GENETIC IMPROVEMENT OF SUGARCANE BY CONVENTIONAL AND MOLECULAR APPROACHES
Location: Sugarcane Research Unit
Title: 50 years of sugarcane germplasm enhancement - roadblocks, hurdles, and success
Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 2, 2009
Publication Date: July 22, 2009
Citation: Hale, A.L., Veremis, J.C., Tew, T.L., Burner, D.M., Legendre, B., Dunckelman, P. 2009. 50 years of sugarcane germplasm enhancement - roadblocks, hurdles, and success [meeting abstract]. International Society of Sugar Cane Technologists 9th Sugarcane Breeding and Germplasm Workshop, Cairns Australia, August 17 - 21, 2009.
In 1959, a sugarcane germplasm enhancement program was initiated in Houma Louisiana, USA. This program was intended to develop parental material with an expanded genetic base for the commercial breeding program. What has come to be known as the “basic breeding program” is a long-term undertaking which utilizes a modified backcross breeding scheme. As a result of these basic breeding efforts, LCP 85-384 was released in 1993 by Louisiana State University, USDA-ARS Sugarcane Research Unit, and the American Sugarcane League. This variety increased Louisiana yields of sugar per hectare by 25%. Continued efforts are underway with new and novel genetic combinations being achieved each year. Currently under evaluation are clones with multiple genera and/or species in their background, many of which resulted by crossing two F1s together. These include but are not limited to clones that contain: Erianthus brevibarbis and S. spontaneum; E. arundinaceus and Miscanthus sp.; Miscanthus. sp., E. brevibarbis, and S. spontaneum; S. officinarum and S. spontaneum; E. arundinaceus and S. spontaneum; and M. sinensis x Saccharum spp. These wide crosses are being evaluated for cold tolerance, insect resistance, disease resistance, agronomic type, and yield characteristics. Selections from 5 m un-replicated yield trials in the basic breeding program in 2008 included an F1 that was 111% of the HoCP96-540 commercial check for theoretical recoverable sugar, as well as a clone that yielded an estimated 213 Mg/hectare. Numerous other clones had higher Brix values and out-yielded the commercial check in sugar per hectare and/or in tons of cane per hectare. Scientifically, the biggest hurdles to overcome when making wide crosses revolve around flower synchronization and cross compatibility. Once the seedlings are germinated, the wide hybrids appear to be more susceptible to herbicide damage, so it becomes difficult to assess their performance in relation to commercial sugarcane, particularly in the vulnerable seedling stage. The increasing interest in sugarcane as a biofuel feedstock presents a challenge during selection since high fiber is a detriment to commercial cane grown for sugar but can be an asset in an energy cane feedstock for used for cellulosic conversion to ethanol. Thus, at times, selections must be made separately for the developing energy-cane and existing sugarcane breeding programs, which has become taxing on the existing resource base. Management and negotiations of intellectual property also pose additional burdens to the program. As was intended, the basic breeding program continues to provide superior parental material in which to develop commercial sugarcane varieties with an expanded genetic base.