Published January 4, 2016
JOURNAL OF PLANT REGISTRATIONS
c u lt i va r
Registration of ‘UFCP 82-1655’ Sugarcane Hardev S. Sandhu,* Robert A. Gilbert, Jack C. Comstock, Vanessa S. Gordon, Pedro Korndörfer, Rebecca A. Arundale, and Nael El-Hout
U
Abstract
FCP 82-1655 (Reg. No. CV-164; PI 673050), a high fiber and low sucrose sugarcane, also called energy cane (a complex hybrid of Saccharum spp.), is released for its potential use in cellulosic ethanol production. “Energy cane” is a distinct form of sugarcane that is selected for high biomass and surplus fiber rather than sucrose (Matsuoka et al., 2014). UFCP 82-1655 was developed through a collaborative effort of the University of Florida (UF) and the USDA-ARS, Canal Point (CP). The cultivar is part of a long-term and ongoing collaboration between UF, USDA, and Florida Sugarcane League to develop new sugarcane cultivars (CP cultivars) in Florida. Sugarcane is a major row crop in Florida, cultivated on approximately 166,000 ha near Lake Okeechobee (Rice et al., 2014), with CP cultivars grown on >80% of the acreage. UFCP 82-1655 was publically released on 30 Sept. 2013 for potential low-input cultivation on marginal or sandy soils of Florida. The major attribute of this cultivar is its moderate to high resistance to naturally occurring and artificially innoculated smut infection (caused by Sporisorium scitamineum). Smut is an economically important disease in sugarcane. Economic loss results because smut-infected stools have poor plant regrowth, resulting in gaps and biomass yield reduction that increase with harvest in later ratoons. UFCP 82-1655 is also resistant to naturally occurring brown rust (caused by Puccinia melanocephala H. & P. Sydow), orange rust (caused by Puccinia kuehnii), and mosaic (caused by Sugarcane mosaic virus). The potential yields of high-fiber sugarcane or energy cane are high in southeastern regions of the United States where sunlight and rainfall are abundant (USDA, 2010). The state of Florida has favorable climatic conditions and opportunities to purchase low cost land for production of biomass crops. It is considered one of the leading areas in the United States for producing renewable plant-based energy. However, a limited number of energy cane cultivars have been released for commercial production in the United States. The high smut susceptibility in some
‘UFCP 82-1655’ (Reg. No. CV-164; PI 673050), a high fiber and low sucrose sugarcane, also called energy cane (a complex hybrid of Saccharum sp.), was developed through the collaborative effort of the University of Florida (UF) and the USDA-ARS, Canal Point (CP) for its potential use in cellulosic ethanol production in Florida. UFCP 82-1655 has moderate to high resistance against smut (caused by Sporisorium scitamineum). UFCP 82-1655 did not have any natural infestation of brown rust (caused by Puccinia melanocephala H. & P. Sydow), orange rust (caused by P. kuehnii), mosaic (caused by Sugarcane mosaic virus) and leaf scald [caused by Xanthomonas albilinenas (Ashby) Dawson]. Dry biomass yield (soluble plus insoluble dry weight) of UFCP 82-1655 was not significantly different from ‘L 79-1002’. Averaged across different crop cycles (plant cane, first ratoon, second ratoon, and third ratoon) at three locations in Florida (Citra, Tecan and Lykes Bros. farms), mean dry biomass yield of UFCP 82-1655 was 32.7 Mg ha−1 compared with 30.6 Mg ha−1 for the reference check, L 79-1002. Plant composition (% fiber) of UFCP 82-1655 is composed of 41.7% cellulose, 27.9% hemicellulose, 22.6% lignin, 2.6% nonstructural ash, 2% structural ash, and 1.6% structural protein, which is quite similar to L 79-1002. UFCP 821655 is released to enhance genetic diversity and to improve disease resistance in energy cane.
H.S. Sandhu, Univ. of Florida, Everglades Research and Education Center, 3200 E. Palm Beach Rd., Belle Glade, FL 33430; R.A. Gilbert, Univ. of Florida, P.O. Box 110500, Gainesville, FL 32611; J.C. Comstock and V.S. Gordon, USDA-ARS, Sugarcane Field Station, 12990 US Hwy. 441 N, Canal Point, FL 33438; P. Korndörfer, Florida Crystals, 21250 US Hwy. 27, South Bay, FL 33493; R.A. Arundale, BP Biofuels North America, Houston, TX; N. El-Hout, BP Biofuels North America, Highlands County, FL.
