PHILSURIN maintains a 2-ha tassel source with 742 varieties in the highlands of Murcia and Victorias where sugarcane flowers are sourced for hybridization. Around 300 parent varieties are used for hybridization each year using biparental and polycrosses to produce about 80,000 to 100,000 clones. Each of these clones is individually evaluated based on agronomic characteristics.
The 80,000 to 100,000 clones produced from various crosses are field tested, and clones with negative morphologic attributes are eliminated. Clones showing extensive growth cracks on stalks, hollow stalks, the presence of severe diseases, extensive aerial roots and side shoot formation, protruding buds, and thin stalks are discarded. Less than 2% of the clones are advanced for field testing to evaluate their resistance to diseases and yield performance.
In 2005, PHILSURIN initiated the family-based selection to increase the efficiency of clone screening in the early stages of selection. In family selection, the progeny of a particular cross are treated as a family and are planted in replicated plots. It is the family that is evaluated for yield performance, and the clones from the good performing families are selected for morphologic characteristics, disease resistance, and yield performance. Family selection is currently used by sugarcane breeders worldwide as a more fiicient method of clone selection.
Marker Assisted Selection (MAS) is also carried out on a limited scale using microsatellite markers supplied by the International Consortium on Sugarcane Biotechnology, MAS involves a search for markers that are associated with a specific morphologic characteristic, disease resistance / suscptibility, or yield performance. When a marker is found to be consistently associated with a trait, then that marker can be used to screen for that specific trait.