Location: Sugarcane Field Station2008 Annual Report
1a. Objectives (from AD-416)
1. Develop more efficient breeding and selection methodologies for cultivar development and to produce seed of selected sugarcane germplasm for use in Florida, Louisiana, and Texas. 2. Develop better agronomic practices for the Florida sugarcane industry. 3. Identify alleles or genes that can be used in molecular marker-assisted selection to complement the conventional approach of sugarcane cultivar development. 4. Identify agronomic and physiological relationships of sugarcane with stress tolerance to improve sugarcane cultivar development.
1b. Approach (from AD-416)
Development of new cultivars with disease resistance, freeze tolerance, and high sucrose content will be advanced through genetic and genomics approaches. These will involve the utilization of a sugarcane genetic map with quantitative trait loci (QTL) and the identification of variation in candidate genes through gene expression profiling, and in some cases through developing markers for gene insertions. To improve cultivar development on sand soils, genetic studies will compare selection efficiencies on organic and sand soils and repeatability between selection stages, and agronomic research will seek useful traits for identifying high-yielding genotypes on sand soils. Agronomic research will also seek useful traits for identifying tolerance to shallow water tables on organic soils, and will examine sampling procedures for estimating fiber content.
3. Progress Report
Two new cultivars, CP 01-1372 and CPCL 97-2730, were released for commercial production in Florida. Production of older cultivars is reduced as new insects, weeds, and diseases, and new races of current diseases continue to appear in Florida, but production remains high across the industry due to the availability of new cultivars. True seeds, developed from crosses at Canal Point, FL were sent to the ARS cultivar development program in Louisiana, and the Texas A&M program in Texas. More than 50,000 seeds from more than 380 crosses were sent to Texas; more than 100,000 seeds from 683 crosses were sent to Louisiana; and more than 300,000 seeds from more than 909 crosses remained in Florida. Cultivars developed from ARS produced seed occupy more than 90% of the sugarcane acreage in Florida, Louisiana, and Texas. This breeding and selection program primarily develops sugarcane cultivars for sand and organic soils in Florida. In 2008, a meeting was held to report to Florida growers on research (underway and completed) to improve cultivar development for sand soils. Presentations reported on research aimed at 1) improving parental selection for sand soils, 2) determining if an early selection stage should be planted on sand as well as an organic soil, 3) identifying one of eight locations used in the final selection stage that could be replaced so that locations in this stage with sand soils could be increased from two to three, and 4) identifying easily measured sugarcane traits that could be used in early selection stages to select genotypes that would yield well on sand soils. In 2007, a sugarcane rust disease (orange rust) was identified for the first time in Florida. In addition, brown rust has continued to substantially affect sugarcane farmers and the breeding program. For example, in an early selection stage of this program in 2007, only about 300 of 1700 genotypes did not have rust. Currently the program is reviewing options in early selection stages that may result in selection of higher percentages of genotypes that do not have rust. Research in this project is relevant to Component 2 Crop Informatics, Genomics, and Genetic Analyses and Component 3 Genetic Improvement of Crops in the Action Plan for National Program 301 Plant Genetic Resources, Genomics, and Genetics Improvement. In Component 2, it is relevant to Problem Statement 2C, Genetic Analyses and Mapping of Important Traits. In Component 3, research is relevant to all three problem statements: A. Genetic Theory and Methods of Crop Improvement, B. Capitalizing on Untapped Genetic Diversity, and C. Germplasm Enhancement/Release of Improved Genetic Resources and Varieties. This research project replaces project #6625-13210-003-00D which expired.
1. Release of Two High Yielding Sugarcane Cultivars in Florida. New sugarcane cultivars in Florida are continuously needed for sustained or improved yields, resistance to intense disease pressures, and for improved adaptability to freezes and high water tables. Also, higher yields are needed on sand soils which comprise about 20% of Florida’s sugarcane. Through the cooperative efforts of the ARS Sugarcane Field Station, Canal Point, FL; the University of Florida Institute of Food and Agricultural Sciences Everglades Research and Education Center at Belle Glade, FL; and the Florida Sugar Cane League, Inc. at Clewiston, FL, two new sugarcane cultivars (CP 01-1372 and CPCL 97-2730) were released in Florida in the fall of 2007. These new cultivars will add genetic variability for disease resistance while yielding well in Florida, the state in the U.S. with the highest sugar production; 19% of all sugar produced in the U.S. CP 01-1372 is expected to yield well on all soils on which sugarcane is produced in Florida while CPCL 97-2730 was released specifically for improved yields on sand soils. This research was in support of National Program 301 Plant Genetic Resources, Genomics, and Genetics Improvement, Component 3 Genetic Improvement of Crops, Problem Statement 3C Germplasm Enhancement/Release of Improved Genetic Resources and Varieties.
2. Sequence-related amplified polymorphism (SRAP) markers for assessing genetic relationships and diversity in sugarcane germplasm collections. Assessing the diversity of wild and cultivated germplasm is essential for any breeding program as the wild germplasm usually represents an untapped source of genes to improve yield and to impart resistance to diseases and environmental stresses. The potential of a new DNA marker system (SRAP) that amplifies gene-rich regions of a genome was evaluated for its ability to generate polymorphisms in a set of important wild species of sugarcane and hybrids. The SRAP assays separated the 30 genotypes tested according to the phylogenetic relationships known in sugarcane. With the capability to generate a large number of markers (1364 DNA fragments from 31 primer combinations were produced) that are not neutral, the SRAP system constitutes a robust tool for diversity studies and genetic mapping in sugarcane aimed at introgression of wild alleles with specific value into the cultivated background. This research was in support of NP 301 Plant Genetic Resources, Genomics, and Genetics Improvement, Component 3 Genetic Improvement of Crops, Problem Statement 3C Germplasm Enhancement/Release of Improved Genetic Resources and Varieties.
5. Significant Activities that Support Special Target Populations