New cover crops for innovation in agriculture and Legumes screening for foot disease tolerance

Root and foot diseases have a significant impact on legume in the agriculture worldwide. Most of the soilborne diseases are difficult to manage using traditional resistant host cultivars and synthetic fungicides. This study is aimed to investigate the disease resistance of legume crop species. Legumes accession was screened for investigation of the novel legume accessions. Experiments conducted in naturally infested field soil involved a total of 38 legume species and accessions belonging to 3 legume genera, namely Pisum (n=2), Lathyrus (n=9) and Vicia (n=20), two Trifolium and Medicago accessions and one accession of Melilotus and Trigonella foenum-graecum. Plants were grown either in autoclaved field soil (control) or non-autoclaved soil (sick soil). Two pea varieties, resistant EFB 33 and susceptible La Mancha KWS were included as controls. The pea control e.g., Pisum sativum La Mancha KWS was highly susceptible, indicating presence of sufficient pathogen pressure in the soil. The second pea control (Pea EFB 33) as expected was resistant and showed no biomass reduction or symptoms of root rot. With respect to the tested legume accessions, most of the Lathyrus and Vicia including the one Medicago (Medics 44) and Melilotus accession 1933 displayed good resistance. Notable exceptions included, four susceptible Lathyrus accessions L1660, L1614, L008 and L1668 with the former three accessions despite the absence of root rot symptoms showed significant decrease in fresh weight biomass in comparison to the corresponding control plants grown in autoclaved soil. L1668 in addition to biomass reduction showed also clear symptoms of root rot. Similar variability in the reaction of single Vicia accessions was observed with the accessions V1515, V1642, V1641 and V823 despite the absence of visible disease symptoms showing significant biomass reductions when compared to the corresponding controls. The two Trifolium accession were resistant whereas Trigonella foenum-graecum and Medicago U365 exhibited biomass reductions when grown in sick soils compared to the corresponding controls and were thus considered susceptible. Finally, legumes in autoclave soil had significantly low disease severity and higher fresh biomass than non-autoclave soil.