Abstract
RB975952 is an early maturing sugarcane cultivar released for the South-Central region of Brazil. It should be harvested between April and May, and it is recommended for planting in environments with medium to high production potential. RB975952 has high resistance levels to the main diseases of the crop, it also has a good shoot development after mechanical harvesting, and high sucrose yields.
Saccharum spp; selection; improvement
INTRODUCTION
The Genetic Improvement Program of the Federal University of Sao Carlos - PMGCA/UFSCar (www.pmgca.ufscar.br) is part of the Inter University Network for the Development of Sugar and Energy Sector - RIDESA (www.ridesa.com.br), a network of 10 public Federal Universities with the purpose to develop improved sugarcane cultivars. PMGCA/UFSCar is responsible for developing RB cultivars for the South-Central region of Brazil, in the states of Sao Paulo and Mato Grosso do Sul. This region has the largest sugarcane area, and the highest sugarcane production in Brazil. The process for release of new cultivars of sugarcane is performed in several locations and crop years (Mattos et al. 2013Mattos PHC, Oliveira RA, Filho JCB, Daros E and Veríssimo MAA (2013) Evaluation of sugarcane genotypes and production environments in Paraná by GGE biplot and AMMI analysis. Crop Breeding and Applied Biotechnology13: 83-90.). The development of cultivars with an early maturity cycle is one of the main objectives of PMGCA/UFSCar.
BREEDING PROGRAM
RB975952 cultivar was obtained from a biparental cross between RB835486 and RB825548 (Figure 1). The cross was carried out at the sugarcane flowering and crossing station Serra do Ouro, in Murici, state of Alagoas (lat 09° 18' S, long 35° 56' W, alt 450 m asl). The obtained seeds were germinated and then planted in the field, establishing the first selection stage (T1). At this stage, clones from a single clump were selected by mass selection in the first sugarcane ratoon cycle (Breaux et al. 1963Breaux RD, Hebert LP and Fanguy HP (1963) Defects for which sugarcane seedlings are eliminated at the U.S. Sugar Cane Field Station, Houma, Louisiana. In Proceedings of congress of international society of sugarcane technologists. Elsevier, Amsterdam, p. 421-424.), based on criteria of important industrial and morphological characteristics, such as brix and stalk number (Hogarth 1987Hogarth DM (1987) Genetics of sugarcane. In Heinz DJ (Ed) Sugarcaneimprovement through breeding., Elsevier, Amsterdam p. 255-271., Berding et al. 2004Berding N, Hogarth M and Cox M (2004) Plant improvement of sugarcane. In James GL (Ed) Sugarcane. Blackwell Science, Oxford, p. 1-19.), flowering, pithiness and resistance to the main diseases (Matsuoka et al. 1999Matsuoka S, Garcia AAF and Arizono H (1999) Melhoramento da cana-de-açúcar. In Borém A (Ed) Melhoramento de espécies cultivadas. Editora UFV, Viçosa, p. 205-252.). Clones were compared to standard commercial varieties with early and medium/late maturity.
Clones selected in T1 with brix equal to or higher than early-maturing standard varieties constituted the second selection stage (T2), together with early-maturing standard varieties. In this stage, clones were established in Araras (lat 22° 21' S, long 47° 23' W, alt 620 m asl) and Valparaiso (lat 21° 13' S, long 50° 52' W, alt 450 m asl), state of Sao Paulo, in an augmented block design (Federer 1956Federer WT (1956) Augmented (or Hoonuiaku) designs. Hawaiian Planters' Record 55: 191-208.). Plots consisted of a 7-m row with no replication. Clones were evaluated in plant-cane, and in first and second ratoon cycles, based on the same criteria as in stage T1, together with the parameters stalk weight per plot and kilogram of brix per plot - KBP (Kang et al. 1983Kang MS, Miller JD and Tai PYP (1983) Genetic and phenotypic path analysis and heritability in sugarcane. Crop Science 23: 643-647.). The third selection stage (T3) and final experimental stage of selection (FE) were carried out according to Carneiro et al. (2011Carneiro MS, Rosa JRBF, Barreto FZ, Balsalobre TWA, Chapola RG, Vieira MAS, Bassinello AI, Hoffmann HP (2011) RB965902 and RB965917 - Early/medium maturing sugarcane varieties. Crop Breeding and Applied Biotechnology11: 280-285.). The variables evaluated were cane yield (TCH), sucrose content (PC in %), tons of pol per hectare (TPH - sucrose yield), and fiber content (%). The coefficient of environmental variation, the effects of genotype-environment interaction, and clone adaptability and stability were estimated by individual (of each location) and combined analysis of variance (of all locations) (Steel and Torrie 1960Steel RGD and Torrie JH (1960) Principles and procedures of statistics. McGraw-Hill, New York, 481p.). The maturation curve of the FE promising clones was evaluated to identify the best harvest time in terms of PC% level. The best-performing genotypes were multiplied and evaluated in the partnership units to observe the performance under production conditions (Barbosa et al. 2001Barbosa MHP, Silveira LCI, Oliveira MW, Souza VFM and Ribeiro SNN (2001) RB867515 Sugarcane cultivar. Crop Breeding and Applied Biotechnology 1: 437-438. , Barbosa et al. 2004Barbosa MHP, Silveira LCI, Souza VFM and Ribeiro SNN (2004) RB928064 - Sugarcane cultivar. Crop Breeding and Applied Biotechnology4: 356-359. , Melo et al. 2014Melo LJOT, Daros E, Neto DES, Chaves A, Silva LJ, Silva AEP and Melo TTAT (2014) CULTIVAR RELEASE - RB962962, A SugarcaneCultivar For Late Harvest. Crop Breeding and Applied Biotechnology14: 132-135.).
