Subgenome Discrimination in Brassica and Raphanus Allopolyploids Using Microsatellites

Abstract

Intergeneric crosses between Brassica species and Raphanus sativus have produced crops with prominent shoot and root systems of Brassica and R. sativus, respectively. It is necessary to discriminate donor genomes when studying cytogenetic stability in distant crosses to identify homologous chromosome pairing, and microsatellite repeats have been used to discriminate subgenomes in allopolyploids. To identify genome-specific microsatellites, we explored the microsatellite content in three Brassica species (B. rapa, AA, B. oleracea, CC, and B. nigra, BB) and R. sativus (RR) genomes, and validated their genome specificity by fluorescence in situ hybridization. We identified three microsatellites showing A, C, and B/R genome specificity. ACBR_msat14 and ACBR_msat20 were detected in the A and C chromosomes, respectively, and ACBR_msat01 was detected in B and R genomes. However, we did not find a microsatellite that discriminated the B and R genomes. The localization of ACBR_msat20 in the 45S rDNA array in ×Brassicoraphanus 977 corroborated the association of the 45S rDNA array with genome rearrangement. Along with the rDNA and telomeric repeat probes, these microsatellites enabled the easy identification of homologous chromosomes. These data demonstrate the utility of microsatellites as probes in identifying subgenomes within closely related Brassica and Raphanus species for the analysis of genetic stability of new synthetic polyploids of these genomes.

FISH Mapping of Telomeric and Non-Telomeric (AG3T3)3 Reveal the Chromosome Numbers and Chromosome Rearrangements of 41 Woody Plants

“…The Arabidopsis -type telomeric repeat sequences T 3 AG 3 are most like AG 3 T 3 , which are still the most frequent even in woody plants—such as species of Abies [ 37 ], Aralia [ 41 ], Cycas [ 39 ], Dendropanax [ 41 ], Eleutherococcus [ 41 ], Kalopanax [ 41 ], Malus [ 23 ], Picea [ 23 ], Pinus [ 23 , 40 , 42 , 43 , 44 ], Populus [ 35 ], Podocarpus [ 46 ], and Zamia [ 23 , 61 ]—but has been shown to be absent in species of Cestrum , Sessea , and Vestia [ 14 ]. Nevertheless, these sequences cannot be entirely equated, due to the existence of at least ten variable telomere sequences (T x A y G z ) n —including TAG 3 [ 4 ], TA 2 G 2 [ 5 ], T 2 AG 2 [ 6 ], T 2 AG 3 [ 7 ], TA 2 G 3 [ 5 ], T 3 AG 3 [ 8 , 9 , 10 ], T 4 AG 3 [ 12 ], A 2 TG 6 [ 13 ], T 2 AT 2 AG 3 [ 7 ], and T 6 AG 3 [ 14 , 15 ]—and at least seven variants, such as TCAG 2 [ 16 ], T 2 AG 2 C [ 17 ], T 2 CAG 2 [ 18 ], T 3 CAG 2 [ 18 ], C 3 TA 3 [ 19 ], T 2 N 4 AG 3 [...…”

“…Furthermore, they are well-conserved, and previous findings have revealed their diversity. There exist at least 17 variable telomeric sequences: TAG 3 [ 4 ], TA 2 G 2 [ 5 ], TA 2 G 3 [ 5 ], T 2 AG 2 [ 6 ], T 2 AG 3 [ 7 ], T 3 AG 3 [ 8 , 9 , 10 ], AG 3 T 3 [ 11 ], T 4 AG 3 [ 12 ], A 2 TG 6 [ 13 ], T 2 AT 2 AG 3 [ 7 ], T 6 AG 3 [ 14 , 15 ], TCAG 2 [ 16 ], T 2 AG 2 C [ 17 ], T 2 CAG 2 [ 18 ], T 3 CAG 2 [ 18 ], C 3 TA 3 [ 19 ], T 2 N 4 AG 3 [ 20 ], and T 2 ATG 3 CTCG 2 [ 21 ]. Undoubtedly, the most widespread telomeric repeat is T 2 AG 3 in animals [ 22 ], while that in most plants is T 3 AG 3 [ 23 ].…”

Perspective Chapter: Creation and Evolution of Intergeneric Hybrids between Brassica rapa and Raphanus sativus

“…Of the 676 ovules cultured, 102 (15.1%) produced plants, including 22 multi-shoot embryos. Of the successfully germinated plants, 22 were harvested and 439 seeds were collected. This study was the first to harvest F 2 seeds from Brassica-Raphnus hybrids [6].…”

“…Terasawa [10] was the first to report intergeneric hybridization between Brassica and Raphanus, followed by Takeshita et al [11], Dolstra [12], Lange et al [13], Lee et al (1986Lee et al ( -2022, and members of the laboratories of Professor Hyo Guen Park [14,15], Professor Jongkee Kim [16][17][18], Professor Il-Sup Noh [19], Professor Jun Gu Lee [20], Professor Hyun Hee Kim [21,22], and Professor Jin Hue Huh [23,24]. Tonosaki et al [25] in Japan, and Lou et al [26], Zhang et al [27], and Jin et al [28] in China, have published papers on hybridization between Brassica and Raphanus.…”

Integration of Genomic and Cytogenetic Data on Tandem DNAs for Analyzing the Genome Diversity Within the Genus Hedysarum L. (Fabaceae)

“…Hedysarum (Yurkevich et al, 2021). Also, various tandem repeats are applied as chromosomal markers to detect intraand interspecific diversities in plant genomes, chromosomal rearrangements, and the evolutionary pathways in various taxa, including Fabaceae species (Pamponét et al, 2019;Ávila Robledillo et al, 2020;Campomayor et al, 2021;Waminal et al, 2021). The use of such molecular chromosomal markers for karyotype analyses in species from the sect.…”