Sena, Eliza Maiara Nogueira de; Silva, Fabricio Francisco Santos da; Silva, Jailton de Jesus; Gomes, Raquel Araujo; Pelacani, Claudineia Regina; Dantas, Barbara França

Resumo:

Erythrina velutina Willd é uma Fabaceae nativa com ampla ocorrência, principalmente no Domínio Caatinga com múltiplos usos. O objetivo deste estudo foi comparar a vulnerabilidade/tolerância de sementes de acessos de E. velutina a estresses osmóticos. Foram semeadas quatro repetições com 25 sementes em soluções osmóticas de NaCl ou PEG até -1,73 MPa. As sementes não germinadas após 14 dias foram recuperadas em água destilada. Os dados obtidos foram ajustados em curvas de Boltzmann e t50 e sincronia foram avaliados. Uma análise probit foi realizada e modelos de hidrotempo e halotempo foram construídos. Em água destilada, a curva de germinação foi semelhante para os acessos. Quando a concentração de sal ou PEG no substrato aumentou, os acessos se diferenciaram em dois grupos. Dois acessos - Jutaí 2012 e Jutaí 2015 - mantiveram alta germinação até -0,86 MPa NaCl, enquanto os acessos Caboclo 2008 e Caiçara 2011 apresentaram menor velocidade de germinação. As análises de hidrotempo e halotempo separaram a resposta germinativa dos acessos de acordo com sua qualidade fisiológica e tolerância às condições osmóticas e salinas. A viabilidade das sementes foi mantida em ambos os estresses, pois a germinação foi restabelecida em água destilada, sendo uma resposta crucial para a sobrevivência e conservação desta espécie.

Termos para indexação:
floresta seca; Mulungu; estresse em sementes; semiárido

[1] *Corresponding author
barbara.dantas@embrapa.br

Acession	Geographic coordinates/Altitude	Precipitation (mm)	Average temperature (°C)	Maximum temperature (°C)	Mínimum temperature (°C)
Caboclo 2008	08° 28’ 29” S; 40°55’45” W; 570 m	191.03	26.26	32.51	20.85
Caiçara 2011	09° 07’ 473” S; 40°23’34” W; 379 m	464.31	25.76	31.98	20.16
Jutaí 2012	08° 33’ 54” S; 40°09’47” W; 396 m	122.68	26.35	32.46	20.49
Jutaí 2015	08° 33’ 54” S; 40°09’47” W; 396 m	333.25	25.79	31.50	20.74

NaCl (MPa)					PEG 6000 (MPa)
Salinity (MPa)	Caboclo 2008	Caiçara 2011	Jutaí 2012	Jutaí 2015	Osmotic (MPa)	Caboclo 2008	Caiçara 2011	Jutaí 2012	Jutaí 2015
t50
0	4.35 dA	3.78 dA	2.52 cB	2.55 dAB	0	4.12 cA	4.08 cA	3.92 cA	4.48 cA
-0.21	5.64 cA	5.22 cA	3.57 cB	3.84 cB	-0.3	9.05 bA	8.65 bA	8.34 bA	8.47 bA
-0.43	6.66 bA	6.27 cA	4.14 bB	3.33 cB	-0.6	11.34 aA	11.15 aA	10.29 aA	10.62 aA
-0.65	7.13 bA	8.32 bA	4.62 bB	4.47 bB	-0.7	8.75 bA	11.11 aA	9.79 aA	10.84 aA
-0.86	7.50 bAB	9.63 bA	5.08 bB	6.18 aAB	-0.8	12.29 aA	3.38 cC	8.63 bB	6.25 bB
-1.29	11.89 aA	11.33 aA	9.67 aB	7.05 aC	-0.9	12.75 aA	0.00 dB	9.63 aA	10.13 aA
-1.73	13.25 aA	13.00 aA	9.63 aB	6.25 aC
Z
0	0.22 bB	0.28 bA	0.31 aA	0.28 aA	0	0.36 aB	0.43 aAB	0.52 aA	0.33 bB
-0.21	0.23 bA	0.23 bA	0.24 bA	0.24 bA	-0.3	0.36 aB	0.41 aAB	0.57 aA	0.47 aAB
-0.43	0.32 aA	0.34 aA	0.34 aA	0.21 bB	-0.6	0.28 bA	0.29 bA	0.26 bA	0.27 cA
-0.65	0.24 bA	0.18 cB	0.27 bA	0.25 bA	-0.7	0.32 bA	0.26 bA	0.29 bA	0.25 cA
-0.86	0.24 bA	0.17 cB	0.25 bA	0.22 bA	-0.8	0.17 cA	0.08 cB	0.18 cA	0.01 dB
-1.29	0.23 bA	0.28 bA	0.19 cB	0.15 cB	-0.9	0.00 dA	0.00 dA	0.00 dA	0.00 dA
-1.73	0.01 cB	0.01 dB	0.30 aA	0.30 aA

