algodones dune sunflower

Recruiting Algodones Dune Sunflowers for Genetic

Improvement of Cultivated Sunflower

Sameer KhanalMS, UGA

Importance of wild Helianthus species

Crop production and extensive cultivation:Resistance to several biotic and abiotic stressesExtending crop to marginal environments

Broadening germplasm base: Crop security from epiphytoticsCrop stability and sustainable production

Novel traits of interest:Male sterility and restoration genesOil quality traitsBiomass traits

Phylogenetic Relationship Among Helianthus species

Rieseber et al. 1991. Sys. Bot.Source: Wikipedia

H. niveus subsp. tephrodes

Helianthus niveus subsp. tephrodes

Mostly obligate perennial psammophiles (plants restricted to active dunes)

Is a “rare” species, some 12 ecotypes are collected at NPGS, USA

Are potential sources of novel traits in cultivated sunflower:

- Drought tolerance- Biomass traits

Most primitive within the genus (represents ancestral karyotype?)1

1. Heiser et al. 1965

Research Projects

1. Macrosynteny between the common and Algodones dune sunflower genomes

2. Phylogeographic diversity and association mapping in Algodones dune sunflower

3. Development and genetic analysis of Algodones dune sunflower Introgression Lines

1. Macrosynteny Between the Common and Algodones Dune Sunflower Genomes

Rationale

1.Dune sunflowers are untapped genetic resources

- Drought and stress resistance

- Novel alleles

2. Introgressive hybridization is desirable

3. Karyotipic differences ensure reproductive barriers among species

2.Rates of chromosomal rearrangements are very high in genus Helianthus1

Long-term goals

1.Understand chromosomal rearrangements between common sunflower (H. annuus) and dune sunflower (H. niveus ssp. tephrodes)2.Assess and predict the effects of such differences on the transmission of alleles across the species barrier

1. Burke et al. 2004, Genetics


Specific Objectives

1.1. Develop “intraspecific” mapping population

1.2. Comparative genetic mapping SyntenyChromosomal rearrangementsDeletions and duplications

1.3. QTL mapping in an “interspecific” hybrid population

Hybrid fertilityFlowering time

1.4. Molecular cytogenetics


Methods and Approaches

Develop “interspecific” hybrid population for “intraspecific” genetic mapping

NIV-E NIV-L

NIV-E NIV-LXNMS373

(NIV-E NIV-L)XXNMS373

Status

About 30 seeds from NIV-1243 (NIV-E, ultra-early) X Ames 27830 (NIV-L, ultra-late) ecotypes

2 out of 22 seeds produced apparently healthy seedlings



Comparative genetic and QTL mapping

Status

Illumina GoldenGate SNP genotyping arrays are underway

NIV-E NIV-L (NIV-E NIV-L)XNMS373

(NIV-E NIV-L)XXNMS373

SNP screening using the arrays:

SNP genotyping:

(NIV-E NIV-L)XXNMS373Phenotyping:

2. Screening 1,536 SNPs in the mapping population

1. SNP screening against mapping population parents

3. Phenotyping population for hybrid fertility and flowering time

2. Phylogeographic Diversity and Association Mapping in Algodones Dune Sunflower

Rationale

1.Relatively obscure species, biodiversity is not known

2.From molecular prospective, it’s almost a “pristine “species

Long-term goals

1.Understand phylogeographic and genetic diversity in H. niveus ssp. tephrodes

2.Assess the allelic diversity within this species relative to domesticated and wild H. annuus

3.Develop test cross hybrids for association mapping


Specific Objectives

2.1. Phylogeographic diversity and population structure

2.2. Developing testcross hybrids

Status

2.3. Association mapping



Phylogeographic diversity and population structure

Procure all 10 ecotypes

Genotype 10 individuals/ecotype

Status



Developing testcross hybrid for association mapping

Crossing 10 ecotypes x CMS-HA412-HO (or a NMS line)

Association mapping

Phenotype F1 for lignocellulosic biomass and flowering time traits

3. Development and Genetic Analysis of Algodones Dune Sunflower Introgression Lines

Specific Objectives

3.1. Develop backcross and advanced populations from an interspecies

3.2. QTL analysis of biologically and economically important traits

3.3. Develop a genome-wide introgression library

3.4. Complete genetic analysis of the introgression library

Status

About 400 seeds from NMS-373 (early, male sterile) X Ames 27830 (ultra-late, male fertile)

F1 showed irregular meiotic behavior


Autosyndesis

Heteromorphism


Specific Objectives


3.2. QTL analysis of biologically and economically important traits



Status

420 seeds from NMS-373 (early, male sterile) X Ames 27830 (ultra-late, male fertile)

F1 showed highly irregular meiotic behavior

Pollen fertility was extremely low (2%)


Specific Objectives


3.2. QTL analysis of a range of biologically and economically important traits



Status

420 seeds from NMS-373 (early, male sterile) X Ames 27830 (ultra-late, male fertile)

F1 showed highly irregular meiotic behavior

Pollen fertility was extremely low (2%)

First initial crosses were unsuccessful


Studies: Interspecies between H. annuus and H. niveus ssp. tephrodes

1.Chandler (1986)Used late flowering accessionPollen viability of F1 around 3.3% (max. 7.3%)

2.Barros (2004)Used an early flowering accessionPollen viability of F1 around 1.98Used embryo rescue Pollen viability of BC1 around 36.9

Backcross first is extremely difficult


Helianthus annuus

(NMS373)

Helianthus niveus ssp. tephrodes

NIV-L (PI 650020)

NMS373 x NIV-LF1

NMS373

NMS373 X BC1-1 NMS373 X BC1-2

NMS373 X BC1-n

X

X

BC2-1-

1

BC2-1-2 BC2-1-n BC2-2-

1

BC2-2-2 BC2-2-n BC2-n-

1

BC2-n-2 BC2-n-n

BC2-1-/S1 BC2-2-/S1 BC2-n-/S1

BC3-1--S1 BC3-2--S1 BC3-n--S1

NMS373 X BC2-1-/S1 NMS373 X BC2-2-/S1 NMS373 X BC2-n-/S1

Parents

Backcrossing F1

Backcrossing BC1

Individual BC2 Families

Selfing BC2

Genetic Analysis and Selection

BC3-1--S2 BC3-2—S2 BC3-n—S2

Backcrossing and Selfing BC2

Met

hods

and

App

roac

hes

Thank You

algodones dune sunflower

Science