Positive interactions of major-effect QTLs with genetic background that enhances rice yield under drought

• Published in: Scientific reports Vol. 8; no. 1; pp. 1626 - 13
• Main Authors: Sandhu, Nitika, Dixit, Shalabh, Swamy, B. P. Mallikarjuna, Vikram, Prashant, Venkateshwarlu, Challa, Catolos, Margaret, Kumar, Arvind
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26-01-2018; Nature Publishing Group
• Subjects: 45/22; 45/29; 45/77; 631/208/711; 631/449/1659; Chromosome 7; Chromosomes; Crop yield; Drought; Droughts; Epistasis; Epistasis, Genetic; Food security; Gene Frequency; Gene loci; Gene mapping; Genetic Background; Humanities and Social Sciences; Marker-assisted selection; multidisciplinary; Oryza; Oryza - genetics; Oryza - growth & development; Population; Quantitative Trait Loci; R&D; Research & development; Rice; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-20116-7

To improve the grain yield of the lowland-adapted popular rice variety Samba Mahsuri under reproductive-stage drought (RS) and to understand the interactions between drought QTLs, two mapping populations were developed using marker-assisted selection (MAS) and marker-assisted recurrent selection (MARS). The mean grain yield of pyramided lines (PLs) with
q
DTY
2.2
 + 
q
DTY
4.1
in MAS is significantly higher under RS and irrigated control than lines with single QTLs. Among MARS PLs, lines with four
qDTYs
(
qDTY
1.1
 + 
qDTY
2.1
 + 
qDTY
3.1
 + 
qDTY
11.1
) and two QTLs (
qDTY
1.1
 + 
qDTY
11.1
) yielded higher than PLs with other
qDTY
combinations. The selected PLs showed a yield advantage of 0.3–2.0 t ha
−1
under RS. An allelic profile of MAS PLs having same
qDTY
combination but with different yields under drought was studied. Hierarchical clustering grouped together the selected lines with high yield under drought. Epistasis test showed the interaction of
qDTY
4.1
and
qDTY
9.1
loci with
qDTY
7.1
significantly increased yield under drought and all the lines with higher yield under drought possessed the conserved region of
qDTY
7.1
on chromosome 7. The positive interactions among QTLs, effectiveness of QTLs in different backgrounds, introgression of
DTY
QTLs together with resistance to biotic stresses shall help enhance grain yield under RS.