Cucurbit Genetics Cooperative Report 7:45 (article
Evidence of a Recessive Powdery Mildew Resistance Gene in
Muskmelon PI 414723
J. D. McCreight
U.S. Department of Agriculture, Agricultural Research Service,
P.O. Box 5098, Salinas, CA
Plant Introduction (PI) 414723 (melon aphid, Aphis
gossypii Glover, resistant inbred of PI 371795) is a source
of aphid resistance (1) and zucchini yellow mosaic virus
resistance in muskmelon. Observations of greenhouse plantings
indicated that it was also resistant to powdery mildew caused by Sphaerotheca fuliginea (Schlecht.) Poll. PI 414723 was
crossed with 'Topmark' which is susceptible to S.
fuliginea races 1, 2, and 3. Twenty-five seedlings of PI
414723 and F1 (PI 414723 x 'Topmark') were inoculated
3X over a 13-day period beginning at the cotyledon stage of
growth. The inoculum, cultured on 'Hales Best Jumbo' and
'Topmark', was previously identified on a set differential hosts
as S. fuliginea race 1 (unpublished data). The plants were
rated for powdery mildew 3 and 4 weeks after the 1st inoculation.
PI 414723 was resistant. The F1 (PI 414723 x 'Topmark')
was susceptible, which indicates that the resistance in PI 414723
is conditioned by a recessive gene(s).
- Kishaba, A.N., G.W. Bohn and H.H. Toba. 1971. Resistance to Aphis gossypii in Cucumis melo from India. J.
Econ. Entomol. 64:935-937.
- Pitrat, M. and H. Lecoq. 1984. Inheritance of zucchini yellow
mosaic virus resistance in Cucumis melo L. Euphytica 33