Genetic relationships among Italian and Mexican maize-rhizosphere Burkholderia cepacia complex (BCC) populations belonging to Burkholderia cenocepaciaIIIB and BCC6 group

Table 3 Linkage disequilibrium analysis of B. cenocepacia IIIB and BCC6 populations according to their geographic origin.

Group selection	Mean genetic diversity (H_mean)^a	Observed variance (V_D)	Expected variance (V_e)	$I_{A}^{S}$	Pvalue^b	Linkage disequilibrium
B. cenocepaciaIIIB population
All isolates	0.6576 ± 0.0680	1.1538	1.0332	0.0292	0.0187	Yes
RTs only	0.6675 ± 0.0671	1.0982	1.0196	0.0193	0.127	No
Italian isolates	0.6462 ± 0.0533	1.0629	1.0865	-0.0054	1.000	No
RTs only	0.6462 ± 0.0533	1.0629	1.0865	-0.0054	1.000	No
Mexican isolates	0.6235 ± 0.0776	1.3282	1.0534	0.0652	0.0041	Yes
RTs only	0.6250 ± 0.0760	1.2806	1.0565	0.0530	0.0323	Yes
BCC6 population
All isolates	0.4918 ± 0.1427	0.9421	0.8423	0.0296	0.0025	Yes
RTs only	0.5447 ± 0.1499	0.7382	0.7906	-0.0165	1.000	No
Italian isolates	0.4518 ± 0.1425	0.9750	0.8324	0.0428	0.0002	Yes
RTs only	0.5195 ± 0.1477	0.7664	0.8118	-0.0140	1.000	No
Mexican isolates	0.5424 ± 0.1483	0.9159	0.8014	0.0357	0.164	No
RTs only	0.5778 ± 0.1573	0.6465	0.7249	-0.0271	1.000	No

^aMean genetic diversity per locus ± standard deviation.
^bThe measure of linkage disequilibrium is performed by testing the null hypothesis (H_O):V_D= V_e, where V_Dis the variance calculated from the distribution of mismatch values of variance and V_eis the variance expected for linkage equilibrium. P values are derived from parametric method [57] and indicate the significance of linkage disequilibrium. If the $I_{A}^{S}$ (P < 0.05) value differs significantly from zero, the null hypothesis of linkage equilibrium is rejected.

ISSN: 1471-2180