Psidium guajava 'Paluma' (the guava plant) as a new bio-indicator of ozone in the tropics.
Psidium guajava 'Paluma' saplings were exposed to carbon filtered air (CF), ambient non-filtered air (NF), and ambient non-filtered air+40ppb ozone (NF+O(3)) 8h per day during two months. The AOT40 values at the end of the experiment were 48, 910 and 12 895ppbh(-1), respectively for the three treatments. After 5 days of exposure (AOT40=1497ppbh(-1)), interveinal red stippling appeared in plants in the NF+O(3) chamber. In the NF chamber, symptoms were observed only after 40 days of exposure (AOT40=880ppbh(-1)). After 60 days, injured leaves per plant corresponded to 86% in NF+O(3) and 25% in the NF treatment, and the average leaf area injured was 45% in NF+O(3) and 5% in the NF treatment. The extent of leaf area injured (leaf injury index) was explained mainly by the accumulated exposure of ozone (r(2)=0.91; p<0.05).
Furlan
C M
CM
Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, CP 11461, São Paulo, SP, Brazil. furlancm@yahoo.com.br
Moraes
R M
RM
Bulbovas
P
P
Domingos
M
M
Salatino
A
A
Sanz
M J
MJ
D001938:Brazil; D004781:Environmental Exposure / Q000009:adverse effects; D004784:Environmental Monitoring / Q000379:methods; D010083:Oxidants, Photochemical / Q000032:analysis*; D010126:Ozone / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects; D031647:Psidium / Q000737:chemistry* / Q000187:drug effects; D014329:Tropical Climate
D010083:Oxidants, Photochemical; D010126:Ozone