TABLE 1.
Occurrence of fungal taxa in the rhizosphere of cucumbera
| Taxon | Mean no. of plates ± SD (no. of plants)
|
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|---|---|---|---|---|---|---|---|---|
| First growth cycle
|
Fifth growth cycle
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| Control | CHA0-Rif | CHA0-Rif (pME3424) | Metalaxyl | Control | CHA0-Rif | CHA0-Rif (pME3424) | Metalaxyl | |
| Paecilomyces marquandii (Massee) Hughes | 2.8 ± 1.7 (9) | 3.9 ± 1.0 (10) | 3.5 ± 1.8 (10) | 3.2 ± 1.6 (10) | 2.8 ± 1.6 (9) | 3.0 ± 1.2 (10) | 3.2 ± 1.5 (10) | 3.2 ± 1.1 (10) |
| Phialocephala humicola S. C. Jong & E. E. Davis | 1.9 ± 1.3 (9) | 3.7 ± 1.6 (9) | 2.5 ± 1.4 (10) | 3.2 ± 1.5 (10) | 2.0 ± 1.2 (9) | 2.1 ± 1.0 (10) | 2.0 ± 1.2 (10) | 2.6 ± 1.7 (9) |
| Fusarium oxysporum Snyder & Hansen | 4.1 ± 1.4 (10) | 4.5 ± 1.3 (10) | 3.1 ± 1.8 (9) | 3.6 ± 1.7 (10) | 1.5 ± 1.0 (8) | 2.2 ± 1.6 (8) | 1.8 ± 1.0 (9) | 1.4 ± 1.0 (8) |
| Gliocladium roseum Bainier | 2.5 ± 2.0 (8) | 2.8 ± 1.6 (9) | 3.6 ± 1.3 (10) | 3.1 ± 1.0 (10) | 1.6 ± 0.8 (9) | 2.1 ± 1.2 (9) | 1.5 ± 1.1 (8) | 1.3 ± 1.2 (8) |
| Penicillium rugulosum Thom | 2.3 ± 1.8 (7) | 3.5 ± 1.6 (10) | 3.4 ± 1.4 (10) | 3.0 ± 1.5 (10) | 1.7 ± 1.6 (8) | 2.1 ± 1.9 (8) | 2.2 ± 1.7 (8) | 1.8 ± 1.1 (9) |
| Mortierella alpina Peyronel | 2.3 ± 1.8 (7) | 3.4 ± 2.2 (8) | 3.4 ± 1.6 (9) | 3.2 ± 1.8 (9) | 1.6 ± 1.1 (9) | 1.7 ± 1.6 (8) | 2.2 ± 1.6 (9) | 2.1 ± 1.4 (8) |
| Verticillium chlamydosporium Goddard | 3.6 ± 1.8 (9) | 4.4 ± 0.8 (10) | 3.7 ± 1.5 (10) | 4.2 ± 0.9 (10) | 1.0 ± 0.9 (7) | 0.7 ± 0.7 (6) | 1.0 ± 1.2 (6) | 1.6 ± 1.4 (7) |
| Trichoderma hamatum (Bonord.) Bainier | 1.4 ± 1.1 (8) | 2.4 ± 1.6 (8) | 2.3 ± 1.8 (8) | 2.2 ± 1.3 (9) | 1.1 ± 0.6 (9) | 0.9 ± 1.0 (6) | 2.1 ± 1.3 (9) | 1.8 ± 1.5 (8) |
| Verticillium nigrescens Pethybr. | 1.6 ± 1.6 (6) | 2.5 ± 1.9 (8) | 1.4 ± 1.6 (5) | 2.3 ± 1.6 (9) | 3.3 ± 1.4 (10) | 2.1 ± 1.8 (8) | 1.8 ± 1.7 (7) | 2.5 ± 1.4 (9) |
| Fusarium tabacinum (Beyma) W. Gams | 2.6 ± 2.1 (7) | 2.6 ± 2.4 (7) | 2.2 ± 2.3 (7) | 2.4 ± 2.2 (7) | 2.5 ± 1.9 (9) | 1.6 ± 2.0 (6) | 3.8 ± 1.5 (10) | 2.2 ± 1.8 (8) |
| Staphylotrichum coccosporum J. Meyer & Nicot | 0.7 ± 1.3 (3) | 1.1 ± 1.3 (5) | 0.6 ± 0.7 (5) | 0.5 ± 0.7 (4) | 3.2 ± 1.5 (9) | 2.9 ± 2.0 (8) | 3.3 ± 1.5 (10) | 3.9 ± 1.9 (9) |
