gametophytic selection as a consequence of self-pollination at 10 °C was operative on chromosome 7 in regions linked to Rrn2. Segregation distortion in favor of the winter parent was found in the doubled-haploid population. There were significant deviations from expected segregation ratios at two loci, but only at one of the loci was the gene number significantly different from the F2C. Despite segregation distortion, the doubled-haploid population should be suitable for linkage analyses, as estimates of recombination based on F2 and doubled-haploid data were in close agreement.Key words: Hordeum vulgare, segregation distortion, doubled haploids, gametophytic selection, cold tolerance.

scholarly journals Mapping of Novel QTL Regulating Grain Shattering Using Doubled Haploid Population in Rice (Oryza sativaL.)

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Gyu-Ho Lee ◽  
In-Kyu Kang ◽  
Kyung-Min Kim
Keyword(s):  
Doubled Haploid ◽  
Chromosome 1 ◽  
Doubled Haploid Population ◽  
Chromosome 6 ◽  
Abscission Layer ◽  
Dh Population ◽  
Severe Reduction ◽  
Rice Chromosomes ◽  
Evolutionary Step ◽  
Haploid Population

The critical evolutionary step during domestication of major cereals was elimination of seed shattering because the easy-to-shatter trait in wild relatives results in a severe reduction in yield. In this study, we analyzed the QTLs associated with shattering employing a high-density genetic map in doubled haploid (DH) population of rice (Oryza sativaL.). A genetic linkage map was generated with 217 microsatellite markers spanning 2082.4 cM and covering 12 rice chromosomes with an average interval of 9.6 cM between markers based on 120 DHLs derived from a cross between Cheongcheong indica type cultivar and Nagdong japonica type cultivar. In the QTL analysis, five QTLs pertaining to the breaking tensile strength (BTS) were detected in 2013 and 2015. Two regions of the QTLs related to BTS on chromosome 1 and chromosome 6 were detected. Several important genes are distributed in 1 Mbp region of the QTL on chromosome 6 and they are related to the formation of abscission layer. We decide to name this QTLqSh6and the candidate genes in theqSh6region can be employed usefully in further research for cloning.

THE EFFICIENCY OF USING DOUBLED HAPLOIDS IN A RECURRENT SELECTION PROGRAM IN A DIPLOID, CROSS-FERTILIZED SPECIES

1978 ◽  
Vol 20 (4) ◽  
pp. 505-511 ◽  
Author(s):  
T. M. Choo ◽  
L. W. Kannenberg
Keyword(s):  
Doubled Haploid ◽  
Recurrent Selection ◽  
Doubled Haploids ◽  
Additive Genetic Variance ◽  
Significant Loss ◽  
Doubled Haploid Population ◽  
Mass Selection ◽  
Complete Dominance ◽  
Haploid Population ◽  
Selection Intensities

Mass selection in both doubled haploid and diploid populations was simulated for a 30-year period under additive and complete dominance models. The response to S1 selection was also included for the purpose of comparison. All selection programs were conducted at two selection intensities, 5% and 25%, under 0.2 heritability with a constant population size of 400. S1 lines were evaluated in 10-plant plots with four replications; use of a winter nursery was assumed. The character under selection was controlled by 20 major (A = 2) genes and 20 minor (A = 1) genes. The initial frequency of ten of the major genes and ten of the minor genes was 0.5; that of the remaining ten of each type was 0.1. The response to mass selection with doubled haploids was about 1.4 times faster than diploid mass selection and equal to S1 selection in terms of gain per year. If replicated trials were used to evaluate the doubled haploids, the rate of gain was faster than in S1 selection. The greater efficiency of using doubled haploids was due to doubling of the additive genetic variance and the elimination of dominance variance. However, significant loss of desirable genes occurred in the mass selected doubled haploid population under both the 5% and 25% selection intensities in the additive and complete dominance models.

Mapping QTL for grain yield, yield components, and spike features in a doubled haploid population of bread wheat

Genome ◽  
2011 ◽  
Vol 54 (6) ◽  
pp. 517-527 ◽  
Author(s):  
Bahram Heidari ◽  
Badraldin Ebrahim Sayed-Tabatabaei ◽  
Ghodratollah Saeidi ◽  
Michael Kearsey ◽  
Kazuhiro Suenaga
Keyword(s):  
Grain Yield ◽  
Doubled Haploid ◽  
Yield Components ◽  
Triticum Aestivum L ◽  
Interval Mapping ◽  
Doubled Haploid Population ◽  
Dh Population ◽  
Spike Number ◽  
Haploid Population ◽  
Major Qtl

