QTL Mapping Reveals the Relationship between Pasting Properties and Malt Extract in Barley

Abstract

Pasting properties are important characteristics of barley starch from a processing standpoint. Many studies reported the close relationship between pasting properties and malting quality, especially malt extract. However, most conclusions were derived from the correlation between pasting properties and malting quality using a set of cultivars or breeding lines. In this study, a doubled haploid population of 150 lines from a cross between a Japanese malting barley and a Chinese feed barley was grown in four different environments (two sites × two years). Based on average values from all different environments, 17 significant quantitative trait loci (QTL) were identified for pasting properties. The genetic variance explained by these QTL varied from 7.0 to 23.2%. Most QTL controlling pasting properties were located on 1H, 2H, 5H, and 7H. Results confirmed the linkage between pasting properties and malt extract, with most of the QTL for pasting properties becoming nonsignificant when using malt extract as a covariate. Breakdown showed the closest correlation with malt extract. Molecular markers closely linked to the QTL can be used to select desired pasting properties to improve malting quality.

Identification of new QTL for salt tolerance from rice variety Pokkali

“…The use of covariates in QTL analysis makes it possible to detect the influences of the covariates on the traits analysed (van Ooijen, ). This approach has been successfully used to reveal the linkage between the correlated traits (Fan, Shabala, Ma, Xu, & Zhou, ; Gill et al, ; Ma et al, ; Wang et al, ). For examples, a new drought tolerant QTL was confirmed to have no significant effect on agronomic trait (Fan et al, ) and a significant contribution of membrane potential to both waterlogging and salinity tolerance was identified (Gill et al, ).…”

“…The use of covariates in QTL analysis makes it possible to detect the influences of the covariates on the traits analysed (van Ooijen, 2009). This approach has been successfully used to reveal the linkage between the correlated traits (Fan, Shabala, Ma, Xu, & Zhou, 2015;Gill et al, 2017;Ma et al, 2015;Wang et al, 2018).…”

Comparison of pasting properties measured from the whole grain flour and extracted starch in barley (Hordeum vulgare L.)

“…RVA has been widely used to determine starch pasting properties [11]. In barley, grain flour was usually used as the sample in RVA measurement to evaluate or predict grain and malting quality [11, 13–18] as the grain flour can be obtained easily and efficiently compared with extracted starch and the whole grain is the main and integral part in utilization and production [11]. However, there is no report on the correlation between RVA profile characteristics measured by grain flour and starch in barley.…”

“…Given that barley is the primary source for malting and brewing industries with starch being the major constituent in barley grain, changes in starch pasting characteristics have direct effects on grain malting properties [12] and RVA has become the instrument of choice for determining and evaluating grain and malt quality in barley [11, 13–16]. It has been reported that pasting properties have a close relationship with malting quality traits especially fine extract in barley, and a shorter time to peak viscosity and lower peak time are considered to be suitable for high malting and food processing [15–18]. However, unlike some other cereals such as rice or wheat, the hull of barley grain (about 13% by weight on average) is difficult to remove.…”