Inoculação e sobrevivência de Xanthomonas vesicatoria em sementes de tomateiro

Abstract

The efficiency of six methods of Xanthomonas vesicatoria (Doidge) (9) inoculation on tomato seeds, and their effects on seed quality were tested : 1) vacuum inoculation with X. vesicatoria cell suspension in PB (0.005M, pH 7.4 e NaCl 0.85%); 2) immersion for 24 hours in with X. vesicatoria cell suspension and PB. 3) vacuum and saline solution in phosphate buffer; 4) immersion in PB for 24 hours; 5) seeds + ethanol; 6) control. Evaluations were performed for germination test and isolation in Modified Agar Nutrient (NAM)) at 1, 15, 30 and 45 days after treatments imposition. The moisture effect on the transmission of X. vesicatoria seeds inoculated under vacuum, followed or not by air drying at 30±1°C, until 4% and 8% moisture were tested. Evaluations were performed as described above, after 24 hours and 30 days after the treatments. The methods of X. vesicatoria inoculation in tomato seeds can be used on routine analyses, however, inoculated seeds should be used until 30 days after inoculation. After this period, a large reduction on the recovery of viable cells occurs. The seed water content interferes with X. vesicatoria survival and transmission and explains the low percentages of X. vesicatoria recovery.