Breeding of Sugarcane - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 33

In the United States, the USDA Repository located in Miami, Florida, maintains
more than 2,400 sugarcane accessions representative of the various species of the
complex Saccharum and related genera, mainly S. arundinaceum (124 accessions),
S. officinarum (748), S. spontaneum (635), S. barberi (57), S. sinense (61), and
Saccharum hybrids (383). The information on these materials are publicly available
in the Germplasm Resources Information Network (GRIN) database maintained by
the National Plant Germplasm System (NPGS) of the United States Department of
Agriculture (USDA). GRIN has detailed information about the conserved acces-
sions including responses to different diseases and data related to growth, morphol-
ogy, and phenology [ 14 ].
In Brazil, four sugarcane improvement programs are currently in progress, those
of the CTC (Sugarcane Technology Center), IAC (Agronomic Institute - Center for
Cana), Monsanto (that includes Canavialis), and RIDESA (University Network for
the Development of Sugar and Alcohol). The RIDESA is responsible for more than
50 % of the sugarcane varieties planted in the country. The germplasm program has
more than 2,700 accessions. Majority are hybrids from RIDESA and other institu-
tions, as well as species of Saccharum and related genera. The RIDESA is an
agreement between ten public universities in Brazil [Federal University of Paran´
(UFPR), Federal University of S˜o Carlos (UFSCar), Federal University of Vi¸osa
(UFV), Federal University of Rio de Janeiro (UFRRJ), Federal University of
Alagoas (UFAL), Federal University of Pernambuco (UFRPE), Federal University
of Sergipe (UFS), Federal University of Goi ´ s (UFG), Federal University of Mato
Grosso (UFMT) and Federal University of Piau ´ (UFPI)]. Significant part of the
sugar and alcohol sector research and development activities are conducted at the
experimental research stations located in the States where the crop is being culti-
vated in addition to the research activities in the campuses of the ten federal
universities.
The conservation of the sugarcane germplasm is generally made asexually
through clonal propagation, made by cutting stalks and replanting. There is also
in vitro conservation where the germplasm is maintained in the laboratory by
culturing plant parts under controlled conditions and preservation of seeds. Clonal
propagation is preferred over the preservation of seeds because it maintains the
genotype while the seeds are preserved as a sample of gametes produced by the
clone.
Over the years, cane sugarcane improvement programs have generated clones
that are increasingly productive and specific for the different edaphoclimatic
conditions. The sugarcane clones are set apart in few generations from their wild
ancestors, indicating the importance of the knowledge about the available genetic
resources and the high potential of use in the expansion of the genetic variability
and generation of more productive varieties and with other attributes in the
improvement programs.