Marker-Assisted Introgression and Stacking of Major QTLs Controlling Grain Number (<i>Gn1a</i>) and Number of Primary Branching (<i>WFP</i>) to NERICA Cultivars
Vincent P. Reyes,
Rosalyn B. Angeles-Shim,
Merlyn S. Mendioro,
Ma. Carmina C. Manuel,
Ruby S. Lapis,
Junghyun Shim,
Hidehiko Sunohara,
Shunsaku Nishiuchi,
Mayumi Kikuta,
Daigo Makihara,
Kshirod K. Jena,
Motoyuki Ashikari,
Kazuyuki Doi
Affiliations
Vincent P. Reyes
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
Rosalyn B. Angeles-Shim
Novel Gene Resources Laboratory, Plant Breeding Division, International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
Merlyn S. Mendioro
Graduate School, University of the Philippines Los Banos, College, Laguna 4031, Philippines
Ma. Carmina C. Manuel
Graduate School, University of the Philippines Los Banos, College, Laguna 4031, Philippines
Ruby S. Lapis
Novel Gene Resources Laboratory, Plant Breeding Division, International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
Junghyun Shim
Current address: Department of Plant and Soil Science, College of Agricultural Sciences and Natural Resources, Texas Tech University, Lubbock, TX 79409, USA
Hidehiko Sunohara
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
Shunsaku Nishiuchi
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
Mayumi Kikuta
Applied Social System Institute of Asia, Nagoya University, Nagoya 464-8601, Japan
Daigo Makihara
International Center for Research and Education in Agriculture, Nagoya University, Nagoya 464-8601, Japan
Kshirod K. Jena
Novel Gene Resources Laboratory, Plant Breeding Division, International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
Motoyuki Ashikari
Bioscience and Biotechnology Center, Nagoya University, Nagoya 464-8601, Japan
Kazuyuki Doi
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
The era of the green revolution has significantly improved rice yield productivity. However, with the growing population and decreasing arable land, rice scientists must find new ways to improve rice productivity. Although hundreds of rice yield-related QTLs were already mapped and some of them were cloned, only a few were utilized for actual systematic introgression breeding programs. In this study, the major yield QTLs Grain Number 1a (Gn1a) and Wealthy Farmer’s Panicle (WFP) were introgressed and stacked in selected NERICA cultivars by marker-assisted backcross breeding (MABB). The DNA markers RM3360, RM3452, and RM5493 were used for foreground selection. At BC3F4 and BC3F5 generation, a combination of marker-assisted selection and phenotypic evaluation were carried out to select lines with target alleles and traits. Further, genotyping-by-sequencing (GBS) was conducted to validate the introgression and determine the recurrent parent genome recovery (RPGR) of the selected lines. The Gn1a and/or WFP introgression lines showed significantly higher numbers of spikelets per panicle and primary branching compared to the recurrent parents. In addition, lines with Gn1a and/or WFP alleles were comparatively similar to the recurrent parents (RP) in most yield-related traits. This study demonstrates the success of utilizing yield QTLs and marker-assisted selection to develop and improve rice cultivars.
