Genomic Regions From an Iranian Landrace Increase Kernel Size in Durum Wheat

Abstract

Kernel size and shape are important parameters determining the wheat profitability, being main determinants of yield and its technological quality. In this study, a segregating population of 118 recombinant inbred lines, derived from a cross between the Iranian durum landrace accession “Iran_249” and the Iranian durum cultivar “Zardak”, was used to investigate durum wheat kernel morphology factors and their relationships with kernel weight, and to map the corresponding QTLs. A high density genetic map, based on wheat 90k iSelect Infinium SNP assay, comprising 6,195 markers, was developed and used to perform the QTL analysis for kernel length and width, traits related to kernel shape and weight, and heading date, using phenotypic data from three environments. Overall, a total of 31 different QTLs and 9 QTL interactions for kernel size, and 21 different QTLs and 5 QTL interactions for kernel shape were identified. The landrace Iran_249 contributed the allele with positive effect for most of the QTLs related to kernel length and kernel weight suggesting that the landrace might have considerable potential toward enhancing the existing gene pool for grain shape and size traits and for further yield improvement in wheat. The correlation among traits and co-localization of corresponding QTLs permitted to define 11 clusters suggesting causal relationships between simplest kernel size trait, like kernel length and width, and more complex secondary trait, like kernel shape and weight related traits. Lastly, the recent release of the T. durum reference genome sequence allowed to define the physical interval of our QTL/clusters and to hypothesize novel candidate genes inspecting the gene content of the genomic regions associated to target traits.

GridFree: A Python Package of Image Analysis for Interactive Grain Counting and Measuring

“…Devices for obtaining digital images of grain kernels include scanners (Gegas et al 2010;Sun et al 2019;Ma et al 2019;Desiderio et al 2019), cameras (Campbell et al 1999), and other photographic apparatus (Yin et al 2015;Cabral et al 2018). The next step, processing grain kernel images, is a critical part of the high-throughput method.…”

Molecular Mapping and Genomics of Grain Yield in Durum Wheat: A Review

“…Thus, the genetic basis of GY has been investigated through the three main yield components which will be explored in this review: kernel weight, kernels number and kernels number per unit area [ 28 , 31 ]. A total of 665 QTLs (100 with a pleiotropic effect) were identified and associated with grain yield and its components ( Table S1 ) [ 7 , 14 , 15 , 17 , 18 , 30 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ]. Specifically, nine additional yield components were considered: kernel length (KL), kernel width (KW), thousand-kernel weight (TKW) associated with the kernel weight, kernels number per spike (KNS), kernels number per spikelet (KNSL), spikelets number per spike (SLNS) associated with the kernels number, grain yield (GY), kernels number per square meter (KNM) and spike number per square meter (SNM) related to the kernels number per unit area ( Figure 1 ).…”

“…Modern durum wheat varieties exhibit large kernels and normally uniform seed size, because of the domestication and breeding processes that have focused on increasing yields. Conversely, durum wheat landraces show a much greater variability for kernel size and shape ([ 32 ], and the reference therein). In durum wheat, there is considerably less information of QTLs controlling kernel weight and most studies have been conducted to decipher the genetic basis of TKW [ 33 , 34 , 35 , 36 , 37 ], and fewer studies have been performed to elucidate the genetic basis of kernel size [ 17 , 30 , 32 ].…”

“…Conversely, durum wheat landraces show a much greater variability for kernel size and shape ([ 32 ], and the reference therein). In durum wheat, there is considerably less information of QTLs controlling kernel weight and most studies have been conducted to decipher the genetic basis of TKW [ 33 , 34 , 35 , 36 , 37 ], and fewer studies have been performed to elucidate the genetic basis of kernel size [ 17 , 30 , 32 ]. In this review, a total of 264 QTLs for kernel weight-related traits (201 for TKW, 33 for KL and 30 for KW) were identified on all chromosomes of durum wheat, however, no QTLs were reported for KW on chromosomes 1A and 2B, and for KL on chromosome 1A ( Table S1 , Figure 1 ).…”

Genetic Variation and Interrelationships Among Agronomic Traits in Egyptian Bread Wheat Landraces and Local Cultivars

“…Landraces are mixture of different genes and evolved by natural and artificial selection under environmental conditions where they were grown. They are very important genetic resource for diversity and specific adaptation to local environmental conditions and increasing agronomic traits in breeding programs (Desiderio et al, 2019;Zhao et al, 2019). Agronomic, morphological and phenological traits are very important for grouping wheat genetic recourses, and also are essential and useful for plant breeders seeking to improve wheat germplasm (Najaphy et al, 2012).…”