Abstract
Legume cultivation is strongly hampered by the occurrence of ascochyta blights. Strategies of control have been developed but only marginal successes achieved. Breeding for disease resistance is regarded the most cost efficient method of control. Significant genetic variation for disease resistance exists in most legume crops with numerous germplasm lines maintained, providing an excellent resource for plant breeders. Fast and reliable screening methods have been adjusted to fulfill breeding program needs. However, the complex inheritance controlled quantitatively by multiple genes, has been difficult to manipulate. Successful application of biotechnology to ascochyta blight resistance breeding in legume crops will facilitate a good biological knowledge both of the crops–pathogen interaction and of the mechanisms underlying resistance. The current focus in applied breeding is leveraging biotechnological tools to develop more and better markers to speed up the delivery of improved cultivars to the farmer. To date, however, progress in marker development and delivery of useful markers has been slow in most legumes. The limited saturation of the genomic regions bearing putative QTLs in legume crops makes difficult to identify the most tightly linked markers and to determine the accurate position of QTLs. The application of next generation sequencing technologies will contribute to the development of new markers and the identification of candidate genes for ascochyta blight resistance.
Highlights
Rubiales and FondevillaAscochyta resistance breeding in legumes interactions both QTLs and major gene have been suggested (Table 1)
Legume cultivation is strongly hampered by the occurrence of ascochyta blights
Ascochyta blights are incited by different pathogens in the various legumes, namely Ascochyta rabiei in chickpea; A. fabae in faba bean; A. lentis in lentil; and A. pisi, Phoma medicaginis var. pinodella, and Mycosphaerella pinodes in pea (Tivoli et al, 2006)
Summary
Ascochyta resistance breeding in legumes interactions both QTLs and major gene have been suggested (Table 1). Other microarray consisting on a set of chickpea unigenes, the grass pea ESTs identified by Skiba et al (2005), and lentil resistance gene analogs (RGAs) was used to study resistance response in chickpea against A. rabiei (Coram and Pang, 2006) allowing identification of 97 differentially expressed genes. Genes involved in a specific ascochyta–legume interaction may not be detected This limitation can be circumvent by the use of non-targeted techniques such as suppression subtractive hybridization cDNA library (SSH) or cDNA–AFLP that do not require knowledge of sequence data, being an excellent tool to identify novel genes in species such as legumes with limited available genomics sequences. The sequencing of the genomes/transcriptome of legumes will represent a great advance in MAS as it will allow discovering new genes, the massive
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
