ABSTRACT
The aim of this study was to test the phytotoxicity and cytotoxicity of ethanolic and aqueous extracts of different structures of Schinus molle L., an ornamental species commonly used in urban afforestation in Brazil, using seeds of lettuce (Lactuca sativa L.) as its plant model. The extracts were prepared from samples of leaves, inflorescence, green and ripe fruits collected in fields located in Alfenas, state of Minas Gerais, Brazil. The parameters assessed were germination (G), germination velocity index (GVI), root elongation (RE), fresh biomass (FB), dry biomass (DB), normal seedlings (NP), mitotic index (MI) and chromosomal abnormalities (CA). According to results, for the aqueous extract, we found interactions between concentration and plant structures in relation to G, GVI, RE, DB, and CA. There were no statistically significant differences among structures in relation to the percentage of normal seedlings, except among concentrations. However, the interaction for all parameters was statistically significant in relation to ethanolic extracts, except the chromosomal abnormalities. Therefore, the increasing of concentration leads to the reduction of the parameters assessed, showing a concentration-dependent effect. The ethanolic and aqueous extracts of Schinus molle showed phytotoxic effect, indicating the need for reassessment and care in the use of this species for reforestation.
Keywords:
Allelopathy; Cytotoxicity; Phytotoxicity
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Authors (2015). In where: A: G% (Ripe Fruit=93,01+1,29X-0,069X², R²=0,99; green fruit= 100-1,4X, R²=0,97; leaf=96,74+0,65X-0,07X², R²= 0,98; inflorescence=94,86+1,4X-0,08X², R²=0,98); B: GVI (ripe fruit=25,32-0,56X, R²=0,98; green fruit= 23,56-0,56X, R²=0,96; leaf=23,70(-0,08X), R²=0,99; inflorescence=23,13(-0,062X), R²=0,95); C: NP% (Y= 43,33-1,19X, R²=0,97); D: RE (ripe fruit=41,02(-0,87X), R²=0,97; green fruit=49,73(-0,173X), R²=0,99; leaf=46,96(-0,233X), R²=0,97; inflorescence=44,73(-0,116X), R²=0,97); E: FB (Y=1,239-0,0048X-0,0005X², R²=0,98) and F: DB (ripe fruit =0,081+0,001X-0,00004X², R²=0,93; green fruit=0,0911-0,000053X², R²= 0,99; leaf= 0,083-0,00007X², R²=0,99; inflorescence=0,076-0,00006X², R²=0,98)
Source: Authors (2015). Where: A: G% (ripe fruit=100-0,67X, R²=0,92; green fruit=96,97-1,14X, R²=0,93; leaf=96,45-0,025X-0,034X², R²=0,99; Inflorescence=95,72+0,09X-0,04X², R²=0,97 ); B: GVI (ripe fruit=4,88-0,045X, R²=0,98, green fruit =4,91-0,074X, R²=0,99, leaf=4,74-0,075X, R²=0,98, inflorescence=4,82-0,075X, R²=0,98); C: NP% (ripe fruit= 86,73+1,25X-0,07X² , R²0,99; green fruit=100-2,34X, R²=0,91; leaf=99,63-2,34X, R²=0,99; Inflorescence =99,45-2,49X, R²=0,98); D: RE (ripe fruit=6,88-0,11X, R²=0,97, green fruit=51,37(-0,104X), R²=0,95; leaf = 52,94(-0,085X), R²=0,99; Inflorescence =52,85(-0,086X), R²=0,98); E: FB (ripe fruit =1,3-0,011X, R²=0,75; green fruit =1,17-0,00087X², R²=0,97; leaf =1,23-0,023X, R²=0,96; inflorescence=1,29-0,027X, R²=0,94); F: DB (ripe fruit=0,0836 [there was no effect], green fruit=0,079-0,00009X², R²=0,97; leaf=0,08-0,0012X, R²=0,92; inflorescence =0,086-0,014X, R²=0,88).
Source: Authors (2015). In where: A: interphase; B: prophase; C: metaphase; D: anaphase; E: telophase; F: micronucleus; G: C-metaphase; H: missing chromosomes; I: chromosomal bridges; J: stickiness.