title: Identification of loci associated with embryo yield in microspore culture of Brassica rapa by segregation distortion analysis.
abstract: We identified three physical positions associated with embryo yield in microspore culture of Brassica rapa by segregation distortion analysis. We also confirmed their genetic effects on the embryo yield. Isolated microspore culture is well utilized for the production of haploid or doubled-haploid plants in Brassica crops. Brassica rapa cv. 'Ho Mei' is one of the most excellent cultivars in embryo yield of microspore culture. To identify the loci associated with microspore embryogenesis, segregation analysis of 154 DNA markers anchored to B. rapa chromosomes (A01-A10) was performed using a population of microspore-derived embryos obtained from an F1 hybrid between 'CR-Seiga', a low yield cultivar in microspore-derived embryos, and 'Ho Mei'. Three regions showing significant segregation distortion with increasing 'Ho Mei' alleles were detected on A05, A08 and A09, although these regions showed the expected Mendelian segregation ratio in an F2 population. The additive effect of alleles in these regions on embryo yield was confirmed in a BC3F1 population. One region on A08 containing Br071-5c had a higher effect than the other regions. Polymorphism of nucleotide sequences around the Br071-5c locus was investigated to find the gene possibly responsible for efficient embryogenesis from microspores.
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 1-1, Tsutsumidori-Amamiyamachi, Sendai, Miyagi, 981-8555, Japan. hkitashiba@m.tohoku.ac.jp.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kitashiba
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 1-1, Tsutsumidori-Amamiyamachi, Sendai, Miyagi, 981-8555, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Taguchi
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 1-1, Tsutsumidori-Amamiyamachi, Sendai, Miyagi, 981-8555, Japan.
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Kaneko
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 1-1, Tsutsumidori-Amamiyamachi, Sendai, Miyagi, 981-8555, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Inaba
authors.affiliation: Faculty of Agriculture, Iwate University, Morioka, Japan.|Graduate School of Life and Environmental Science, Osaka Prefecture University, Sakai, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Yokoi
authors.affiliation: Faculty of Agriculture, Iwate University, Morioka, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Takahata
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 1-1, Tsutsumidori-Amamiyamachi, Sendai, Miyagi, 981-8555, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishio
mesh_terms: D000483:Alleles; D029741:Brassica rapa / Q000196:embryology* / Q000235:genetics*; D020090:Chromosome Segregation / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics; D003433:Crosses, Genetic; D056426:Genetic Loci; D005819:Genetic Markers; D011058:Pollen / Q000196:embryology* / Q000235:genetics; D012639:Seeds / Q000196:embryology* / Q000235:genetics*
chemical_list: D005819:Genetic Markers
keywords: Brassica rapa; Microspore culture; Microspore-derived embryo; Segregation distortion