Combining ability and molecular marker approach for developing early maturing high yielding hybrid rice

Area of Science:

• Agricultural Science
• Genetics
• Plant Breeding

Background:

• Hybrid rice breeding is crucial for increasing grain yield and ensuring global food security.
• Combining ability analysis helps identify superior parental lines for developing high-yielding and early-maturing rice varieties.

Purpose of the Study:

• Evaluate general and specific combining ability (GCA and SCA) effects, heterosis, and gene action for eight yield-related traits in rice.
• Assess the association between parental genetic distance (GD) and hybrid performance, heterosis, and SCA effects.
• Identify promising parental lines and hybrid combinations for high-yielding and early-maturing rice.

Main Methods:

• A line × tester mating design was employed with fourteen rice genotypes.
• General and specific combining ability, heterosis, and gene action were evaluated for eight yield and yield-related traits.
• Parental genetic distance (GD) was assessed using 25 simple sequence repeat markers.

Main Results:

• Both additive and non-additive gene actions influenced trait inheritance, with non-additive gene action being predominant for most traits.
• SH-3A, SH-4A, BUR, and SH-802R were identified as excellent general combiners.
• Specific hybrids like SHD-1 (SH-3A × BUR) and SHD-36 (SH-4A × SH-802 R) showed significant potential for improving grain yield and maturity.
• Positive correlations were observed between GD and heterosis for flowering and maturity, while SCA showed a significant positive correlation with hybrid performance and heterosis.

Conclusions:

• Non-additive gene action plays a significant role in controlling yield and maturity traits in hybrid rice.
• Specific parental lines and hybrid combinations are identified as valuable for developing high-yielding and early-maturing rice.
• Specific combining ability (SCA) is a primary determinant of hybrid performance, and integrating molecular markers like GD can aid in heterosis prediction for certain traits.