Salinity (MPa)	Caboclo 2008	Caiçara 2011	Jutaí 2012	Jutaí 2015	Osmotic (MPa)	Caboclo 2008	Caiçara 2011	Jutaí 2012	Jutaí 2015
TG (tolerance germination) (b/c) × 100
0	100 aA	99 aA	100 aA	100 aA	0	97 aA	99 aA	100 aA	100 aA
-0.21	98 aA	100 aA	100 aA	100 aA	-0.3	95 aA	98 aA	100 aA	97 aA
-0.43	98 aA	99 aA	100 aA	98 aA	-0.6	45 bB	59 bB	71 bA	85 bA
-0.65	99 aA	98 aA	99 aA	97 aA	-0.7	27 cB	37 cB	72 bA	74 bA
-0.86	83 bB	94 aA	99 aA	100 aA	-0.8	8 dB	11 dB	54 cA	10 cB
-1.29	44 cC	44 bC	86 bA	73 bB	-0.9	1 dA	0 eB	3 dA	3 cA
-1.73	1 dB	1 cB	13 cA	12 cA
RG (recovery germination) [(a−b)/(c−b)] × 100
0	0	0	0	0	0	0	0	0	0
-0.21	0	0	0	0	-0.3	100	100	0	0
-0.43	100	0	0	0	-0.6	100	73	83	93
-0.65	100	100	0	0	-0.7	99	78	29	100
-0.86	76	83	0	0	-0.8	98	79	85	97
-1.29	88	55	93	74	-0.9	98	71	92	95
-1.73	83	24	57	70
FG (final germination) (a/c) × 100
0	100 aA	99 bB	100 aA	100 aA	0	97 dC	99 bB	100 aA	100 aA
-0.21	98 bB	100 aA	100 aA	100 aA	-0.3	100 aA	100 aA	100 aA	97 cB
-0.43	100 aA	99 bB	100 aA	98 bC	-0.6	100 aA	95 cC	95 bC	99 bB
-0.65	100 aA	100 aA	99 bB	97 cC	-0.7	99 bB	86 dC	80 eD	100 aA
-0.86	96 cC	99 bB	99 bB	100 aA	-0.8	98 cA	81 eD	93 cC	97 cB
-1.29	93 dB	75 cC	99 bA	93 aA	-0.9	98 cA	71 fD	92 dC	95 dB
-1.73	83 eA	25 dD	63 cC	74 eB

Acession	Osmotic potential (PEG solutions)				Osmotic potential (NaCl solutions)
Acession	^Ψb Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). ** P <0.01; * P < 0.05. _PEG (MPa)	^σ Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). ** P <0.01; * P < 0.05.	^R2 Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). ** P <0.01; * P < 0.05.	θ_Hydro (MPa d^-1)	Ψ_bNaCl (MPa)	σ	R²	θ_Halo (MPa d^-1)
Caboclo 2008	-0.706	4.642	0.734^ Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). P <0.01; * P < 0.05.	2.92	-1.379	2.229	0.755^ Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). P <0.01; * P < 0.05.	5.00
Caiçara 2011	-0.772	4.810	0.755^ Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). P <0.01; * P < 0.05.	2.91	-1.573	3.429	0.854^ Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). P <0.01; * P < 0.05.	5.83
Jutaí 2012	-1.022	2.875	0.584^* Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). ** P <0.01; * P < 0.05.	4.17	-1.730	1.913	0.753^* Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). ** P <0.01; * P < 0.05.	3.75
Jutaí 2015	-1.001	2.192	0.635^* Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). ** P <0.01; * P < 0.05.	3.75	-1.712	1.738	0.796^ Ψb is base osmotic potential; σ is standard deviations and R2 is square of the correlation coefficients for germination and different hydrotimes and halotimes (θHydro and θHalo, respectively). P <0.01; * P < 0.05.	4.58

Brasil

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Resumo: