Reaction of CMS, Restorer Lines and Hybrids of Sunflower to Alternaria helianthi

Tolerant reaction for Alternaria leaf blight has been observed in hybrid CMS 17A × RHA-857 and KBSH-44. Among lines, FMS R265A and restorer lines 6-D-1 and RHA-274 shown high degree of susceptibility with grades of 9 and remaining parents shown susceptible reaction with grade of 7 or 8. It indicates that it is possible to synthesize hybrids with reasonable degree of tolerance by involving susceptible parents also. The extent of resistance however, can be enhanced when allelic differences exist between parents and by subjecting above crosses to recurrent selection. The high yielding hybrids CMS 17A × 6-D-1P#2 and CMS 234A × 6-D-1P#2 exhibited some degree of tolerant reaction. Based on disease severity, CMS 17A × RHA-857, CMS 234A × 6-D-1P#2 and CMS 302A × VI-34 were termed as slow blighters, whereas hybrids, CMS 234A × VI-34, CMS 234A × 6-D-1, CMS 234A × VI-66, CMS 302A × R-16 and CMS 302A × V-20 could be termed as intermediate blighters.