EFFECTS OF ROOT DEFORMATION AND LIGHT AVAILABILITY ON GROWTH AND BIOMASS ALLOCATION OF <i>Senna multijuga</i> SEEDLINGS (Rich) H. S. Irwin &amp; Barneby

Lopes, Emile Caroline Silva; Dalmolin, Ândrea Carla; Allama, Ivan Bezerra; Pereira, Karine Ferreira; Aitken II, William Martin; Santos, Martielly Santana dos; Santos, Aline Pinto dos; Mielke, Marcelo Schramm

doi:10.1590/1806-908820200000018

Acessibilidade / Reportar erro

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Scientific Article • Rev. Árvore 44 • 2020 • https://doi.org/10.1590/1806-908820200000018 copy

EFFECTS OF ROOT DEFORMATION AND LIGHT AVAILABILITY ON GROWTH AND BIOMASS ALLOCATION OF Senna multijuga SEEDLINGS (Rich) H. S. Irwin & Barneby

EFEITOS DA DEFORMAÇÃO RADICULAR E DA DISPONIBILIDADE DE LUZ NO CRESCIMENTO E NA DISTRIBUIÇÃO DE BIOMASSA DE Mudas DE Senna multijuga (Rich) H. S. Irwin & Barneby

Authorship SCIMAGO INSTITUTIONS RANKINGS

ABSTRACT

The effects of root deformation caused by errors in the pricking-out process in forest nurseries are still unknown for tropical tree seedlings. We analyzed the effects of light availability and root deformation on growth and biomass allocation in seedlings of Senna multijuga, a pioneer tropical tree commonly used in forest restoration programs. Our hypotheses were: (a) as a typical light-demanding species, the seedlings of S. multijuga may have their growth compromised by low light availability; (b) root deformation impairs growth rates and induces changes in biomass allocation; and (c) the effects of low light availability on growth and biomass allocation are increased by root deformation. Seedlings with and without root deformation were cultivated for 43 days under three levels of total daily photosynthetically active radiation (PAR) (28, 12, and 1 mol photons m^-2 day^-1). Seedlings of S. multijuga had their growth rates severely affected by values of PAR at about 1 mol photons m^-2 day^-1, but root deformation did not affect the relative growth rates of the whole plant. Instead, root deformation caused a decrease in the relative growth rate of roots in all light availabilities. The changes in root growth affected biomass allocation to the roots. The interactive effects of light availability and root deformation on the allocation of biomass to leaves are more pronounced at low light availability. Root deformations may lead to the production of seedlings with a low competitiveness capacity regardless of light conditions.

Keywords:
Brazilian Atlantic Rainforest; Pricking-out; Seedling quality

Table 1 Mean values and standard errors of growth and biomass allocation variables and significance levels of ANOVA while comparing the effects of light (L) and root (R) deformation for young plants of S. multijuga, without (R1) and with (R2) root deformation and under three light environments (L28- 28 mol photons m-2 day-1, L12 - 12 mol photons m-2 day-1, and L1 - 1 mol photons m-2 day-1), for 43 days. For the variables presented, there were no significant interactions between root deformation and light.

Variable	Light (L)			Root (R)		ANOVA
Variable	L28	L12	L1	R1	R2	L	R
H (cm)	37.4 ± 1.0 a	40.31 ± 0.1 a	25.20 ± 1.0 b	35.1 ± 0.82 a	33.5 ± 0.82 a	***	ns
D (mm)	4.84 ± 0.1 a	4.73 ± 0.1 b	2.24 ± 0.1 c	3.88 ± 0.07 a	3.82 ± 0.07 a	***	ns
RGR (mg g^-1 day^-1)	73.22 ± 1.2 a	68.25 ± 1.2 a	28.64 ± 1.2 b	57.1 ± 1.10 a	56.3 ± 1.11 a	***	ns
RGR_S (mg g^-1 day^-1)	76.30 ± 0.4 a	74.80 ± 0.3 a	36.00 ± 0.3 b	58.60 ± 0.31b	66.20 ± 0.33 a	***	**
RGR_R (mg g^-1 day^-1)	74.20 ± 0.2 a	66.00 ± 0.2 b	16.20 ± 0.1 c	56.60 ± 0.11 a	45.90 ± 0.16 b	***	***
SMR₂ (g g^-1)	0.19 ± 0.01 a	0.23 ± 0.02 a	0.28 ± 0.04 a	0.20 ± 0.03 a	0.27 ± 0.06 a	ns	ns
RMR₂ (g g^-1)	0.31 ± 0.01 a	0.24 ± 0.01 b	0.18 ± 0.01 c	0.26 ± 0.01 a	0.24 ± 0.01 a	***	ns
D/H	0.13 ± 0.002 a	0.11 ± 0.002 b	0.9 ± 0.002 c	0.11 ± 0.002 a	0.11 ± 0.002 a	***	ns
D/RV (mm mL^-1)	0.33 ± 0.1 c	0.64± 0.1 b	2.04 ± 0.16a	1.13 ± 0.08 a	0.08 ± 0.08 b	***	**
H/RV (cm mL^-1)	2.50 ± 1.8 c	5.73 ± 1.2 b	22.30 ± 1.8 a	11.53 ± 0.96 a	8.82 ±0.96 b	***	**

Table 2 Mean values and standard errors of relative growth rate based on leaf dry mass (RGRL) and leaf mass ratio (LMR2) of S. multijuga seedlings, without (R1) and with (R2) root deformation and under three light levels (L28- 28 mol photons m-2 day-1, L12 - 12 mol photons m-2 day-1, and L1 - 1 mol photons m-2 day-1), at the end of 43 days.

Variable	Root	L28	L12	L1
RGR_L	R1	70.20 ± 0.2 Aa	69.70± 0.2 Aa	0.51± 0.02 Ba
	R2	63.10± 0.2 Aa	67.70± 0.2 Aa	0.48 ±0.03 Cb
LMR₂	R1	34.40 ± 0.2 Ba	23.10± 0.2 Ba	0.64± 0.03 Aa
	R2	63.10± 0.2 Aa	23.10± 0.2 Ba	0.52± 0.03 Bb

Sociedade de Investigações Florestais Universidade Federal de Viçosa, CEP: 36570-900 - Viçosa - Minas Gerais - Brazil, Tel: (55 31) 3612-3959 - Viçosa - MG - Brazil
E-mail: rarvore@sif.org.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Corresponding author.