Influence of stem and root vascular anatomy of eggplant germplasm on severity of vascular bacterial wilt disease

摘要

The present investigation was attempted to study the anatomy of eggplant root and stem to eloquent the mechanism of susceptibility/tolerance of twelve germplasm against vascular bacterial wilt (VBW). Cross sections of root and stem of various germplasm seedlings were made at the age of 25 days after sowing using simple light microscope followed by severity measurement in a sick plot using pair row planting system.The results clearly indicated that the higher number of large vessel (metaxylem) in comparison to small vessel (protoxylem) in stem and higher inner area of large vessel in roots negatively correlated with disease severity as observed in 09/BRBWRES2, 09/BRBWRES5,10/BRBWRES5, Horti, Utsav and Arka Nidhi. Stepwise multiple regression analysisshowed that the ratio of large and small vessels sqm m1 in vascular area in stem was the single most important anatomical character governing susceptibility/tolerance of the germplasm under study against VBW disease of eggplant. The susceptibility increased with decrease in metaxylem to protoxylem ratio in stem.The present finding would be a useful marker, identified as early as seedling stage, for breeders to develop tolerant variety to combat this serious disease.