© 2004 The American Genetic Association
The Psm Locus Controls Paternal Sorting of the Cucumber Mitochondrial Genome
From the Vegetable Crops Unit, Agricultural Research Service, U.S. Department of Agriculture, Department of Horticulture, 1575 Linden Dr., University of Wisconsin, Madison, WI 53706 (Havey); Department of Horticulture, 1575 Linden Dr., University of Wisconsin, Madison, WI 53706 (Park); and Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture and Landscape Architecture, Warsaw Agricultural University, ul. Nowoursynowska 166, 02-787 Warsaw, Poland (Bartoszewski)
Address correspondence to Michael J. Havey at the address above.
The mitochondrial genome of cucumber shows paternal transmission and there are no reports of variation for mitochondrial transmission in cucumber. We used a mitochondrially encoded mosaic (MSC) phenotype to reveal phenotypic variation for mitochondrial-genome transmission in cucumber. At least 10 random plants from each of 71 cucumber plant introductions (PIs) were crossed as the female with an inbred line (MSC16) possessing the MSC phenotype. Nonmosaic F1 progenies were observed at high frequencies (greater than 50%) in F1 families from 10 PIs, with the greatest proportions being from PI 401734. Polymorphisms near the mitochondrial cox1 gene and JLV5 region revealed that nonmosaic hybrid progenies from crosses of PI 401734 with MSC16 as the male possessed the nonmosaic-inducing mitochondrial DNA (mtDNA) from the paternal parent. F2, F3, and backcross progenies from nonmosaic F1 plants from PI 401734 x MSC16 were testcrossed with MSC16 as the male parent to reveal segregation of a nuclear locus (Psm for Paternal sorting of mitochondria) controlling sorting of mtDNA from the paternal parent. Psm is a unique locus at which the maternal genotype affects sorting of paternally transmitted mtDNA.