Journal of Resources and Ecology >
Effects of Seedling Methods on Germination and Growth of Sophora japonica L.
YAO Jingjing, Email: yaojing1989_lucky@163.com 
Received date: 20220825
Accepted date: 20230418
Online published: 20230714
Supported by
Key Research and Development Program of China(2017YFC0504404)
The Key Research and Development Plan Projects of Ningxia Hui Autonomous Region(2018BFG02002)
Bud seedlings were used in this study to overcome the disadvantages of the frequentlyused active vegetation restoration methods such as direct seeding and plant seedlings for mining areas. Survival and growth characteristics of Sophora japonica L. by bud seedlings, seedling planting, and direct seeding methods were investigated through field plantation experiments in Changping District of Beijing, China. Nine plots (5 m×1 m) with slope of 25° were conducted and divided into 3 groups according to aspects of west, southwest, as well as south, and seeds were planted by following the three methods in each aspect. Germination, survival, seedling growth, and root parameters of each treatment were analyzed through oneway analysis of variance, pairedsample t test, repeated measures analysis of variance, and multivariate analysis of variance to evaluate the effectiveness of the three seedling methods. The results showed that seedling planting and bud seedlings promoted seeds germination and growth, with a germination percentage of 70.58% and seedling height of 9.97 cm before transplantation, which were 1.48 times and 1.53 times higher than direct seeding, respectively. Moreover, bud seedlings showed the largest survival rate, seedling height, and root biomass under all aspects after transplantation (P<0.05), and at the end of the study, the largest values of the above indicators were 88.33 % in BW (the plot with seedling method of bud seedlings in aspect west), 158.36 cm in BS (the plot with seedling method of bud seedlings in aspect west south), and 131.5 g in BS, respectively. The effect of seedling method on seedling growth was most significant and increased with time, with effect sizes of 0.290 and 0.199 on seedling height and growth rate in 2020, respectively. Overall, bud seedlings could extract the advantages and overcome the disadvantages of seedling planting and direct seeding, which can be considered as a better method for vegetation restoration in the mining areas.
YAO Jingjing , ZHANG Chengliang , HAN Shuang , LIU Mengfan , WANG Yan , CAO Wenbo . Effects of Seedling Methods on Germination and Growth of Sophora japonica L.[J]. Journal of Resources and Ecology, 2023 , 14(4) : 868 879 . DOI: 10.5814/j.issn.1674764x.2023.04.019
Table 1 Plots characteristics 
Plots/Treatment  Slope (°)  Aspect  Seedling methods 

DW  25  West  Direct seeding 
BW  25  West  Bud seedlings 
SW  25  West  Seedling planting 
DSW  25  Southwest  Direct seeding 
BSW  25  Southwest  Bud seedlings 
SSW  25  Southwest  Seedling planting 
DS  25  South  Direct seeding 
BS  25  South  Bud seedlings 
SS  25  South  Seedling planting 
Fig. 1 Plant germination percentage and seedling height of different seedling methodsNote: (a) Germination percentage, and different letters of a given seedling method indicate that germination percentage varies significantly (0.05 level) with time; (b) Seedling height, and different letters of a given seedling method indicate that seedling height varies significantly (0.05 level) with time. 
Table 2 Pairedsample t test results of germination percentage and seedling height at a given time across sowing methods 
Days after sowing  P  

Germination percentage  Seedling height  
5  0.032  0.015 
10  0.010  0.003 
15  0.007  0.004 
20  0.003  0.005 
Table 3 Seedling height and survival rate of different seedling methods 
Treatment  Seedling height (cm)  Survival rate (%)  