Copyright © 2015 Crop Science Society of America. All rights reserved.
Journal of Plant Registrations 10:22–27 (2016). doi:10.3198/jpr2014.10.0074crc Received 23 Oct. 2014. Accepted 28 Aug. 2015. Registration by CSSA. 5585 Guilford Rd., Madison, WI 53711 USA *Corresponding author (
[email protected])
Abbreviations: CP, Canal Point; NIR, near-infrared reflectance; PCR, polymerase chain reaction; SSR, simple sequence repeat; UF, University of Florida.
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of the released cultivars (e.g., ‘L 79-1002’; Bischoff et al., 2008) further limits the number of available cultivars. The release of UFCP 82-1655 increases genetic diversity and gives growers an additional option when growing energy cane cultivars with disease resistance.
Methods Initial Genotype Selection UFCP 82-1655 and other energy cane clones were initially selected from wide crosses of S. spontaneum × commercial sugarcane made at the USDA Sugarcane Field Station at Canal Point, FL. These crosses were made to generate cold-tolerant progeny and are described in Tai and Miller (1993). In December 2006, 53 progenies were selected and planted in single-row plots (5 m long) with three replications on a Lauderhill muck soil (euic, hyperthermic, Lithic Haplosaprist) at UF Everglades Research and Education Center in Belle Glade, FL. From these 53 clones, 8 were selected on the basis of biomass and disease resistance for commercial field-testing at three locations in Florida: Tecan (26°37¢84² N, 80°56¢19² W; southern Florida), Citra (29°27¢36² N, 82°10¢15² W; northern Florida), and Lykes Bros. farms (27°12.2¢ N, 81°5.28¢ W; central Florida).
Field Trials UFCP 82-1655 was one of eight genotypes chosen from the original 53 energy cane selections, for evaluation in field trials. These eight genotypes and a commercial check, L 79-1002, were planted at the Tecan farm in 2007, the UF/Institute of Food and Agricultural Sciences Plant Science Research and Education Unit at Citra in 2009, and Lykes Bros. farm in 2010. All three locations had mineral soil with low organic matter, also called marginal soils with low inherent soil fertility. The soil was Pomona series (sandy, siliceous, hyperthermic Ultic Alaquods) at Tecan, Arredondo fine sand (loamy, siliceous, semiactive, hyperthermic Grossarenic Paleudults) at Citra, and Pineda fine sand (loamy, siliceous, active, hyperthermic Arenic Glossaqualfs) at Lykes Bros. farm. Trial designs were randomized complete blocks with four replications at each site. Plots were 7.6 m long and three rows (4.5 m) wide and were arranged in tiers. Two plots were side by side (total six rows) in each tier with 4.5-m alleys on each side of the tier. The planting dates at Tecan, Citra, and Lykes Bros. farm were 19 Dec. 2007, 14 Jan. 2009, and 20 Jan. 2010, respectively. High dry biomass yield (Mg ha−1) and resistance to natural disease infections in the field were the main selection criteria. Tests were harvested using brush cutters (FS550, STIHL) at Citra and Lykes Bros. farm and a sugarcane harvester at Tecan. At Citra, the cane was harvested on 12 Jan. 2010 as plant cane, 11 Jan. 2011 as first ratoon, 5 Oct. 2011 as second ratoon, and 18 Sept. 2012 as third ratoon. At Lykes Bros. farm, the plant cane was harvested on 20 Jan. 2011 and first ratoon was harvested on 22 Nov. 2011. At Citra and Lykes Bros., fresh biomass yields were estimated by weighing a sample of 3-m-row length from the center row of each plot on a hanging weight scale. A 10-stalk subsample was collected from each plot to estimate dry biomass (soluble plus insoluble dry weight) and fiber composition. The subsample was shredded using a modular sugarcane disintegrator (Codistil S/A Denini, Mod: 23
132S) and mixed thoroughly in a plastic container. A sample of approximately 1 kg shredded material was weighed from fresh biomass and then dried at 60°C until constant weight, and dry biomass yield was calculated as: Dry biomass yield = Mg fresh biomass × (dry biomass/fresh biomass × 100) The dry samples were weighed and then ground to pass through a 2-mm screen in a Wiley-Mill, standard model #3 (Thomas Scientific). A 40-g subsample of the finely ground material was collected into 20-mL vials (HDPE scintillation vials, Fisher Scientific) for fiber compositional analysis. At Tecan, the cane was harvested on 15 Dec. 2008 (plant cane) and 13 Dec. 2009 (first ratoon) using commercial cane harvesters. Case IH 7700 and Case IH 8800, respectively. All primary and secondary fans from the sugarcane harvester were turned off for a total biomass harvest. Fresh biomass yields were estimated by dumping harvested cane, tops and leaves included, into a weigh-wagon equipped with load cells (Avery Weigh-Tronix, 715). The two center rows of each plot were weighed individually before taring the scale and proceeding to the following plot. Dry biomass yield estimation and collection of subsamples for fiber compositional analysis were conducted the same way as at Citra and Lykes Bros. farm, as mentioned above.
