Phenolic compounds in black currant leaves – an interaction between the plant and foliar diseases?

Figures & data

Figure 1. Mean (n = 50) content (µg/g DW) for the analyzed phenolic compounds (A) flavan-3-ols and chlorogenic acids, (B) flavonols in different black currant populations. Error bars indicate ± standard deviation (SD) of means. Codes: 1 = epigallocatechin; 2 = catechin; 3 = epicatechin; 4 = neochlorogenic acid; 5 = chlorogenic acid; 6 = myricetin-malonylglucoside; 7 = quercetin-3-O-galactoside; 8 = quercetin-3-O-glucoside; 9 = quercetin-3-O-rutinoside; 10 = quercetin-3-6-malonylglucoside; 11 = kampferol-3-O-rutinoside; 12 = kaempferol-3-O-glucoside; 13 = isorhamnetin-3-O-rutinoside; 14 = isorhamnetin-3-O-glucoside; 15 = kaempferol-malonylglucoside.

Figure 2. Mean (n = 50) scores (scale 1-9, no disease symptoms to heavy disease symptoms) of foliar diseases between black currant populations. Different letter/letters indicate significant differences (p < .05) between the populations for each foliar disease. Error bars represent ± standard error (SE) of mean.

Table 1. Within-groups correlations between discriminating variables and standardized canonical discriminant functions for black currant populations according to their phenolic compounds in leaves.

	Function
	1	2	3	4
Eigenvalue	8.424^a	1.818^a	1.000^a	0.377^a
% of variance	72.5	15.7	8.6	3.2
Cumulative %	72.5	88.2	96.8	100
Canonical correlation	.945	.803	.707	.523
Functional coefficients
EGC	−0.879	0.224	0.388	−0.283
CAT	0.368	0.272	0.198	0.148
ECAT	−0.282	0.667	−0.801	−0.087
NCA	0.016	0.219	0.375	−0.308
CGA	0.261	0.388	0.299	−0.094
MMGLU	0.454	0.006	−0.229	−0.257
QRUT	0.053	0.057	0.19	−0.552
QGAL	−0.058	0.214	0.557	0.579
QGLU	0.574	−0.815	0.191	−0.667
QMGLU	−0.309	0.108	−0.617	1.194
KRUT	−0.06	−0.029	−0.049	0.381
KGLU	−0.295	0.665	0.302	0.651
IRUT	0.146	0.312	−0.009	0.247
IRGLU	0.186	−0.198	0.014	0.196
KMGLU	0.332	−0.22	−0.052	−1.008

Note: Values in bold indicate phenolic compounds that are the most important for each function. EGC, epigallocatechin; CAT, catechin; ECAT, epicatechin; NCA, neochlorogenic acid; CGA, chlorogenic acid; MMGLU, myricetin-malonylglucoside; QGAL, quercetin-3-O-galactoside; QGLU, quercetin-3-O-glucoside; QRUT, quercetin-3-O-rutinoside; QMGLU, quercetin-3-6-malonylglucoside; KRUT, kampferol-3-O-rutinoside; KGLU, kaempferol-3-O-glucoside; IRUT, isorhamnetin-3-O-rutinoside; IRGLU, isorhamnetin-3-O-glucoside; KMGLU, kaempferol-malonylglucoside.

^aFirst four canonical discriminant functions were used in the analysis.

Figure 3. Canonical discriminant analyses plot for scores of phenolic compounds based on the first two canonical discriminant functions separating black currant population.

Table 2. Significant spearman correlation coefficients between phenolic compounds and foliar diseases in black currant populations.

		Foliar diseases
Population	Phenolic compounds	Anthracnose	Septoria	Rust	Mildew
	EGC	–	−0.34*	−0.36*	–
	CAT	–	–	−0.29**	–
	NCA	–	−0.32*	–	–
Rib-0701	KGLU	–	−0.3*	–	–
	IRUT	–	−0.29*	–	−0.3*
	IRGLU	–	−0.33*	–	–
	Total flavan-3-ols^a	–	−0.45**	–	–
	QGAL	–	–	−0.43**	–
Rib-0702	QGLU	–	–	−0.53**	–
	QMGLU	–	–	−0.33*	–
	KMGLU	–	–	–	0.4**
	Total flavonols^b	–	–	−0.35*	–
Rib-0704	CGA	0.33*	–	–	–
	KMGLU	–	–	−0.33*	–
	Total chlorogenic acids^c	0.32*	–	–	–
Rib-0720	EGC	–	–	0.3*	–
	QRUT	–	−0.32*	–	–
Rib-0722	CAT	−0.34*	–	–	–
	ECAT	–	−0.31*	–	–

Note: EGC, epigallocatechin; CAT, catechin; ECAT, epicatechin; NCA, neochlorogenic acid; CGA, chlorogenic acid; QGAL, quercetin-3-O-galactoside; QGLU, quercetin-3-O-glucoside; QRUT, quercetin-3-O-rutinoside; QMGLU, quercetin-3-6-malonylglucoside; KGLU, kaempferol-3-O-glucoside; IRUT, isorhamnetin-3-O-rutinoside; IRGLU, isorhamnetin-3-O-glucoside; KMGLU, kaempferol-malonylglucoside.

^aEstimated by taking the sum of flavan-3-ols.

^bEstimated by taking the sum of flavonols.

^cEstimated by taking the sum of chlorogenic acids.

*Significant at p < .05.

**Significant at p < .01.

***Significant at p < .005.