Molecular Mapping of QTLs Associated with Lodging Resistance in Dry Direct-Seeded Rice (Oryza sativa L.)

Abstract

Dry direct-seeded rice (DSR) is an alternative crop establishment method with less water and labor requirement through mechanization. It provides better opportunities for a second crop during the cropping season and therefore, a feasible alternative system to transplanted lowland rice. However, lodging is one of the major constraints in attaining high yield in DSR. Identification of QTLs for lodging resistance and their subsequent use in improving varieties under DSR will be an efficient breeding strategy to address the problem. In order to map the QTLs associated with lodging resistance, a set of 253 BC3F4 lines derived from a backcross between Swarna and Moroberekan were evaluated in two consecutive years. A total of 12 QTLs associated with lodging resistance traits [culm length (qCL), culm diameter (qCD), and culm strength (qCS)] were mapped on chromosomes 1, 2, 6, and 7 using 193 polymorphic SNP markers. Two major and consistent effect QTLs, namely qCD1.1 (with R2 of 10%) and qCS1.1 (with R2 of 14%) on chromosome 1 with id1003559 being the peak SNP marker (flanking markers; id1001973-id1006772) were identified as a common genomic region associated with important lodging resistance traits. In silico analysis revealed the presence of Gibberellic Acid 3 beta-hydroxylase along with 34 other putative candidate genes in the marker interval region of id1001973-id1006772. The positive alleles for culm length, culm diameter, and culm strength were contributed by the upland adaptive parent Moroberekan. Our results identified significant positive correlation between lodging related traits (culm length diameter and strength) and grain yield under DSR, indicating the role of lodging resistant traits in grain yield improvement under DSR. Deployment of the identified alleles influencing the culm strength and culm diameter in marker assisted introgression program may facilitate the lodging resistance under DSR.

More and more of less and less: Is genomics‐based breeding of dry direct‐seeded rice (DDSR) varieties the need of hour?

“…The APO1 gene controlling panicle architecture also enhances culm strength and thickness (Ookawa et al, 2010). Yadav et al (2017) reported two major effects: QTLs, qCD 1.1 and qCS 1.1 (chromosome 1) for culm diameter and strength, respectively. A stable QTL (chromosome 2) for the traits contributing to lodging resistance (SMsection modulus and ODMAouter diameter of the major axis) reported recently by Jiang et al (2019) was found to possess putative genes responsible for cytokinin signalling, cell cycle signalling, NAC transcription factor signalling and other biological processes.…”

Development and Characterization of an Efficient Mutant Resource of the Mega Variety, Samba Mahsuri for Rice Improvement

“…For the identi cation of strong culm mutants, the diameter and physical strength of the culm was taken into account. Culm diameter was measured using a Digital sliding Vernier caliper in the eld from the plants at a height of 30cm above ground level (Yadav et al 2017), while the physical strength of the culms was measured with a 'prostrate tester' (DIK-7401 Daiki Rika Kogyo co Ltd, Tokyo, Japan) where the plant was pushed at an angle of 45 • to calculate the pushing resistance (Hai et al 2005).…”

Deciphering the Genetic Basis of Lodging Resistance in Wild Rice Oryza longistaminata

“…Lodging in cereal crops is a major problem that results in decreased grain yield and deteriorated grain quality (Berry et al, 2004). Development of lodging-resistant varieties to cope with this challenge has been widely attended to increase yield in rice, maize, and other crops (Zhu et al, 2013;Peng et al, 2014;Yadav et al, 2017). Plant breeders have reduced lodging risk by introducing the semi-dwarf gene sd1, known as the "Green Revolution Gene" (Peng et al, 1999).…”