Disease Resistance Field data on natural disease infection were collected for nine location-years (5 yr at Citra, 2 yr each at Tecan and Lykes Bros. farm). Natural infection under field conditions for UFCP 82-1655 was determined for brown rust and orange rust based on size and number of uredia. Field ratings for both rusts consisted of five classes: 0 (resistant), 1 (moderately resistant), 2 (moderately susceptible), 3 (susceptible), and 4 (highly susceptible). For natural infection of smut, smut whips were counted in each plot at each location. Mean smut whips per 10 m2 were calculated to normalize the data and to make comparisons with the L 79-1002 check. Leaf scald and sugarcane mosaic were never observed in the field. All disease ratings in UFCP 82-1655 were compared with reference cultivar L 79-1002. In addition to natural infection ratings, artificial disease inoculation tests were performed for smut, leaf scald, and mosaic in a greenhouse at USDA, Canal Point by using standard methods developed for the CP sugarcane cultivar development program (Comstock et al., 1999; Sood et al., 2009). Artificial smut infection in UFCP 82-1655 was compared with the energy cane cultivar L 79-1002 and sugarcane cultivar CP 78-1628 (Tai et al., 1991). L 79-1002 is smut susceptible, and susceptibility in CP 78-1628 is at the upper end of acceptability for commercial sugarcane production in Florida. UFCP 82-1655 was compared with CP 80-1743 (Deren et al., 1991) and CP 72-2086 (Miller et al., 1984) for leaf scald and mosaic susceptibility, respectively. Both CP 80-1743 and CP 72-2086 are commercial sugarcane cultivars and are at the upper end of acceptability for leaf scald and mosaic, respectively.
Plant Composition Plant composition of mature stalks was analyzed in the samples collected from Citra and Lykes Bros. farm. Compositional Journal of Plant Registrations
analysis was performed via near-infrared reflectance (NIR) spectroscopy on dried and finely ground biomass subsamples at a contract laboratory (Hauser Division, Microbac Laboratories, Inc.). Samples packed in 4-mL glass vials were scanned using an autosampler on a Fourier transform NIR analyzer (Antaris II, Thermo Scientific) fitted with an integrating sphere module. We used NIR chemometric software (OPUS, Version 7.0, Bruker Optik GmBH) for spectral processing and analysis utilizing an independently developed calibration model. Each of the 72 samples collected were run on the NIR analyzer in duplicate and the average result was used. Compositional results are reported on a percentage of total H2O extractives free basis (% fiber).
Morphological and Botanical Descriptions Morphological and botanical descriptions were based on a representative 10-stalk sample cut from the center row of one plot each of UFCP 82-1655 and reference cultivar L 79-1002 at Lykes Bros. farm at 330 d after planting. Munsell Color Charts for Plant Tissues (Munsell Color Co., 1977) was used to characterize the colors. Botanical descriptions were based on Artschwager and Brandes (1958).