A doubled haploid (DH) population derived from a cross between the Japanese cultivar ‘Fukuho-kumogi’ and the Israeli wheat line ‘Oligoculm’ was used to map genome regions involved in the expression of grain yield, yield components, and spike features in wheat (Triticum aestivum L). A total of 371 markers (RAPD, SSR, RFLP, AFLP, and two morphological traits) were used to construct the linkage map that covered 4190 cM of wheat genome including 28 linkage groups. The results of composite interval mapping for all studied traits showed that some of the quantitative trait loci (QTL) were stable over experiments conducted in 2004 and 2005. The major QTL located in the Hair–Xpsp2999 interval on chromosome 1A controlled the expression of grains/spike (R2 = 12.9% in 2004 and 22.4% in 2005), grain weight/spike (R2 = 21.4% in 2004 and 15.8% in 2005), and spike number (R2 = 15.6% in 2004 and 5.4% in 2005). The QTL for grain yield located on chromosomes 6A, 6B, and 6D totally accounted for 27.2% and 31.7% of total variation in this trait in 2004 and 2005, respectively. Alleles inherited from ‘Oligoculm’ increased the length of spikes and had decreasing effects on spike number. According to the data obtained in 2005, locus Xgwm261 was associated with a highly significant spike length QTL (R2 = 42.33%) and also the major QTL for spikelet compactness (R2 = 26.1%).

Doubled haploids for locating polygenes

1983 ◽  
Vol 25 (5) ◽  
pp. 425-429 ◽  
Author(s):  
T. M. Choo
Keyword(s):  
Doubled Haploid ◽  
Quantitative Trait ◽  
Doubled Haploids ◽  
Marker Gene ◽  
Marker Genes ◽  
Doubled Haploid Population ◽  
Crossing Over ◽  
Marker Loci ◽  
Haploid Population ◽  
Map Distance

A biometrical method, making use of one or two marker genes, was proposed for use in doubled-haploid populations to locate polygenes. A polygene, if located between two closely linked marker loci, can be detected in a doubled-haploid population derived from a cross of two diploid inbred parents. In addition, the presence of additive epistasis can be detected. If the map distance between the two marker loci is so close that the frequency of double crossing-over can be neglected, then the recombination values between the polygene and either marker gene can be estimated, and the additive effect of the polygene can be determined in the absence of pleiotropy. Further, the contribution of the polygene to the quantitative trait relative to all other polygenes can be measured from the experiment if double crossing-over and epistasis are absent. Note that the proposed method can be used as an adjunct to haploid breeding routines and other genetical experiments.

scholarly journals DOUBLED HAPLOIDS FOR STUDYING THE INHERITANCE OF QUANTITATIVE CHARACTERS

Genetics ◽  
1981 ◽  
Vol 99 (3-4) ◽  
pp. 525-540
Author(s):  
T M Choo
Keyword(s):  
Doubled Haploid ◽  
Doubled Haploids ◽  
Doubled Haploid Population ◽  
Breeding Methods ◽  
Weighted Mean ◽  
Quantitative Characters ◽  
Haploid Population ◽  
Parental Lines ◽  
The Difference ◽  
Two Populations

ABSTRACT By using a doubled-haploid population derived from F2 plants, additive and additive x additive genetic variances, as well as the number of segregating genes, can be estimated. An F2-derived doubled-haploid population may contain almost 50%more of the best recombinant than an F1-derived population. However, the best recombinant occurs in the same frequency in the two populations when there is no linkage between genes. The difference in the frequency of the best recombinant between F2- and F3-derived populations is small. This implies that the doubled-haploid method using F2 plants provides only slightly less opportunity for recombination than the conventional breeding methods of selfpollinating crops. In the absence of additive epistasis, a weighted mean of recombination values can be estimated using an F2-derived population and its parental lines. When additive epistasis is present, it can be estimated from doubled-haploid populations derived from two backcrosses. Studies on the linkage of quantitative characters are needed for determining whether doubled haploids should be produced from F2 or from F1 plants in a breeding program.

Mapping QTL controlling agronomic traits in a doubled haploid population of winter oilseed rape (Brassica napus L.)

2018 ◽  
Vol 97 (5) ◽  
pp. 1389-1406 ◽  
Author(s):  
Farshad Fattahi ◽  
Barat Ali Fakheri ◽  
Mahmood Solouki ◽  
Christian Möllers ◽  
Abbas Rezaizad
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Doubled Haploid ◽  
Agronomic Traits ◽  
Doubled Haploid Population ◽  
Winter Oilseed Rape ◽  
Brassica Napus L ◽  
Mapping Qtl ◽  
Haploid Population
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