Cucurbit Genetics Cooperative Report 7:9 (article
4) 1984
Pickling Cucumber Population
Improvement for Increased Fruit Yield II
K. Lertrat and R. L. Lower
University of Wisconsin, Madison, WI
53706
Direct selection to improve fruit number per plant has been used
as one of the breeding strategies to improve pickling cucumber
yield for a once-over mechanical harvesting system in our
breeding program. The population improvement program has been
conducted for several generations (1).
The second cycle of recurrent selection for specific combining
ability using GY 14 as an inbred tester in two breeding
populations, the hardwickii semiexotic (HSE) and the gynoecious
synthetic population (GS), was completed in 1983.
In this cycle, the GY 2 tester was discarded due to the lack of
scab resistance. Average fruit yield, at optimum harvest time,
for GY 14 test crosses of HSE and GS were 1.75 and 1.63 fruit per
plant, respectively (Table 1).
Table 1. Summary of the second cycle of
recurrent selection for specific combining ability for increased
fruit yield in pickling cucumber populations, HSE and GS, using
Gy 14 as an inbred tester. |
Population |
Number of test crosses
|
Average fruit no. per plant
|
Range
|
Average fruit no. per plant of selected
lines
|
HSE |
123
|
1.75
|
1.14-3.67
|
2.16 (SI 20%)
|
GS |
123
|
1.63
|
1.06-2.44
|
1.93 (SI 20%)
|
Hybrid checksa |
|
1.29
|
0.90-1.88
|
|
aIncluded three gynoecious F1 hybrids
(Calypso, Calico and Southern Belle) and three monoecious
cultivars (SMR 18, Clinton and Liberty). |
Test cross yields were higher than hybrid checks (1.29 fruit per
plant). In summer 1983 the top 25 lines of HSE and GS (SI 20%),
with their average fruit yield of 2.16 and 1.93, were selected
for further population improvement. Yield was lower in 1983 than
1982 - presumably due to an unusually warm growing season.
Literature cited:
- Lertrat, K. and R. L. Lower. 1983. Pickling cucumber population
improvement for increased fruit yields. Cucurbit Genetics Coop.
Rpt. 6:18-19.
