Effect of pollination time on the frequency of 2n+n fertilization in apomictic buffelgrass Academic Article uri icon

abstract

  • Fertilization of an unreduced egg (2n + n) increases ploidy level and creates a new hybrid. It occasionally occurs in apomictic species but at a frequency too low to be a reliable method for genetic improvement. This investigation was undertaken to determine if 2n + n fertilization could be increased by early pollination. Six buffelgrass, Pennisetum ciliare (L.) Link [syn. Cenchrus ciliaris L.], accessions, five apomicts and one sexual, were self-pollinated and cross-pollinated with birdwoodgrass, P. ciliare (L.) Link var. setigerum (Vahl.) Leek, at 3, 2, 1, and 0 d before anthesis. The 2u + n progeny were identified by flow cytometry. DNA content (pg 2C-1) was determined for 1962 self-pollinated and 3072 cross-pollinated plants. Twenty-eight self- and 80 cross-pollinated plants had a higher DNA content and were products of 2u + n fertilization. The overall frequency of 2u + n fertilization when self- and cross-pollinated was 1.4 and 2.6%, respectively. For all protogynous intervals, the frequency ranged from 0 to 5.2% for self-pollinated plants and 0 to 8.2% for cross-pollinated plants. When self-pollinated, there was no correlation between time of pollination and recovery of 2n + n hybrids. When cross-pollinated, there was a linear relationship between time of pollination and number of 2n + n hybrids recovered. More 2n + n hybrids were recovered from crosses made 2 or 3 d before anthesis. Thus in apomictic buffelgrass, the frequency of 2n + n fertilization can be increased by pollinating early, and in apomictic species where sexual germplasm is not available, this approach has potential to produce new apomictic hybrids.

published proceedings

  • CROP SCIENCE

author list (cited authors)

  • Burson, B. L., Hussey, M. A., Actkinson, J. M., & Shafer, G. S.

citation count

  • 25

complete list of authors

  • Burson, BL||Hussey, MA||Actkinson, JM||Shafer, GS

publication date

  • January 1, 2002 11:11 AM

publisher