| Coniothyrium fuckelii Sacc. | 1.5 ± 1.4 (7) | 2.0 ± 1.9 (6) | 1.1 ± 1.4 (5) | 1.2 ± 1.0 (7) | 1.0 ± 0.9 (7) | 1.0 ± 1.2 (5) | 1.0 ± 1.2 (6) | 1.3 ± 1.1 (7) |
| Fusarium solani (Mart.) Sacc. | 1.5 ± 2.0 (6) | 2.4 ± 1.9 (8) | 1.3 ± 1.3 (7) | 1.8 ± 1.9 (7) | 0.7 ± 0.7 (6) | 0.9 ± 0.9 (7) | 0.2 ± 0.4 (2) | 0.6 ± 0.5 (6) |
| Trichoderma harzianum Rifai | 1.0 ± 0.8 (7) | 1.3 ± 1.2 (7) | 1.2 ± 1.1 (7) | 1.7 ± 0.8 (10) | 0.3 ± 0.5 (3) | 0.3 ± 0.5 (3) | 0.4 ± 0.5 (4) | 0.4 ± 0.7 (3) |
| Cylindrocarpon destructans (Zins.) Scholten | 0.7 ± 0.8 (5) | 0.5 ± 0.7 (4) | 0.5 ± 0.8 (3) | 0.8 ± 1.3 (4) | 0.7 ± 0.8 (5) | 0.7 ± 1.1 (4) | 0.5 ± 0.7 (4) | 0.4 ± 0.5 (4) |
| Myrothecium roridum Tode ex Steudel | 0.4 ± 0.7 (3) | 0.6 ± 0.7 (5) | 0.5 ± 1.0 (3) | 0.7 ± 0.7 (6) | 0.4 ± 0.7 (3) | 0.4 ± 0.7 (3) | 0.5 ± 0.5 (5) | 0.3 ± 0.7 (2) |
| Monocillium mucidum W. Gams | 0.8 ± 1.6 (3) | 0.3 ± 0.9 (1) | 0.9 ± 1.5 (3) | 0.6 ± 1.0 (4) | 0.5 ± 0.5 (5) | 0.5 ± 0.7 (4) | 0.6 ± 0.7 (5) | 0.3 ± 0.5 (3) |
| Mycelium sterile moniliaceum 1 | 1.5 ± 1.4 (7) | 1.6 ± 1.8 (6) | 2.2 ± 2.0 (6) | 1.8 ± 2.0 (6) | ||||
| Fusarium equiseti (Corda) Sacc. | 0.1 ± 0.3 (1) | 1.4 ± 1.7 (5) | 0.6 ± 1.3 (2) | 0.9 ± 1.7 (3) | 0.2 ± 0.4 (2) | 0.2 ± 0.4 (2) | 0.6 ± 0.5 (6) | 0.2 ± 0.4 (2) |
| Myrothecium verrucaria (Alb. & Schw.) Ditm. ex Steudel | 0.2 ± 0.4 (2) | 0.8 ± 1.2 (5) | 0.3 ± 0.7 (2) | 1.0 ± 1.3 (5) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | 0.3 ± 0.5 (3) | 0.3 ± 0.5 (3) |
| Coniothyrium cerealis E. Müll. | 0.3 ± 0.7 (2) | 0.6 ± 1.0 (4) | 0.2 ± 0.4 (2) | 0.2 ± 0.4 (2) | 0.4 ± 0.5 (4) | 0.5 ± 1.0 (3) | 0.2 ± 0.4 (2) | 0.5 ± 0.8 (3) |
| Cladosporium cladosporioides (Fres.) de Vries | 0.1 ± 0.3 (1) | 0.7 ± 0.9 (4) | 0.7 ± 0.8 (5) | 0.7 ± 1.1 (4) | 0.4 ± 0.7 (3) | 0.1 ± 0.3 (1) | 0.4 ± 0.7 (3) | |
| Exophiala sp. | 0.2 ± 0.4 (2) | 0.2 ± 0.6 (1) | 0.3 ± 0.7 (2) | 1.1 ± 1.0 (7) | 0.3 ± 0.5 (3) | 0.6 ± 1.1 (3) | 0.4 ± 0.7 (3) | |
| Acremonium roseo-griseum (S. B. Saksena) W. Gams | 0.3 ± 0.7 (2) | 0.3 ± 0.7 (2) | 0.5 ± 0.7 (4) | 0.4 ± 0.5 (4) | 0.3 ± 0.5 (3) | 0.4 ± 0.7 (3) | ||
| Trichosporon beigelii (Küchenm. & Rabenh.) Vuill. | 0.4 ± 0.8 (2) | 0.7 ± 1.1 (4) | 0.9 ± 1.5 (5) | 0.2 ± 0.6 (1) | 0.1 ± 0.3 (1) | 0.2 ± 0.6 (1) | 0.3 ± 0.7 (2) | 0.1 ± 0.3 (1) |
| Mucor hiemalis Wehmer f. hiemalis | 0.9 ± 1.1 (5) | 0.4 ± 0.5 (4) | 0.6 ± 0.8 (4) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | |||
