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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #137371
Title: MEGAGAMETOPHYTE ABNORMALITIES OF NEAR-ISOGENIC FEMALE PARTIAL-STERILE (PS) SOYBEAN MUTANTS (GLYCINE MAX; LEGUMINOSAE)

Author
item ILARSLAN, H - ANKARA UNIVERSITY
item HORNER, H - ISU
item PALMER, REID

Submitted to: Journal of Plant Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2003
Publication Date: 7/10/2003
Citation: ILARSLAN, H., HORNER, H.T., PALMER, R.G. MEGAGAMETOPHYTE ABNORMALITIES OF NEAR-ISOGENIC FEMALE PARTIAL-STERILE (PS) SOYBEAN MUTANTS (GLYCINE MAX; LEGUMINOSAE). JOURNAL OF PLANT RESEARCH. 2003. V. 116. P. 141-149.

Interpretive Summary: Reproductive development in plants is a complex process. An error in development can result in partial or complete sterility. Usually such changes cause male sterility, while female development remains normal. A female partial-sterile soybean plant (mutant) was identified. Our objective was to determine the genetics and to compare female development in fertile plants with female development in the female partial-sterile plant. We used a special microscope that allows us to optically section developing plant tissues. The mutant was inherited as a co-expressed trait. The mutant expresses female partial-sterility only in cross-pollination. The female partial-sterility is the result of incomplete development of the female tissues that participate in fertilization. This genetic trait will be useful to study female development in soybean plants from egg to fertilization to mature seed. We hope to be able to identify characteristics that contribute to ovule abortion in these mutants and then make changes in commercially grown soybeans that prevent abortion. Soybean yields and seed quality should be more stable from environment to environment, which would benefit the farmer and ultimately the consumer.

Technical Abstract: Megagametogenesis of the Clark, Clark k2, and F1 hybrid plants of Clark crossed with the female partial-sterile trait of Clark k2 were studied using stereo light microscopy and confocal scanning laser microscopy. F1 hybrid plants were compared to the reproductive development in Clark and Clark k2 plants. In mature pods, 6.4 % of the ovules of Clark, 8.1 % of the ovules of Clark k2, and 41.4 % of the ovules of F1 hybrid were aborted. The reasons for this female partial sterility were due to incomplete megagametophyte development: undeveloped polar nuclei or they are developed but not in a position for fertilization; increased megagametophyte wall thickness; abnormal shape and or premature degeneration of synergids and intact synergids throughout the life of the ovule; egg cell not well-developed or absent; and megagametophyte remains uninucleate. Each of these abnormalities contributed to either lack of double fertilization or early megagametophyte abortion.