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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #409898
Research Project: Gene Discovery and Crop Design for Current and New Rice Management Practices and Market Opportunities

Location: Dale Bumpers National Rice Research Center

Title: Substitution mapping yield-related traits using chromosome segment substitution lines derived from three ancestral donors in the background of elite Indica and Japonica rice

Author
item Eizenga, Georgia
item Edwards, Jeremy
item Jackson, Aaron
item Huggins, Trevis

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/20/2023
Publication Date: 11/2/2023
Citation: Eizenga, G.C., Edwards, J., Jackson, A.K., Huggins, T.D. 2023. Substitution mapping yield-related traits using chromosome segment substitution lines derived from three ancestral donors in the background of elite Indica and Japonica rice. Meeting Abstract. ASA-CSSA-SSSA International Annual Meeting, Oct 28-Nov 2, 2023, St. Louis, Missouri.

Interpretive Summary:

Technical Abstract: Cultivated rice (Oryza sativa) has two strongly diverged varietal groups, Japonica and Indica. The Oryza rufipogon species complex (ORSC) which includes the rice ancestral species, O. rufipogon and O. nivara, is an underutilized resource for rice improvement. To make this genepool more accessible, three genotypically and phenotypically diverse ORSC accessions, OrA (W1944), OrB (IRGC106148) and OrC (IRGC105567), from China, Laos and Indonesia, respectively, were used as donors, to develop six chromosome segment substitution line (CSSL) libraries from crosses with ‘Cybonnet’, a U.S. tropical japonica long grain and ‘IR64’, an IRRI indica long grain. The objective of this study was to characterize the libraries for yield-related traits to discover genes currently not deployed for rice improvement. Greenhouse grown CSSLs from the three IR64 libraries were characterized for six agronomic (heading, height, culm habit, flag leaf length and width, etc.), two panicle architecture and five seed traits. Cybonnet and 212 Cybonnet CSSLs from the three libraries were evaluated in field studies for six agronomic, six panicle architecture and eight seed traits. Across the three libraries, 62 CSSLs were significantly different from Cybonnet for one or more traits. To ascertain the chromosome region and underlying candidate gene(s) causing these differences, substitution mapping was performed with previously reported genotypes and results compared to substitution mapping with the IR64 libraries. Mapping with the Cybonnet CSSLs which had delayed heading under long days, revealed five known genes associated with rice flowering time pathways. The OsMADS50, RFT1, HD3A, SE1 and GHD7 genes were mapped in the OrB and OrC derived CSSLs but only OsMADS50 mapped in OrA derived CSSLs. Employing this approach for the other 19 traits, revealed 28 total candidate genes, of which 12 are not currently deployed. The introgressed ORSC regions associated with these genes are potential sources of novel variation for rice improvement.