Cs. Cramer et Tc. Wehner, PERFORMANCE OF 3 SELECTION CYCLES FROM 4 SLICING CUCUMBER POPULATIONSHYBRIDIZED WITH A TESTER, Journal of the American Society for Horticultural Science, 123(3), 1998, pp. 396-400
Recurrent selection has been used as a breeding method to improve trai
ts having low heritability such as fruit yield, earliness, and fruit s
hape. The objective of this study was to measure the progress of recur
rent selection in four slicing cucumber populations in terms of hybrid
performance when crossed with a common tester. The four populations,
North Carolina wide-base slicer (NCWBS), medium-base slicer (NCMBS), e
lite slicer 1 (NCES1), and Pelt Alpha 1 (NCBA1) populations, which dif
fered in their genetic diversity and mean performance, were developed
using modified intrapopulation half-sib recurrent selection to improve
fruit yield and quality. Eleven So families were taken randomly from
each of three selection cycles (early, intermediate, and advanced) fro
m each population. Those families were self-pollinated to form S-1 fam
ilies, and the S-1 families were crossed to 'Poinsett 76', a popular s
licing cucumber cultivar. The experiment was a split-plot treatment ar
rangement in a randomized complete-block design with 22 replications p
er population, with the four populations as whole plots and the three
cycles as subplots. When 10 % of fruit were oversized >60 mm in diamet
er), plants were sprayed with paraquat to defoliate them for once-over
harvest. Plots were evaluated for total, early, and marketable yield
and fruit shape. Recurrent selection for improved fruit yield and shap
e per se resulted in improved hybrid performance of the NCWBS and NCBA
1 populations for fruit geld and shape rating when tested in the selec
ted or nonselected environment. The NCWBS population had the largest g
ain (21%) in hybrid performance averaged over all traits. In addition,
early yield was improved an average of 18% from early to late cycles
for each population. Even though the fruit yield and shape rating of '
Dasher II' was greater than the hybrid performance of each population
mean for the same traits, several F-1 families within each population
exceeded the fruit yield of 'Dasher II).