Identification of QTLs for zinc deficiency tolerance in a recombinant inbred population of rice (Oryza sativa L.).

Background: Deficiency of Zn is a major soil constraint in rice plant growth and yield. Edaphic factors such as Zn deficiency in soil in relation to plant performance are still poorly understood. Here, we report promising quantitative trait loci (QTL) conferring tolerance to Zn deficiency, which were identified through biparental mapping. The experiment was conducted using the 236 F recombinant inbred line mapping population derived from the cross of Kinandang Patong (Zn deficiency sensitive) and A69-1 (Zn deficiency tolerant).

Results: A total of six QTLs (qLB-2B, qLB-4B, qPM-4B, qPM-6B, qRZC-4B, qSZC-4B) on chromosomes 2, 4 and 6 were identified for environment 1, whereas five QTLs (qLB-2 N, qLB-4 N, qPM-4 N, qRZC-4 N, qSZC-4 N) on chromosomes 2 and 4 were detected for environment 2. Among these, five major (51.30, 48.70, 28.60, 56.00, 52.00 > 10 R ) and one minor (5.40 < 10 R ) QTLs for environment 1 and four major (51.48, 50.20, 53.00, 48.00 > 10 R ) and one minor (4.44 < 10) QTLs for environment 2 for Zn deficiency tolerance with a logarithm of odd threshold value higher than 3 were identified. The QTLs (qLB-4B, qPM-4B, qRZC-4B, qSZC-4B, qLB-4 N, qPM-4 N, qRZC-4 N, qSZC-4 N) for leaf bronzing, plant mortality root zinc concentration and shoot zinc concentration identified on chromosome 4 were found to be the most promising and highly reproducible across the locations that explained phenotypic variation from 48.00% to 56.00% with the same marker interval RM6748-RM303.

Conclusion: The new QTLs and its linked markers identified in the present study can be utilized for Zn deficiency tolerance in elite cultivars using marker-assisted backcrossing. © 2022 Society of Chemical Industry.