Identification of the Parental Lines for Hybrid Rice Through a Three-Way Test Cross-System in Egypt

Abo Yousef, M. I.; Talha, I. A.; Ghidan, W. F.; Gomaa, M. A.

doi:10.21608/jpp.2025.371861.1444

Identification of the Parental Lines for Hybrid Rice Through a Three-Way Test Cross-System in Egypt

Document Type : Original Article

Authors

¹ Rice Research Department, Field Crops Research Institute, Agricultural Research Center, 33717 Kafr El Sheikh, Egypt.

² Rice Research and Training Center, Field Crops Research Institute, Agricultural Research Center, Egypt

10.21608/jpp.2025.371861.1444

Abstract

A three-way test cross was employed to evaluate the genetic fertility restoration systems in hybrid rice and identify efficient restorers and maintainers. Ten elite diverse lines and cytoplasmic male sterile (CMS) lines from the WA source IR 69625 A were assessed. The results indicated that Giza 178 and Giza 179 exhibited the highest values for pollen and spikelet fertility. Among the twenty-four crosses studied, four full fertility crosses of single crosses (A/R), four crosses (R/R), one cross (M/M), and three crosses (R/M) demonstrated high pollen and spikelet fertility percentages. Furthermore, four TWTC hybrids, utilizing restorer/restorer combinations as male parents, yielded offspring exhibiting fertility levels that varied from absolute fertility to complete sterility. The offspring of crossings with maintainer/maintainer combinations as male parents had sterile or partially fertile plants in addition to fully fertile plants. The progenies created from the crosses of IR 69625 B and G 46 B failed to yield any fertile plants, indicating that G 46 B possessed a high genetic load for maintenance. Both totally fertile and partially fertile or sterile plants were produced by the three-way test cross using partial restorer/restorer and partial restorer/partial restorer as the male parents, indicating the complex genetics of rice fertility restoration. Allelic similarity genes for restoring fertility are present in the four restorers, Giza 178, Giza 179, Giza 182, and GZ 9399, used in this study. It is believed that sterile plants utilizing restorers will only develop if allelic Rf genes segregate independently in TWTC.

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