PERFORMANCE
RB975952
The growth habit of this cultivar is slightly decumbent, and leaves (trash) can be easily removed; it has good canopy cover and excellent ratoon regrowth from green and burnt sugarcane, sparing an early replanting of sugarcane fields. Tillering capacity in both plant and ratoon cane is good. RB975952 has medium fiber content, early maturation, rare flowering and low pithiness. In the South-Central region, RB975952 is indicated for harvesting between April and May (Figure 2). The constant sucrose content of this variety allows harvesting until mid-June. TCH of RB975952 in unfavorable environments is higher than that of RB855453, and yields are more stable under favorable conditions (Figure 3). For commercial production, RB975952 is recommended for planting in environments of medium to high fertility. The high agricultural productivity (TCH above 114.9 t ha-1) and sucrose content of about 14.5% of RB975952 indicate an equivalent or higher TPH than of the early-maturing commercial standard varieties (Figure 3). Experiments were carried out at 13 different locations in São Paulo state during three harvests.
Maturation curve of RB975952 cultivar, compared to RB855156 and RB855453 standard commercial cultivars, for sucrose content (%) in cane.
Adaptability and stability of RB975952 cultivar, compared to RB855453 standard commercial cultivar. The average data of sugar yield (TCH) in 17 field trials in first ratoon cane cycle were adjusted based on regression analysis.
OTHER FEATURES
Disease reaction
RB975952 was subjected to natural disease infection and artificial inoculation tests, along with other genotypes. These tests are carried out to verify the reaction of varieties and clones regarding the major diseases of sugarcane in the South-Central region of Brazil (Table 1). Tests were carried out in regions with high inoculum pressure, favorable to natural infection of various diseases, such as brown rust (Puccinia melanocephala), orange rust (P. kuehnii), smut (Sporisorium scitamineum), mosaic (Sugarcane Mosaic Virus - SCMV), and leaf scald (Xanthomonas albilineans). RB975952, as the others, was evaluated based on the number of infected tillers (infection %) for smut, mosaic and leaf scald, and based on the leaf area with symptoms for brown rust and orange rust (Amorim et al. 1987Amorim L, Bergamin Filho A, Sanguino A, Cardoso COM, Moraes VA and Fernandes CR (1987) Metodologia de avaliação de ferrugem da cana-de-açúcar (Puccinia melanocephala). Boletim Técnico Copersucar 39: 13-16. , Klosowski et al. 2013Klosowski AC, Ruaro L, Bespalhok Filho JC and De Mio LLM (2013) Proposta e validação de escala para a ferrugem alaranjada da cana-de-açúcar. Tropical Plant Pathology 38: 166-171.). Taking into account the presence of the Bru1 gene, and the lack of naturally infected plants (rating = 0), RB975952 was determined to be resistant to brown rust.
In the greenhouse artificial test, RB975952 plants were inoculated with the causal agents of smut and mosaic, according to the methods described by Matsuoka (1979Matsuoka S (1979) Método para pré-testagem de clones de cana-de-açúcar ao carvão e ao mosaico conjuntamente. In I Congresso nacional da sociedade dos técnicos açucareiros e alcooleiros do Brasil. STAB, Maceió, p. 231-233.). Cultivars were evaluated based on a rating scale for each disease, where the number of infected tillers is counted (% infection), and the genotypes are classified as resistant, intermediate and susceptible. Based on natural infection and artificial inoculation tests, RB975952 was considered resistant to brown rust, orange rust, smut, mosaic and leaf scald.
Characterization by microsatellite genotyping and Bru1 marker
SSR markers used to molecular fingerprints of RB975952 were generated with a panel of 383 microsatellite markers derived from sugarcane expressed sequence tags (EST-SSRs), developed by Oliveira et al. (2009Oliveira KM, Pinto LR, Marconi TG, Mollinari M, Ulian EC, Chabregas SM, Falco MC, Burnquist W, Garcia AAF and Souza AP (2009) Characterization of new polymorphic functional markers for sugarcane. Genome 52: 191-209.) and Marconi et al. (2011Marconi TG, Costa EA, Miranda HR, Mancini MC, Cardoso-Silva CB, Oliveira KM and Souza AP (2011) Functional markers for gene mapping and genetic diversity studies in sugarcane. BMC Research Notes 4: 264.), and were compared with those of eight other cultivars (RB925211, RB835054, RB855453, SP91-1049, RB835486, RB855156, RB825548 and RB966928). The 27 EST-SSR loci amplifications revealed high levels of polymorphism among the nine sugarcane genotypes, and detected 360 alleles polymorphic, with a range of 5 (ESTC19) to 23 (ESTB 432), and sizes ranging from 142 to 278 base pairs (bp). The Polymorphic Information Content (PIC) value was calculated by Pinto et al. (2004Pinto LR, Oliveira KM, Ulian EC, Garcia AAF, and Souza AP (2004) Survey in the expressed sequence tag database (SUCEST) for simple sequence repeats. Genome47: 795-804. ) and had an average value of 0.84, ranging from 0.92 (ESTB 423) to 0.50 (ESTB99). The information of discriminatory power (DP) was calculated based on Tessier et al. (1999Tessier C, David J, This P, Boursiquot JM and Charrier A (1999) Optimization of the choice of molecular markers for varietal identification in Vitis vinifera L. Theoretical and Applied Genetics 98: 171-177.), and ranged from 1 and 0.89, with an average value of 0.99. Polymorphic bands were used to construct a binary matrix to evaluate the genetic similarity among all the genotypes (Santos et al. 2014Santos JM, Barbosa GVS, Neto CER and Almeida C (2014) Efficiency of biparental crossing in sugarcane analyzed by SSR markers. Crop Breeding and Applied Biotechnology14: 102-107.). The EST-SSR-based genetic similarity (SSR-GS) among all of the genotypes was estimated according to the Simple Matching similarity coefficient. The corresponding genetic similarity matrix was used to generate a dendrogram based on the Unweighted Pair Group Method with the Arithmetic Average (UPGMA) algorithm (Figure 5). All analyses were carried out using NTSYSpc 2.11X (Rohlf 2000Rohlf FJ (2000) NTSYSpc: numerical taxonomy and multivariate analysis system, version 2.11X. Applied Biostatistics, New York.). Results indicate that the genetic similarities based on the Simple Matching coefficient varied from 0.58 to 0.76 with RB966928 and RB835054, meaning that these cultivars were genetically closer to each other than to the others.
Isoquants of average data of sucrose content (PC%), and cane yield (TCH) in 13 field trials and three cycles in different production environments. The diagram shows RB975952 cultivar (black circle) for comparison with standard commercial cultivars (gray circles) and clones.
Dendrogram of nine sugarcane cultivars revealed by UPGMA cluster analysis of SSR genetic similarity (Simple Matching's coefficient) estimates, using 360 SSR polymorphic bands obtained by 27 primer combinations.
BASIC SEED MAINTENANCE AND DISTRIBUTION
RB975952 has been produced by PMGCA/UFSCar and is available for research purposes at the Agricultural Science Center (CCA/UFSCar), in Araras, state of Sao Paulo, where it will be maintained for at least five years from the date of publication.
REFERENCES
- Amorim L, Bergamin Filho A, Sanguino A, Cardoso COM, Moraes VA and Fernandes CR (1987) Metodologia de avaliação de ferrugem da cana-de-açúcar (Puccinia melanocephala). Boletim Técnico Copersucar 39: 13-16.
