Characterization of Chromosome Constitution in Three Wheat-Thinopyrum intermedium Amphiploids Revealed Frequent Rearrangement of Alien and Wheat Chromosomes
Background: Thinopyrum intermedium (2n=6x=42) is an important wild perennial Triticeae species exhibiting many potentially favorable traits for wheat improvement. Wheat-Th. intermedium partial amphiploids serve as a bridge to transfer desirable genes from Th. intermedium into common wheat.
Results: Three octoploid Trititrigia accessions (TE261-1, TE266-1, and TE346-1) with good resistances to stripe rust, powdery mildew and aphids were selected from hybrid progenies between Th. intermedium and the common wheat variety ‘Yannong 15’ (YN15). Genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH) and multicolor GISH (McGISH) analyses demonstrated that the three octoploid Trititrigia possess 42 wheat chromosomes and 14 Th. intermedium chromosomes. The 14 alien (Th. intermedium) chromosomes belong to a mixed genome consisting of J-, JS- and St-genome chromosomes rather than a single J, JS or St genome. Different types of chromosomal structural variation were also detected in the 1A, 6A, 6B, 2D and 7D chromosomes via FISH, McGISH and molecular marker analysis. The identity of the alien chromosomes and the variationes in the wheat chromosomes in the three Trititrigia octoploids were also different.
Conclusions: The wheat-Th. intermedium partial amphiploids possess 14 alien chromosomes which belong to a mixed genome consisting of J-, JS- and St- chromosomes, and 42 wheat chromosomes with different structural variations. These accessions could be used as genetic resources in wheat breeding for the transfer of pest resistance genes from Th. intermedium to common wheat.
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Supplemental Fig. 1. Chromosomal configuration and GISH results for PMC MI in TE261-1, TE266-1 and TE346-1. Supplemental Fig. 2. Patterns of PCR amplification with St-chromosome-specific molecular markers Supplemental Fig. 3. Patterns of PCR amplification with E-chromosome-specific molecular markers Supplemental Fig. 4. Results of the amplification of wheat chromosome-specific markers. Supplemental Table 1. Chromosomal configurations of TE261-1, TE266 and TE346-1 at PMC MI. Supplemental Table 2. St-chromosome-specific molecular markers used in the study (Hu et al. 2014). Supplemental Table 3. E-chromosome-specific molecular markers used in the study (Hu et al. 2012).
Posted 23 Dec, 2020
Received 05 Jan, 2021
On 05 Jan, 2021
Received 28 Dec, 2020
On 20 Dec, 2020
Invitations sent on 16 Dec, 2020
On 16 Dec, 2020
On 14 Dec, 2020
On 14 Dec, 2020
On 14 Dec, 2020
Characterization of Chromosome Constitution in Three Wheat-Thinopyrum intermedium Amphiploids Revealed Frequent Rearrangement of Alien and Wheat Chromosomes
Posted 23 Dec, 2020
Received 05 Jan, 2021
On 05 Jan, 2021
Received 28 Dec, 2020
On 20 Dec, 2020
Invitations sent on 16 Dec, 2020
On 16 Dec, 2020
On 14 Dec, 2020
On 14 Dec, 2020
On 14 Dec, 2020
Background: Thinopyrum intermedium (2n=6x=42) is an important wild perennial Triticeae species exhibiting many potentially favorable traits for wheat improvement. Wheat-Th. intermedium partial amphiploids serve as a bridge to transfer desirable genes from Th. intermedium into common wheat.
Results: Three octoploid Trititrigia accessions (TE261-1, TE266-1, and TE346-1) with good resistances to stripe rust, powdery mildew and aphids were selected from hybrid progenies between Th. intermedium and the common wheat variety ‘Yannong 15’ (YN15). Genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH) and multicolor GISH (McGISH) analyses demonstrated that the three octoploid Trititrigia possess 42 wheat chromosomes and 14 Th. intermedium chromosomes. The 14 alien (Th. intermedium) chromosomes belong to a mixed genome consisting of J-, JS- and St-genome chromosomes rather than a single J, JS or St genome. Different types of chromosomal structural variation were also detected in the 1A, 6A, 6B, 2D and 7D chromosomes via FISH, McGISH and molecular marker analysis. The identity of the alien chromosomes and the variationes in the wheat chromosomes in the three Trititrigia octoploids were also different.
Conclusions: The wheat-Th. intermedium partial amphiploids possess 14 alien chromosomes which belong to a mixed genome consisting of J-, JS- and St- chromosomes, and 42 wheat chromosomes with different structural variations. These accessions could be used as genetic resources in wheat breeding for the transfer of pest resistance genes from Th. intermedium to common wheat.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5