TY - JOUR AU - You, Jianing AU - Liu, Hang AU - Wang, Surong AU - Luo, Wei AU - Gou, Lulu AU - Tang, Huaping AU - Mu, Yang AU - Deng, Mei AU - Jiang, Qiantao AU - Chen, Guoyue AU - Qi, Pengfei AU - Peng, Yuanying AU - Tang, Liwei AU - Habib, Ahsan AU - Wei, Yuming AU - Zheng, Youliang AU - Lan, Xiujin AU - Ma, Jian PY - 2021 M3 - Original Research TI - Spike Density Quantitative Trait Loci Detection and Analysis in Tetraploid and Hexaploid Wheat Recombinant Inbred Line Populations JO - Frontiers in Plant Science UR - https://www.frontiersin.org/articles/10.3389/fpls.2021.796397 VL - 12 SN - 1664-462X N2 - Spike density (SD) is an agronomically important character in wheat. In addition, an optimized spike structure is a key basis for high yields. Identification of quantitative trait loci (QTL) for SD has provided a genetic basis for constructing ideal spike morphologies in wheat. In this study, two recombinant inbred line (RIL) populations (tetraploid RIL AM and hexaploid RIL 20828/SY95-71 (2SY)) previously genotyped using the wheat55K SNP array were used to identify SD QTL. A total of 18 QTL were detected, and three were major and one was stably expressed (QSd.sau-2SY-7A.2, QSd.sau-AM-5A.2, QSd.sau-AM-7B, and QSd.sau-2SY-2D). They can explain up to 23.14, 19.97, 12.00, and 9.44% of phenotypic variation, respectively. QTL × environment and epistatic interactions for SD were further analyzed. In addition, pyramiding analysis further revealed that there were additive effects between QSd.sau-2SY-2D and QSd.sau-2SY-7A.2 in 2SY, and QSd.sau-AM-5A.2 and QSd.sau-AM-7B in AM. Pearson’s correlation between SD and other agronomic traits, and effects of major or stable QTL on yield related traits indicated SD significantly impacted spike length (SL), spikelet number per spike (SNS) and kernel length (KL). Several genes related to spike development within the physical intervals of major or stable QTL were predicted and discussed. Collectively, our research identified QTL with potential applications for modern wheat breeding and broadening the genetic basis of SD. ER -