Submitted to: Crop Science
Publication Type: Germplasm Release
Publication Acceptance Date: July 31, 1998
Publication Date: N/A
Interpretive Summary: Plant mutants are key to identifying genes and understanding gene function and location. For many crops, mutant forms are studied, published, maintained in collections, and distributed to researchers. Very few sugarcane mutants have been registered, and this has complicated studies of its genetic makeup. In this study, we registered seven mutant sugarcane plants that possessed more than one bud at each node (called multiple-bud mutants). We found that the mutants produced substantial numbers of nodes having multiple buds, and that this trait was stable. Shoot production of mutants in the field tended to be lower than in commercial types even though mutants produced about 2 shoots per node in greenhouse tests. This was probably because commercial types, unlike the mutants, were selected for high shoot number and vigor. We also found that the multiple-bud trait was only weakly transmitted to offspring. This trait could have value to sugarcane farmers who normally plant whole stalks or stalk pieces. Stalks with multiple buds could potentially reduce seed cane requirements and increase planting efficiency. We are registering these mutants so that they may be distributed to other researchers for genetic, breeding, and physiological studies of sugarcane.
Technical Abstract: Sugarcane (Saccharum L. interspecific hybrids) has complex, polyploid genetics. Few sugarcane mutants have been registered, which further complicates genetic analysis. Seven sugarcane genetic stocks (CP 68-413, MB 84-3065, US 89-23, US 93-13, US 93- 14, US 94-12, and WHW SEL) were developed by the USDA-ARS. The clones exhibited a multiple-bud phenotype characterized by two or more adjacent, apparently normal axillary buds instead of a single bud. Identified during routine, single plant selection in the breeding program, the clones have not exhibited reversion to normal phenotype despite numerous cycles of vegetative propagation. Most multiple-bud genotypes produced about two shoots per node, except that US 94-12 produced 4.5 shoots per node. The multiple-bud trait was sexually transmitted at low frequency, only 2.2% of progeny had the phenotype. The multiple- bud trait was stable in parents, but progeny exhibited intermittent gene expression. These genetic stocks should serve as useful markers in breeding, genetic, and physiology studies.