Data/hora: 20/05/2024 09:14:35

Biblioteca(s): 	Epagri-Sede.	
Tipo da produção científica: 	Resumo em Anais de Congresso	
Data corrente: 	08/11/2016	
Data da última atualização: 	08/11/2016	
Autoria: 	PINTO, C. E.; COSTA, M. D.; PASSOS, J. F. M.; GARAGORRY, F. C.; BETTONI, J. C.; SOUZA, J. A.; COSTA JÚNIOR, N. B.; WERNER, S. S.; BALDISSERA, T. C.	
Título: 	Light quality effect on biomass allocation of Axonopus catharinensis Valls.	
Ano de publicação: 	2016	
Fonte/Imprenta: 	In: REUNIÃO DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 53., 2016, Gramado, RS. Resumos... Viçosa, MG: Sociedade Brasileira de Zootecnia, 2016.	
Idioma: 	Inglês	
Conteúdo: 	Light is the major resource driving plant production, plant architecture and vegetation dynamic.
Different species can exhibit contrasted strategies to capture and use light. Understanding plant
responses for light is helpful to forecast production and management practices for heterogeneous
light environments (e.g. forage species under trees canopy). The objective was to evaluate the
biomass production and allocation of individual plants of giant missionary grass (Axonopus
catharinensis Valls.) in function of alterations in light quality in a controlled environment. Three
light conditions were simulated in a growth room: low blue light level (B-), low red light level (R-
), and neutral (N - control). Sodium vapor (400 w) and fluorescent lamps was used as light source
and the light conditions were obtained with a Lee filter HT 015, Lee 117 and Lee 216 for low blue,
low red:far red and neutral light respectively. The distance between plants and light sources plus
filters was adjusted in order to provide photon flux with the similar photosynthetic efficiency in
B- (Photosynthetic Active Radiation = 308 &#956;mol m2 s-1), R- (PAR = 363 &#956;mol m2 s-1) and N (PAR
= 381 &#956;mol m2 s-1). Twenty plants (i.e. replicates) from clones was grown individually in pots of
3.6 L in each light treatment at 25 ± 3ºC and 16 h photoperiod. Plants was watered with Hoagland
nutrient solution. After 35 days of growth, plants were colected and separeted in the following
morphological components: leaves, stems and roots. Statistical analysis was performed using R
software. The total biomass production (p-value 0.056) was higher in the neutral (5.54 ± 1.24 g)
and R- (4.90 ± 1.77 g) conditions compared to the B- (3.89 ± 1.30 g). There was no significant
differences in the leaf and stem mass (p-value>0.2325), either for total shoot mass (p-value
0.2385). The roots biomass was lower in the B- (0.86 ± 0.30 g) compared to N and R- (1.42 ± 0.38
and 1.14 ± 0.47 g respectively). Finally, the shoot:root ratio was higher in the B- (3.71 ± 1.51).
The biomass production and allocation on giant missionary grass is more affected by low blue
light than changes in the red:far red light. Blue light has a direct impact on stomatal functioning,
this could be the main factor affecting biomass accumulation. The investment on biomass
allocation to shoot in detriment of roots can be considered a plant strategy to capture more light;
this process can be a result of hormonal balance in function of the plant light
perception.	
Palavras-Chave: 	blue light; forage; light competition; morphological components; red:far red light; roots.	
Categoria do assunto: 	X Pesquisa, Tecnologia e Engenharia	
URL: 	http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_38501.pdf	
Registro original: 	Epagri-Sede (Epagri-Sede)	
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