Effects of low temperature stress on the physiology and growth of Caragana korshinskii seedlings from different mother tree ages

doi:10.17521/cjpe.2022.0210

Abstract

Abstract:

Aims This study investigated the effects of mother tree age, low temperature stress, and their interaction on the growth and leaf physiological characteristics of Caragana korshinskii seedlings.

Methods In this study, seeds of C. korshinskii were selected from an artificial forest in the hilly and sandy area of northwest Shanxi Province, representing five mother tree ages (7, 13, 19, 41 and 51 a). These seeds were germinated, and the resulting seedlings (about 2 months) were used as test material. The low temperature stress was applied at (-8 ± 1) °C with varying stress levels: W1 (6 h), W2 (12 h), W3 (24 h), W4 (48 h) and W5 (72 h). A control group (CK) was maintained at 25 °C (normal temperature). Different growth and physiological indicators related to frost resistance were determined, and a comprehensive evaluation was conducted using the membership function method.

Important findings The results showed that: (1) There were significant differences in the impact of low temperature stress on photosynthetic pigments and osmotic adjustment substances in C. korshinskii seedlings from different mother tree ages. Notably, mother tree age and low temperature stress had significant effects on chlorophyll (Chl) a content, while the contents of Chl b, Chl (a+b), carotenoid and Chl a/b in C. korshinskii seedlings were influenced by mother tree age, low temperature stress and their interaction. Low temperature stress as well as the interaction between low temperature stress and mother tree ages, had a significant effect on soluble sugar content, while mother tree ages, low temperature stress and their interaction significantly influenced free proline content. With the increasing low temperature stress duration, the contents of Chl a, Chl b, and Chl (a+b) in the leaves of C. korshinskii seedlings initially decreased and later increased, while the Chl a/b and carotenoid content exhibited an initial increase followed by a decreased, and the content of free proline increased. (2) Low temperature stress had variable effects on the growth of C. korshinskiiseedlings from different mother tree ages. Plant height, leaf number, dry mass, main root length and root shoot ratio of seedlings germinated from seeds from different age plants displayed significant differences, with values initially increasing and then decreasing with the increase in mother tree age. However, low temperature stress significantly inhibited the plant height of the seedlings, with no significant interaction observed between mother tree age and low temperature stress on the aforementioned growth parameters. (3) Seedlings germinated from the seeds of young mothers (7, 13 a) showed stronger frost resistance than those from older mothers (19, 41, 51 a). In summary, physiological parameters including Chl b content, Chl (a+b) content, Chl a/b, carotenoid content and growth parameters such as plant height, leaf number, dry mass, main root length and root shoot ratio can serve as indicators for assessing frost resistance in C. korshinskii seedlings. Besides that, when promoting the natural regeneration of C. korshinskii forest through artificial means, selecting seeds from young and middle-aged C. korshinskii plants can enhance the success of regeneration.

Key words: windy and sandy hilly area in northwest Shanxi, Caragana korshinskii, seedling, low temperature stress, osmoregulation, photosynthetic pigment, root shoot ratio

GAO Min, GOU Qian-Qian, WANG Guo-Hua, GUO Wen-Ting, ZHANG Yu, ZHANG Yan. Effects of low temperature stress on the physiology and growth of Caragana korshinskii seedlings from different mother tree ages[J]. Chin J Plant Ecol, 2024, 48(2): 201-214.

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https://www.plant-ecology.com/EN/Y2024/V48/I2/201

