Interactions among Loci Conferring Photoperiod Insensitivity for Heading Time in Spring Barley

Abstract

The inheritance of extreme earliness for heading time, as measured by days to awn appearance (DAA), in ‘Super Precoz (2H)’ (SP), a photoperiod‐insensitive spring barley (Hordeum vulgare L.), was investigated in field studies under short daylengths at Davis, CA, and Ciudad Obregón, Sonora, Mexico, to obtain additional information on gene action. The DAA data from parental, F1, F2, F3, and F4 generations indicated that extreme earliness in SP was conferred by a single locus when homozygous recessive. Data from 75 F3 families evaluated for DAA in a field study and by starch gel electrophoresis of seedling‐plumule extracts indicated that the locus conferring extreme earliness was linked to Est 1 and Est 3 on the long arm of Chromosome 3 with ≈2% recombination. The locus was assigned gene symbol Easp. The dominant allele Easp suppressed the recessive allele easp and permitted the expression of other unidentified Ea loci conferring relative lateness. Allelism tests indicated recessive epistatic interactions between the Easp locus and the Eak and Ea7 loci. The easp recessive homozygote suppressed numerous other Ea maturity loci and headed earlier than the other three recessive homozygotes (i.e., eak, ea7, or eac), which were phenotypically similar.

A Distorted Circadian Clock Causes Early Flowering and Temperature-Dependent Variation in Spike Development in the Eps-3Am Mutant of Einkorn Wheat

“…This would be consistent with Eam10 and Eam8 in barley forming a complex similar to AtLUX and AtELF3 (and AtELF4) in Arabidopsis . Interestingly, the genetic location of eam10 in barley and earliness per se 3A m (Eps-3A m ) in einkorn wheat (Triticum monococcum L.) appears to be syntenic (Gallagher et al 1991;Börner et al 2002;Gawroński and Schnurbusch 2012). Both mutants also display similar phenotypic features and flower early under both long and short day conditions, thus resembling mutants in the Arabidopsis EC (Hicks et al 2001;Shindo and Sasakuma 2001;Doyle et al 2002;Hazen et al 2005;Zakhrabekova et al 2012).…”

“…eam8 appears to be epistatic to eam10 (syn. ea sp ), which in turn seems to be a possible ortholog of LUX/PCL1 (Gallagher et al 1991;Zakhrabekova et al 2012; Campoli et al 2013). This would be consistent with Eam10 and Eam8 in barley forming a complex similar to AtLUX and AtELF3 (and AtELF4) in Arabidopsis .…”

Phenological development–yield relationships in spring barley in a subarctic environment

“…Barley is a long-day plant, and is induced ,, to flower when night length is sufficiently short. Although genetic variation for photoperiod response exists (Gallagher et al 1991), the long daylength of northern latitudes causes both photoperiod-sensitive and insensitive cultivars to flower early. Therefore, genetic variability for other developmental components such as phyllochron interval, leaf number, and grain fill rate become more important.…”

Barley and Wheat Share the Same Gene Controlling the Short Basic Vegetative Period

“…Previous conventional genetic studies identified some possible Eps loci including eam7 (syn ea7), eam8 (eak), eam9 (eac), and eam10 (easp), located on chromosomes 6HS, 1HL, 4HL, and 3HL, respectively (Gallagher et al 1991). In addition, Laurie et al (1995) identified eight QTLs, located on 2H, 3H, 4H, 5H, 6H (×2), and 7H (×2), that contribute to variation in flowering time for reasons other than photoperiod or vernalization.…”