Discovery of a novel cytoplasmic male-sterility and its restorer lines in radish (Raphanus sativus L.)

Abstract

A male-sterile (MS) radish (Raphanus sativus L.) was found in an accession collected from Uzbekistan. Unlike Ogura MS radishes in which no pollen grain is typically visible during anthesis, a small number of pollen grains stuck together in the dehiscing anthers was observed in the newly identified MS radish. Fluorescein diacetate tests and scanning electron micrographs showed that pollen grains in the new MS radish were severely deformed and non-viable. Cytological examination of pollen development stages showed a clear difference in the defective stage from that seen in Ogura male-sterility. Reciprocal cross-pollination with diverse male-fertile lines indicated that pollen grains of the new MS radish were completely sterile, and the female organs were fully fertile. When the new MS radish and Ogura MS lines were cross-pollinated with a set of eight breeding lines, all F1 progeny originating from crosses with the new MS radish were male-sterile. In contrast, most of the F1 progeny resulting from crosses with Ogura MS lines were male-fertile. These results demonstrated that factors associated with induction of the newly identified male-sterility are different from those of Ogura male-sterility. The lack of restorer lines for the newly identified male-sterility led us to predict that it might be a complete cytoplasmic male-sterility without restorer-of-fertility genes in nuclear genomes. However, cross-pollination with more diverse radish germplasm identified one accession introduced from Russia that could completely restore fertility, proving the existence of restorer-of-fertility gene(s) for the new male-sterility. Meanwhile, the PCR amplification profile of molecular markers for the classification of radish mitochondrial genome types revealed that the new MS radish contained a novel mitotype.

Identification of Rfd1, a novel restorer-of-fertility locus for cytoplasmic male-sterility caused by DCGMS cytoplasm and development of simple PCR markers linked to the Rfd1 locus in radish (Raphanus sativus L.)

“…The mitochondrial gene, orf138, responsible for male-sterility induction (Bonhomme et al 1991;Grelon et al 1994), along with the fertility restorer gene, Rfo, were cloned (Brown et al 2003;Desloire et al 2003;Koizuka et al 2003). Male-sterility conferred by a different cytotype, DCGMS, was recently discovered (Lee et al 2008). At first, this was assumed to be complete CMS line without any fertility restorers since most breeding lines actually maintained CMS.…”

Proteomics Analysis of Photo-Thermo-Sensitive Male Sterility Wheat Line BNS during Its Thermosensitive Period

“…The pollen number might be related with the development of meiosis of microspore mother cell, or the daparture of pollen grains from tapetum and the realeasement from anther, and the pollen viability might be related with normal development of pollen grains after meiosis of microspore mother cell. Lee et al (2008) reported that no pollen grain is typically visible during anthesis in a male sterile radish, but a small number of pollen grains could be observed stuck together in the dehiscing anthers in another male sterile radish. Gothandam et al (2007) showed that pollen viability and grain production decreased significantly when treated at a low temperature in a rice MS line, and the male sterility is due to functional loss of the tapetum which is the most sensitive to low-temperature stress.…”

Construction of a high-resolution linkage map of Rfd1, a restorer-of-fertility locus for cytoplasmic male sterility conferred by DCGMS cytoplasm in radish (Raphanus sativus L.) using synteny between radish and Arabidopsis genomes

“…The F 1 hybrid was produced in a previous study (Lee et al 2008). F 2 seeds were germinated in a greenhouse in 128-cell plug trays measuring 54 9 28 9 8 cm 3 .…”

“…In the past decade, a new CMS, designated Dongbu cytoplasmic and genic male-sterility (DCGMS), was discovered in radish germplasm introduced from Western Europe (Lee et al 2008). Cytological examination of pollen development of DCGMS plants showed that microspore abortion occurred at later stages than in Ogura CMS plants.…”

“…Cytological examination of pollen development of DCGMS plants showed that microspore abortion occurred at later stages than in Ogura CMS plants. DCGMS plants are particularly useful in radish breeding programs since the frequency of DCGMS maintainer lines in radish breeding germplasm in Korea was much higher than Ogura CMS maintainer lines (Lee et al 2008). Molecular markers for distinguishing the DCGMS cytotype from three other radish cytotypes were developed based on the mitochondrial ) and chloroplast variation ).…”