Effects of eustress induced by low concentrations of salinity on broccoli (<i>Brassica oleracea</i>) and purslane (<i>Portulaca oleracea</i>) microgreens

Gretchen Plocek; Shivani Kathi; Catherine Simpson; Gretchen Plocek; Shivani Kathi; Catherine Simpson

doi:10.48130/TIH-2023-0004

Treatment	Trial 1				Trial 2
	Broccoli		Purslane		Broccoli		Purslane
	TIV	TS	TIV	TS	TIV	TS	TIV	TS
0 dS·m⁻¹	203.3	0	190.1	0	196.0	0	173.8	0
0.5 dS·m⁻¹	205.6	0.066	194.9	0.062	194.4	0.062	161.4	0.051
1 dS·m⁻¹	214.7	0.137	187.8	0.12	196.4	0.126	174.4	0.112
1.5 dS·m⁻¹	192.0	0.184	184.9	0.178	198.4	0.190	172.0	0.165
TIV = Total Irrigated Volume (mL); TS = Total NaCl (g).

Table 1.

Irrigation treatments of broccoli and purslane microgreens for trials 1 and 2.

Treatments	Broccoli				Purslane
Treatments	Fresh weight (g)	Dry weight (g)	% DM	% MC	Fresh weight (g)	Dry weight (g)	% DM	% MC
Trial 1
0 dS·m⁻¹	4.91	0.638	13.0	87.0	1.93	0.219 B	11.3	88.7
0.5 dS·m⁻¹	5.32	0.646	12.4	87.6	2.15	0.244 B	11.4	88.6
1.0 dS·m⁻¹	6.37	0.709	11.2	88.8	2.59	0.306 A	12.3	87.7
1.5 dS·m⁻¹	5.65	0.697	12.6	87.4	2.08	0.237 A B	11.2	88.8
p value	0.238	0.524	0.213	0.303	0.185	0.0395	0.859	0.895
Trial 2
0 dS·m⁻¹	6.11 B	0.794	13.2 A	86.8 C	3.57	0.306	9.2	0.908
0.5 dS·m⁻¹	6.22 B	0.760	12.2 A B	87.8 B C	3.04	0.262	8.9	0.911
1.0 dS·m⁻¹	8.84 A	0.935	10.6 C	89.4 A	2.93	0.360	13.2	0.868
1.5 dS·m⁻¹	7.54 AB	0.821	11.1 B C	88.9 A B	2.57	0.298	13.7	0.863
p value	0.043	0.314	0.0077	0.0077	0.847	0.773	0.152	0.152
Values followed by the same letter are not significantly different at the p < 0.05 level. p treatments were identified using a student's t test.

Table 2.

Average fresh weight (g), dry weight (g), dry matter (%), and moisture content (%) of broccoli and purslane microgreens for trials 1 and 2. Table data represents the mean of the five containers of samples in each treatment.

Treatments	Broccoli			Purslane
Treatments	T-AsA (mg/100 g FM)	AsA (mg/100 g FM)	Proline (umol/g DW)	T-AsA (mg/100 g FM)	AsA (mg/100 g FM)	Proline (umol/g DW)
Trial 1
0 dS·m⁻¹	53.6 A	40.1 A	19.0 B	29.8	17.6	6.44
0.5 dS·m⁻¹	21.6 B	20.7 C	22.0 A B	26.9	17.9	7.97
1.0 dS·m⁻¹	22.6 B	24.4 C	18.4 B	28.2	18.8	7.47
1.5 dS·m⁻¹	27.2 B	28.7 B	28.9 A	27.9	20.6	7.29
p value	<0.0001	<0.0001	0.0740	0.642	0.165	0.560
Trial 2
0 dS·m⁻¹	45.0 A	28.0 A B	9.57 B	20.5	12.2	6.47
0.5 dS·m⁻¹	54.4 A	19.2 B	13.2 B	18.9	11.6	5.84
1.0 dS·m⁻¹	41.9 A	19.9 B	15.9 A B	23.3	12.1	6.27
1.5 dS·m⁻¹	19.0 B	36.8 A	21.8 A	24.5	14.7	6.79
p value	0.0006	0.0093	0.0119	0.109	0.287	0.887
Values followed by the same letter are not significantly different at the p < 0.05 level. p treatments were determined using a student's t test.

Table 3.

Results for vitamin C and proline concentration in broccoli and purslane microgreens for trials 1 and 2.

