Isolation Of Epicoccum Sorghinum And Resistance Identification Of Multi-transgenes Maize Lines

Maize(Zea mays L.)is one of the most important crops in many countries and playing a significant role to fulfill the food and energy requirements.Although it is the world’s largest biofuel-producing feedstock,there are uncertainties and increasing concerns for the reliance on maize production due to plant diseases caused by necrotrophic pathogens.Rhizoctonia solani AG-1 IA,Bipolaris maydis and Epicoccum sorghinum are the casual agents of maize sheath blight,southern corn leaf blight and an uncharacterized E.sorghinum disease,respectively.These are the necrotrophic fungal pathogens and a major threat to human food security.E.sorghinum is a new maize pathogen,and has never been reported in China.In this study,7 different fungi were isolated from diseased maize leaf samples,and 3 pathogens with strong pathogenicity were identified as R.solani,B.maydis and E.sorghinum.Based on the fungistatic and toxic secretion activities,E.sorghinum can also be considered as a strong antifungal agent.Management of diseases caused by R.solani,B.maydis and E.sorghinum,with traditional breeding methods has encountered limited success due to characteristics of necrotrophic pathogen’s life style.The results of this study have shown that a transgenic pyramiding breeding strategy can combat with these diseases in different aspects and stages of their life cycle.Different 9 genes viz Chi,Glu,Ace-AMP1,Tlp,Rs-AFP2,Zm PROPEP1,Pti4,Iap and p35 with different resistance mechanisms were transformed into maize.Transgenic maize lines,particularly 111 and 112 have shown resistance not only against R.solani but also to B.maydis.Another transgenic maize line 912,has exhibited high resistance against R.solani and E.sorghinum.Transgenic maize line 211 was showing resistance not only against pathogens but also to salt and drought conditions.The resistance level of 910 transgenic maize line against biotic and abiotic stresses was significantly higher than other transgenic maize lines.This study has proved that the different res istance genes with different mechanisms can be combined together in one maize line to create potential resistance against necrotrophic maize pathogens.It has also explored the fungistatic potential of E.sorghinum,however,it needs further investigations to study its exact mechanism.Altogether,our research provides a new direction to develop different disease management strategies,for better sustainable agricultural system to combat the future food security.