Table 2.

Compounds identified by GC–MS analysis in rapeseed root exudates.

Group	Peak	Closest compound	Formula	Molecular weight	Characteristic fragments	Spectra similarity (%)a
Acids	3	2-Butenoic acid	C4H6O2	86	86, 69, 57, 53, 49, 45	91
	4	Valeric acid	C5H10O2	102	73, 60, 55, 45, 43, 42, 41, 39	83
	6	2-Pentenoic acid	C5H8O2	100	100, 55, 57, 45, 43, 41, 39	90
	15	Nonanoic acid	C9H18O2	158	129, 115, 98, 73, 60, 55	80
	22	n-Hexadecanoic acid	C16H32O2	256	256, 213, 129, 73, 43	98
	21	9-Hexadecenoic acid	C16H30O2	254	254, 236, 97, 83, 69, 55, 41	96
Esters	2	Methyl thiocyanate	C2H3NS	73	73, 58, 49, 47, 45	90
	7	Cyclohexyl isocyanate	C7H11NO	125	125, 97, 82, 67, 41	93
	13	Cyclohexyl isothiocyanate	C7H11NS	141	141, 83, 55	87
	24	Linoleic acid ethyl ester	C20H36 O2	308	308, 263, 123, 109, 95, 81, 67, 55, 41	99
Ketones	5	2-Heptanone	C7H14O	114	114, 99, 71, 58, 43, 39	80
	14	1-(4-Ethylphenyl)-ethanone	C10H12O	148	148, 133, 105,	97
Aldehydes	1	3-Methyl butyraldehyde	C5H10O	86	86, 71, 58, 55, 44, 41, 38	86
	10	Nonanal	C9H18O	142	124, 119, 98, 82, 57, 41	80
Nitrogen-containing compounds	12	Benzothiazole	C7H5NS	135	135, 108, 91	83
	19	2-(Methylthio)benzothiazole	C8H7NS2	181	181, 148, 136, 108, 69	95
	26	9-Octadecenamide	C18H35NO	281	281, 126, 98, 72, 59, 41	99
Alkanes	8	Decane	C10H22	142	142, 113, 85, 71, 57, 43	94
	9	Undecane	C11H24	156	156, 85, 71, 57, 43, 39	90
	11	Dodecane	C12H26	170	170, 85, 71, 57, 43, 39	94
	16	Tetradecane	C14H30	198	198, 155, 85, 71, 57, 43	96
	18	Hexadecane	C16H34	226	226, 85, 71, 57, 43	87
	20	Octadecane	C18H38	254	254, 99, 85, 71, 57, 43	98
	23	Eicosane	C20H42	282	282, 99, 85, 71, 57	98
	25	1-Docosene	C22H44	308	125, 111, 97, 83, 69, 55, 43	99
Indoles	17	4-Methoxyindole	C9H9NO	147	147, 132, 104	94

^aSpectra similarity compared with mass spectrum of the reference compounds stored in Wiley71.1 (%).