- Barbosa MHP, Silveira LCI, Oliveira MW, Souza VFM and Ribeiro SNN (2001) RB867515 Sugarcane cultivar. Crop Breeding and Applied Biotechnology 1: 437-438.
- Barbosa MHP, Silveira LCI, Souza VFM and Ribeiro SNN (2004) RB928064 - Sugarcane cultivar. Crop Breeding and Applied Biotechnology4: 356-359.
- Berding N, Hogarth M and Cox M (2004) Plant improvement of sugarcane. In James GL (Ed) Sugarcane. Blackwell Science, Oxford, p. 1-19.
- Breaux RD, Hebert LP and Fanguy HP (1963) Defects for which sugarcane seedlings are eliminated at the U.S. Sugar Cane Field Station, Houma, Louisiana. In Proceedings of congress of international society of sugarcane technologists. Elsevier, Amsterdam, p. 421-424.
- Carneiro MS, Rosa JRBF, Barreto FZ, Balsalobre TWA, Chapola RG, Vieira MAS, Bassinello AI, Hoffmann HP (2011) RB965902 and RB965917 - Early/medium maturing sugarcane varieties. Crop Breeding and Applied Biotechnology11: 280-285.
- Federer WT (1956) Augmented (or Hoonuiaku) designs. Hawaiian Planters' Record 55: 191-208.
- Hogarth DM (1987) Genetics of sugarcane. In Heinz DJ (Ed) Sugarcaneimprovement through breeding., Elsevier, Amsterdam p. 255-271.
- Kang MS, Miller JD and Tai PYP (1983) Genetic and phenotypic path analysis and heritability in sugarcane. Crop Science 23: 643-647.
- Klosowski AC, Ruaro L, Bespalhok Filho JC and De Mio LLM (2013) Proposta e validação de escala para a ferrugem alaranjada da cana-de-açúcar. Tropical Plant Pathology 38: 166-171.
- Marconi TG, Costa EA, Miranda HR, Mancini MC, Cardoso-Silva CB, Oliveira KM and Souza AP (2011) Functional markers for gene mapping and genetic diversity studies in sugarcane. BMC Research Notes 4: 264.
- Mattos PHC, Oliveira RA, Filho JCB, Daros E and Veríssimo MAA (2013) Evaluation of sugarcane genotypes and production environments in Paraná by GGE biplot and AMMI analysis. Crop Breeding and Applied Biotechnology13: 83-90.
- Matsuoka S (1979) Método para pré-testagem de clones de cana-de-açúcar ao carvão e ao mosaico conjuntamente. In I Congresso nacional da sociedade dos técnicos açucareiros e alcooleiros do Brasil. STAB, Maceió, p. 231-233.
- Matsuoka S, Garcia AAF and Arizono H (1999) Melhoramento da cana-de-açúcar. In Borém A (Ed) Melhoramento de espécies cultivadas. Editora UFV, Viçosa, p. 205-252.
- Melo LJOT, Daros E, Neto DES, Chaves A, Silva LJ, Silva AEP and Melo TTAT (2014) CULTIVAR RELEASE - RB962962, A SugarcaneCultivar For Late Harvest. Crop Breeding and Applied Biotechnology14: 132-135.
- Oliveira KM, Pinto LR, Marconi TG, Mollinari M, Ulian EC, Chabregas SM, Falco MC, Burnquist W, Garcia AAF and Souza AP (2009) Characterization of new polymorphic functional markers for sugarcane. Genome 52: 191-209.
- Pinto LR, Oliveira KM, Ulian EC, Garcia AAF, and Souza AP (2004) Survey in the expressed sequence tag database (SUCEST) for simple sequence repeats. Genome47: 795-804.
- Rohlf FJ (2000) NTSYSpc: numerical taxonomy and multivariate analysis system, version 2.11X. Applied Biostatistics, New York.
- Santos JM, Barbosa GVS, Neto CER and Almeida C (2014) Efficiency of biparental crossing in sugarcane analyzed by SSR markers. Crop Breeding and Applied Biotechnology14: 102-107.
- Steel RGD and Torrie JH (1960) Principles and procedures of statistics. McGraw-Hill, New York, 481p.
- Tessier C, David J, This P, Boursiquot JM and Charrier A (1999) Optimization of the choice of molecular markers for varietal identification in Vitis vinifera L. Theoretical and Applied Genetics 98: 171-177.
Publication Dates
-
Publication in this collection
Sept 2015
History
-
Received
29 June 2014 -
Accepted
07 Nov 2014