QTL mapping and improvement of pre-harvest sprouting resistance using japonica weedy rice

Chang-Min Lee; Hyun-Su Park; Man-Kee Baek; O-Young Jeong; Jeonghwan Seo; Suk-Man Kim

doi:10.3389/fpls.2023.1194058

QTL mapping and improvement of pre-harvest sprouting resistance using japonica weedy rice

Front Plant Sci. 2023 Jun 5:14:1194058. doi: 10.3389/fpls.2023.1194058. eCollection 2023.

Authors

Chang-Min Lee¹, Hyun-Su Park¹, Man-Kee Baek¹, O-Young Jeong¹, Jeonghwan Seo¹, Suk-Man Kim²

Affiliations

¹ Crop Breeding Division, National Institute of Crop Science, Rural Development Administration, Wanju, Republic of Korea.
² Department of Ecological & Environmental System, Kyungpook National University, Sangju, Republic of Korea.

Abstract

The stability of cultivation and production in terms of crop yield has been threatened by climate change due to global warming. Pre-harvest sprouting (PHS) is a threat to crops, especially staple foods, including rice, because of reductions in yield and quality. To address the problem of precocious germination before harvest, we performed quantitative trait loci (QTL) analysis for PHS using F₈ RILs populations derived from japonica weedy rice in Korea. QTL analysis revealed that two stable QTLs, qPH7 and qPH2, associated with PHS resistance were identified on chromosomes 7 and 2, respectively, explaining approximately 38% of the phenotypic variation. The QTL effect in the tested lines significantly decreased the degree of PHS, based on the number of QTLs included. Through fine mapping for main QTL qPH7, the region for the PHS was found to be anchored within 23.575-23.785 Mbp on chromosome 7 using 13 cleaved amplified sequence (CAPS) markers. Among 15 open reading frames (ORFs) within the detected region, one ORF, Os07g0584366, exhibited upregulated expression in the resistant donor, which was approximately nine times higher than that of susceptible japonica cultivars under PHS-inducing conditions. Japonica lines with QTLs related to PHS resistance were developed to improve the characteristics of PHS and design practical PCR-based DNA markers for marker-assisted backcrosses of many other PHS-susceptible japonica cultivars.

Keywords: dormancy; germination; pre-harvest sprouting (PHS); quantitative trait loci (QTL); rice.

Grants and funding

This work was carried out with the support of the Cooperative Research Program for Agricultural Science & Technology Development (“A study on the resistance of breeding materials to environmental stresses originating from Korean native resources”) (project no. PJ01480402), Rural Development Administration, Republic of Korea.