Location: Sugarcane Field Station2013 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:
As new diseases and new races of current diseases infect previously resistant cultivars, the yields of these cultivars are reduced. The most recent challenge facing Florida sugarcane growers is the introduction of orange rust. True seeds, developed from crosses at Canal Point, Florida, were sent to the ARS cultivar development program in Louisiana. It is estimated that 206,703 seeds from 315 crosses were sent to Louisiana; and 492,164 seeds from 1,188 crosses remained in Florida. Cultivars developed by ARS occupied more than 86% of the sugarcane acreage in Florida in 2012. This breeding and selection program at Canal Point develops sugarcane cultivars for sand and organic (muck) soils in Florida. Improvements are needed in cultivar selection for sand soils. In 2013, for the third consecutive year, all stages of the selection program were planted on sand soils, beginning with the seedling stage. In addition, all stages of the selection program were conducted on muck soils. Two recently released varieties, CP 00-1101 and CP 01-1372 are being expanded rapidly and now are grown on more than 16% of the sugarcane acreage in Florida. In addition, in 2013, there was one new variety released, CP 06-2400. It is expected to yield well on muck soils. CP 06-2400 was resistant to brown rust and orange rust. Water deficit during the early growing season and nutrients are key abiotic stresses which limit sugarcane yields on sand soils in Florida. Pot studies indicated that nondestructive measurements of stomatal conductance, chlorophyll fluorescence and leaf photosynthesis could be useful for early detection of sugarcane water-deficit stress, but not for nitrogen deficiency. Genotype differences were detected in most physiological and growth traits measured for responses to the stresses. Field studies are underway to test if these physiological traits can be used to screen and evaluate sugarcane genotypes for water stress tolerance. In research to help growers meet Best Management Practices for reduction of phosphorus export and to conserve muck soils on which sugarcane in Florida is grown, a lysimeter experiment was conducted to learn how shallow water tables and periodic flooding affect the yields of recently harvested sugarcane. For recently planted sugarcane it was found that flood durations from 0 to 6 days applied in March and April caused increasingly severe losses in biomass. However, these losses were diminished when drainage depth was 15 rather than 42 cm below the soil surface. For the first-ratoon crop (recently harvested sugarcane) flood durations from 2-4 days caused moderate yield increases, regardless of drainage depth. However, for sugarcane that was not flooded, a water-table depth of 42 cm below the soil surface resulted in higher yields than a 15 cm water-table depth.
1. New sugarcane variety with high yield potential for widely-used planting system. In Florida, following three annual harvests, about half of the sugarcane is planted after a 1-year fallow period (fallow planted) and the other half is planted about 1 month after the third annual harvest (successive planted). Fallow planted sugarcane generally has higher yields, but successively planted sugarcane allows for more intense use of the land. In cooperation with University of Florida and Florida Sugar Cane League, Inc., researchers, ARS scientists at Canal Point, Florida, released a new variety (CPCL 05-1201) with outstanding 3-year experimental yields under successive planting. This group at Canal Point has been testing promising varieties under successive planting for about 20 years and CPCL 05-1201 is by far the most promising variety found for this planting system. Now that it is released, growers will evaluate CPCL 05-1201 over the next 3-5 years in successively planted commercial fields. If its experimental yields are confirmed under commercial conditions, this new variety will increase sugarcane yields by about 37.5% on the 50% of the land in Florida that is successively planted, and will be a parental source for developing newer genotypes with high yields under successive planting.
Davidson, R., Milligan, S.B., Gilbert, R.A., Glynn, N.C., Zhao, D., Comstock, J.C., Glaz, B.S., Edme, S.J., Hu, C., Holder, D., Sood, S.G. 2012. Registration of ‘CPCL 95-2287’ Sugarcane. Journal of Plant Registrations. doi:10.3198/jpr2012.03.0189crc.