Limits...
Marker Assisted Transfer of Two Powdery Mildew Resistance Genes PmTb7A.1 and PmTb7A.2 from Triticum boeoticum (Boiss.) to Triticum aestivum (L.).

Elkot AF, Chhuneja P, Kaur S, Saluja M, Keller B, Singh K - PLoS ONE (2015)

Bottom Line: The PM resistance gene PmTb7A.1 maps in a region very close to Sr22, a stem rust resistance gene effective against the race Ug99.Analysis of selected plants with markers linked to Sr22 showed introgression of Sr22 from T. boeoticum in several BC2F1 plants.Thus, in addition to PM resistance, these progeny might also carry resistance to stem rust race Ug99.

View Article: PubMed Central - PubMed

Affiliation: School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, 141 004, India.

ABSTRACT
Powdery mildew (PM), caused by Blumeria graminis f. sp. tritici, is one of the important wheat diseases, worldwide. Two PM resistance genes, designated as PmTb7A.1 and PmTb7A.2, were identified in T. boeoticum acc. pau5088 and mapped on chromosome 7AL approximately 48cM apart. Two resistance gene analogue (RGA)-STS markers Ta7AL-4556232 and 7AL-4426363 were identified to be linked to the PmTb7A.1 and PmTb7A.2, at a distance of 0.6cM and 6.0cM, respectively. In the present study, following marker assisted selection (MAS), the two genes were transferred to T. aestivum using T. durum as bridging species. As many as 12,317 florets of F1 of the cross T. durum /T. boeoticum were pollinated with T. aestivum lines PBW343-IL and PBW621 to produce 61 and 65 seeds, respectively, of three-way F1. The resulting F1s of the cross T. durum/T. boeoticum//T. aestivum were screened with marker flanking both the PM resistance genes PmTb7A.1 and PmTb7A.2 (foreground selection) and the selected plants were backcrossed to generate BC1F1. Marker assisted selection was carried both in BC1F1 and the BC2F1 generations. Introgression of alien chromatin in BC2F1 plants varied from 15.4-62.9 percent. Out of more than 110 BC2F1 plants showing introgression for markers linked to the two PM resistance genes, 40 agronomically desirable plants were selected for background selection for the carrier chromosome to identify the plants with minimum of the alien introgression. Cytological analysis showed that most plants have chromosome number ranging from 40-42. The BC2F2 plants homozygous for the two genes have been identified. These will be crossed to generate lines combining both the PM resistance genes but with minimal of the alien introgression. The PM resistance gene PmTb7A.1 maps in a region very close to Sr22, a stem rust resistance gene effective against the race Ug99. Analysis of selected plants with markers linked to Sr22 showed introgression of Sr22 from T. boeoticum in several BC2F1 plants. Thus, in addition to PM resistance, these progeny might also carry resistance to stem rust race Ug99.

No MeSH data available.


Related in: MedlinePlus

Meiotic analysis in selected BC2F1 plants a) PBW114/T. boeoticum pau5088 //3*PBW343-IL with 2n = 40 (18''+4'), b) PBW114/T. boeoticum pau5088//3*PBW621 with 2n = 42 (19''+4').
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4466026&req=5

pone.0128297.g002: Meiotic analysis in selected BC2F1 plants a) PBW114/T. boeoticum pau5088 //3*PBW343-IL with 2n = 40 (18''+4'), b) PBW114/T. boeoticum pau5088//3*PBW621 with 2n = 42 (19''+4').

Mentions: The breeding strategy for the transfer of the PM resistance genes from T. boeoticum followed in the present study is presented in Fig 1. The F1 plants of the cross T. durum cv PBW114/T. boeoticum were vigorous but completely male sterile. A total of 12,317 florets from 14 F1 plants were pollinated either with PBW343-IL or PBW621 and 126 pentaploid F1 seeds were generated. However, only 78 pentaploid F1 seeds germinated and survived in the field, which were later backcrossed to the respective recurrent parent (Table 2). Selected BC1F1 plants from a total of 239 were backcrossed to recurrent parents to generate BC2F1. Out of a total of 527 BC2F1 plants, 214 plants were used for marker analysis. All the selected BC2F1 plants were backcrossed as well as selfed to generate BC3F1 and BC2F2, respectively. Chromosome number in the selected BC2F1 plants varied from 40–42 and number of univalents varied from 2–4 (Fig 2).


