GENETIC CONTROL OF FLOWER HOMOSTYLY OF TWO ACCESSIONS OF THE AUTOGAMOUS SPECIES FAGOPYRUM HOMOTROPICUM OHNISHI
2022
Fesenko, N.N. | Fesenko, I.N.
Using interspecific hybridization the genetic structure of the reproductive system of Fagopyrum homotropicum Ohnishi has been studied as a part of a common genetic system with F. esculentum Moench. Flower homostyly of two morphologically different accessions (C9139 and C9606) of F. homotropicum is determined by single “switch” gene S4 (linkage group #4), which is hypostatic to dominant allele of the heterostyly supergene S (linkage group #1) and epistatic to recessive allele s of F. esculentum Moench. S4 gene is tightly linked to SHT gene (seed shattering habit). S4 of both samples includes the dominant allele of subgene A (long stamens) and the recessive allele of subgene G (long pistil). The P subgene determining pollen size variability was found to be multiallelic: in addition to the P (large pollen) and p (small pollen) alleles, the PC9139 allele was found, which determines the intermediate pollen size of the C9139 accession of F. homotropicum. The translocation of the genome fragment, including the S locus, into another chromosome, which arose during the formation of F. homotropicum, could have a certain significance for the formation of resistance to long-termed inbreeding. Since the S-locus of a functional self-incompatibility system is always heterozygous, genome fragments linked to it can be subjected to selection for combination ability. Even if it is not an universal phenomenon, the translocation of any genome fragment can create a situation where this fragment will be represented by two copies. And if these copies are different, there will be preadaptation for increasing the resistance of such genotypes to inbreeding depression
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