2011 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.
This project relates to inhouse objective 1: Develop more efficient breeding and selection methodologies for cultivar development and to produce seed of seclected sugarcane germplasm for use in Florida, Louisiana, and Texas.
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 2010/2011 crossing season, 862 crosses using 1443 female tassels were used by ARS for the Florida breeding program. An additional 114 crosses using 293 female tassels were divided between the ARS Louisiana sugarcane program or the Texas AgriLife A&M University sugarcane breeding program with Canal Point. It is estimated that a total of 677,978 seeds were developed for use at Canal Point. Selections from approximately 70,000 seedlings 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 70,000 seedlings were planted at Canal Point and 10,000 seedlings were planted on a sand soil at a cooperator’s farm. In Stage 1, selections from about 15,000 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. 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 ten cooperating growers. In Stage 2 in 2011, 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 one location had a sand soil. In Stage 4, seven test locations had muck soils and three had sand soils. In Stage 4 there were 7, 8, and 8 clones planted on muck and sand soils in 2008, 2009, and 2010, respectively. There were an additional 6, 5, and 5 clones planted on either muck or sand soils in 2008, 2009, and 2010, respectively, in Stage 4.