Key message
Two QTL with pleiotropic effects on plant height and spike length linked in coupling phase on chromosome 2DS were dissected, and diagnostic marker for each QTL was developed.
Abstract
Plant height (PHT) is a crucial trait related to plant architecture and yield potential, and dissection of its underlying genetic basis would help to improve the efficiency of designed breeding in wheat. Here, two quantitative trait loci (QTL) linked in coupling phase on the short arm of chromosome 2D with pleiotropic effects on PHT and spike length,
QPht/Sl.cau
-
2D.1
and
QPht/Sl.cau
-
2D.2,
were separated and characterized.
QPht/Sl.cau
-
2D.1
is a novel QTL located between SNP makers
BS00022234_51
and
BobWhite_rep_c63957_1472. QPht/Sl.cau
-
2D.2
is mapped between two SSR markers,
SSR
-
2062
and
Xgwm484
, which are located on the same genomic interval as
Rht8
. Moreover, the diagnostic marker tightly linked with each QTL was developed for the haplotype analysis using diverse panels of wheat accessions. The frequency of the height-reduced allele of
QPht/Sl.cau
-
2D.1
is much lower than that of
QPht/Sl.cau
-
2D.2
, suggesting that this novel QTL may be an attractive target for genetic improvement. Consistent with a previous study of
Rht8
, a significant difference in cell length was observed between the NILs of
QPht/Sl.cau
-
2D.2
. By contrast, there was no difference in cell length between NILs of
QPht/Sl.cau
-
2D.1
, indicating that the underlying molecular mechanism for these two QTL may be different. Collectively, these data provide a new example of QTL dissection, and the developed diagnostic markers will be useful in marker-assisted pyramiding of
QPht/Sl.cau
-
2D.1
and/or
QPht/Sl.cau
-
2D.2
with the other genes in wheat breeding.
Electronic supplementary material
The online version of this article (10.1007/s00122-019-03318-z) contains supplementary material, which is available to authorized users.
Greenbug (Schizaphisgraminum Rondani) is one of the aphids causing significant cereal yield losses worldwide, and greenbug Biotype H is virulent to all known greenbug resistance genes in barley (Hordeum L.). Wild barley (Hordeum vulgare ssp. spontaneum) accession WBDC336 (PI 682028) exhibits resistance to greenbug Biotypes C, E, H, I, WY81, WY12 MC, and WY86. To investigate the genetics of greenbug resistance in WBDC336, a recombinant inbred line (RIL) population was developed from the cross Weskan × WBDC336. The RIL population was evaluated for responses to greenbug Biotype E and genotyped using genotyping‐by‐sequencing. Among 67,238 single nucleotide polymorphisms (SNPs) identified, 3,907 high quality SNPs were selected for gene mapping after several filtering steps. Linkage analysis positioned the greenbug resistance gene to a 1.14‐Mb interval in the terminal region of the long arm of chromosome 3H in WBDC336, where the greenbug resistance gene Rsg1 resides. Greenbug assays and an allelism test indicated that the greenbug resistance gene in WBDC336 is likely an allele at the Rsg1 locus and was given the allele designation Rsg1.a3. Two Kompetitive allele‐specific polymerase chain reaction (KASP) markers were developed from SNPs closely linked to Rsg1.a3, and these markers can be used to tag both alleles at the Rsg1 locus in breeding program utilizing marker‐assisted selection.
Leaf rust, caused by Puccininia triticina (Pt), is one of the most common wheat diseases in the Great Plains of the USA. A population of recombinant inbred lines (RILs) from CI 17884 x Bainong 418 was evaluated for responses to leaf rust race Pt52-2 and genotyped using single nucleotide polymorphism (SNP) markers. Quantitative trait locus (QTL) analysis identified a minor gene for resistance to leaf rust, designated QLr.stars-1RS, on the 1BL.1RS translocation segment in Bainong 418, and another leaf rust resistance gene, Lr47, on chromosome 7A of CI 17884. Lr47, originally identified in CI 17884 and located in a wheat-T. speltoides translocation segment 7S#1S, remains one of only a few race-specific resistance genes still effective in the Great Plains. A set of 7A-specific simple sequence repeat (SSR) markers were developed and used to genotype CI 17884 and a pair of near-isogenic lines differing in the presence or absence of 7S#1S, PI 603918 and Pavon F76. Haplotype analysis indicated that the estimated length of 7S#1S was 157.23 to 174.42 Mb, accounting for about 23% of the 7A chromosome. Two SNPs on 7S#1S and 4 SNPs on the 1RS chromosome arm were converted to KASP markers, which were subsequently validated in a panel of cultivars and recently released elite breeding lines. Of these, one and two KASP markers are specific to the 1RS chromosome arm and 7S#1S, respectively, indicating that they can facilitate the introgression of Lr47 and QLr.stars-1BS into locally adapted wheat cultivars and breeding lines.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.