2010 Annual Report
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).
A total of 63 advanced spring lentil breeding lines, 34 advanced spring pea and 19 advanced chickpea lines were evaluated in 2010 in field trials conducted in Washington, Idaho, Montana and North Dakota. A new Spanish Brown lentil cultivar “Morena” was released. A new café Kabuli chickpea germplasm that has high yield and excellent resistance to Ascochyta blight was also released. Breeder seed was produced in 2010 of three pea, two chickpea and three lentil advanced breeding lines subsequent to their consideration for release in 2011 as new germplasms or cultivars.
Efforts to control diseases of peas, chickpeas, and lentils are largely focused on identifying sources of disease resistance in these crop species. Field locations for screening peas and lentils for resistance to Aphanomcyes root rot were identified, trials were conducted and lines of pea and lentil with enhanced levels of tolerance were identified. Peas were also screened in the field for resistance to Fusarium wilt and chickpeas were screened in the field for resistance to Ascochyta blight. A second year of field trials was also conducted on chickpea to examine the effect of the size of seed planted on harvest yield and size of harvested seed. This information is desperately desired by growers due to costs and difficulties associated with planting large size seed.
Laboratory efforts have focused on applying molecular markers and plant biotechnology to the development of improved cool season food legumes. Molecular markers were identified in lentils that are linked to resistance to Stemphyllium blight and rust. Approaches based on real-time PCR have been developed to examine how multiple genes interact to confer resistance in pea to Aphanomyces root rot. Plant transformation and regeneration systems are being developed for lentil and chickpea.
Lentil DNA markers associated with disease resistance. Stemphylium blight and rust are two severe diseases of lentil. It is difficult to identify sources of resistance to these diseases because breeders must rely on naturally occurring inoculum, which may not be present at levels needed to provoke disease symptoms. In collaborative research with ICARDA, ARS scientists in Pullman, WA, have identified three DNA markers that are associated with resistance to Stemphyllium blight and a single DNA marker associated with resistance to rust. These markers will be useful for reliably identifying resistant lentil lines and will also serve as guides for the eventual isolation of genes involved in disease resistance.
Release of Morena Lentil. Production in the US of Spanish Brown lentils, which are very nutritious and in high demand as an export crop, has been dominated for the past 20 years by a single cultivar, “Pardina”. In 2010 ARS Scientists in Pullman, WA, released “Morena”, a Spanish Brown lentil that has greater yield than Pardina and is also significantly taller than Pardina, which is a very desirable trait resulting in improved harvest efficiency. Foundation seed of Morena was produced in 2010 by the Washington State Crop Improvement Association. Approximately $20 million of Spanish Brown lentils are produced annually in the US and Morena will provide growers with a new high yielding cultivar with excellent market characteristics that is easier to harvest than other available Spanish Brown cultivars.
Vandemark, G.J., Porter, L. 2010. First report of root rot of lentil caused by Aphanomyces euteiches in Idaho. Plant Disease. 94:480.
Vandemark, G.J., Fourie, D., Larsen, R.C., Miklas, P.N. 2009. Interactions Between QTL SAP6 and SU91 on Resistance to Common Bacterial Blight in Red Kidney Bean and Pinto Bean Populations. Euphytica. 170:371-381.
Njambere, E., Vandemark, G.J., Chen, W. 2010. Development and characterization of microsatellite markers of the fungal plant pathogen Sclerotinia trifoliorum. Genome. 53:494-200.
Vandemark, G.J., Ariss, J., Hughes, T. 2010. Real-time PCR suggests that Aphanomyces euteiches is associated with reduced amounts of Phytophthora medicaginis in alfalfa that is co-inoculated with both pathogens. Journal of Phytopathology. 158:117-124.
Njambere, E., Attanayake, R., Chen, W. 2010. Applications of molecular markers and DNA sequences in identifying fungal pathogens of cool season grain legumes. In: Gherbawy, Y. and Voigt, K., editors. Current Advances in Molecular Fungal Identification. Berlin: Springer. p 79-92.