Figures/Tables 10

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指标 Index	梯度 Gradient	叶绿素a含量 Chl a content (mg·g^-1)	叶绿素b含量 Chl b content (mg·g^-1)	总叶绿素含量 Chl (a+b) content (mg·g^-1)	叶绿素比 Chl a/b	类胡萝卜素含量 Carotenoids content (mg·g^-1)	可溶性糖含量 Soluble sugar content (mg·g^-1)	游离脯氨酸含量 Free proline content (mg·g^-1)	丙二醛含量 Malondialdehyde content (μmol·g^-1)
L	L1	1.700 ± 0.088^a	0.968 ± 0.059^a	2.668 ± 0.125^a	1.910 ± 0.186^c	0.414 ± 0.037^c	0.003 ± 0.000^a	0.673 ± 0.040^a	0.032 ± 0.002^a
	L2	1.700 ± 0.084^a	0.727 ± 0.068^b	2.426 ± 0.129^b	2.581 ± 0.184^b	0.494 ± 0.028^b	0.003 ± 0.000^a	0.648 ± 0.048^ab	0.032 ± 0.008^a
	L3	1.569 ± 0.082^ab	0.648 ± 0.106^c	2.217 ± 0.178^c	2.899 ± 0.182^a	0.469 ± 0.024^bc	0.003 ± 0.000^a	0.590 ± 0.041^bc	0.026 ± 0.008^a
	L4	1.526 ± 0.064^ab	0.641 ± 0.099^c	2.167 ± 0.157^c	1.874 ± 0.077^c	1.033 ± 0.090^a	0.003 ± 0.000^a	0.552 ± 0.021^c	0.027 ± 0.002^a
	L5	1.482 ± 0.074^b	0.634 ± 0.095^c	2.117 ± 0.159^c	2.804 ± 0.218^a	0.439 ± 0.019^bc	0.003 ± 0.000^a	0.513 ± 0.017^c	0.028 ± 0.002^a
W	CK	2.068 ± 0.067^a	1.409 ± 0.051^a	3.476 ± 0.088^a	1.494 ± 0.072^d	0.367 ± 0.043^d	0.003 4 ± 0.000 0^b	0.547 ± 0.036^bc	0.035 ± 0.002^a
	W1	1.625 ± 0.037^b	0.469 ± 0.017^d	2.094 ± 0.049^b	3.259 ± 0.183^a	0.683 ± 0.074^a	0.003 5 ± 0.000 0^a	0.549 ± 0.042^bc	0.027 ± 0.001^a
	W2	1.360 ± 0.071^c	0.656 ± 0.079^b	2.016 ± 0.135^b	2.208 ± 0.190^c	0.543 ± 0.079^c	0.003 5 ± 0.000 0^a	0.532 ± 0.033^c	0.024 ± 0.002^a
	W3	1.545 ± 0.069^bc	0.599 ± 0.070^bc	2.144 ± 0.124^b	2.596 ± 0.199^b	0.619 ± 0.090^ab	0.003 5 ± 0.000 0^a	0.636 ± 0.039^ab	0.029 ± 0.002^a
	W4	1.432 ± 0.075^c	0.567 ± 0.060^c	2.000 ± 0.109^b	2.515 ± 0.204^b	0.569 ± 0.060^bc	0.003 4 ± 0.000 0^b	0.646 ± 0.033^a	0.030 ± 0.011^a
	W5	1.543 ± 0.071^bc	0.641 ± 0.058^b	2.184 ± 0.106^b	2.408 ± 0.186^bc	0.636 ± 0.100^a	0.003 4 ± 0.000 0^b	0.632 ± 0.055^ab	0.030 ± 0.002^a
F	L	3.086^**	56.385^**	9.640^**	50.915^**	161.596^**	1.032	6.192^**	0.375
	W	16.050^**	274.704^**	50.649^**	58.151^**	24.314^**	5.103^**	2.838^**	0.504
	L × W	1.166	20.123^**	2.324^**	10.380^**	13.488^**	1.960^**	3.856^**	0.145