Characterization of Microsatellite Genotyping Young tissue was collected from UFCP 82-1655 and immediately frozen at −80°C for 24 h, before freeze-drying. Sample DNA was retrieved using a standard cetyltrimethylammonium bromide (CTAB) protocol. DNA extracts were incubated with RNase to remove remnant-contaminating RNA. DNA quality (A260/280 ratio of 1.7–2.0) and concentrations were quantified using a Nanodrop Lite spectrophotometer (NanoDrop Technologies), and integrity was confirmed on a 1% (v/v) agarose gel using lambda monocot as a DNA quantification marker. Twenty simple sequence repeat (SSR) markers, spanning the 10 chromosomes of sugarcane, were used to molecularly genotype the five cultivars that were concurrently released for commercial cultivation. Marker targets were amplified in the DNA using polymerase chain reaction (PCR). Each 10 mL PCR reaction contained the following reagents [final concentration]: magnesium chloride [2.50 mM], dNTP (deoxinucleotide triphosphates) mix [200 µM each], forward tailed primer [50 nM], reverse primer [100 nM], M13 dye-labeled primer [50 nM], Taq polymerase [1 U], and template DNA [5 ng]. Thermocycler programming for amplification was: denaturation (95°C, 5 min); amplification 1, repeated four times (denaturation [96°C, 1 min], annealing [68°C, 5 min, −2.0°C per cycle], extension [72°C, 1 min]); amplification 2, repeated four times (denaturation [96°C, 1 min], annealing [58°C, 2 min, −2.0°C per cycle], extension [72°C, 1 minute]); hold cycle (4°C, 15 min). Amplicons were confirmed on a 1% (w/v) agarose gel, pooled, and then processed on an ABI 3730 Genetic Analyzer (Applied Biosystems) at the Cancer and Genetics Research Complex (CGRC) Biotechnology Center (University of Florida, Gainesville). Publication sources of primer
Journal of Plant Registrations
sequence are Cordeiro et al. (2000), Parida et al. (2010), Singh et al. (2010), and James et al. (2012).
Statistical Analyses Data on dry biomass and field diseases were analyzed for each crop cycle separately as well as combined for plant cane, first-ratoon, second-ratoon, and third-ratoon crops. A PROC MIXED model in SAS (SAS Institute 2003) was used to analyze the collected data. Cultivar was considered a fixed effect and location and replication within location as a random effect in a mixed model for analysis for each crop cycle. To analyze the data across crop cycles, which were confounded with years, cultivar was considered a fixed effect and crop cycle, location, and replication within location as random effects. Crop cycles were used in repeated measures statements. To normalize, data on stalk composition (% of fiber) were arcsine square root transformed for analysis and back transformed for presentation purposes. A PROC MIXED model in SAS with cultivar as a fixed effect and location and replication as random effects was used to analyze fiber composition data. Student’s paired t test (P = 0.1) was used to separate the means for dry biomass yields.
Characteristics Diseases UFCP 82-1655 was assessed for natural infection of smut, brown rust, orange rust, leaf scald, and Sugarcane mosaic virus at all experimental locations, but smut was the only disease observed on the cultivar. The natural smut infection in UFCP 82-1655 was lower than L 79-1002, and the differences were highly significant at all the locations (Table 1). The mean (across different crop cycles) number of smut whips per 10-m 2 area in UFCP 82-1655 ranged from 0.6 to 0.9 (mean = 0.8) compared with 6.8 to 54.2 (mean = 25.5) in L 79-1002 at different locations. Very low natural smut infection (3.1% of the mean number of smut whips in L 79-1002) in UFCP 82-1655 compared with L 79-1002 indicated its moderate to high resistance to smut, which is a highly desirable characteristic in energy cane breeding and selection program. Artificial laboratory inoculation data were collected for smut, leaf scald and mosaic diseases in both UFCP 82-1655 and L 79-1002. The results from artificial laboratory inoculation tests indicated UFCP 82-1655 had 11% smut infection compared with 37.8% in the reference check L 79-1002 and 41.6% in the commercial sugarcane cultivar CP 78-1628 (Table 2). In 2010, leaf scald infection in UFCP 82-1655 (18.8%) was comparatively higher than L 79-1002 (10.3%), but it was still lower than CP 80-1743 (26.5%). Similarly, in 2011, leaf scald infection in UFCP 82-1655 (14.5%) was lower than CP 80-1743 (17.7%). Leaf scald infection levels in CP 80-1743 Table 1. Mean number of smut whips per 10 m2 in UFCP 82-1655 and reference cultivar L 79-1002, obtained from disease data collected through 9 location-years (5 yr at Citra, 2 yr at Lykes Bros. farm, and 2 yr at Tecan). Cultivar UFCP 82-1655 L 79-1002 P
Citra
Lykes Bros.
Tecan
Mean
0.6 6.8
