Apomictic Interspecific Hybrids Between Pearl Millet and Pennisetum orientale L. C. Rich1
- Wayne W. Hanna and
- Michael Dujardin2
Pearl millet, Pennisetum americanum (L.) Leeke, is an important world food and forage crop. Pennisetum orientale L. C. Rich has genes for apomixis, perennial growth habit, pest resistance, and droughtolerance which could be used to improve pearl millet. The objectives of this research Were to determine the cytotaxonomic relationship of these two species and to explore the feasibility of interspecific germplasm transfer. Five interspecific hybrids, 2n = 25, with 7 large P. americanum millet (A) and 18 small P. orientale (0) chromosomes were produced by pollinating cytoplasmic male sterile pearl millet with P. orientale pollen. The O chromosomes paired mainly as bivalents and the A chromosomes remained as univalents. A low frequency of AO chromosome associations were observed. Although the possibility of germplasm exchange existed, the two species appeared to be not closely related. Among three hybrids examined, one was a facultative apomict, one was an obligate apomict and another was highly apomictic with 3% of ovules with sexual embryo sacs. Sixteen backcross progenies were established from interspecific hybrids pollinated with pearl millet pollen. Seven plants were 2n = 23 with 14 A + 9 0 chromosomes, five were 2n = 27 with 7 A + 20 O chromosomes and four were 2n = 32 with 14 A and 18 O chromosomes. The balanced chromosome number for both species in these latter plants should provide a mechanism for restoring fertility in the interspecific hybrid thus enabling germplasm transfer. The interspecific hybrids were male sterile but set about 1% seed when pollinated with pearl millet pollen.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .