QTL for yield and associated traits in the Seri/Babax population grown across several environments in Mexico, in the West Asia, North Africa, and South Asia regions

Abstract

Heat and drought adaptive quantitative trait loci (QTL) in a spring bread wheat population resulting from the Seri/Babax cross designed to minimize confounding agronomic traits have been identified previously in trials conducted in Mexico. The same population was grown across a wide range of environments where heat and drought stress are naturally experienced including environments in Mexico, West Asia, North Africa (WANA), and South Asia regions. A molecular genetic linkage map including 475 marker loci associated to 29 linkage groups was used for QTL analysis of yield, days to heading (DH) and to maturity (DM), grain number (GM2), thousand kernel weight (TKW), plant height (PH), canopy temperature at the vegetative and grain filling stages (CTvg and CTgf), and early ground cover. A QTL for yield on chromosome 4A was confirmed across several environments, in subsets of lines with uniform allelic expression of a major phenology QTL, but not independently from PH. With terminal stress, TKW QTL was linked or pleiotropic to DH and DM. The link between phenology and TKW suggested that early maturity would favor the post-anthesis grain growth periods resulting in increased grain size and yields under terminal stress. GM2 and TKW were partially associated with markers at different positions suggesting different genetic regulation and room for improvement of both traits. Prediction accuracy of yield was improved by 5 % when using marker scores of component traits (GM2 and DH) together with yield in multiple regression. This procedure may provide accumulation of more favorable alleles during selection.

Genome-Wide Linkage Mapping of Quantitative Trait Loci for Late-Season Physiological and Agronomic Traits in Spring Wheat under Irrigated Conditions

“…Previous studies reported a large number of QTL for several physiological and agronomic traits under different conditions [9][10][11]27,28]. In the present study, we detected QTL for CTa, CTg1, and CTg2 on Chr.…”

“…Physiological traits, as well as PH and TKW, are critical elements of GY. The wide use of molecular markers has made possible the study of quantitative traits [9,11,23] and detect QTL that allow the development of high-yield cultivars via MAS. Previous studies identified numerous QTL associated with yield-related traits in various populations [1,9,10,[19][20][21]27].…”

“…Environmental diversity affects CT heritability, which ranges from low under heat or water-stressed conditions [9] to high under irrigated conditions [28]. GY is a complex trait highly affected by the environment and thus, has low heritability [48].…”

“…Canopy temperature (CT) or CT depression and chlorophyll content index (CCI) or SPAD value of leaf chlorophyll content are important physiological traits significantly associated with GY in wheat [7][8][9][10][11]. CT is considered an indicator of the transpiration level, whereas the chlorophyll content of flag leaf is and irrigation was applied from May to July with a total amount of 362.7 mm, 373.4 mm, 384.0 mm and 453.4 mm, respectively, making total moisture 580.1 mm, 590.8 mm, 601.4 mm and 702.4 mm, using aluminum sprinkler pipes.…”

Consequences of 1BL/1RS translocation on agronomic and physiological traits in wheat

“…Molecular markers consisted of 27 AFLP, 6 SSR and 10 DArT Lopes et al 2013). 1B-a was considered as the T1BL/1RS region (for more details see Mathews et al 2008 andMcIntyre et al 2010).…”