Quantitative Trait Loci Mapping of Dark‐Induced Senescence in Winter Wheat (Triticum aestivum)

Abstract

In order to explore the genetics of dark-induced senescence in winter wheat (Triticum aestivum L.), a quantitative trait loci (QTL) analysis was carried out in a doubled haploid population developed from a cross between the varieties Hanxuan 10 (HX) and Lumai 14 (LM). The senescence parameters chlorophyll content (Chl a+b, Chl a, and Chl b), original fluorescence (Fo), maximum fluorescence level (Fm), maximum photochemical efficiency (Fv/Fm), and ratio of variable fluorescence to original fluorescence (Fv/Fo) were evaluated in the second leaf of whole three-leaf seedlings subjected to 7 d of darkness. A total of 43 QTLs were identified that were associated with dark-induced senescence using composite interval mapping. These QTLs were mapped to 20 loci distributed on 11 chromosomes: 1B, 1D, 2A, 2B, 3B, 3D, 5D, 6A, 6B, 7A, and 7B. The phenotypic variation explained by each QTL ranged from 7.5% to 19.4%. Eleven loci coincided with two or more of the analyzed parameters. In addition, 14 loci co-located or were linked with previously reported QTLs regulating flag leaf senescence, tolerance to high light stress, and grain protein content (Gpc), separately.

Quantitative trait loci for leaf chlorophyll fluorescence parameters, chlorophyll and carotenoid contents in relation to biomass and yield in bread wheat and their chromosome deletion bin assignments

“…Comparative mapping shows this QTL to be close to our QTL for F v / F m QF v /F m .csdh - 2A identified near marker Xgwm339 by both CIM and SMA. In the same study, Li et al (2012) also located QTL on 6B and 7A ( QF v /F m .igdb - 7A ) which appear to be at the same chromosomal regions as our QTL QF v /F m .csdh - 6B.1 and - 6B.2 and QF v /F m .csdh - 7A.2 . A QTL associated with F v / F m at anthesis stage was detected by Liang et al (2010) on chromosome 6A close (about 10 cM difference) to the position of the QTL for F v / F m detected in our studies.…”

“…Although the genetic maps are not easy to compare, the QTL of Li et al (2012) appear to span the same region where our highly significant QTL for CF parameters, pigments and GWE were located. In contrast to these results, Zhang et al (2010) found no QTL for CF parameters on chromosome 6B.…”

“…Thus, we located QTL for F v / F m on chromosomes 2A, 3A, 6A, 7A, 2B, 5B, 6B, 1D and 2D. On chromosome 2A the QTL QF v /F m .igdb - 2A was detected during dark-induced senescence by Li et al (2012) in a wheat DH population. Comparative mapping shows this QTL to be close to our QTL for F v / F m QF v /F m .csdh - 2A identified near marker Xgwm339 by both CIM and SMA.…”

“…Li et al (2012) located QTL on chromosome 6B for both F v / F m and total chlorophyll that mapped near a QTL for grain protein content identified by Prasad et al (2003). Although the genetic maps are not easy to compare, the QTL of Li et al (2012) appear to span the same region where our highly significant QTL for CF parameters, pigments and GWE were located.…”

“…Understanding the genetic determinants of chlorophyll fluorescence parameters and chlorophyll contents would help establish a genetic basis for increasing biomass and therefore yield in wheat. Few QTL studies have been reported so far on CF parameters in wheat (Yang et al 2007a; Liang et al 2010; Zhang et al 2010; Czyczyło-Mysza et al 2011; Kumar et al 2012; Li et al 2012) and wheat leaf chlorophyll contents (Cao et al 2004; Quarrie et al 2006; Yang et al 2007a; Zhang et al 2009, 2010). As far as we are aware, QTL for the JIP-test parameters (Strasser and Strasser 1995) ABS/CS m , DI o /CS m , TR o /CS m , RC/CS m and ET o /CS m , based on phenomenological energy fluxes per excited cross section (CS m ), have not previously been reported for wheat, though QTL associated with some of the JIP-test parameters were recently reported in soybean (Yin et al 2010).…”