Cucurbit Genetics Cooperative Report 20:18 (article 9) 1997
CMV Resistance in Cucumber – A Correction
Michael J. Havey
Agricultural Research Service – USDA, Department of Horticulture, 1575 Linden Drive, University of Wisconsin, Madison, WI 53706 USA
In a previous report published in the Cucurbit Genetics Cooperative Report (Havey 1996), I erroneously stated that the primary source of CMV resistance currently used commercially traced back to an accession of ‘Tokyo Long Green’. Dr. Henry Munger, Cornell University, brought this error to my attention. Although ‘Tokyo Long Green’ shows resistance to CMV, research by Dr. Munger and colleagues (Munger and Newhall 1953) indicated that this source of resistance is less desirable than that of ‘Chinese Long’. Porter observed CMV-resistant cucumber germplasm in China in 1926 and acquired the first accession of ‘Chinese Long’ (Porter 1932). CMV resistance from this accession was used to develop ‘Shamrock’, the first CMV-resistant commercial cucumber (Munger and Newhall 1953). ‘Chinese Long’ was also used by Dr. Munger to develop his CMV-resistant cucumbers‘Table green’ and ‘Marketmore’ and by Walker (Wasuwat and Walker 1961) to develop ‘WI SMR12’ and WI SMR18’. Shifriss et al. (1942) proposed that three genes may condition CMV resistance in ‘Chinese Long’ by ‘Early Russian’ (CMV susceptible) crosses, although Munger and Newhall (1953) indicated that inheritance of CMV resistance in ‘Chinese Long’ may be more complex. Wasuwat and Walker (1961) proposed that a single dominant gene conditioned CMV resistance in their pickling cultivars derived from ‘Chinese Long’.
As described by Munger and Newhall (1953), Dolittle et al. (1939) discovered CMV resistance in ‘Tokyo Long Green’ and used this as the source of CMV resistance in Ohio 31, the first CMV-resistant pickling cucumber. Waker used ‘Tokyo Long Green' and 'Chinese Long' as the sources
of CMV resistance in ‘WI SMR15’ (Wasuwat and Walker 1961). Munger and Newhall (1953) described contrasting development of CMV symptoms in ‘Chinese Long’ and ‘Tokyo Long Green’. ‘Chinese Long’ developed a slight mottling after inoculation and grew out of the symptoms to produce newer leaves with no transmission of the virus from the fifth or sixth leaves. ‘Tokyo Long Green’ showed less mottling on leaves two weeks after inoculation, as compared to ‘Chinese Long’. However, the newer leaves of ‘Tokyo Long Green’ continued to show some mottling and did not develop symptomless newer leaves. Kooistra (1969) studied the inheritance of CMV resistance in material derived from ‘Tokyo Long Green’ and proposed three incompletely dominant resistance genes.
Dr. Munger shared unpublished results from the Ph.D. thesis (Cornell University, 1954) of his student, Lester Schaible. Munger and Schaible inoculated 37 F2 progenies from ‘Chinese Long’ x ‘ Tokyo Long Green’ with CMV. They observed segregation of CMV resistance, indicating that the same gene(s) were not conditioning CMV resistance in both populations. F3 progenies from 27 of these F2 plants were inoculated and reactions correlated well (0.89) with the parental phenotypes.
Acknowledgement: I gratefully acknowledge this correction and salient information provided by Dr. Munger.
- Havey, M.J. 1996. CMV resistance in three sources of cucumber. Cucurbit Genetics Coop. 19:32-33.
- Kooistra, E. 1969. The inheritance of resistance to Cucumis virus 1 in cucumber. Euphytica 18:326-332.
- Munger, H.M., and A.G. Newhall. 1953. Breeding for disease resistance in celery and cucurbits. Phytopathology 43: 254-259.
- Porter, R.H. 1932. The reaction of cucumbers to types of mosaic. Iowa State Coll. Jour. Sci. 6:95-129.
- Schaible, L. 1954. Some aspects of resistance to cucumber virus 1 in cucumber and squash. Ph.D. thesis. Cornell University. 56 p.
- Shifriss, O., C.H. Myers, and C. Chupp. 1942. Resistance to mosaic virus in cucumber. Phytopathology 32:773-784.
- Wasuwat, S., and J. Walker. 1961. Inheritance of resistance in cucumber to cucumber mosaic virus. Phytopathology 51:423-428.