2018  2019  2020  2018  2019  2020  
All  Surviving in September, 2020  All  Surviving in September, 2020  Surviving in September, 2020  
DW  47.47±9.00a  47.94±9.33aA  73.78±9.01a  73.73±9.10aB  100.71±12.61aC  95.00  83.33  81.67 
BW  55.48±13.21b  56.21±13.42bA  94.38±17.94bc  94.38±17.94bcB  133.58±25.70dC  96.67  88.33  88.33 
SW  48.87±9.32a  49.10±9.47aA  77.24±13.81a  77.38±13.92aB  107.06±17.76aC  90.00  81.67  80.00 
DSW  47.58±7.50a  48.93±7.38aA  78.51±7.47a  78.68±7.61aB  104.52±10.59aC  91.67  78.33  73.33 
BSW  58.31±11.89bc  60.18±11.89bA  102.51±18.39d  103.42±18.75dB  136.56±24.37dC  91.67  81.67  75.00 
SSW  47.79±9.21a  49.51±9.09aA  89.04±15.11b  89.91±15.59bB  117.26±19.56bC  86.67  80.00  71.67 
DS  48.73±8.22a  50.24±8.17aA  93.17±14.85bc  95.15±13.89bcB  123.80±16.63bcC  85.00  76.67  68.33 
BS  61.98±16.04c  66.30±14.29cA  115.13±25.37e  117.48±24.00eB  158.36±35.57eC  90.00  78.33  73.33 
SS  57.74±11.34bc  60.61±10.04bA  97.22±20.17cd  99.68±19.36cdB  131.90±26.76cdC  83.33  75.00  68.33 
Note: (a) Different lowercase letters indicate that seedling height of a given year varies significantly (0.05 level) with treatments. (b) Different capital letters indicate that seedling height of a given plot varies significantly (0.05 level) with time. 
Table 4 Multivariate tests for the effects of time and treatment on seedling height based on repeated measures analysis of variance ^{a} 
Effect  Inspection methods  Multivariate tests  F  Hypothesis df  Error df  Sig.  Partial eta squared 

Time  Pillai’s Trace  0.949  3681.474^{b}  2.000  398.000  <0.001  0.949 
Wilks’ Lambda  0.051  3681.474^{b}  2.000  398.000  <0.001  0.949  
Hotelling’s Trace  18.500  3681.474^{b}  2.000  398.000  <0.001  0.949  
Roy’s Largest Root  18.500  3681.474^{b}  2.000  398.000  <0.001  0.949  
Time × Treatment  Pillai’s Trace  0.524  17.702  16.000  798.000  <0.001  0.262 
Wilks’ Lambda  0.535  18.239^{b}  16.000  796.000  <0.001  0.268  
Hotelling’s Trace  0.757  18.778  16.000  794.000  <0.001  0.275  
Roy’s Largest Root  0.558  27.845^{c}  8.000  399.000  <0.001  0.358 
Note: The withinsubjects variables are seedling height data in 2018, 2019, and 2020 of seedlings surviving in 2020. The betweensubjects variable is treatment. a. Design: Intercept + treatments, and within subjects design: time. b. Exact statistic. c. The statistic is an upper bound on F that yields a lower bound on the significance level. 
Fig. 2 Estimated marginal means of seedling height based on repeated measures analysis of variance 
Table 5 Tests of betweensubjects effects for the effects of seedling method and aspect on seedling height based on multivariate analysis of variance 
Source  Sig.  Partial eta squared  

2018  2019  2020  2018  2019  2020  
Corrected model  <0.001  <0.001  <0.001  0.260^{a}  0.406^{b}  0.388^{c} 
Intercept  <0.001  <0.001  <0.001  0.964  0.970  0.969 
Seedling method  <0.001  <0.001  <0.001  0.181  0.261  0.290 
Aspect  <0.001  <0.001  <0.001  0.093  0.244  0.178 
Seedling method×Aspect  0.011  0.562  0.775  0.032  0.007  0.004 
Note: The dependent variables are seedling height data in 2018, 2019, and 2020 of seedlings surviving in 2020, respectively. The fixed variables are seedling method and aspect. a. R^{2}=0.260 (adjusted R^{2}=0.245). b. R^{2}=0.406 (adjusted R^{2}=0.394). c. R^{2}=0.388 (adjusted R^{2} = 0.376). 
Fig. 3 Estimated marginal means of seedling height in 2018, 2019, and 2020 based on multivariate analysis of variance 
Table 6 Annual growth (cm) of seedlings under different seedling methods 
Treatment  2018  2019  2020  

