Investigation of pollen competition between wild and cultivated sorghums (Sorghum bicolor (L.) Moench) using simple sequence repeats markers

Muraya, M M and Geiger, H H and Villiers, S de and Sagnard, F and Kanyenji, B M and Kiambi, D and Parzies, H K (2011) Investigation of pollen competition between wild and cultivated sorghums (Sorghum bicolor (L.) Moench) using simple sequence repeats markers. Euphytica, 178 (3). pp. 393-401. ISSN 0014-2336

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Abstract

In self-compatible plant species stigmata receive a mixture of self and outcrossed pollen and competition between them is expected to play a major role in determining the pollen-mediated gene flow. The use of male sterile bait plants in field trials to demonstrate the rate of gene flow is questionable due to lack of pollination competition. However, little direct evidence has been published. A field experiment of male sterile and male fertile sorghum pollen recipient bait plants was conducted to evaluate pollen competition between wild and cultivated sorghums and the effects of pollen competition on gene flow assessment. Pollen competition between wild and cultivated sorghums was estimated from two-component pollen mixtures of wild and cultivated sorghum (1:1 ratio) applied to wild, cultivated and male-sterile maternal bait plants. Paternity was determined in the progeny using two diagnostic Simple Sequence Repeat markers. The study found that self pollen has higher seed-siring success. Maternal genotype influences the siring ability of the pollen donor components which significantly deviated from the 1:1 pollen loads. The study showed that published estimates of gene flow derived from studies using male-sterile bait plants seriously overestimate gene flow and that pollen competition may be a significant factor influencing outcrossing rates. The results suggest that the predominant direction of gene flow is from cultivated to wild sorghum, potentially leading to introgression of crop genes into wild sorghum. Pollen competition should be taken into account in gene flow estimation, since presence of self-pollen can account for over half of seed produced irrespective of maternal genotype

Item Type:	Article
Divisions:	UNSPECIFIED
CRP:	UNSPECIFIED
Uncontrolled Keywords:	Sorghum bicolor; Pollen competition; Outcross pollen; Self pollen; Pollination; Pollen-mediated gene flow
Subjects:	Mandate crops > Sorghum Others > Genetics and Genomics
Depositing User:	Ms K Syamalamba
Date Deposited:	25 Jan 2013 08:47
Last Modified:	07 Feb 2014 05:14
URI:	http://oar.icrisat.org/id/eprint/6471
Official URL:	http://dx.doi.org/10.1007/s10681-010-0319-4
Projects:	UNSPECIFIED
Funders:	UNSPECIFIED
Acknowledgement:	UNSPECIFIED
Links:	Google Scholar

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