Cs. Cramer et Tc. Wehner, FRUIT YIELD AND YIELD COMPONENT MEANS AND CORRELATIONS OF 4 SLICING CUCUMBER POPULATIONS IMPROVED THROUGH 6 TO 10 CYCLES OF RECURRENT SELECTION, Journal of the American Society for Horticultural Science, 123(3), 1998, pp. 388-395
Increased fruit yield in slicing cucumber (Cucumis sativus L.) has bee
n difficult to achieve since yield is quantitatively inherited with lo
w heritability. From 1981 to 1993, four slicing cucumber populations d
iffering in their genetic diversity (wide, medium, elite, and 'Beit Al
pha') were advanced through six to ten cycles of modified half-sib rec
urrent selection. The objectives of this research were to determine 1)
the fruit yield and yield component means; 2) the correlations betwee
n yield components, between yield traits, and between components and y
ield; and 3) the change in means and correlations with selection for i
mproved yield of four slicing cucumber populations. In 1994 and 1995,
four families were randomly selected from three cycles (early, interme
diate, and late) from each population and self-pollinated. Thirty plan
ts from each SI family were evaluated in 3.1-m plots in Spring and Sum
mer 1995 and 1996 at the Horticultural Crops Research Station in Clint
on, N.C. Plants were harvested and data were collected on number of br
anches per plant and nodes per branch, proportion of pistillate nodes,
fruit set and shape, and total, early, and marketable yield. When ave
raged over all populations, seasons, and years, fruit yield and qualit
y increased with selection while yield components remained unchanged w
ith selection. Fruit yield and components differed between populations
, seasons, and years. Most correlations between yield components and b
etween yield components and fruit yield were weak, and strong correlat
ions varied between populations, seasons, and yield components. Indire
ct selection of proportion of pistillate nodes has potential for impro
ving yield for certain population-season combinations. Selection weake
ned many strong correlations between yield components and between yiel
d and components. Changes in correlations often did not correspond wit
h changes in trait means. Based on this research, selection for yield
components would not be advantageous for improving fruit yield in all
slicing cucumber populations. Additional yield components, yield compo
nent heritability, and better component selection methods ne ed to be
determined before component selection can be used to improve fruit yie
ld.