REDUCING SOYBEAN YIELD LOSSES THROUGH GENETIC IMPROVEMENT
Location: Crop Genetics Research Unit
Title: A new gene that controls seed coat wrinkling in soybean
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 13, 2012
Publication Date: November 6, 2012
Citation: Kebede, H.A., Smith, J.R., Ray, J.D. 2012. A new gene that controls seed coat wrinkling in soybean. Euphytica. 189:309-320.
Interpretive Summary: In the midsouthern United States, high temperatures that frequently occur during soybean seed development and maturity have a considerable effect on seed quality, particularly for early planted soybean. Seed coat wrinkling is one of the major factors affecting the germinability and seedling vigor of soybean seed produced under these environments. Early planting has been adopted by midsouthern US soybean producers for its benefits in alleviating late season insect and drought stress problems and to take advantage of increased prices for August and September delivery. However, achieving acceptable seed quality can be a challenge due to the negative effects of elevated temperatures during seed fill. Previous studies identified a gene (shr) that causes seed shriveling and seed coat wrinkling in soybean. The objective of the present study was to identify and genetically map seed coat wrinkling gene(s) in a different soybean line (PI 87623) and determine if it is different from the shr gene. Genetic analysis indicated that the seed coat wrinkling gene in PI 87623 is different from the shr gene. Genetic mapping placed the gene in PI 87623 on a chromosome different from that of the shr gene, confirming that the gene from PI 87623 is a new gene. Identification of these genes offers the potential for selecting cultivars with less seed coat wrinkling for heat-stressed production environments.
Seed coat wrinkling is a major factor affecting the germinability of soybean [Glycine max (L.) Merr.] seed produced in high-temperature environments, such as in the early soybean production system (ESPS) of the midsouthern United States. Exposure of seed to high temperatures, coupled with alternating periods of wet and dry conditions, promotes seed coat wrinkling. This can predispose the seed to mechanical damage at harvest, further reducing germinability, and reducing the usability of the grain for seed beans. Previous studies identified a single recessive gene (shr) in a mutant line (T-311), located on chromosome 13 (linkage group F), which causes seed shriveling and seed coat wrinkling. The current study was undertaken to identify and genetically map new gene(s) that affect seed coat wrinkling. Crosses were made between a smooth-seeded accession (PI 567743) and a wrinkled-seeded accession (PI 87623). The parents, F1, F2, and BC1 generations were phenotyped for seed coat wrinkling in a greenhouse in Stoneville, MS during the summer of 2006. Genetic analysis indicated that the wrinkled seed coat trait in PI 87623 was inherited as a single recessive gene. A test for allelism, conducted in the greenhouse with a segregating F2 population derived from T-311 x PI 87623, showed that the gene from PI 87623 is different from the shr gene in T-311. A field study of a larger population confirmed these results, but also suggested epistatic interactions between the genes. A linkage map was developed using 195 SSR and SNP markers on 168 F2 individuals of the cross PI 567743 x PI 87623. Linkage analysis identified only one significant locus which was located on chromosome 5 (linkage group A1), confirming identification of a new gene that controls seed coat wrinkling in soybean. This study demonstrates genetic control of seed coat wrinkling, which offers the potential for selecting cultivars with less seed coat wrinkling for heat-stressed production environments.