Observations were done in P1 (10 plants), P2 (10 plants), F1 (90 plants), F2 (111 plants), BC1 (40 plants), BC2 (40 plants) and 17 F3 plants selected according to 15% selection intensity
, also measurements were made for plant height (cm), peduncle length (cm) (the length from below the spike to node of flag leaf), spike length (cm), spikelet number per spike and number of kernels per spike as described by Acevedo et al.
For somatic cell count and total solids, indexes IV and VIII had the best results, regardless of the selection intensity
of the latter.
When both the selection intensity
within habitats and costs of plasticity were high, the fitness set became concave [ILLUSTRATION FOR FIGURE 6 OMITTED].
This selection scheme allowed a stable flow in production of pigs, but selection criteria changed continuously with selection intensity
Therefore, a selection intensity
applied to these traits results in predictable changes in the phenotype values of the traits among environments (Falconer 1989).
The change in allele frequency at each individual locus is now much less and, for the same selection intensity
, less of the possible genetic advance has been achieved after a given number of generations.
If this change is described in units of standard deviations of the character, a standardized selection differential is obtained that estimates the selection intensity
, i, on the character.
Assuming a selection intensity
of 1 for all the selection-related traits (i.
There was no change in rank according to selection intensity
among all levels of N for predicted yield based on the usefulness criterion (Table 3).
Mathematical Expression Omitted] is the selection intensity
(Falconer 1989), also known as the standardized directional selection gradient (Lande and Arnold 1983).
The cause of loss for the long-term selection response is that QTL is given high emphasis in early generations, and reduces the selection intensity
of polygenes, consequently resulting in a reduced early response at polygenes.
From a practical point of view, poor efficiency of indirect selection also implies that selection intensity
must be low.
A natural choice here is the selection intensity
that they produce.
We compared a 10 versus 20% selection intensity
within the base index, by examining the mean of the selected clonal lines.
n] are the trait values at generation n in males and females respectively, [Mathematical Expression Omitted] is the additive genetic variance, C is a measure of directional (sexual) selection, [Theta] is the optimal (natural selection) trait value, B is the genetic covariance between the sexes, D is a measure of the selection intensity
, and [Omega] is the width of the Gaussian fitness function for stabilizing (natural) selection.