Improvement of Combining Ability for Restorer Lines with the Identified SSR Markers in Hybrid Rice Breeding

To maximize heterosis, it is important to understand the genetic diversity of germplasm and associate useful phenotypic traits such as fertility restoration for hybrid rice breeding. The objectives of the present study were to characterize genetic diversity within a set of rice germplasm groups using coefficient of parentage (COP) values and 58 simple sequence repeat (SSR) markers for 124 genotypes having different attributes such as resistance/tolerance to various biotic and abiotic stresses. These lines were also used for identifying prospective restorers and maintainers for wild abortive-cytoplasmic male sterile (CMS) line. The mean COP value for all the lines was 0.11, indicating that the genotypes do not share common ancestry. The SSR analysis generated a total of 268 alleles with an average of 4.62 alleles per locus. The mean polymorphism information content value was 0.53, indicating that the markers selected were highly polymorphic. Grouping based on COP analysis revealed three major clusters pertaining to the indica, tropical japonica and japonica lines. A similar grouping pattern with some variation was also observed for the SSR markers. Fertility restoration phenotype based on the test cross of the 124 genotypes with a CMS line helped identify 23 maintainers, 58 restorers and 43 genotypes as either partial maintainers or partial restorers. This study demonstrates that COP analysis along with molecular marker analysis might encourage better organization of germplasm diversity and its use in hybrid rice breeding. Potential restorers identified in the study can be used for breeding high-yielding stress-tolerant medium-duration rice hybrids, while maintainers would prove useful for developing new rice CMS lines.

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Combining ability test of parental lines for three-line hybrid rice breeding

Agriculture and Natural Resources ◽

10.34044/j.anres.2020.54.4.12 ◽

2020 ◽

Keyword(s):

Combining Ability ◽

Hybrid Rice ◽

Rice Breeding ◽

Ability Test ◽

Parental Lines

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Exploiting heterosis and combining ability in two-line hybrid rice

Acta agriculturae Slovenica ◽

10.14720/aas.2021.117.1.1847 ◽

2021 ◽

Vol 117 (1) ◽

pp. 1

Author(s):

Mahmoud M. GABALLAH ◽

Aziz F. EL-EZZ ◽

Adel M. GHONEIM ◽

Baochang YANG ◽

Langtao XIAO

Keyword(s):

Oryza Sativa ◽

Grain Yield ◽

Leaf Area ◽

Negative Correlation ◽

Combining Ability ◽

Hybrid Rice ◽

Flag Leaf ◽

Rice Breeding ◽

Male Sterile ◽

Mating Design

<p>Twenty hybrids were developed from crossing four environmental genic male sterile (EGMS) lines with five testers in line × tester mating design to magnitude of heterosis over better parent for grain yield and contributing traits in rice (<em>Oryza sativa </em>L.). Five hybrids ‘WTSC9059’ × ‘Sakha101’, ‘WTSC9039’ × ‘Sakha102’, ‘WTSC9059’ × ‘Sakha108’, ‘WTSC9039’ × ‘Sakha108’ and ‘WTSC9039’ × ‘Sakha101’ express superior value for number of panicles, fertility percentage, 100-grain mass, grain yield, apparent heterosis and phenotypic acceptance. The top three heterotic combinations identified for grain yield/ha were ‘WTSC9059’ × ‘Sakha101’, ‘WTSC9039’ × ‘Sakha102’ and ‘Longping’ × ‘Sakha105’ which exhibited 100.00, 71.51 and 66.61 % heterobeltiosis, respectively. The lines ‘WTSC9059’ and ‘‘Longping’’ and testers ‘Sakha101’, ‘Sakha102’ and ‘Sakha108’ was found to be good general combiner for most of the characteristics and could be extensively used in future hybrid rice breeding program. The grain yield was correlated highly significant and positive with panicle exertion, panicle mass, fertility percentage and appearance of heterosis, otherwise the negative correlation and significant was found with flag leaf area.</p>

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