Table 3.

Confirmation of hybrids between Amaranthus palmeri and related Amaranthus species from field and greenhouse studies using 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) relative copy number, flowering phenotype, and glyphosate resistance in progeny of self-pollinated hybrids

Maternal parent	Year*	Distance from pollen source (m)	EPSPS copy no.†	Hybrid plant flowering phenotype	No. progeny tested	Mean % resistance in progeny ± SE‡	χ2 for 75% survival
3-Amaranthus hybridus	2007	1	104	A		n/a
	2007	3	67	G		No seed
8-Amaranthus spinosus	2006	1	64	M		Not tested
	2006	1	22	A		n/a
9-A. spinosus	2007	3	40	M	49	70 ± 16	0.17; n.s.
	2007	3	49	M		Not tested
	2007	3	19	A		n/a
	2007	3		M	24	61 ± 15	0.16; n.s.
	2007	1		M	50	94 ± 4	7.7; P = 0.006
	2007	1		M	8	50 ± 0	2.7; n.s.
	2007	1		M	49	95 ± 3	11; P = 0.0007
	2007	1		M	14	92 ± 8	0.9; n.s.
	2007	3		M	20	48 ± 16	17; P < 0.0001
	GH		29	M	14	78 ± 22	0.86; n.s.
	GH		34	A		n/a
	GH		77	A		n/a
	GH		67	M	10	83 ± 17	1.2; n.s.
10-Amaranthus tuberculatus	2007	1	99	A		n/a
	2007	1	58	A		n/a
11-A. tuberculatus	2007	1	79	A		n/a
	2007	1	58	G		No seed
	2007	3	122	A		n/a
	2007	3	70	A		n/a

G, gynoecious; A, androecious; M, monoecious.

^*Year of field study or GH, greenhouse study; underlined within a species indicates hybrids originated from the same maternal plant.

^†EPSPS copy number measured relative to acetolactate synthase copy number using quantitative PCR on genomic DNA.

^‡If confirmed hybrid produced seed through self-pollination, mean of three replications following 0.4 kg a.e. ha⁻¹ glyphosate application