Marker Assisted Transfer of Two Powdery Mildew Resistance Genes PmTb7A.1 and PmTb7A.2 from Triticum boeoticum (Boiss.) to Triticum aestivum (L.).

Elkot AF, Chhuneja P, Kaur S, Saluja M, Keller B, Singh K - PLoS ONE (2015)

Meiotic analysis in selected BC2F1 plants a) PBW114/T. boeoticum pau5088 //3*PBW343-IL with 2n = 40 (18''+4'), b) PBW114/T. boeoticum pau5088//3*PBW621 with 2n = 42 (19''+4').
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4466026&req=5

pone.0128297.g002: Meiotic analysis in selected BC2F1 plants a) PBW114/T. boeoticum pau5088 //3*PBW343-IL with 2n = 40 (18''+4'), b) PBW114/T. boeoticum pau5088//3*PBW621 with 2n = 42 (19''+4').
Mentions: The breeding strategy for the transfer of the PM resistance genes from T. boeoticum followed in the present study is presented in Fig 1. The F1 plants of the cross T. durum cv PBW114/T. boeoticum were vigorous but completely male sterile. A total of 12,317 florets from 14 F1 plants were pollinated either with PBW343-IL or PBW621 and 126 pentaploid F1 seeds were generated. However, only 78 pentaploid F1 seeds germinated and survived in the field, which were later backcrossed to the respective recurrent parent (Table 2). Selected BC1F1 plants from a total of 239 were backcrossed to recurrent parents to generate BC2F1. Out of a total of 527 BC2F1 plants, 214 plants were used for marker analysis. All the selected BC2F1 plants were backcrossed as well as selfed to generate BC3F1 and BC2F2, respectively. Chromosome number in the selected BC2F1 plants varied from 40–42 and number of univalents varied from 2–4 (Fig 2).

Bottom Line: The PM resistance gene PmTb7A.1 maps in a region very close to Sr22, a stem rust resistance gene effective against the race Ug99.Analysis of selected plants with markers linked to Sr22 showed introgression of Sr22 from T. boeoticum in several BC2F1 plants.Thus, in addition to PM resistance, these progeny might also carry resistance to stem rust race Ug99.

View Article: PubMed Central - PubMed

Affiliation: School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, 141 004, India.

ABSTRACT
Powdery mildew (PM), caused by Blumeria graminis f. sp. tritici, is one of the important wheat diseases, worldwide. Two PM resistance genes, designated as PmTb7A.1 and PmTb7A.2, were identified in T. boeoticum acc. pau5088 and mapped on chromosome 7AL approximately 48cM apart. Two resistance gene analogue (RGA)-STS markers Ta7AL-4556232 and 7AL-4426363 were identified to be linked to the PmTb7A.1 and PmTb7A.2, at a distance of 0.6cM and 6.0cM, respectively. In the present study, following marker assisted selection (MAS), the two genes were transferred to T. aestivum using T. durum as bridging species. As many as 12,317 florets of F1 of the cross T. durum /T. boeoticum were pollinated with T. aestivum lines PBW343-IL and PBW621 to produce 61 and 65 seeds, respectively, of three-way F1. The resulting F1s of the cross T. durum/T. boeoticum//T. aestivum were screened with marker flanking both the PM resistance genes PmTb7A.1 and PmTb7A.2 (foreground selection) and the selected plants were backcrossed to generate BC1F1. Marker assisted selection was carried both in BC1F1 and the BC2F1 generations. Introgression of alien chromatin in BC2F1 plants varied from 15.4-62.9 percent. Out of more than 110 BC2F1 plants showing introgression for markers linked to the two PM resistance genes, 40 agronomically desirable plants were selected for background selection for the carrier chromosome to identify the plants with minimum of the alien introgression. Cytological analysis showed that most plants have chromosome number ranging from 40-42. The BC2F2 plants homozygous for the two genes have been identified. These will be crossed to generate lines combining both the PM resistance genes but with minimal of the alien introgression. The PM resistance gene PmTb7A.1 maps in a region very close to Sr22, a stem rust resistance gene effective against the race Ug99. Analysis of selected plants with markers linked to Sr22 showed introgression of Sr22 from T. boeoticum in several BC2F1 plants. Thus, in addition to PM resistance, these progeny might also carry resistance to stem rust race Ug99.

No MeSH data available.


Related in: MedlinePlus