All  Surviving in September, 2020  All  Surviving in September, 2020  
DW  47.47±9.00a  47.94±9.33aB  25.76±6.52a  25.80±6.58aA  26.98±7.36aA 
BW  55.48±13.21b  56.21±13.42bB  38.17±11.70b  38.17±11.70bA  39.21±11.54dA 
SW  48.87±9.32a  49.10±9.47aB  28.43±8.76a  28.27±8.78aA  29.69±7.91abcA 
DSW  47.58±7.50a  48.93±7.38aB  29.79±6.00a  29.75±5.69aA  25.84±5.53aA 
BSW  58.31±11.89bc  60.18±11.89bC  42.80±12.06bc  43.24±12.49cdB  33.13±8.87cA 
SSW  47.79±9.21a  49.51±9.09aC  40.35±10.60bc  40.40±11.10bcdB  27.35±6.42aA 
DS  48.73±8.22a  50.24±8.17aB  43.63±9.77c  44.90±9.30dB  28.66±7.17abA 
BS  61.98±16.04c  66.30±14.29cC  50.00±17.55d  51.18±17.29eB  40.89±13.91dA 
SS  57.74±11.34bc  60.61±10.04bC  38.27±13.33b  39.07±13.64bcB  32.22±10.47bcA 
Note: (a) 2018 annual growth values are equal to seedling height values in Table 3. (b) Different lowercase letters indicate that annual growth of seedlings in a given year varies significantly (0.05 level) with treatments. (c) Different capital letters indicate that annual growth of seedlings in a given plot varies significantly (0.05 level) with time. 
Table 7 Multivariate tests for the effects of time and treatment on annual growth based on repeated measures analysis of variance^{a} 
Effect  Inspection methods  Multivariate tests  F  Hypothesis df  Error df  Sig.  Partial eta squared 

Time  Pillai’s Trace  0.831  979.207^{b}  2.000  398.000  <0.001  0.831 
Wilks’ Lambda  0.169  979.207^{b}  2.000  398.000  <0.001  979.207^{b}  
Hotelling’s Trace  4.921  979.207^{b}  2.000  398.000  <0.001  979.207^{b}  
Roy’s Largest Root  4.921  979.207^{b}  2.000  398.000  <0.001  979.207^{b}  
Time×Treatment  Pillai’s Trace  0.291  8.477  16.000  798.000  <0.001  0.145 
Wilks’ Lambda  0.726  8.649^{b}  16.000  796.000  <0.001  0.148  
Hotelling’s Trace  0.355  8.821  16.000  794.000  <0.001  0.151  
Roy’s Largest Root  0.273  13.638^{c}  8.000  399.000  <0.001  0.215 
Note: The withinsubjects variables are annual growth data in 2018, 2019, and 2020 of seedlings surviving in 2020. The betweensubjects variable is treatment. a. Design: Intercept + treatments, and within subjects design: time. b. Exact statistic. c. The statistic is an upper bound on F that yields a lower bound on the significance level. 
Table 8 Tests of BetweenSubjects Effects for the effects of seedling method and aspect on annual growth based on multivariate analysis of variance 
Source  Sig.  Partial eta squared  

2019  2020  2019  2020  
Corrected model  <0.001  <0.001  0.341^{a}  0.242 
Intercept  <0.001  <0.001  0.921  0.923 
Seedling method  <0.001  <0.001  0.148  0.199 
Aspect  <0.001  <0.001  0.219  0.049 
Seedling method× Aspect  <0.001  0.325  0.057  0.012 
Note: The dependent variables are annual growth data in 2018, 2019, and 2020 of seedlings surviving in 2020, respectively. The fixed variables are seedling method and aspect. Values in 2018 are by definition identical to those in Table 5. a. R^{2}= 0.341 (adjusted R^{2} = 0.328). b. R^{2}= 0.242 (adjusted R^{2}=0.227). 
Fig. 4 Estimated marginal means of annual growth based on repeated measures analysis of variance 
Fig. 5 Estimated marginal means of annual growth in 2019 and 2020 based on multivariate analysis of variance 
Fig. 6 Biomass and length of roots under different seedling methodsNote: (a) Root length of < 1 mm under different seedling methods; (b) Root length of 12 mm, 25 mm, 510 mm and > 10 mm under different seedling methods; (c) Biomass of belowground, and different letters indicate that biomass aboveground varies significantly (0.05 level) with treatments. 
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