Pickling Cucumber Population Improvement for Increased Fruit Yield II

Cucurbit Genetics Cooperative Report 7:9 (article 4) 1984

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

1. Lertrat, K. and R. L. Lower. 1983. Pickling cucumber population improvement for increased fruit yields. Cucurbit Genetics Coop. Rpt. 6:18-19.