| Mycelium sterile moniliaceum 2 | 0.3 ± 0.7 (2) | 0.1 ± 0.3 (1) | 0.4 ± 0.7 (3) | 0.4 ± 1.0 (2) | 0.2 ± 0.6 (1) | 0.3 ± 0.5 (3) | 0.2 ± 0.4 (2) | 0.2 ± 0.6 (1) |
| Truncatella angustata (Pers. ex Lk) Hughes | 0.4 ± 0.8 (2) | 0.8 ± 1.5 (3) | 0.4 ± 0.7 (3) | 0.2 ± 0.6 (1) | 0.3 ± 0.7 (2) | 0.3 ± 0.5 (3) | ||
| Stachybotrys chartarum (Ehrenb. ex Link) Hughes | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.3 ± 0.7 (2) | 0.6 ± 0.8 (4) | 0.3 ± 0.5 (3) | ||
| Mycelium sterile dematiaceum 4 | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.7 ± 1.6 (3) | 0.3 ± 0.5 (3) | 0.4 ± 0.7 (3) | |||
| Scedosporium apiospermum (Sacc.) Sacc. ex Castell. & Chalm. | 0.2 ± 0.4 (2) | 0.3 ± 0.7 (2) | 0.2 ± 0.4 (2) | 0.2 ± 0.6 (1) | 0.3 ± 0.9 (1) | 0.1 ± 0.3 (1) | ||
| Penicillium canescens Sopp | 0.2 ± 0.6 (1) | 0.1 ± 0.3 (1) | 0.2 ± 0.6 (1) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.3 ± 0.5 (3) | 0.1 ± 0.3 (1) | |
| Talaromyces luteus (Sacc.) Stolk & Samson | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | ||
| Mucor minutus (Baijal & B.R. Mehrotra) Schipper | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | |||
| Mucor racemosus Fres. f. racemosus | 0.5 ± 0.5 (5) | 0.3 ± 0.9 (1) | ||||||
| Humicola fuscoatra Traaen var. fuscoatra | 0.1 ± 0.3 (1) | 0.4 ± 0.7 (3) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | ||||
| Phoma eupyrena Sacc. | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | ||||
| Gonytrichum macrocladum (Sacc.) Hughes | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | |||
| Stilbella aciculosa (Ellis & Everhart) Seifert | 0.1 ± 0.3 (1) | 0.3 ± 0.9 (1) | 0.6 ± 1.6 (2) | 0.2 ± 0.6 (1) | ||||
| Mortierella humilis Linnem. ex W. Gams | 0.2 ± 0.4 (2) | 0.4 ± 1.0 (2) | 0.1 ± 0.3 (1) | |||||
| Ramichloridium schulzeri (Sacc.) de Hoog | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | ||||
| Trichosporon sp. | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (3) | 0.1 ± 0.3 (1) | |||||
| Fusarium sambucinum Fuckel | 0.1 ± 0.3 (1) | 0.2 ± 0.6 (1) | 0.3 ± 0.7 (2) | |||||
| Penicillium simplicissimum (Oudem.) Thom | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | |||||
| Chaetomium bostrychodes Zopf | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | |||||
| Fusarium culmorum (W. G. Sm.) Sacc. | 0.2 ± 0.4 (2) | 0.1 ± 0.3 (1) | 0.1 ± 0.3 (1) | |||||
