TROCAS GASOSAS E GRAU DE TOLERÂNCIA AO ESTRESSE HÍDRICO INDUZIDO EM PLANTAS JOVENS DETabebuia aurea(PARATUDO) SUBMETIDAS A ALAGAMENTO

Ciencia Florestal

关键词: fotossíntese;    estresse por inundação;    condutância estomática;    tolerância a hipóxia.;   

DOI  :  10.5902/1980509826457

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Pesquisas Florestais

【 摘 要 】

‘Paratudo’,Tabebuia aurea , is a common Brazilian tree from ‘Pantanal de Miranda’, Mato Grosso do Sul state, Brazil, an area with seasonal floodplain. To evaluate the gas exchange ofTabebuia aureaunder flooding stress, groups of eight-month-old plants were grown in soil covered by a 2 to 3 cm layer of water and a control group. Stomatal conductance, transpiration and photosynthetic rates were measured during the experiment (115 days), with an infrared portable analyzer. The values of stomatal conductance of the control group and stress plants at the beginning of the experiment were 0.22 mol m -2s -1and reached 0.02 mol m -2s -1at the end of this event. The initial photosynthesis rate was 8.0 mmol m -2s -1and, by the 108 thday, it had reached zero. When the photosynthesis rate reached zero, the rigid plastic container was dried and the rate analyzed (8 days). The values obtained for plants in drained soil were: stomatal conductance = 0.21 mol m -2s -1and photosynthesis rate = 8.0 mmol m -2s -1 , indicating a recovery response, returning to initial values. Flooded soil reduced photosynthesis and stomatal conductance, and it affected the shoot growth, leading to the symptoms resulting from flooding stress, such as hypertrophy of the lenticels. However, the species has a tolerance to the flooding process, indicating adaptability to areas under seasonal water stress.

【 授权许可】

CC BY-NC