Location: Sugarcane Research2009 Annual Report
1a. Objectives (from AD-416)
The long-term goals of this project are to develop sugarcane cultivars that are better adapted and more economical to grow and harvest, to meet current and evolving needs of both a sugar and a biofuels industry, and to gain a greater understanding of sugarcane from genetic and physiological perspectives. The objectives are to utilize: (1) a basic breeding program to broaden the genetic base of parental germplasm and increase the adaptability of sugarcane to more temperate climates through the introgression of genes from wild species (Saccharum spontaneum) and related genera of sugarcane, and (2) parental clones from the basic program to develop sugarcane cultivars that are: higher yielding (gross cane and sugar), require fewer inputs, more tolerant to disease and insect pests, and adapted to a broader range of environments than current cultivars (commercial breeding program). To assist in the selection process, trait-specific molecular markers for early sucrose accumulation, sugarcane borer resistance, and cold tolerance will be developed.
1b. Approach (from AD-416)
Included in the basic program’s breeding strategy to increase the genetic diversity of parental clones are: (1) acquisition and maintenance of germplasm from wild species of Saccharum and related genera; (2) characterization of parents and progeny for traits (cold tolerance, stubbling ability, disease resistance, and sugarcane borer resistance) that will increase the adaptation of sugarcane to Louisiana’s temperate climate; (3) utilization of crossing and molecular marker techniques to produce interspecific and intergeneric hybrids containing new sources of disease and insect resistance and cold tolerance; and (4) recombination of progeny through backcrossing to develop parental material containing a concentration of desirable genes for the commercial breeding program. Screening procedures will be developed to determine relative cold tolerance among clonal material in the basic breeding program. In the development of cultivars for sugar and bioenergy, emphasis will be placed on yield components (stalk number, height, and diameter), quality components (sucrose and fiber accumulation), longevity (stubbling ability), harvestability (root anchorage, stalk erectness, and stalk brittleness), hardiness (winter survival, early spring vigor, and stalk freeze tolerance), stress tolerance (droughts, floods, and heavy clay soils), and resistance to stalk boring insects (sugarcane borer and Mexican rice borer) and diseases (smut, rust, leaf scald, mosaic, yellow leaf virus, and ratoon stunting disease). Recurrent selection techniques will be utilized to accelerate the rate of genetic improvement for important traits. In addition, trait-specific markers closely associated with desirable traits such as sucrose accumulation, cold tolerance, and resistance to the sugarcane borer will be developed to assist breeders in eliminating undesirable plants early in the selection process.
3. Progress Report
Project receives support from the American Sugar Cane League (6410-21000-014-04T) through a Trust Fund Cooperative Agreement, ”Improving Sugarcane Production Efficiency", as well as the in-house project 6410-21000-014-00D, "Genetic Improvement of Sugarcane by Conventional and Molecular Approaches". Additional details of research can be found in the reports of the subordinate and inhouse projects. A total of 61,550 new commercial seedlings were set to the field in spring 2009 from crosses made in the fall of 2008. Parental lines, consisting of commercial varieties having a history of producing superior progeny and promising experimental varieties based on early stages of yield testing were placed in Agricultural Research Service's crossing facilities in Houma, Louisiana, and Canal Point, Florida, in preparation for the fall 2009 crossing season. The impending threat of the Mexican rice borer (Eoreuma loftini) and orange rust (Puccinia kuehnii) affected the choice of seedlings set to the field and parents to be used in 2009. Last fall, 6,460 seedlings (Stage 1) were advanced to Stage 2, 808 individuals were avanced to Stage 3, and 26 individuals were were given permanent alphanumeric designations and advanced into multi-location nurseries in Louisiana's sugarcane belt for yield testing. Regional tests involving five high-fiber varieties developed by the SRU were established in GA (2), LA (2), MS (2), and TX (2) to fulfill the requirements of a Department of Energy dedicated energy crop grant in the SunGrant Initiaitive to develop regional bioenergy feedstocks. A total of total of 28,620 basic seedlings made by crossing wild relatives of sugarcane and related grasses to commercial or near-commercial sugarcane varieties were planted in the field in the spring of 2009. Two-thousand-four-hundred 2006 seedlings were selected for further testing in first-line trials. An additional 385 selections were selected from 2007 first-line trials and planted in a second-line trial in the fall of 2008. Sixty-two individuals with recent wild ancestory were selected for inclusion as parents in the 2009 crossing season at the SRU. Chacterization of wild sugarcane varieties for traits of interest, in particular, cold tolerance and disease resistance, is continuing.
1. Starch Interferes with the Quantity and Quality of Sugar From Sugarcane. The Sugarcane Research Unit’s (SRU's)collection of breeding material (clones) representing collections of various types of wild and commercial sugarcane and related grasses were assayed for their content of starch. Results revealed significant differences in starch levels among the types of breeding clones and significant differences in starch content within each type. Commercial varieties of sugarcane produced more sucrose and less starch than the wild species of sugarcane (Saccharum spontaneum) suggesting a link between starch content and sucrose production. Environmental conditions, such as freezing temperatures tended to decrease starch content. Since differences in starch content were found within the clones, breeders should consider starch content in selecting parental combinations for crossing to minimize the impact of starch on commercial sugar production.
Tew, T.L., Dufrene Jr, E.O., Garrison, D.D., White, W.H., Grisham, M.P., Pan, Y.-B., Richard Jr, E.P., Legendre, B.L., Miller, J.D. 2009. Registration of "HoCP 00-950" Sugarcane. Journal of Plant Registrations. 3(1):42-50. DOI:10.3198/jpr.2008.07.0430crc