Table 8.

Transformation results and molecular event data using the Hsp17.7 heat shock promoter for controlled excision of both morphogenic gene and marker gene in three maize inbreds (HC69, PH85E, and PH84Z).

Inbred	Selectable marker	Embryos transformed (number)	T0 plants (number)	T0 transformation (%)	Total Single copy events	Quality event (number)	Quality events (%)	Excision frequency (%)	Usable event (%)	Null (%)
HC69	NPTII	315	200	63.5	53	46	23	87	14.6	17.1
	HRA	407	281	69	55	45	16	82	11.1	37.3
PH85E	NPTII	219	64	29.2	24	23	35.9	96	10.5	15.3
	HRA	320	124	38.8	32	31	25	97	9.7	42.5
PH84Z	NPTII	356	145	40.7	38	19	13.1	50	5.3	14.2
	HRA	365	169	46.3	23	14	8.3	61	3.8	41.8

Data from two independent transformers was used to determine T0 transformation frequency. The quality events (QE) were identified as single copy, backbone-free, morphogenic and marker gene-free (excised). The number of QEs was divided by the total number of events analyzed to calculate the QE frequency. The excision frequency was determined as the ratio of the number of excised single-copy events relative to the total single-copy events. The usable event (UE) frequency is a measure of the number of acceptable transgenic events per 100 embryos that was determined as the product of QE frequency and transformation frequency.

Two different SMGs were evaluated, HRA (resistance to the sulfonylurea herbicide ethametsulfuron) and NPTII (resistance to antibiotic G418), using the same construct design with the same set of morphogenic genes as shown in Figure 3 . Transformation results and qPCR detection of the number of excised quality events, frequencies of excision and usable event are presented.