Genetic Control of Embryo Lethality in Crosses between Common Wheat and Rye

Abstract

The phenotypic manifestation and genetic control of embryo lethality observed in crosses between common wheat and rye were studied. It was found that crosses between common wheat and inbred self-fertile rye lines L2 and 535 gave rise to ungerminating grains, in which the development and differentiation of the hybrid embryo are arrested. Study of the degree of embryo development in the hybrid grains obtained by crossing common wheat varieties with inbred rye lines L2 and 535 showed that genotypes of the parents affected the ratio between undifferentiated embryos of various sizes. Analysis of this trait was performed by test crosses according to a novel pedigree program with the use of interlinear hybrids and a set of fourth-generation hybrid recombinant inbred lines. Rye line L2 was shown to bear the Eml (Embryo lethality) gene, which terminates the development of the hybrid embryo in amphihaploids. The suggestion of complementary interaction between wheat and rye genes during formation of a "new" character in wheat-rye F 1 hybrids is discussed. A method of detecting an allele not complementary to the rye Eml allele in wheat is proposed. The proposed test program allows appropriate study of the system of wheat and rye genes involved in complementary interaction in the genotype of a distant hybrid. PLANT GENETICS

Single nucleotide polymorphisms in rye (Secale cereale L.): discovery, frequency, and applications for genome mapping and diversity studies

“…This is consistent with known pedigree and provenance (Korzun et al 2001;Malyshev et al 2003;Tikhenko et al 2005). P87 and P105 were developed together at the Institute of Genetics and Cytology, Minsk, Belarus, both having been selected from the progeny of a single cross.…”

Gene mutations in rye causing embryo lethality in hybrids with wheat: allelism and chromosomal localisation

“…In addition to the kr gene complex, other genetic systems also may cause reproductive barriers between wheat and rye at different developmental stages of the zygote. Among ~100 rye inbred lines, used in crosses with wheat carrying the recessive crossability alleles, four (L2, L3, L564, genetically related, and L535) were detected to be carriers of mutations causing embryo lethality after hybridization (Tikhenko et al 2005). The genetic analysis presented here revealed a monogenic inheritance for embryo lethality, as well as allelism between the genetically different lines L2 and L535.…”

“…Rye lines L2 (and by inference, also the genetically related lines L3 and L564), as well as the unrelated line L535, carry the allele preventing the normal development of a hybrid embryo. This gene was named by Tikhenko et al (2005Tikhenko et al ( , 2008 Eml (embryo lethality). Because we cannot determine yet, whether the allele for embryo lethality is dominant or recessive, we designate the alleles determining the production of differentiated (normal or wild-type) and undifferentiated (lethal or mutant) embryos Eml-R1a and Eml-R1b, respectively, following the rules for gene symbolization (McIntosh et al 2008).…”

“…The hybrid seeds of all other lines were viable. The non-germinating hybrid seeds obtained from crosses with both L2 and L535 had a normal endosperm, but hybrid embryos were either absent, or varied in size from small to normal, but without any indication of tissue differentiation (Tikhenko et al 2005(Tikhenko et al , 2008. In the present paper, we describe the identification and mapping of the gene(s) responsible for the failure of these wheat × rye hybrid embryos to develop, i.e.…”

Analysis of hybrid lethality in F1 wheat-rye hybrid embryos

“…Rye line L2 carries the mutation Eml (Embryo lethality), which terminates the development of the hybrid embryos in amphihaploids. Monogenic control of development of the hybrid embryo by the rye parent was conWrmed by crossing CS with a set of rye recombinant inbred lines (Tikhenko et al 2005). Embryos of non-germinating swelling hybrid seeds from these amphihaploids were not normally diVerentiated, whereas the endosperms from these seeds looked similar to those from control crosses.…”