| Stachybotrys cylindrospora Bainier & Sartory | 0.3 ± 0.5 (3) | 0.1 ± 0.3 (1) | ||||||
| Paecilomyces carneus (Duché & Heim.) A.H.S. Brown & G. Sm. | 0.3 ± 0.9 (1) | 0.2 ± 0.6 (1) | 0.1 ± 0.3 (1) | |||||
| Mycelium sterile dematiaceum 1 | 0.1 ± 0.3 (1) | 0.4 ± 1.0 (2) | ||||||
| Mycelium sterile dematiaceum 5 | 0.1 ± 0.3 (1) | 0.2 ± 0.4 (2) | ||||||
| Chaetomium sp. | 0.1 ± 0.3 (1) | |||||||
| Gliocladium sp. | 0.3 ± 0.9 (1) | 0.1 ± 0.3 (1) | ||||||
| Mycelium sterile dematiaceum 3 | 0.4 ± 1.0 (2) | |||||||
| Byssochlamys nivea Westling | 0.2 ± 0.6 (1) | 0.1 ± 0.3 (1) | ||||||
| Cladosporium cucumerinum Ellis & Arth. | 0.2 ± 0.6 (1) | 0.1 ± 0.3 (1) | ||||||
| Absidia spinosa Lendner | 0.2 ± 0.4 (2) | |||||||
| Aspergillus candidus Link ex Link | 0.2 ± 0.4 (2) | |||||||
| Aspergillus niger Tiegh. | 0.2 ± 0.4 (2) | |||||||
| Talaromyces sp. | 0.2 ± 0.4 (2) | |||||||
| Mycelium sterile moniliaceum 3 | 0.5 ± 1.6 (1) | |||||||
| Gliocladium solani (Harting) Petch | 0.4 ± 1.3 (1) | |||||||
| Penicillium chrysogenum Thom | 0.3 ± 0.9 (1) | |||||||
| Mycelium sterile dematiaceum 2 | 0.2 ± 0.6 (1) | |||||||
| Total no. of fungal taxab | 45 | 68 | 57 | 50 | 57 | 52 | 63 | 55 |
| Total no. of fungal propagules (105 CFU/g of rhizosphere soil)c | 3.24 | 3.31 | 2.99 | 2.95 | 1.18 | 5.62 | 1.81 | 1.31 |
The numbers of plates and individual plants in which each taxon was found are indicated. Each treatment was studied using 10 plants per cycle, and for each plant, five plates were used to recover fungi. Data are shown for fungal taxa recovered in at least two plates for one of the treatments in one cycle, and taxa are listed according to their overall occurrence. Fungal taxa occurring in no more than one plate for a given treatment in one cycle were as follows (treatment and cycle are specified in parentheses [c1, 1st cycle control; n1, 1st cycle CHA0-Rif; g1, 1st cycle CHA0-Rif(pME3424); r1, 1st cycle metalaxyl; c5, 5th cycle control; n5, 5th cycle CHA0-Rif; g5, 5th cycle CHA0-Rif(pME3424); r5, 5th cycle metalaxyl]): Acremonium sp. (g1, n1); Acremonium strictum W. Gams (g1, n1, g5); Arthrinium phaeospermum (Corda) M. B. Ellis (g5); Arthrobotrys oligospora Fres. (c1); Ascodesmis microscopica (Croulan) Le Gal (n5); Aspergillus fumigatus Fres. (n1, r5); Aspergillus speluneus