Cytogenetics and Reproductive Behavior of 48-Chromosome Pearl Millet ✕ Pennisetum squamulatum Derivatives
- Michel Dujardin and
- W. W. Hanna
Pennisetum squamulatum Fresen is a perennial, hexaploid (2n = 6x = 54) species belonging to the tertiary gene pool of cultivated pearl millet [P. glaucum (L.) R. Br.]. Pennisetum squamulatum is a source of genes controlling apomixis, and useful genetic variability can be released in hybrids between sexual pearl millet and apomictic species. New genome combinations were produced between tetraploid pearl millet (2n = 4x = 28) and P. squamulatum by pollinating a sexual interspecific F1 hybrid (2n = 41) with an apomictic 56-chromosome derivative from another F1 interspecific hybrid (2n = 41). Fifteen hybrids with 2n = 47 or 48 chromosomes resulted from the crosses. All were perennial and morphologically similar to or taller than their parents, showed irregular metaphase I chromosome behavior, and were partially male and female fertile. Nine plants reproduced sexually, two by facultative apomixis, and four by obligate apomixis. This cross allowed the increase of the pearl millet genome in the new hybrids while introducing apomictic reproduction into several genotypes.
Copyright © 1990.