The fungus Cylindrocladium spathiphylli causes collar and root rot in spathe flowers, inducing yellowing and wilting of leaves in the shoot. This fungus has been scarcely studied for extracellular enzymes. Therefore, an in vitro assay was carried out in randomized design, with three treatments (two normal isolates: LFEE1016 - EPAGRI and MMBF 01/01 - IB/SP; plus control) and six replicates, for enzyme detection. Amylase (AM), lipase (LP), carboxymethylcellulase (CMC) and laccase (LC) were measured by calculating the annulus area, the activity site of the enzymes. Catalase (CT) and gelatinase (GL) were measured by symbols subsequently transformed into scores (1 to 4, from absence to intense production). MMBF 01/01 isolate had the largest areas and enzymes with the highest intensity. Of the enzymes, the largest area was that of LC, followed by LP. LFEEI016 and MMBF 01/01 showed no area for AM and CMC and exhibited weak and equal intensity for CT. The intensity of GT was moderate for MMBF 01/01 (mean score 3.0) and absent for LFEEI016 (mean score 1.0). After production of extracellular enzymes, the isolates were vegetatively altered by temperatures. The assay was in completely randomized factorial design including mycelial discs of the fungal isolates versus three temperatures [23ºC (T1), 33ºC (T2) and 33ºC to 23ºC (T3)] versus four periods (3, 6, 9 and 12 days) and eight replicates in a Petri dish containing PDA and maintained in a BOD chamber. The diameter of colonies was daily measured (mm) in both directions. The noted changes were: innocuous, fungistatic (FS) and fungicide (FC) effect. Statistics was used for temperatures T1 and T3 to verify FS effect and choose the isolates that had higher and lower effect. LFEEI016 isolate showed FS effect at three days at temperatures 33ºC and from 33ºC to 23ºC. In the remaining periods, this isolate suffered FC effect. MMBF 01/01 showed FS effect in all periods. Both isolates statistically showed FS effect. MMBF 01/01 showed higher FS effect at nine days, at the mentioned temperatures, and lower effect at three days. After detection of the change in the mycelial growth rate of the isolates, the production of extracellular enzymes was again verified. The changed isolates were MMBF 01/01 at three and nine days and LFEEI016 at three days. Enzyme production and evaluation were carried out as for normal isolates. MMBF 01/01 isolate - three days, produced the largest areas and enzymes with the highest intensity. Of the enzymes, the largest area was that of LC. Following LC, the area of LP was larger than that of CMC in the isolates. The area of AM was not detected in the isolates. The intensity of GL was higher than that of CT in MMBF 01/01 isolates at three and nine days. For LFEEI016 - three days, the mean intensity of CT was score 2.0 and absence of GL (mean score 1.3). The disease severity should be investigated in the plant among isolates, as well as under natural conditions to determine the evolution of LC compared to the remaining enzymes in the pathogenesis of this fungus in the culture.
Laccase; characterization; spathe flower; collar and root rot
