03431naa a2200289 a 450000100080000000500110000800800410001910000170006024501030007726000090018052025390018965300150272865300110274365300220275465300290277665300220280565300100282770000170283770000210285470000210287570000190289670000170291570000250293270000180295770000220297577301440299711256692016-11-08       2016    bl uuuu     u00u1 u    #d1 aPINTO, C. E.  aLight quality effect on biomass allocation of Axonopus catharinensis Valls.h[electronic resource]  c2016  aLight 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 μmol m2 s-1), R- (PAR = 363 μmol m2 s-1) and N (PAR = 381 μmol 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 ?? 3??C 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&gt0.2325), 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.  ablue light  aforage  alight competition  amorphological components  ared:far red light  aroots1 aCOSTA, M. D.1 aPASSOS, J. F. M.1 aGARAGORRY, F. C.1 aBETTONI, J. C.1 aSOUZA, J. A.1 aCOSTA J??NIOR, N. B.1 aWERNER, S. S.1 aBALDISSERA, T. C.  tIn: REUNI??O DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 53., 2016, Gramado, RS. Resumos... Vi??osa, MG: Sociedade Brasileira de Zootecnia, 2016.