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Pollen Tube Growth After Intergeneric Pollinations of iap-Homozygous Sorghum
- Bartek, Matthew S., Hodnett, George L., Burson, Byron L., Stelly, David M., Rooney, William L.
- Crop science 2012 v.52 no.4 pp. 1553-1560
- Miscanthus, Pennisetum, Sorghastrum, Sorghum bicolor, Zea, adhesion, alleles, biotic stress, gene pool, genetic variation, germplasm, intergeneric hybridization, pistil, pollen, pollen tubes, pollinators, stress tolerance
- Hybridization within sorghum [Sorghum bicolor (L.) Moench] has been the primary means of creating genetic diversity for improvement. While considerable variation exists within S. bicolor, traits such as biotic stress tolerance could be improved if secondary and tertiary germplasm pools were accessible through hybridization. Sorghum germplasm possessing the inhibition of alien pollen (iap) allele has enhanced the ability to make successful wide hybridizations between secondary and tertiary gene pools. However, the range of this efficacy has not been tested. Pollen from Miscanthus Andersson, Pennisetum Rich., Sorghastrum Nash, and Zea L. was transferred to the stigmas of S. bicolor lines Tx3361 (with the iap allele) and ATx623 (without the iap allele). Pollen of all genera exhibited tube growth, but the frequencies of germination and growth rates varied among species and accessions within a genus. Significantly more pollen germinated and grew into the pistils of Tx3361 than ATx623. Pollen grains were noticeably more numerous on stigmas of Tx3361, implying that factors within Tx3361 may also affect pollen adhesion. The results indicate that the potential for intergeneric hybridization of S. bicolor via Tx3361 will vary based on the individual species and accessions within a species that are used as pollinators.