History and Current Status of Sugarcane Breeding, Germplasm Development and Molecular Genetics in Brazil

Abstract

Brazil is the world’s largest producer of sugarcane and one of the leading suppliers of sugar and ethanol worldwide. In the 2019–2020 crop season, the country produced 642.7 million tons of sugarcane in a harvest area of 8.44 million hectares. Historically, sugarcane breeding has contributed continuously to increasing yields by regularly releasing superior cultivars for use by the Brazilian industry. In the last 40 years, an average annual increase of 155.7 kg ha−1 of sugar yield has been reported, about half of which may be attributed to breeding programs. However, due to the size of the country, the intensive expansion of the crop to low-fertility soils in the last few years, especially in degraded pasture areas, and the widespread adoption of mechanization, new challenges have been imposed on national breeding programs. This review covers the current situation with sugarcane breeding in Brazil and the main advances that have allowed the country to maintain world leadership in developing the industry. Additionally, the history of sugarcane breeding, current national breeding institutions, germplasm development, key breeding objectives, selection stages and methodologies are summarized. An overview is also presented of biotechnological approaches which have become key tools for improving Brazilian traditional breeding programs. The adoption of strategies to increase Brazilian sugarcane yield, aiming to consolidate crop production in a food and energy matrix, is also discussed.

Genomic Selection in Sugarcane: Current Status and Future Prospects

“…About 1,002 accessions and 3,345 accessions of Saccharum germplasm are maintained at Canal point and Coimbatore, respectively (Amalraj and Balasundaram, 2006 ; Nayak et al, 2014 ). Besides, wild relatives are also maintained in Fiji, Brazil, Australia, China, and many other countries and are actively being used in the breeding programme (Ramdoyal and Badaloo, 2002 ; Wang et al, 2008 ; da Silva, 2017 ; Bhuiyan et al, 2019 ; Cursi et al, 2021 ). Several studies of core collection in Saccharum germplasm are described based on morphological features and molecular markers (Balakrishnan et al, 2000 ; Tai and Miller, 2001 ; Balakrishnan and Nair, 2003 ; Amalraj et al, 2006 ; Nayak et al, 2014 ; Shadmehr et al, 2017 ; Tena Gashaw et al, 2018 ; Fickett et al, 2019 ).…”

“…The pedigree analysis of Indian “Co” varieties ( Figure 1 ) showed that only two S. spontaneum accessions viz., S. spontaneum CBE and S. spontaneum Java, were used in the breeding programmes (Kumar et al, 2012 ). Although there were efforts made to utilize the Saccharum germplasm in sugarcane hybridization programme for pre-breeding and base-broadening programmes (Wang et al, 2008 ; Mohanraj and Nair, 2014 ; da Silva, 2017 ; Nair et al, 2017 ; Cursi et al, 2021 ), still it was not a complete utilization of Saccharum germplasm or all the favorable alleles contributing to the cane yield and sucrose. Therefore, characterization of the Saccharum germplasm with genome-wide markers and genome-wide association studies certainly identifies the alleles contributing to the cane yield, sucrose content, and other agronomic traits.…”

“…Pre-breeding and genetic base-broadening is the most important component of the sugarcane breeding programme followed in many countries (Ramdoyal and Badaloo, 2002 ; Wang et al, 2008 ; Matsuoka et al, 2014 ; da Silva, 2017 ; Cursi et al, 2021 ). The importance of S. spontaneum and other Saccharum spp.…”

“…The genetic variability in the present working sugarcane germplasm is not fully exhausted or no yield plateau was observed in sugarcane (Edm et al, 2005 ), but there is evidence of slow genetic gain (Wei and Jackson, 2017 ). Additionally, new variability is continuously created through pre-breeding in many countries (da Silva, 2017 ; Nair et al, 2017 ; Cursi et al, 2021 ), yet the application of genomic selection in sugarcane is capable of capturing the entirety of the allelic variability and enhancing the generic gain (Deomano et al, 2020 ; Hayes et al, 2021 ; Voss-Fels et al, 2021 ; Yadav et al, 2021 ). The recent review on genomic selection in sugarcane highlighted the recurrent selection schemes (Yadav et al, 2020 ) and we reviewed the feasibility of genomic selection at various stages of sugarcane breeding programmes, such as germplasm evaluation and formation of core germplasm, pre-breeding and genetic base-broadening programmes, and multi-environmental trails of breeding lines.…”

Applications of Quantitative Genetics and Statistical Analyses in Sugarcane Breeding

“…1. Despite many differences in details between selection programs of different countries such as population sizes and duration (Milligan 1994;Cox et al 2000;Scortecci et al 2012;Zhou 2013;Dumont et al 2019Dumont et al , 2021Santchurn et al 2021;Cursi et al 2021), a sequence of selection trials typically follows the four typical successive stages of Fig. 1.…”