To produce BC1 progenies, about 20 plants were produced for each donor F1 population (B. rapa, B. napus), with five resistant plants selected based on their clubroot reaction, assessed as described previously.
During preliminary simulation studies, the relatively limited size of the data set (about three half-sib progeny from about 100 sires) was shown to enable detection of only relatively large QTL (with effects greater than 0.5 STD) for traits with a heritability of 0.5, and power was less than 30% when the effect of the QTL or trait heritability was reduced [ 37].
This great matriarch, whose progeny included about 80 of the 600 or so slaves that Jefferson owned during his lifetime, was initially a slave of Martha Jefferson's father, John Wayles.
Once-mated D. montana females produce progeny for about six days [ 53], though most (fertilized) eggs are laid on the second to fourth day following insemination (own observation).
For example, the mean of 20 halfsib progeny has about 3.6 times the value of the mean of 5 progeny when c is 0.1, and 2.5 times the value when c is 0.8.
This method reduced F of prospective progeny by about a third to a half compared to the other methods when bulls are mated to current and future cows that will be available 5 to 6 years from now.
Quince (Cydonia oblonga) was at the low extreme of epicatechin content, far below that found for the lowest member of the 'Royal Gala' × 'Braeburn' segregating population, while the highest epicatechin concentration in the 'Royal Gala' × 'Braeburn' progeny was about the same as that in crab apple (Malus hybrida 'Oekonomierat Echtermeyer ').
Hermaphrodites from strain PS312 pdl-9 (sy372), when mated to males, produced cross-progeny for about 4 days.
The present results corroborate previous QTL mapping simulation studies, where the use of small segregating populations (progeny size of about 200) resulted in low power detection, with disproportionately large effects on phenotype and with poor congruence of QTL position [ 67- 70].
