Table 3.

Candidate reference genes ranked by BestKeeper. α-EF: α-Elongation factor; His: Histone; UBC: Ubiquitin conjugating enzyme; 18S: 18S rRNA; GAPDH: Glyceraldehyde 3-phosphate dehydrogenase.

Ranking	All samples				Samples of wounded stems at different times				Samples of different organs
	Candidate reference genes	SD	CVa	rb	Candidate reference genes	SD	CV	r	Candidate reference genes	SD	CV	r
1	18S	0.41	1.76	0.581	18S	0.56	2.41	0.614	18S	0.12	0.50	0.758
2	α-EF	0.52	3.22	0.824	α-EF	0.65	4.08	0.888	α-EF	0.24	1.45	0.969
3	Actin	0.69	3.10	0.897	UBC	0.74	3.52	0.962	β-tubulin	0.42	1.80	0.849
4	β-tubulin	0.69	3.03	0.876	β-tubulin	0.74	3.30	0.950	Actin	0.59	2.61	0.928
5	UBC	0.90	4.18	0.801	GAPDH	0.82	3.60	0.853	UBC	0.81	3.66	0.651
6	His	1.07	4.51	0.940	Actin	0.88	3.95	0.929	His	1.29	5.38	0.938
7	GAPDH	1.56	7.03	0.776	His	0.99	4.14	0.983	GAPDH	2.59	11.65	0.975

^acoefficient of variation, indicates the degree of data dispersion. The larger the CV value is, the more discrete the data. ^bcorrelation coefficient, indicates the correlation between variables. The larger the absolute value of r is, the greater the correlation.