指标 Index	梯度 Gradient	叶绿素a含量 Chl a content (mg·g^-1)	叶绿素b含量 Chl b content (mg·g^-1)	总叶绿素含量 Chl (a+b) content (mg·g^-1)	叶绿素比 Chl a/b	类胡萝卜素含量 Carotenoids content (mg·g^-1)	可溶性糖含量 Soluble sugar content (mg·g^-1)	游离脯氨酸含量 Free proline content (mg·g^-1)	丙二醛含量 Malondialdehyde content (μmol·g^-1)
L	L1	1.700 ± 0.088^a	0.968 ± 0.059^a	2.668 ± 0.125^a	1.910 ± 0.186^c	0.414 ± 0.037^c	0.003 ± 0.000^a	0.673 ± 0.040^a	0.032 ± 0.002^a
	L2	1.700 ± 0.084^a	0.727 ± 0.068^b	2.426 ± 0.129^b	2.581 ± 0.184^b	0.494 ± 0.028^b	0.003 ± 0.000^a	0.648 ± 0.048^ab	0.032 ± 0.008^a
	L3	1.569 ± 0.082^ab	0.648 ± 0.106^c	2.217 ± 0.178^c	2.899 ± 0.182^a	0.469 ± 0.024^bc	0.003 ± 0.000^a	0.590 ± 0.041^bc	0.026 ± 0.008^a
	L4	1.526 ± 0.064^ab	0.641 ± 0.099^c	2.167 ± 0.157^c	1.874 ± 0.077^c	1.033 ± 0.090^a	0.003 ± 0.000^a	0.552 ± 0.021^c	0.027 ± 0.002^a
	L5	1.482 ± 0.074^b	0.634 ± 0.095^c	2.117 ± 0.159^c	2.804 ± 0.218^a	0.439 ± 0.019^bc	0.003 ± 0.000^a	0.513 ± 0.017^c	0.028 ± 0.002^a
W	CK	2.068 ± 0.067^a	1.409 ± 0.051^a	3.476 ± 0.088^a	1.494 ± 0.072^d	0.367 ± 0.043^d	0.003 4 ± 0.000 0^b	0.547 ± 0.036^bc	0.035 ± 0.002^a
	W1	1.625 ± 0.037^b	0.469 ± 0.017^d	2.094 ± 0.049^b	3.259 ± 0.183^a	0.683 ± 0.074^a	0.003 5 ± 0.000 0^a	0.549 ± 0.042^bc	0.027 ± 0.001^a
	W2	1.360 ± 0.071^c	0.656 ± 0.079^b	2.016 ± 0.135^b	2.208 ± 0.190^c	0.543 ± 0.079^c	0.003 5 ± 0.000 0^a	0.532 ± 0.033^c	0.024 ± 0.002^a
	W3	1.545 ± 0.069^bc	0.599 ± 0.070^bc	2.144 ± 0.124^b	2.596 ± 0.199^b	0.619 ± 0.090^ab	0.003 5 ± 0.000 0^a	0.636 ± 0.039^ab	0.029 ± 0.002^a
	W4	1.432 ± 0.075^c	0.567 ± 0.060^c	2.000 ± 0.109^b	2.515 ± 0.204^b	0.569 ± 0.060^bc	0.003 4 ± 0.000 0^b	0.646 ± 0.033^a	0.030 ± 0.011^a
	W5	1.543 ± 0.071^bc	0.641 ± 0.058^b	2.184 ± 0.106^b	2.408 ± 0.186^bc	0.636 ± 0.100^a	0.003 4 ± 0.000 0^b	0.632 ± 0.055^ab	0.030 ± 0.002^a
F	L	3.086^**	56.385^**	9.640^**	50.915^**	161.596^**	1.032	6.192^**	0.375
	W	16.050^**	274.704^**	50.649^**	58.151^**	24.314^**	5.103^**	2.838^**	0.504
	L × W	1.166	20.123^**	2.324^**	10.380^**	13.488^**	1.960^**	3.856^**	0.145

生长参数 Growth factor	母树年龄 Mother tree age		低温胁迫 Low temperature stress		母树年龄×低温胁迫 Mother tree age × low temperature stress
生长参数 Growth factor	F	p	F	p	F	p
株高 Plant height (cm)	42.297	0.000	2.406	0.039	0.000	1
主根长 Taproot length (cm)	57.832	0.000	2.065	0.730	0.000	1
叶片数 Number of blades	23.410	0.000	2.826	0.533	0.026	1
干质量 Dry mass (g·plant^-1)	46.560	0.000	0.253	0.938	0.002	1
根茎比 Root stem ratio	51.376	0.000	1.790	0.118	0.062	1
根冠比 Root shoot ratio	12.779	0.000	0.047	0.999	0.005	1

