|Coyne, Clarice - Clare|
Submitted to: Food Legume Research International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/2/2005
Publication Date: 11/30/2005
Citation: Coyne, C.J., Baum, M., Sharma, P.C., Gaur, P.M., Muehlbauer, F.J., Mcphee, K.E., Chen, W., Timmerman-Vaughan, G.M., Pilet-Nayel, M., Brown, A., Mcgee, R.J., Udupa, S.M., Hamwieh, A., Choumane, W. 2005. Application of molecular markers in cool season food legume breeding. Proceedings of the International Food Legume Research Conference IV, October 18-22, 2005, New Delhi, India. p. 1-29.
Interpretive Summary: As the marker density has increased in linkage maps of the cool season food legumes over the last ten years, numerous markers closely linked to economic traits, both qualitatively and quantitatively inherited, have been identified and published. Developments in recent years have contributed to increases in both the utility and application of MAS in public and private institutes’ breeding and germplasm enhancement programs. These developments include directly (1) the development of PCR-based markers, sequence-tagged sites and co-dominant microsatellite markers available for pea, chickpea, lentil per se and the development of cross-taxa markers from Medicago truncatula and Lotus japonicus, (2) the reduction in costs of the MAS technology, and indirectly (3) increases in genomic tools such as the construction of legume EST and BAC libraries and sequencing of Medicago truncatula and Lotus japonicus, along with the elucidation of plant gene functions, particularly from Arabidopsis thaliana. This review covers the developmental status of MAS for breeding and germplasm enhancement of pea (Pisum sativum), chickpea (Cicer arietinum), and lentil (Lens culinaris), and conclude with prospects for the future.
Technical Abstract: Given the numerous abiotic stresses and biotic agents that attack cool season food legumes reducing yield and harvested crop quality, there is a significant need to identify additional markers tightly linked to genes that can be used for MAS in breeding programs. Further fine mapping is required to identify more closely linked markers to undertake projects on map based cloning of resistance genes to design perfect or direct markers. Implementation of MAS for QTL might well include problems like possible overestimation of the sizes of QTL effects and uncertainty around genetic distances between markers and true QTL locus position. Progress toward applying MAS for quantitative resistance will require a number of future research steps, including validation, improving the integration of the molecular maps used for QTL mapping studies to date, increasing marker saturation in the QTL regions so that flanking markers tightly linked to QTL are available, and developing robust PCR markers that are less pedigree specific than RAPDs and AFLPs in particular. The standards to which we should aspire include developing perfect or direct markers for qualitatively inherited traits and the Mendelization of a quantitative traits.