Agriculture Reference
In-Depth Information
plant breeding activities, especially those conducted by established farmers
seed groups, which rely on a broad network seed exchanges to maintain and
enhance diversity and agronomic performance.
11.4.2 RESPONSE TO SELECTION IN EARLY GENERATIONS
The response to selection in early generations that was measured at Le
Moulon was of interest to researchers and farmers because it allowed us to
evaluate different selection strategies, or example, deciding the generation
at which individual spike selection within segregating population might be
efficiently introduced, or the number of years to observe a bulk population
before selecting among bulks. There were many significant changes when
comparing F3 progeny from selected and unselected F2 generation spikes.
Some families had more significant changes than others, which may be a
function of the heterogeneity of the parental varieties or the degree of dif-
ference between the two parents. Within families that responded to selec-
tion for multiple traits, some traits responded more frequently to selection
in early generations. This includes traits such as PH that are easy to assess
visually when selecting spikes in the field, and those that are not, such as
TKW. Other traits may not change in early generations, or may change in
the opposite direction of what is desired, such as LLSD. This may mean
that for certain traits it is better to wait to conduct selection till later gen-
erations, and a potential function of the collaboration with researchers
could be to identify which traits respond to selection and which do not,
or to identify easy techniques in the field to avoid undesirable changes in
the populations. Further analyses will investigate the relation between the
parents of the crosses and the response to selection in the F2 progenies.
Results in terms of means and variances for each trait measured for all
the
Croisements du Roc
populations evaluated on their farms were distrib-
uted to each farmer, as well as the results from the side-by-side trials of se-
lected and unselected F3 families at Moulon. While there were differences
among families tested at the same farm, often with one or two families
being identifi ed as very promising by the farmer, farmers and researchers
always use more than one year to evaluate the potential of new popula-
tion varieties and the early-generation cross populations are no exception.
