Comparison of the sensitivity of Monilinia fructicola isolates to tebuconazole in Brazil using three methods

Figures & data

Table 1. Location, year and Monilinia fructicola isolate codes sampled for this study.

City^a	State^b	2009	2010	2011
Holambra	SP	722, 750, 752, 753, 754, 755, 756, 757, 758, 761, 775, 777, 781, 786, 787, 792, 793, 794, 795, 796, 797, 802, 806, 807, 809, 811, 826, 827, 828, 829, 831, 832, 834, 839, 850, 851, 854, 855, 856, 857, 859, 860, 862, 864, 868, 869, 870, 888, 911, 912, 914, 915, 927, 929, 940, 941, 945, 950, 951,952,956	1094, 1095, 1096, 1097, 1098, 1099, 1100, 1101	152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 203
Jarinú	SP	NA	NA	145, 146, 147, 148, 149, 150, 151, 183, 184, 186, 187
Araucária	PR	NA	1023, 1024, 1025, 1026, 1027, 1028, 1030, 1033, 1035, 1036, 1038, 1039, 1040, 1041, 1042, 1043, 1044	1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
Campo do Tenente	PR	NA	1083, 1085, 1086, 1088	38, 39, 40
Campo Largo	PR	NA	1049, 1051, 1052, 1053, 1054, 1056, 1057, 1058	17, 18, 19
Faxinal dos Castilhos	PR	NA	1060, 1062, 1063	NA
Lapa	PR	638, 639, 643, 646	1067, 1068, 1069, 1070, 1071, 1073, 1075	21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36
Mandirituba	PR	NA	1077, 1079, 1080, 1081, 1089, 1090, 1092, 1093	45, 46, 47, 48
Rio Negro	PR	NA	NA	41, 42, 43, 44
Bento Gonçalves	RS	NA	993, 996, 997, 998, 999	129, 130, 132, 133, 134, 135, 136
Capão do Leão	RS	NA	1016, 1019, 1020, 1022	125, 126, 127, 128
Dourado do Sul	RS	NA	959, 961, 962, 964, 965, 968	NA
Farropilha	RS	NA	974, 979, 982, 983	NA
Pelotas	RS	NA	1002, 1004, 1006, 1007, 1009, 1010, 1013	97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 140, 141, 142, 143, 144
Picada Café	RS	NA	1000	NA
Pinto Bandeira	RS	NA	989	138, 139

^aCities in which M. fructicola was sampled from the same farm location.

^bState from which the isolates were sampled. SP = São Paulo, PR = Paraná, RS = Rio Grande do Sul.

^cNA = sample not available in the text.

Fig. 1 Frequency of Monilinia fructicola sensitivity to tebuconazole among the isolates collected between 2009 and 2011 based on the relative growth under the discriminatory dose of 0.3 µg mL⁻¹ method (a), the EC₅₀ value using the 0.3 µg mL⁻¹ as the discriminatory dose (b) and the EC₅₀ value using the baseline value of 0.046 µg mL⁻¹ as the discriminatory dose (c). SP = São Paulo, PR = Paraná, RS = Rio Grande do Sul, R = resistant, and S = sensitive. The entire values correspond to the sample size, and values in brackets correspond to the percentages [n (%)].

Table 2. Comparison of the effective concentrations of tebuconazole required for 50% population inhibition (EC₅₀ value) of the Monilinia fructicola isolates from three different populations in Brazil.

Populations^a	n	Mean EC50^b values (µg mL^−1) and P-value^c			Median	Percentiles (10% and 90%)
		BL	IP	CP
BL	31	0.046^b	0.052^c	0.006^c	0.036	0.02 and 0.07
IP	88	–	5.593^b	0.054^c	0.06	0.02 and 0.53
CP	120	–	–	0.093^b	0.031	0.003 and 0.28

^aBL = baseline population (2000–2004). IP = intermediate population (2005–2008). CP = current population (2009–2011).

^bMean EC₅₀ values are in bold.

^cP-value obtained with the Welch t-test.

Fig. 2 Monilinia fructicola density distributions (a) and cumulative relative frequencies (b) for the tebuconazole effective concentration for 50% population inhibition (EC₅₀) in Brazil comparing the baseline (BL, 2000–2004), intermediate (IP, 2005–2008) and current (CP, 2009–2011) populations.

Table 3. Comparisons of effective concentrations of tebuconazole required for 50% population inhibitions (EC₅₀ value) of Monilinia fructicola isolates collected between 2009–2011 in São Paulo (SP), Paraná (PR) and Rio Grande dos Sul (RS).

Origin	n	Mean EC50 values^a (µg mL^−1) and P-value^b			Median	Percentiles (10% and 90%)
		SP	PR	RS
SP	45	0.186^a	0.001^b	1.24 × 10^–5^b	0.131	0.010 and 0.393
PR	32	–	0.053^a	0.143^b	0.016	0.003 and 0.115
RS	43	–	–	0.026^a	0.013	0.002 and 0.067

^aThe mean EC₅₀ values are in bold.

^bP-values obtained with the Welch t-test.

Fig. 3 Monilinia fructicola density distributions (a) and cumulative relative frequencies (b) of the tebuconazole effective concentrations required for 50% population inhibition (EC₅₀) in Brazil comparing the origins within the actual population (2009–2011). SP = São Paulo, PR = Paraná, RS = Rio Grande do Sul.

Table 4. Mean tebuconazole sensitivity differences due to Monilinia fructicola storage.

Evaluation years	Storage method	n	Mean of the differences (µg mL^−1)^a	P-value^b	CI95%^c
2010–2014	25% glycerol	17	3.76 (2010 > 2014)	1.8 × 10^–6	2.66–4.85
2012–2013	filter paper	15	2.2 (2012 > 2013)	1.4 × 10^–5	1.47–2.93

^aMean of the differences between the earlier and later EC₅₀ value evaluations.

^bP-values obtained with the paired t-test.

^c95% confidence interval of the mean.