Treatments		Broccoli
Treatments		Fresh weight	Dry weight	% MC	% DM	T-AsA	AsA	Proline
0 dS·m⁻¹	Fresh weight	1
	Dry weight	0.9312***	1
	%MC	0.5300	0.1926	1
	% DM	−0.5296	−0.1921	−1.000***	1
	T-AsA	0.0962	0.2844	−0.3143	0.3144	1
	AsA	−0.2944	−0.3595	0.1050	−0.1048	0.4336	1
	Proline	0.6026	−0.6530*	−0.0169	0.0167	0.2401	0.7005*	1
0.5 dS·m⁻¹	Fresh weight	1
	Dry weight	0.7505***	1
	%MC	0.6142	−0.5220	1
	%DM	−0.6129	0.0527	−1.000***	1
	T-AsA	0.3352	0.5327	−0.0941	0.0946	1
	AsA	0.0968	0.2995	−0.2846	0.2845	−0.1707	1
	Proline	−0.7628	−0.5170	−0.5597	0.5587	−0.4473	0.2567	1
1.0 dS·m⁻¹	Fresh weight	1
	Dry weight	0.9664***	1
	%MC	0.6151	0.4100	1
	%DM	−0.6434*	−0.4299	−0.9414***	1
	T-AsA	0.2723	0.2824	0.2447	−0.1560	1
	AsA	−0.6928*	−0.5800	−0.6211	0.6436*	−0.1336	1
	Proline	−0.5280	−0.4962	−0.3846	0.2497	0.0678	0.5033	1
1.5 dS·m⁻¹	Fresh weight	1
	Dry weight	0.09629***	1
	%MC	0.8306**	0.6659*	1
	%DM	−0.8295**	−0.6646*	−1.000*	1
	T-AsA	−0.6654*	−0.5550	−0.7671**	0.7664**	1
	AsA	−0.0967	−0.1354	0.0557	−0.0545	−0.2588	1
	Proline	−0.8163**	−0.7476*	−0.7696**	0.7690**	0.5210	−0.0442	1
Order of significance is represented by * p < 0.0001, p < 0.01, * p < 0.05.

Table 4.

Data correlation between all variables measured for broccoli microgreens.

Treatments		Purslane
Treatments		Fresh weight	Dry weight	% MC	% DM	T-AsA	AsA	Proline
0 dS·m⁻¹	Fresh weight	1
	Dry weight	0.9215**	1
	%MC	0.7837**	0.5110	1
	%DM	−0.7836**	−0.5108	−1.000***	1
	T-AsA	−0.3355	−0.1582	−0.5585	0.5588	1
	AsA	−0.3718	−0.2186	−0.4611	0.4615	0.9348***	1
	Proline	−0.1510	−0.0997	−0.1580	0.1586	−0.0779	−0.1119	1
0.5 dS·m⁻¹	Fresh weight	1
	Dry weight	0.9692***	1
	%MC	0.8837**	0.7677*	1
	%DM	−0.8838**	−0.7697*	−1.000***	1
	T-AsA	−0.3889	−0.2668	−0.4450	0.4445	1
	AsA	−0.4437	−0.3489	−0.5353	0.5348	0.9474**	1
	Proline	−0.4920	−0.4995	−0.2918	0.2915	0.7421*	0.6802*	1
1.0 dS·m⁻¹	Fresh weight	1
	Dry weight	0.6296	1
	%MC	0.8086**	0.0943	1
	%DM	−0.8165**	−0.1016	−0.9984***	1
	T-AsA	−0.1020	−0.0028	−0.0815	0.1096	1
	AsA	−0.2123	−0.3741	0.0182	0.0049	0.8671**	1
	Proline	−0.3062	−0.5166	0.0397	−0.0360	−0.0458	0.3514	1
1.5 dS·m⁻¹	Fresh weight	1
	Dry weight	0.6449	1
	%MC	0.6686	−0.0763	1
	%DM	−0.6685	0.0765	−1.000***	1
	T-AsA	−0.8680	−0.8333	−0.3945	0.3944	1
	AsA	−0.7501*	−0.7763*	−0.1968	0.1966	0.7527*	1
	Proline	−0.3970	0.0382	−0.5932	0.5931	0.1183	0.3700	1
Order of significance is represented by * p < 0.0001, p < 0.01, * p < 0.05.

Table 5.

Data correlation between all variables measured for purslane microgreens.