Strain improvement of edible fungi with Pleurotus eryngii ...

More documents

Recommendations

Info

Proceedings of the 7 th International Conference on Mushroom Biology and Mushroom Products (ICMBMP7) 2011 MATERIALS AND METHODS Strains. Following strains were used for production of hybrids by mating neohaplonts and dikaryotic strains: A commercial P. eryngii dikaryon [1], 11 neohaplonts (designated from PeC9 to PeC45) recovered by dedikaryotization from the commercial P. eryngii dikaryon [2], 4 L. edodes dikaryons (L9, L10, L18, L21) [3], a dikaryotic Pleurotus djamor strain [4], 8 Pleurotus spp. dikaryons (Asp14, CP50, CP253, HK3539, IE200, IE201, P401 and Pleurotus sp. PB) and 6 neohaplonts (designated from L10-1S to L21-2S) recovered by dedikaryorization of L. edodes strains [2]. All strains are stored in the fungal collection of the Department of Food Science and Biotechnology at the Faculty of Chemistry (University of México). The strains were propagated in malt extract agar (MEA) (1.5% malt extract and 2% agar); cultures on MEA plates (Petri dishes) were stored at 2 to 4°C [3]. Hybrids from Matings of P. eryngii Neohaplonts with L. edodes Neohaplonts. Agar cubes (2 mm) full with growing mycelia were cut from the edge of growing cultures of selected P. eryngii and L. edodes neohaplonts. They were placed side by side on MEA plates and incubated at 24ºC. Developing colonies were inspected under the microscope during the following 7 days and those showing clamp connections were reseeded on MEA plates for further evaluation. Hybrids from Di-mon Matings of P. eryngii Neohaplonts with Pleurotus spp. Dikaryons. Four agar cubes (2 mm) full with growing mycelia were cut from the edge of a growing culture of a selected P. eryngii neohaplont and symmetrically distributed on the surface of a MEA plate and incubated at 24ºC until development of 1 cm (∅) colonies. At this stage, a 2 mm agar cube was cut from the edge of a growing culture of a selected dikaryon and placed on the periphery of the growing neohaplont culture. Plates were again incubated at 24ºC and inspected under the microscope every day until appearance of clamp connections on the side opposite to the point of inoculation of the dikaryotic culture. The newly emerging dikaryotic strain (hybrid) was recovered on MEA plates. Mycelium growth of all resulting hybrids as well as of their respective parental dikaryons and neohaplonts was evaluated by placing 8 mm (∅) inocula cut from the edge of a growing culture and placed on MEA, with 3 replicates per strain. Colony diameters were measured after 3, 6 and 9 days incubation and when significant differences were established by variance analysis, strains were classified according to Duncan test. Fruiting of Hybrid Strains. Two types of substrates were used for fruiting of hybrids, one is recommended for fruiting of P. eryngii and the second one for L. edodes (Table 1). Table 1: Substrates for fruiting of P. eryngii and L. edodes hybrids and parental strains Components Substrates (% fresh weight) L. edodes P. eryngii Sawdust 50.0 20.0 Cottonseed waste 36.0 60.0 Millet 6.0 ----- Sorghum (milled) 6.0 ----- Wheat bran ----- 16.0 Ammonium sulfate 0.5 ----- Citric acid 0.5 ----- Benlate 1.0 ----- Calcium carbonate ----- 3.0 Calcium sulfate ----- 1.0 Section: Genomics, Genetics and Breeding 63
Proceedings of the 7 th International Conference on Mushroom Biology and Mushroom Products (ICMBMP7) 2011 Both substrates were used for fruiting hybrids of P. eryngii with L. edodes since each genus requires different substrates for good mycelium growth and fruiting. Hybrids of Pleurotus eryngii neohaplonts with Pleurotus spp. dikaryons were fruited only on P. eryngii substrate. Sawdust, cottonseed waste and millet were soaked in water for 24 h; after draining excess water, ingredients were thoroughly mixed according to formulation and water content of substrate was adjusted to 60%. Lentinula substrate (1.5 Kg) was filled into 25 x 35 cm polypropylene bags and Pleurotus substrate (1 Kg) was filled into 17 x 45 cm polypropylene bags. Sterilization and inoculation of substrates as well as preparation of spawn was according to Ramírez et al. [3]. After incubation for 9 weeks, Lentinula substrates were transferred into the fruiting room and polypropylene bags were completely detached in order to expose the whole surface of the substrate to the environment. After incubation for 9 weeks, P. eryngii substrates were transferred to the fruiting room, polypropylene bags were folded down in order to leave only the upper surface of the substrate exposed to the environment. Conditions in the fruiting room throughout the experiment were 70 to 80% air humidity, 20 to 23°C air temperature and 700 to 900 ppm CO 2 . Fruit bodies developing on the substrates were harvested before pileus edge turned up completely. Harvesting period was 12 weeks for P. eryngii substrates and 8 weeks for L. edodes substrates. Weight of fresh fruit bodies was registered for each substrate bag and biological efficiency was determined as BE = g fresh fruit bodies/100 g dry substrate. Statistical Analysis. Variance analysis of biological efficiencies of hybrids and parental strains were performed to evaluate significant differences and Duncan multiple range test was used to identify the highest producing strains (SPSS ver. 17 for Windows was used for both tests). RESULTS Hybrids from Matings of P. eryngii Neohaplonts with L. edodes Neohaplonts. Eleven hybrids obtained by mating L. edodes and P. eryngii neohaplonts were fruited on both types of substrates shown in Table 1 and biological efficiencies of the six hybrids presenting L. edodes morphology are shown in Table 2. Table 2: Biological efficiencies of hybrids with L. edodes morphology Biological efficiency (g fresh fruit bodies / 100 g dry substrate) Strains L. edodes substrate P. eryngii substrate Duncan Duncan ± σ ± σ test test L10 33.82 ± 9.22 A PeC40 / L18-2S 50.63 ± 16.25 B 44.17 ± 8.04 a L21 62.51 ± 4.21 BC L18 67.67 ± 7.53 C L9 84.13 ± 7.84 D PeC40 / L18-1S 91.32 ± 12.88 D 55.25 ± 7.06 b PeC40 / L10-1S 119.44 ± 15.27 E 53.68 ± 3.18 ab PeC40/ L10-4S2 123.64 ± 6.98 E 61.43 ± 8.45 bc PeC40 / L10-4S 123.64 ± 6.98 E 53.68 ± 3.18 ab PeC40/ L21-2S 153.38 ± 9.32 F 68.60 ± 11.88 c Different letters indicate significant differences in the same substrate Section: Genomics, Genetics and Breeding 64
Page 1: Proceedings of the 7 th Internation
Page 5 and 6: Proceedings of the 7 th Internation
Page 7 and 8: Proceedings of the 7 th Internation
Page 9: Proceedings of the 7 th Internation

Strain improvement of edible fungi with Pleurotus eryngii ...

Create successful ePaper yourself

Delete template?

Save as template?