title: Genomic characteristics of a diploid F(4) festulolium hybrid (Lolium multiflorum × Festuca arundinacea).
abstract: The grass festulolium, a hybrid between the genera  Festuca  and  Lolium , has a variety of beneficial agronomic attributes derived from both parents. Compared with high-ploidy festulolium, diploid festulolium is well suited to stabilizing ploidy and for studying agronomic traits and  genetic relationships. We sought to produce a diploid festulolium hybrid that was resistant to summer depression, by hybridizing diploid  Lolium multiflorum  Lam. and hexaploid  Festuca arundinacea  Schreb., which has a high tolerance to summer depression. We obtained seven diploid F(4) plants that were capable of surviving the extremely hot summer in Morioka, Japan, in 2010, which was 2.7 °C higher than the average summer temperature. The observed resistance to summer depression in these plants was likely due to heat stress tolerance. The genomic constitutions of these seven hybrids were analyzed by GISH, and the chromosomal characteristics of a single diploid F(4) was analyzed by FISH using rDNA probes. The results showed that although no Festuca-specific genome remained in any of the seven diploid F(4) plants, extensive chromosomal rearrangement was observed in one of them. Our findings suggested that hybridizing diploid L. multiflorum and hexaploid F. arundinacea may be useful for modifying chromosome architecture in the Lolium genome with potential applications in chromosome engineering.
authors.affiliation: Livestock and Forage Research Division, Tohoku Agricultural Research Center, National Agriculture and Food Research Organization, Akahira 4, Shimokuriyagawa, Morioka, Iwate 020-0198, Japan. akky@affrc.go.jp
authors.forename: Yukio
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Kenji
authors.initials: K
authors.lastname: Kimura
authors.forename: Hitomi
authors.initials: H
authors.lastname: Yamada-Akiyama
authors.forename: Akito
authors.initials: A
authors.lastname: Kubota
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takahara
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Ueyama
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics; D004171:Diploidy; D019143:Evolution, Molecular; D031751:Festuca / Q000235:genetics*; D018745:Genome, Plant; D017403:In Situ Hybridization; D007564:Japan; D007621:Karyotyping; D008129:Lolium / Q000235:genetics*; D013696:Temperature