生长参数 Growth factor	母树年龄 Mother tree age		低温胁迫 Low temperature stress		母树年龄×低温胁迫 Mother tree age × low temperature stress
生长参数 Growth factor	F	p	F	p	F	p
株高 Plant height (cm)	42.297	0.000	2.406	0.039	0.000	1
主根长 Taproot length (cm)	57.832	0.000	2.065	0.730	0.000	1
叶片数 Number of blades	23.410	0.000	2.826	0.533	0.026	1
干质量 Dry mass (g·plant^-1)	46.560	0.000	0.253	0.938	0.002	1
根茎比 Root stem ratio	51.376	0.000	1.790	0.118	0.062	1
根冠比 Root shoot ratio	12.779	0.000	0.047	0.999	0.005	1

母树年龄 Mother tree age (a)	低温胁迫 Low tempera- ture stress	株高 Plant height (cm)	主根长 Taproot length (cm)	叶片数 Number of blades	干质量 Dry mass (g·plant^-1)	根茎比 Root stem ratio	根冠比 Root shoot ratio
7	CK	16.71 ± 1.63^Ab	19.68 ± 1.42^Abc	49.00 ± 1.26^Ac	0.13 ± 0.01^Ac	1.24 ± 0.15^Aab	0.39 ± 0.01^Bab
	W1	15.00 ± 1.47^Ab	18.70 ± 1.35^Abc	48.00 ± 1.35^ABc	0.13 ± 0.01^Ac	1.49 ± 0.21^Aab	0.42 ± 0.01^Aab
	W2	14.43 ± 1.53^Ab	18.92 ± 1.46^Abc	47.00 ± 2.26^ABc	0.12 ± 0.01^Ac	1.49 ± 0.22^Aab	0.41 ± 0.01^ABab
	W3	13.87 ± 1.66^Ab	19.39 ± 2.03^Abc	46.00 ± 1.24^ABc	0.12 ± 0.01^Ac	1.50 ± 0.20^Aab	0.40 ± 0.01^ABab
	W4	13.60 ± 1.75^Ab	20.26 ± 1.55^Abc	45.00 ± 2.34^ABc	0.12 ± 0.01^Ac	1.49 ± 0.17^Aab	0.40 ± 0.01^ABab
	W5	13.45 ± 1.58^Ab	21.15 ± 1.45^Abc	44.00 ± 1.36^Bc	0.16 ± 0.03^Ac	1.49 ± 0.16^Aab	0.39 ± 0.01^Bab
13	CK	28.40 ± 2.98^Aa	15.78 ± 1.27^Ac	72.00 ± 7.68^Aa	0.29 ± 0.03^Aa	0.60 ± 0.10^Ac	0.19 ± 0.01^Ab
	W1	26.68 ± 2.44^Aa	14.73 ± 1.22^Ac	70.00 ± 6.72^Aa	0.28 ± 0.03^Aa	0.65 ± 0.13^Ac	0.22 ± 0.01^Ab
	W2	26.13 ± 2.65^Aa	14.95 ± 1.46^Ac	68.00 ± 7.43^Aa	0.27 ± 0.03^Aa	0.65 ± 0.13^Ac	0.20 ± 0.01^Ab
	W3	25.56 ± 2.78^Aa	15.40 ± 2.26^Ac	67.00 ± 7.72^Aa	0.27 ± 0.03^Aa	0.66 ± 0.13^Ac	0.20 ± 0.01^Ab
	W4	25.28 ± 3.15^Aa	16.28 ± 1.58^Ac	66.00 ± 6.55^Aa	0.27 ± 0.03^Aa	0.68 ± 0.13^Ac	0.19 ± 0.01^Ab
	W5	25.14 ± 2.66^Aa	17.17 ± 1.33^Ac	65.00 ± 4.72^Aa	0.26 ± 0.03^Aa	0.70 ± 0.12^Ac	0.19 ± 0.01^Ab
