Results of my Graduate researches at South Dakota State University

Transcription

1 EVALUATION AND IDENTIFICATION OF SOYBEAN APHID RESISTANCE SOURCES AND MAPPING OF SOYBEAN APHID RESISTANCE LOCI IN EARLY MATURING SOYBEAN GERMPLASM ACCESSION Results of my Graduate researches at South Dakota State University S J Bhusal, G-L Jiang, L Hesler, K Tilmon, J Orf, P Cregan, Q Song, D Wright, and J Gonzalez Soybean Breeders Workshop Feb 13-15, 2017

2 Soybean aphid in the United States One of the major pests of Soybean First reported in 2000 Spread up to 80% of soybean cultivation area in 2002 Detected in 30 states by Hartman et al., 2001; Venette and Ragsdale, 2004; Ragsdale et al., 2011

3 Soybean aphid, Aphis glycines Matsumara Suck the plant sap Transmit viral diseases Sooty mold development Yield loss of 40% or more on severe infestation Hartman et al., 2001; Venette and Ragsdale, 2004; Ostlie, 2002.

4 Soybean aphid, Aphis glycines Matsumara Life cycle: heteroecious holocyclic (host-alternating with sexual reproduction during part of its life cycle). Ragsdale et al. (2004)

5 Soybean aphid resistance sources Resistant loci Source Maturit y Group Remarks Rag1 PI (Dowling) VIII Hill et al., 2006 Rag2 PI and PI IV VIII Mian et al., 2008; Hill et al., 2009 Rag3 PI C III Zhang et al., 2010 rag4 and rag1c PI B III Zhang et al., 2009 rag1b and rag3 PI B III Bales et al., 2013 Rag6 P203 from China VIII Xiao et al., Keeps coming.

6 Soybean aphid distribution vs Maturity Group Map Hartman et al., 2001; Venette and Ragsdale, 2004; Ragsdale et al., 2011

7 Soybean aphid biotypes Biotype 1: Avirulent to known resistance sources Biotype 2: Virulent to Rag1 Biotype 3: Virulent to Rag2 Biotype 4: Virulent to both Rag1 and Rag2.. Keeps coming Ragsdale et al. (2004)

8 Objectives Identify soybean aphid resistance sources in early maturing soybean germplasm accessions Map and characterize soybean aphid resistance and identify associated markers to be used in soybean breeding programs

9 Evaluation of Soybean aphid resistance in Early Maturing soybeans 1.a. Maturity Group (MG) 00 and soybean germplasm accessions 326 accessions from MG 0 and 00 6 resistant checks 2 susceptible checks 1.b. Maturity Group (MG) I 341 soybean germplasm accessions 330 accessions from MG I 8 resistant checks 3 susceptible checks

10 Results: Maturity group 00 and 0 Categor y Caged Greenhouse tests Non-caged R 4 <60 aphids plant-1 MR aphids plant-1 4 score score R, resistant; MR, moderately resistant

11 Results: Maturity group 00 and 0 Categor y Caged Greenhouse tests Non-caged Field tests R PI <60 aphids plant-1 score score MR PI aphids score score plant-1 R, resistant; MR, moderately resistant

12 12 Field screening (Aurora, SD), 2011 PI (Rag1, VIII ) PI567541B (rag4, III ) PI (New, 00 ) PI (Rag2, IV ) PI (Sus.Ck, 00 ) PI (New, 0 ) PI567543C (Rag3, III ) PI (Sus.Ck, II ) Soybean aphid infestation in different soybean genotypes (with resistance source and maturity group) in Aurora, 2011.

13 Results: Maturity group 00 and 0 S M R R

14 Results: Maturity group I 1 Category Greenhouse tests Caged R 8 <85 aphids plant-1 MR aphids plant-1 Non-caged 3 score score R, resistant; MR, moderately resistant

15 Results: Maturity group I 1 Category Greenhouse tests Field test Caged Non-caged R 8 <85 aphids plant-1 3 score <110 aphids plant-1 PI A PI A MR aphids plant-1 14 score aphids PI PI plant-1 R, resistant; MR, moderately resistant

16 Results: Maturity group I 1 S M R R

17 Linkage mapping of SA Resistance in PI SD x PI ( Roberts ) F1 Phenotyping of 142 F2 plants in greenhouse Genotyping by BARCSoySNP6k Beadcheap Mapping

18 Results: Phenotypic distribution 1 PI SD Histogram of soybean aphid resistance in F2 plants.

19 QTL Mapping 1

20 Segregation analysis: Chromosome 7 locus 2 Segregation analysis suggested dominance effects of resistant QTL on Chromosome 7 b b a AA Aa aa

21 Location of resistant locus on chromosome 7 2 Physical map (Mb) Positio n (Regio n) (cm) SNP ID Positi on Physic al positio n (Mbp) P valu e R2 valu e ( ) ss ss ss ss ss ss Rag7? < < < < < <

22 Segregation analysis: Chromosome 16 locus 2 Segregation analysis suggested partial (or additive) dominance effects of resistant QTL on Chromosome 16 c b a BB Bb bb

23 Location of resistant locus on chromosome 16 2 Physical map (Mb) Position SNP ID Positi Physic P R (Region on al value val ) positi (cm) on (Mbp) ss < ss < ( ) 50 ss < ss < ss <

24 QTL Mapping 2

25 Segregation analysis: Chromosome 13 and 17 loci 2 a a b a a b

26 Location of susceptibility locus on chromosome 13 2 Physical map (Mb)

27 Location of susceptibility locus on chromosome 17 2 Physical map (Mb)

28 Conclusions 2 We identified several early maturing soybean germplasm accessions with different levels of resistance against soybean aphid Resistant accessions: PI (MG 0), PI A and PI A (MG I) Moderately Resistant accessions: PI (MG 00) PI and PI (MG I) PI carries oligogenic resistance against soybean aphid with two loci on chrom_07 and chromo_16.

29 Acknowledgements 2 Dr Guo-Liang Jiang, Dr David Wright, Dr Jose Gonzalez Soybean breeding crew, Plant Science Dept., SDSU Dr. Kelley and Soybean entomology lab, SDSU Dr Karl Glover Dr. Hesler and Soybean entomology team, USDA-ARS, Brookings, SD. USDA National Soybean Research Center. P Cregan and Q Song Fundings:

30 30 Thank you