Location: Grain Legume Genetics Physiology Research
Project Number: 2090-21000-038-004-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 30, 2021
End Date: Sep 29, 2025
Objective:
Identify markers and candidate genes associated with resistance to Ascochyta blight in a chickpea diversity panel and develop green and café kabuli chickpea breeding lines with improved disease resistance.
Approach:
A. Approaches for genetic analysis.
1. A chickpea diversity panel consisting of 252 accessions will be screened for reaction to Ascochyta blight in growth chambers using a ‘mini-dome’ assay. Plants are rated on a scale of 1 (healthy plant) to 9 (dead plant), and ratings ranging from 1-3, 4-6, and 7-9 are considered resistant, intermediate, and susceptible reactions, respectively.
2. The diversity panel includes 161 desi-type accessions and 91 kabuli-type accessions. Genotype-by-Sequencing (GBS) has been performed on the entire diversity panel and more than 90,000 single nucleotide polymorphisms (SNPs) have been detected.
3. Genome Wide Association Studies (GWAS) will be conducted to identify genetic markers and candidate genes associated with resistance.
B. Approaches for developing Ascochyta blight-resistant Green and Café Kabuli Chickpea Breeding Lines.
1. Accessions that are significantly more resistant than the check cultivar ‘Sierra’ will be selected as parents. Resistant kabuli accessions are more preferable as parents than resistant desi selections for crosses with green and café kabuli lines and cultivars. Two green kabuli breeding lines will be selected from the USDA, Agricultural Research Service (ARS) chickpea breeding program based on results of 2021 field trials. Café kabuli cultivars will include ‘Sierra’ and ‘Nash’ along with one or two extra-large seed breeding lines from the ARS.
4. F2 populations will be produced in a greenhouse from crosses between Ascochyta blight resistant accessions and selected green kabuli breeding lines and café kabuli cultivars.
5. F2 populations will be screened for reaction to Ascochyta blight as described above (A1). Materials that are more resistant than Sierra will be grouped into two classes based on seed type: 1. Kabuli-type, and 2. Non-kabuli type.
6. Resistant kabuli-type F2 plants will be increased by single seed descent in either greenhouse or field conditions to advance homozygous lines. Resistant F2 plants that are non-kabuli type may be selected as parents based on several additional traits, including seed protein concentration, early maturity, and yield potential. These selected resistant F2s may be used as parents in a backcrossing strategy using adapted green and café kabuli materials as recurrent parent.
