QTLs Analysis and Validation for Fiber Quality Traits Using Maternal Backcross Population in Upland Cotton

Abstract

Cotton fiber is renewable natural fiber source for textile. Improving fiber quality is an essential goal for cotton breeding project. In present study, F14 recombinant inbred line (RIL) population was backcrossed by the maternal parent to obtain a backcross (BC) population, derived from one Upland cotton hybrid. Three repetitive field trials were performed by randomized complete block design with two replicates in three locations in 2015, together with the BC population, common male parent and the RIL population. Totally, 26 QTLs in BC population explained 5.00–14.17% of phenotype variation (PV) and 37 quantitative trait loci (QTL) were detected in RIL population explaining 5.13–34.00% of PV. Seven common QTLs detected simultaneously in two populations explained PV from 7.69 to 23.05%. A total of 20 QTLs in present study verified the previous results across three environments in 2012. Particularly, qFL-Chr5-2 controlling fiber length on chromosome 5 explained 34.00% of PV, while qFL-Chr5-3 only within a 0.8 cM interval explained 13.93% of PV on average in multiple environments. These stable QTLs explaining great variation offered essential information for marker-assisted selection (MAS) to improve fiber quality traits. Lots of epistasis being detected in both populations acted as one of important genetic compositions of fiber quality traits.

QTL and genetic analysis controlling fiber quality traits using paternal backcross population in Upland Cotton

“…The parental backcross (BC/P) population was obtained by backcrossing the original male parent (GX100-2) to 177 RI lines, respectively. The maternal backcross (BC/M) population referred to the previous study (Ma et al 2017; Ma et al 2019). The control set was performed in each experimental trial, including GX100-2, “Xinza 1”, GX1135 and a competition hybrid “Ruiza 816” in Yellow River Region.…”

“…Three BC/P field trials and one maternal BC trial were conducted in 2015 and 2016 in two locations in China, E1: Quzhou Experimental Station in Handan City, and E2: Guoxin Seed Company Ltd in Cangzhou City (Ma et al 2017, 2018a, 2019). The field trials were designed and planted same to the previous study for BC field trials (Shang et al 2016a; Ma et al 2017, 2018a, 2019). Field management followed the local conventional standard field practice.…”

“…It is very important to detect novel QTLs and to validate the reported QTLs using diverse populations. In our previous study, serial genetic analyses were performed in multiple segregating populations including F 2 , F 2: 3 , RIL and BC/M population derived from the hybrid ‘Xinza 1’ across multiple years and various locations (Liang et al 2013; Liang et al 2015; Shang et al 2015, 2016a,b,c,d; Ma et al 2017, 2018a, 2019). In previous study, 111 quantitative trait loci (QTLs) were detected for fiber quality using four populations derived from RIL (XZ) and backcross (XZV) hybrids (Shang et al 2016d).…”

“…In previous study, 111 quantitative trait loci (QTLs) were detected for fiber quality using four populations derived from RIL (XZ) and backcross (XZV) hybrids (Shang et al 2016d). Recently, a total of 55 QTLs were detected which distributed in 21 chromosomes using BC/M population in three locations (Ma et al 2017). In addition, 32 QTLs at five stages and 24 conditional QTLs at four intervals were detected for plant height in different years or populations or stages (Ma et al 2018a).…”

“…And 26 and 27 QTLs including heterotic loci were identified in TC/P and TC/M populations, respectively (Ma et al 2019). In addition, 10 and 16 clusters improved more than one trait for fiber quality and yield and yield-components, respectively (Ma et al 2017; Ma et al 2019). In order to identify and validate genetic components related fiber quality traits, we further developed BCF 1 progenies population based on RIL population by backcrossing with the paternal parent of ‘Xinza 1’.…”