Table 4.

Analyses of multilocus population structure in C. parasitica based on vic genotypes

Population	n	No. of polymorphic loci*	No. of vic genotypes (Nvc)†			Genotypic diversity (Ĝ)‡				Index of association (IA)§				Cankers with perithecia¶
			Observed	Expected	P	Ĝobs	Ĝexp	%	P	sk2	σk2	IA	P	n	%
Italy
Donnaz, AO	50	2	4	4	0.757	1.32	2.23	59	<0.001	0.43	0.38	0.14	<0.001	23	77
Crevoladossola, VB	131	4	10	12	0.126	3.66	4.73	77	0.005	0.94	0.76	0.23	<0.001	46	100
Ponte in Valtellina,  SO	46	5	8	12	0.028	2.79	4.99	56	0.003	2.08	0.91	1.29	<0.001	86	50
Bergamo, BG	158	5	16	17	0.500	3.96	4.59	86	0.074	1.14	0.84	0.35	<0.001	49	100
Pigna, IM	48	2	4	4	0.665	1.79	2.14	83	0.128	0.62	0.43	0.44	<0.001	58	57
Corniglio, PR	50	5	12	16	0.022	1.56	7.61	20	<0.001	4.94	1.13	3.39	<0.001	25	55
Pomina, FI	50	5	7	11	0.024	2.99	3.95	76	0.067	1.49	0.81	0.84	<0.001	48	50
Tonara, NU	33	5	5	10	<0.001	1.69	4.04	42	<0.001	3.00	0.92	2.28	<0.001	—‖
Teano, CE	194	2	4	4	0.593	0.80	2.15	37	<0.001	0.82	0.43	0.89	<0.001	36	77
Cittanova, RC	50	4	4	12	<0.001	1.68	5.78	29	<0.001	3.50	0.93	2.78	<0.001	20	82
Zafferana, CT	50	3	2	6	<0.001	0.10	2.28	4	<0.001	1.67	0.55	2.04	<0.001	0	74
Switzerland
Lumino	86	5	14	16	0.269	4.82	6.56	74	0.010	1.23	0.93	0.32	<0.001	—
Gnosca	61	5	15	18	0.109	5.77	9.04	64	0.010	1.63	1.12	0.45	<0.001	—
U.S.
Finzel, MD	54	6	23	23	0.525	12.68	13.18	96	0.442	1.47	1.35	0.09	0.132	—
Bartow, WV	50	6	22	22	0.503	13.16	14.40	91	0.316	1.42	1.31	0.09	0.073	83	78
Depot Hill, NY	37	6	19	19	0.575	11.31	12.55	90	0.335	1.27	1.33	−0.04	0.729	83	72

^*A locus was considered polymorphic for these analyses if the frequency of the less common allele was >0.05. 

^†Number of vic genotypes is based only on polymorphic vic loci (as defined above). 

^‡Genotypic diversity Ĝ was calculated as 1/Σp₁², where p_i is the frequency of the ith genotype (38, 39). Expected values were estimated as the mean of the null distribution generated from 1,000 randomizations under the assumption of random mating. Percentage of the expected genotypic diversity observed was calculated as 100 × G_obs/G_exp. P values were estimated as the proportion of the null distribution with values of G greater than equal to the observed diversity (see text). 

^§Index of association (I_A) was estimated as s_k²/σ_k² − 1, where s_k² and σ_k² are the observed and expected variances in k, the number of heterozygous loci between pairs of individuals (40, 41). P values were estimated as the proportion of the null distribution with values of s_k² greater than equal to the observed variance (see text). 

^¶Percent of cankers with sexual structures (perithecia) of C. parasitica were determined for 10 populations in Italy. n are the number of canker samples examined. 

^‖No data available for these populations.