19	CK	18.89 ± 1.46^Ab	27.18 ± 2.02^Aa	64.83 ± 4.08^Aab	0.25 ± 0.02^Aa	1.46 ± 0.13^Aa	0.43 ± 0.10^Aa
	W1	17.17 ± 1.55^Ab	26.19 ± 2.44^Aa	63.83 ± 3.37^Aab	0.24 ± 0.02^Aa	1.72 ± 0.17^Aa	0.43 ± 0.10^Aa
	W2	16.62 ± 2.34^Ab	26.42 ± 2.03^Aa	62.83 ± 3.28^Aab	0.24 ± 0.02^Aa	1.72 ± 0.17^Aa	0.43 ± 0.10^Aa
	W3	16.05 ± 1.41^Ab	26.87 ± 2.35^Aa	61.83 ± 3.45^Aab	0.24 ± 0.02^Aa	1.72 ± 0.17^Aa	0.43 ± 0.10^Aa
	W4	15.77 ± 1.98^Ab	27.75 ± 1.77^Aa	60.83 ± 3.01^Aab	0.24 ± 0.02^Aa	1.71 ± 0.16^Aa	0.45 ± 0.09^Aa
	W5	15.63 ± 1.43^Ab	28.65 ± 2.33^Aa	59.83 ± 3.22^Aab	0.23 ± 0.02^Aa	1.71 ± 0.15^Aa	0.43 ± 0.10^Aa
41	CK	18.54 ± 0.58^Ab	23.17 ± 2.33^Aab	58.58 ± 2.49^Abc	0.22 ± 0.02^Aab	1.25 ± 0.06^Aab	0.44 ± 0.12^Aa
	W1	16.83 ± 0.65^ABb	22.17 ± 1.56^Aab	57.58 ± 3.45^Aabc	0.22 ± 0.02^Aab	1.46 ± 0.07^Aab	0.44 ± 0.12^Aa
	W2	16.38 ± 0.73^Bb	22.40 ± 1.44^Aab	56.58 ± 2.28^Aabc	0.21 ± 0.02^Aab	1.46 ± 0.07^Aab	0.44 ± 0.12^Aa
	W3	15.71 ± 0.65^Bb	22.85 ± 1.39^Aab	55.58 ± 2.33^Aabc	0.21 ± 0.02^Aab	1.46 ± 0.07^Aab	0.44 ± 0.12^Aa
	W4	15.43 ± 0.99^Bb	23.73 ± 2.06^Aab	55.58 ± 2.28^Aabc	0.21 ± 0.02^Aab	1.46 ± 0.07^Aab	0.44 ± 0.12^Aa
	W5	15.28 ± 0.78^Bb	24.63 ± 1.07^Aab	54.58 ± 1.96^Aabc	0.21 ± 0.02^Aab	1.47 ± 0.07^Aab	0.44 ± 0.12^Aa
51	CK	18.35 ± 1.23^Ab	18.82 ± 1.08^Ac	53.33 ± 3.77^Abc	0.17 ± 0.02^Abc	1.04 ± 0.06^Ab	0.30 ± 0.04^Aab
	W1	16.63 ± 1.16^Ab	17.81 ± 2.09^Ac	52.33 ± 3.37^Abc	0.17 ± 0.02^Abc	1.20 ± 0.08^Ab	0.29 ± 0.04^Aab
	W2	16.07 ± 1.26^Ab	18.04 ± 1.08^Ac	51.33 ± 4.22^Abc	0.17 ± 0.02^Abc	1.20 ± 0.08^Ab	0.30 ± 0.04^Aab
	W3	15.52 ± 1.44^Ab	18.50 ± 1.46^Ac	52.33 ± 3.78^Abc	0.16 ± 0.02^Abc	1.21 ± 0.08^Ab	0.30 ± 0.04^Aab
	W4	15.24 ± 1.35^Ab	19.37 ± 1.37^Ac	51.33 ± 3.26^Abc	0.16 ± 0.02^Abc	1.22 ± 0.08^Ab	0.30 ± 0.03^Aab
	W5	15.09 ± 1.22^Ab	20.28 ± 1.28^Ac	50.33 ± 3.66^Abc	0.16 ± 0.02^Abc	1.24 ± 0.07^Ab	0.29 ± 0.04^Aab