sugarcane Genetics
“Sugarcane (Saccharum spp., Poaceae) is a large, perennial, tropical or subtropical crop that accounts for 70% of the world’s total sucrose production. The sugarcane crop is vegetatively propagated from axillary buds on stem pieces for commercial production; however, micropropagation via tissue culture is a faster alternative to vegetative bud propagation and is used in some countries to establish new varieties.
Agronomically, the first crop, initiated from stem cuttings, is generally harvested 12 to 24 months after planting, and several regrowths from the stubble, known as “ratoon” crops, may be harvested at time periods of shorter to equal duration. Ratoon crops may be grown from one to five to eight and occasionally more cycles depending on variety, methods of culture and harvest, and the environment. The mature culms contain juice of 9 to 18% sucrose. Based on conventional taxonomy, the genus Saccharum includes six species including S. spontaneum, S. robustum, S. officinarum, S. barberi, S. sinense, and S. edule. The two wild species, S. spontaneum and S. robustum, have a basic chromosome number x = 8 and x = 10 and are thought to be the founding species of this genus.
The high sugar content S. officinarum likely evolved from S. robustum as they share the same center of origin and diversity in Papua New Guinea. The origin and center of diversity of S. spontaneum is likely in northern India, where the lowest chromosome number accessions of this species (2n=40) were found. The remaining three species of this genus are hybrids. S. barberi, originated in India and S. sinense, originated in China, are interspecific hybrids between S. officinarum and S. spontaneum. S. edule has been postulated to be an intergeneric hybrid between either S. officinarum or S. robustum and an unknown species of another genus in the Saccharum complex, which might explain its aborted inflorescence.”
-Sugarcane Genetics and Genomics, Jisen Zhang, Marvellous Zhou, James Walsh, Lin Zhu, Youqiang Chen, and Ray Ming