Poster Presentation Science Protecting Plant Health 2017

Evaluation of sunflower genetic resources to charcoal rot caused by Macrophomina phaseolina (#141)

Siamak Rahmanpour Ozan 1 , Alireza Nabipour 2 , Araz M Noori Davaji 3 , Masumeh Kheirgoo 3
  1. Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization, Karaj, ALBORZ, Iran
  2. Rice Research Institute of Iran, Agircultural Research, Education and Extension Organization, Amol, Iran
  3. Golestan Agricultural and Natural Resources Research and Training Center, Agricultural Research, Education and Extension Organization, Gorgan, Iran

Sunflower charcoal rot is considered as one of the most important diseases on crops and infects more than 400 plants worldwide. In the current investigation, to achieve tolerant sources of sunflower, among restorer lines, the seeds were sown in research field located at research complex fields of Seed and Plant Improvement institute, Karaj, Iran. The pathogen, Macrophomoina phaseolina, was collected from infected sunflower plants during last cropping season at the same area. It was first isolated and sub-cultured using single hyphe technique and then mass-produced on potato dextrose agar medium for three days. The culture medium plugs with mycelium and some micro sclerotia produced by the pathogen were provided from the edge of Petri plates as 5 mm diameter round plugs. The stems of treatment plants were injured at seed filling stage and then the plugs were put onto which were covered with a small piece of wet cotton wool to provide humidity. The complex was covered finally with two layers of Parafilm to keep the humidity for infection progress. The lesion length produced was measured at days 7, 14, and 21 post-inoculation. For greenhouse experiments, 75-day-old oil type sunflower restorer plants were inoculated by the same technique used for field evaluation. To monitor the disease process, the lesion length on inoculated plants was measured at days 9 and 14 post inoculation. The analysis of data resulted in significant differences between genotypes showing reaction to the disease, and also days of measurements. On the basis of field evaluations, the lines R-140 and R-201 demonstrated resistance reaction to the pathogen. In greenhouse experiments, four lines including R-133, R-139, R-140, and R-141 showed the same reactions.


Key words: Sunflower, genotypes, charcoal rot, Macrophomina  phaseolina, disease resistance.