Identification and Validation of Quantitative Trait Loci for Grain Number in Rice (Oryza sativa L.)

Abstract

Grains number is one of the most important agronomic traits in the determination of rice productivity. To explore the underlying genetic basis of grain number in rice, quantitative trait locus (QTL) analysis was performed using three recombinant inbred line populations derived from indica rice crosses of Teqing/IRBB lines, Zhenshan 97/Milyang 46, and Xieqingzao/Milyang 46, respectively. A total of 58 QTLs distributed on all 12 rice chromosomes were identified, including 22 for number of grains per panicle (NGP), 17 for number of spikelets per panicle, and 19 for spikelet fertility. The individual QTL counted for 1.5 to 22.1% of phenotypic variation. Among them, 15 QTLs shared by two or three populations and eight QTLs showed large effects with R2 larger than 10%. Furthermore, three QTLs with minor effects for NGP, qNGP5.5, qNGP9.1, and qNGP12.1, were detected and validated by eliminating the segregation of major-effect QTL using four residual heterozygote-derived populations. These results not only enrich our understanding of the mechanism of grain number, but also provide a foundation for cloning and selecting candidate for marker-assisted selection breeding in rice.

Identification and Validation of High LD Hotspot Genomic Regions Harboring Stem Rust Resistant Genes on 1B, 2A (Sr38), and 7B Chromosomes in Wheat

“…While six SNPs (S1B_547524267, S1B_561712520, S1B_561712544, S2B_28097761, SUN_12527313 and SUN_12527317) were considered a minor QTL with R 2 less than 10%. Many earlier studies reported that large-effect QTLs controlling target trait have R 2 of >10% (Hussain et al, 2017;Mourad A. M. I. et al, 2018;Alqudaha et al, 2019;Mourad et al, 2019;Niu et al, 2020). Kumar et al)2020) detected 349 SNPs associated with stem rust resistance at seedling stage with R 2 ranging from 3.04 to 7.47% which was lower range than reported in this study.…”

Genomic Regions Associated With Stripe Rust Resistance Against the Egyptian Race Revealed by Genome-Wide Association Study

“…The ve stable SNPs located on two chromosomes (2A and 4A) with R 2 greater than 10% indicating that all the ve signi cant SNPs are controlling major QTLs for stripe rust resistance in the studied materials. All QTLs that explain more than 10% of the total variation is considered major QTLs [23,38].…”

Verification and dissection of one quantitative trait locus for grain size and weight on chromosome 1 in rice

“…Approximately 200 fully filled grains were selected by 3.5 mol/L NaCl solution. TGW, GL and GW were measured by the methods of Zhang et al 32 .…”

“…This type of NIL-F 2 population has been used in cloning many QTLs 7 , 19 , 28 , 31 . NIL-F 2 populations generated by self-pollinating residual heterozygotes (RH) in the recombinant inbred line (RIL) population have validated and dissected many QTLs for grain size and weight 32 – 34 .…”