Raper & Fennel (n1); Botryotrichum piluliferum Sacc. & March. (g1, n1); Chaetomium nozdrenkoae Serg. (n5); Chrysosporium ana. Renispora flavissima Sigler et al. (r5); Cladosporium herbarum (Pers.) Link ex Gray (r1); Coniothyrium minitans W. A. Campbell (n1); Curvularia inaequalis (Wakker) Boedijn (g1, n1, r5); Cylindrocarpon magnusianum (Sacc.) Wollenw. (r1); Cylindrocarpon obtusisporum (Cooke & Harkness) Wollenw. (g5, r5); Doratomyces stemonitis (Pers. ex Steud.) Morton & G. Sm. (n1); Embellisia chlamydospora (Hoes, Bruehl & Shaw) Simmons (n5); Emericellopsis terricola van Beyma (r1); Fusarium sp. (c5, n5); Geomyces pannorum (Link) Sigler & Carmich. var. pannorum (g5); Humicola grisea Traaen (n1); Leptodontium sp. (c5); Mariannea elegans (Corda) Samson var. punicea Samson (g5); Mortierella sp. (g1, n1); Mucor racemosus Fres. f. sphaerosporus (Haghem) Schipper (c1, n1); Paecilomyces sp. (n1); Penicillium commune Thom (g1); Penicillium olsonii Bain. & Sartory (c1); Penicillium purpurogenum Stoll (g1, n1, c5); Penicillium velutinum van Beyma (c1); Penicillium sp. (n1); Periconia macrospinosa Lefebvre & A. G. Johnson (g1, r1, n5); Petriellidium boydii (Shear) Malloch (g5); Phoma leveillei Boerema & Bollen (c5, n5); Phoma medicaginis Malbr. & Roum. var. pinodella (L.K. Jones) Boerema (c5, r5); Phoma sp. (g1, n1, r1, c5); Preussia terricola Cain (c5, g5); Pseudoeurotium sp. (c5, g5, n5); Rhinocladiella sp. (n1); Rhizopus stolonifer (Ehrenb. ex Link) Lind (g1, n1); Sordaria fimicola (Rob.) Ces. & de Not. (r5); Sporothrix schenckii Hektoen & Perkins (c5, n5, r5); Stachybotrys elegans (Pidopl.) W. Gams (r1, g5, r5); Teniolella sp. (n1); Trichocladium opacum (Corda) Hughes (g1, n5); Trichurus spiralis Hasselbr. (g1, r1); Verticillium lecanii (Zimm.) Viégas (g1, c5); Verticillium tenerum (Nees ex Pers.) Link (c1); Zygorrhinchus moelleri Vuill. (n1); M. sterile moniliaceum 4–25 (in either treatment or control); M. sterile dematiaceum 6–25 (in either treatment or control).
Including taxa listed in footnote a.
Treatments had no statistical influence on results within the first or the fifth cycle. When comparing each treatment over the first and the fifth cycles, the only significant difference was found in the case of the control (P < 0.05; two-way analysis of variance with post hoc simple contrasts).