The finding that even the smallest of plant genomes has incurred multiple genome-wide chromatin duplication events, some of which may predate the origins of the angiosperms and therefore shape all of flowering plant biology, adds new importance to the molecular analysis of polyploidization/diploidization cycles and their phenotypic consequences. Early clues as to the possible phenotypic consequences of polyploidy derive from recent QTL mapping efforts in a number of diverse crop plants of recent and well-defined polyploid origins. A small sampling examples of the role(s) of polyploidy in conferring crop adaptation from human needs include examples of (1) dosage effects of multiple alleles in autopolyploids, and (2) ‘intergenomic heterosis’ conferring novel traits or transgressive levels of existing traits, associated with merging divergent genomes in a common allopolyploid nucleus. A particularly interesting manifestation of #2 is the evolution of complementary alleles at corresponding (‘homoeologous’) loci in divergent polyploid taxa derived from a common ancestor. Burgeoning genomic data for both botanical models and major crops offer new avenues for investigation of the molecular and phenotypic consequences of polyploidy, promising new insights into the role of this important process in the evolution of botanical diversity.
Keywordsdiversity gene dosage genome duplication QTL transgressive variation
quantitative trait locus
restriction fragment length polymorphism
water use efficiency
Unable to display preview. Download preview PDF.
- Arabidopsis Genome Initiative2000Analysis of the genome sequence of the flowering plant Arabidopsis thalianaNature408796815Google Scholar
- Anonymous, 1997. Zonal Coordinators Annual Report of All-India Coordinated Cotton Improvement Project.Google Scholar
- Boyer, J. 1982Plant productivity and environmentScience281443448Google Scholar
- D’Hont, A., Rao, P.S., Feldmann, P., Grivet, L., Islamfaridi, N., Taylor, P., Glaszmann, J.C. 1995Identification and characterization of sugarcane intergeneric hybrids, Saccharum officinarum x Erianthus arundinaceus, with molecular markers and DNA in situ hybridizationTheor. Appl. Genet.91320326Google Scholar
- Eckhardt, N. 2001A sense of self: the role of DNA sequence elimination in allopolyploidizationPlant Cell1316991704Google Scholar
- Hilu, K.W. 1993Polyploidy and the evolution of domesticated plantsAm. J. Bot.8014941499Google Scholar
- Irvine, J.E. 1999Saccharum species as horticultural classesTheor. Appl. Genet.98186194Google Scholar
- Martin, W., Gierl, A., Saudler, H. 1989Molecular evidence for pre-Cretaceous angiosperm originsNature3394648Google Scholar
- McGrath, J.M., Jancso, M.M., Pichersky, E. 1993Duplicate sequences with a similarity to expressed genes in the genome of Arabidopsis thalianaTheor. Appl. Genet.86880888Google Scholar
- Niles, G.A., Feaster, C.V. 1984BreedingKohel, R.J.Lewis, C.F. eds. CottonAmerican Society of AgronomyMadison, WI, USA202229Google Scholar