1a. Objectives (from AD-416)
The long-term objectives of this project are the following: 1) Develop improved varieties of pea, chickpea, and lentil that have enhanced resistance to diseases and abiotic stresses along with improved nutritional and processing traits; 2) Characterize the genetic basis for agronomically important traits in pea, lentil and chickpea; 3) Identify and characterize the genetic domains in pathogens of these crops that are responsible for disease, and 4) Develop improved methods for detecting pathogens and screening for disease resistance.
1b. Approach (from AD-416)
Identify and select improved germplasm and cultivars for pea, lentil, and chickpea through systematic evaluation under biotic and abiotic stress conditions to identify tolerant or resistant types for release to stakeholders.Identify genetic factors through classical breeding methods contributing to cold tolerance and winter hardiness in pea and lentil germplasm. Saturate genetic maps for the genomic regions that control Ascochyta blight resistance (ABR) in chickpea for fine mapping and identification of molecular markers for selection. Saturate genetic maps to identify markers linked to a broad range of agronomically important traits in pea, lentil, and chickpea. Increase mechanistic understanding of host-pathogen interactions to improve breeding and selection strategies for disease resistance in pea, lentil, and chickpea by challenging plants with respective pathogens and studying disease responses and pathogen biology. Formerly 5348-21000-014-00D (3/08).
3. Progress Report
Extensive field trials were conducted to evaluate advanced breeding lines of cool season food legumes during 2008. Winter survival was evaluated in 18 advanced lentil breeding lines and 20 advanced pea breeding lines planted in Fall 2007 at two locations in Washington and one location in Idaho. Another 62 advanced lentil breeding lines, 22 advanced pea breeding lines and 14 advanced chickpea breeding lines were planted in Spring 2008 at three locations in Washington and one location in Idaho. These materials have been evaluated for several growth habit traits including height, days to flower and days to maturity, and will be harvested and assessed for yield in August 2008. This work directly relates to Component 3 (Genetic Improvement of Crops) of the NP 301 Action Plan, and is especially relevant to Problem Statement 3C: Germplasm Enhancement/Release of Improved Genetic Resources and Varieties. Considerable progress has also been made towards identifying useful molecular markers that can be used for further saturating the genetic maps of cool season food legumes and identifying associations between markers and traits of agronomic importance. Simple sequence repeat (SSR) and randomly amplified polymorphic DNA (RAPD) markers have been screened on available mapping populations of pea. Development of recombinant inbred line (RIL) populations of pea derived from hybridizations between parents that differ in winter survival has been initiated. Two different sets of lentil RIL populations that vary in resistance to foliar and stem diseases caused by fungal pathogens have been evaluated using sequence related amplified polymorphism (SRAP) markers. Chickpea populations suitable for identifying molecular markers associated with resistance to Ascochyta blight have also been developed. Progress in these areas of investigation directly relates to Component 2 (Crop Informatics, Genomics, and Genetic Analyses) of the NP 301 Action Plan and is especially relevant to Problem Statement 2C: Genetic Analyses and Mapping of Important Traits. DNA has been extracted from all advanced breeding lines of the Spanish Brown lentil market class and also from all Plant Introduction (PI) accessions within the lentil core collection that belong to the Spanish Brown market class. Molecular marker work has begun to determine genetic relationships among the breeding lines and PI accessions. Progress in this area of investigation relates to Component 1 (Plant and Microbial Genetic Resource Management) of the NP301 Action Plan and Problem Statement 1B: Assess the Systematic Relationships and Genetic Diversity of Crop Genetic Resources.
1. Identification of Sclerotinia trifoliorum causing crown rot of chickpea Crown and stem rot of chickpea have become prevalent in California. Previously Sclerotinia sclerotiorum, and S. minor have been reported as pathogens of chickpea, however, the species occurring in California appeared to be different from the two previously known pathogens. For the first time in North America, ARS scientists in the Grain Legume Genetics Physiology Research Unit in Pullman, WA identified the fungus Sclerotinia trifoliorium as a chickpea pathogen based on morphology and molecular data. Identification of the new pathogen will facilitate management practices of the disease in selecting appropriate rotational crops. This accomplishment addresses Component 3 (Genetic Improvement of Crops) of the NP 301 Action Plan and Problem Statement 3A: Genetic Theory and Methods of Crop Improvement.
2. Release of Sawyer Chickpea Chickpea production in the Pacific Northwest is severely impacted by Ascochyta blight caused by the fungus Ascochyta fabiei. Improved varieties with resistance to this disease are essential to maintain and increase existing levels of chickpea production. A new café color chickpea variety named Sawyer was released in 2008 by ARS scientists in the Grain Legume Genetics Physiology Research Unit in Pullman, WA. The new variety is higher yielding than previous café colored chickpea varieties, has improved levels of resistance to Ascochyta blight, and has desirable canning qualities. Sawyer will provide growers in the Pacific Northwest with a new variety that can replace previously developed varieties that lack acceptable canning qualities and are more susceptible to Ascochyta blight. This accomplishment addresses Component 3 (Genetic Improvement of Crops) of the NP 301 Action Plan and Problem Statement 3C: Germplasm Enhancement\Release of Improved Resources and Varieties.
5. Significant Activities that Support Special Target Populations
Attanayake, K., Glawe, D., Mcphee, K.E., Dugan, F.M., Chen, W. 2008. First report of powdery mildew of chickpea (Cicer arietinum) caused by Leveillula taurica in Washington State. Plant Health Progress.doi:10.1094/PHP-2008-0702-01-BR.