Assessing the suitability of antibiotic resistance markers and the indirect ELISA technique for studying the competitive ability of selected Cyclopia Vent. rhizobia under glasshouse and field conditions in South Africa

Table 3 Competitiveness of antibiotically-marked strains compared to their unmarked parents.

Treatment	Number of isolates tested	Number able to grow on YMA + antibiotics	% nodule occupancy by marked strain	Competitive ability of marked strain
UCT40a + UCT40aMkd1	40	30	75.0 *	I
UCT40a + UCT40aMkd2	28	14	50.0	U
UCT44b + UCT44bMkd1	18	4	22.2 *	R
UCT44b + UCT44bMkd2	38	12	31.6 *	R
UCT44b + UCT44bMkd3	26	10	38.5	U
UCT61a + UCT61aMkd1	50	0	0.0 *	R
UCT61a + UCT61aMkd2	52	0	0.0 *	R
UCT61a + UCT61aMkd3	60	0	0.0 *	R
PPRICI3 + PPRICI3Mkd1	35	21	60.0	U
PPRICI3 + PPRICI3Mkd2	31	19	61.2	U
PPRICI3 + PPRICI3Mkd3	31	10	32.3	U

* Denotes significant deviation from the expected frequency of 50% nodule occupancy using a χ² test on pooled data, P < 0.05. Symbols indicate I = increased, U = unchanged and R = reduced competitive ability of the marked strain compared to its unmarked parent.

ISSN: 1471-2180