Fig 1.
Representative pictures of P. lilacinum.
(A) Fungus culture on PDA media. (B) Mycelium of fungi. Scale bar = 25 μm (C and D) Mycelium and conidia of fungi. Scale bars = 50 μm.
Fig 2.
Representative pictures of disease symptoms caused by juveniles of the root-knot nematode M. incognita.
(A) Large root galls or knots were formed throughout the root system of eggplants infected by M. incognita. (B) A closed up picture of a root gall. (C) Juveniles in J2 stage. Scale bar = 200 μm. (D) Egg mass on infected roots. Scale bar = 10 mm.
Fig 3.
Effects of P. lilacinum on egg hatching and juvenile viability of M. incognita.
The eggs or J2s of M. incognita were incubated with suspension cultures of P. lilacinum in petri dishes at different concentrations with serial dilution (S, S/5, S/10, S/20, S/50, S/100), where S is 10 g mycelia in 100 mL distilled water. (A) The number of hatched juveniles was measured to count the rates of egg hatching after 48 h of incubation. (B) The mortality of J2 M. incognita was measured after 48 h of incubation. Different letters indicate statistically significant differences at P < 0.05 (n = 5). DW, distilled water control.
Fig 4.
Direct effects of P. lilacinum on M. incognita eggs and juveniles.
Microscopic observation was performed during the incubation of P. lilacinum with M. incognita eggs (B and C) and juveniles (D) on PDA agar plates. A intact egg was shown in (A). Arrows indicate penetration and aggregation of fungal conidia and mycelia in eggs (B and C) and attaching to a J2 juvenile (D). Scale bars = 50 μm.
Fig 5.
Effect of P. lilacinum on plant growth of eggplants infected by M. incognita.
The plants were inoculated withM. incognita with (P+M) or without (M) preinoculation with P. lilacinum. No inoculation of either M. incognita orP. lilacinum was used as a control (C). Plants were collected 90 days after nematode inoculation to measure plant height (A), fresh weight (B), shoot dry weight (C), and root dry weight (D). Different letters indicate statistically significant differences at P < 0.05 (n = 5).
Fig 6.
Effects of P. lilacinum on photosynthetic pigments and nematode propagation in eggplants infected by M. incognita.
The plants were inoculated with M. Incognita with (P+M) or without (M) preinoculation with P. lilacinum. No inoculation of either M. incognita orP. Lilacinum was used as a control as labeled “C”. Plants were collected 90 days after nematode inoculation to measure total chlorophyll (A) and carotenoids (B) as well as the nematode population (C) and the numbers of galls per root (D). Different letters indicate statistically significant differences at P < 0.05 (n = 5) and “n.d.” represents “not detected”.
Fig 7.
P. lilacinum mitigates the damage to root tissues caused by M. incognita.
Transverse section of the eggplant roots inoculated with M. incognita with (A) or without (B) preinoculation of P. lilacinum. The arrows indicate the females of M. incognita. present in the root tissue. Bar = 0.5 mm.