Location: Sugarcane Production Research2012 Annual Report
1a. Objectives (from AD-416):
(1) Produce enough true seed of recommended crosses at Canal Point to supply the Florida cooperative sugarcane breeding program. (2) Select, develop and release high-yielding sugarcane cultivars. (3) Evaluate varieties under different sugarcane production systems in use in Florida. (4) Develop marker assisted selection for hard to select traits. (5) Develop and institute new disease screening methods for important sugarcane pathogens.
1b. Approach (from AD-416):
Make crosses with basic species of Saccharum and related genera. All known techniques will be used to synchronize flowering to increase the probability of making desirable crosses, hybrids will be crossed and backcrossed under unconventional systems of breeding in an effort to increase the genetic contribution of the exotic parents in commercial cultivars. The influence of environmental conditions, stalk preservation techniques of both male and female and pollen loading (ratio of male: female tassels) will be evaluated. Screening methods for important diseases will be refined and incorporated in the cultivar development program. Variety yield trials will be assessed under various production methods, including tolerance to high water tables.
3. Progress Report:
This research relates to inhouse objective 2: Develop better agronomic practices for the Florida sugarcane industry. The Florida sugarcane development program at Canal Point requires at least 9 years to develop a commercial cultivar from the time a cross is made. In the 2011/2012 crossing season, 717 crosses using 1600 female tassels were used by ARS for the Florida breeding program. An additional 9 crosses using 40 female tassels were divided with the ARS Louisiana program at Houma. It is estimated that a total of 708,611 seeds were developed for use at Canal Point. Selections from approximately 72,390 seedlings planted on muck were advanced based on visual assessment of yield in conjunction with evaluation of sucrose content on a per cross basis. Traditionally all seedlings were planted on muck soils in Canal Point, but in 2011 about 8,000 seedlings were also planted on a sand soil at a cooperator’s farm and this year about 16,000 seedlings were planted on that sand soil. Selections from the first planting of 8,000 will begin later this year when those seedlings are in the first-ratoon crop. This year In Stage 1, selections from 14,276 clones planted on a muck soil at Canal Point were advanced based on visual assessment in conjunction with Brix analyses. In addition to vigor, visual assessments in Stage 1 also included resistance to the brown and orange rust pathogens as well as other diseases. Beginning with selections made later this year in Stage 1, the assessments for resistance to brown rust will be more robust than in the past. Selections were advanced through Stages 2 (about 1500 clones) and 3 (135 clones) based on high sucrose content, high cane yields, disease resistance or tolerance, and general adaptability. In recent years, increasing emphasis has been placed on rust resistance in Stages 1 and 2. In the final stage, Stage 4, selections were evaluated in the plant-cane, first ratoon, and second-ratoon crops on farms of cooperating growers. In Stage 2 in 2012, about 1500 clones were planted on a muck soil and 500 were planted on a sand soil. In Stage 3, three test locations had muck soils and two locations had a sand soil. In Stage 4, seven test locations had muck soils and four had sand soils. A new Stage 4 test was added on a sand soil to accommodate selections from the early stages made on sand soils. In the other 10 Stage 4 tests, genotype advancements were made independently for the muck locations vs. the locations with sand soils. Six genotypes were planted at all 10 locations, 7 genotypes were planted only on muck soils, and seven genotypes were planted only on sand soils. Progress was monitored by several meetings between ARS personnel at Canal Point and personnel representing the Florida Sugar Cane League as well as at two formal meetings of the “Florida Sugarcane Variety Committee.” This committee also reviewed results and progress on clones tested for freeze tolerance in Gainesville, FL and recommended releasing five genotypes based on Stage 4, freeze tolerance, and disease data. Four employees of the Florida Sugar Cane League are located at Canal Point and funding from this agreement is used to support several temporary ARS employees at Canal Point.