Biological parameters and host preference of Tyrophagus putrescentiae (Schrank) on different Pleurotus ostreatus cultivars

Tyrophagus putrescentiae (Acari: Acaridae) is a destructive pest of edible fungi. Different species of edible fungi have variable effects on the growth, development and fecundity of T. putrescentiae, but it is unclear whether these effects exist in the same species. We used nine cultivars of the oyster mushroom (Pleurotus ostreatus) to evaluate the development and reproduction parameters of T. putrescentiae at 26 ± 1°C and 80 ± 5% humidity. Different P. ostreatus cultivars had significant effects on the immature stages, female fertility, and reproductive lifespan. Total egg-to-adult development time ranged from 10.0 ± 1.2 d (on Po389 cultivar) to 12.5 ± 1.0 d (on Po62 cultivar). Mite mortality ranged from 54.3 ± 4.2% (on Po86 cultivar) to 100.0 ± 0.0% (on Po62 cultivar). The number of eggs laid per female ranged from 3.2 ± 0.4 (on Po45 cultivar) to 9.1 ± 1.1 (on Po86 cultivar). The average lifespan of females ranged from 3.0 ± 0.5 d (on Po45 cultivar) to 16.3 ± 1.7 d (on Po86 cultivar). Host preference of the mite was significantly different among the nine cultivars with a preference for cultivars Po65, Po80, Po389, and Po86. These results indicate that P. ostreatus cultivars significantly affect the biology of T. putrescentiae and the relationship between mite damage and mushroom yield.

Study on the effect of substrates on some growth and yield indicators of red reishi mushroom (Ganoderma lucidum)

The research aimed to evaluate the effects of 3 types of substrate (containing the main ingredient being Bodhi sawdust, which was treated and mixed according to 3 different formulas) on the growth and productivity of red reishi mushrooms. The results of the study showed that, of the three types of research medium formulations, Bodhi sawdust treated long-term with incubating for 168 hours was the substrate for the highest mushroom yield, reaching 96.73 g\bag, showing through the indexes of the number of fruiting body bunches\bag (3.47 bunches), fruiting body thickness (1.09 cm), fruiting body diameter (14.8 cm), polysaccharide content of mushroom (2.128%). Meanwhile, the substrate containing 70% sawdust and 30% straw substrates had the highest mycelial growth rate (1.02 cm\day) and the shortest mycelial growth time (the mushroom silk covered the whole bag at 26.3 days). Compared with the above two types of media, the formula using sawdust for short-term treatment (incubated for 48 hours) is ineffective in both the mycelial growth and fruiting body formation stages. The obtained research results contribute to perfecting the production process of red reishi mushrooms on the substrate of agricultural by-products, reducing environmental pollution and bringing economic efficiency to the farmers.

Bacterial community diversity, lignocellulose components, and histological changes in composting using agricultural straws for Agaricus bisporus production

Agricultural straws (AS) may serve as potential base-substances in the production of Agaricus bisporus. Six AS that occur across China were investigated in a two-stage composting experiment; lignocellulose components, AS morphology, and the effects of different AS on mushroom yields from 2015–2017 were examined. In addition, microbial biodiversity and their impact on substrate degradation were studied using 16S gene sequenc based on six different AS on the 3rd (I.F), 6th (I.S), and 10th (I.T) day of Phase I, and Phase II (II). Results showed that the six different AS exhibited differences in the progression of degradation under the same compost condition; the wheat straw, rice straw, and cotton straw induced a significantly higher mushroom yield than did the others (P < 0.05); Thermobispora, Thermopolyspora, and Vulgatibacter genera may play an important role in the different AS degradations. According to our experiments, we can adjust formulations and compost methods to obtain high-yield mushroom compost based on different AS in the future.

Performance of oyster mushroom (Pleurotus ostreatus) grown on different fingermillet husk substrates

Substrate type is one of the major factors affecting the growth and yield of oyster mushroom (Pleurotus ostreatus). Five substrates; Finger millet husk, Fingermillet husk + Molasses, Fingermillet husk + Rice bran, Fingermillet husk + Wheat bran, Fingermillet husk +Mustard oilseed cake, were evaluated for growth and productivity of oyster mushroom. The experiment was conducted in a completely randomized design with each treatment replicated seven times. Additives were added on finger millet husk @5% of its dry weight. Standard cultivation practice was followed with steam sterilization and spawning was done in poly bags containing 2.5 kg of wet substrate. Data were collected on time taken for full spawn run, fresh mushroom yield, biological efficiency and cropping duration upto three flushes. Molasses took the least duration (16.86 days) for full spawn run which was found to be statistically at par with wheat bran(17.13 days) and rice bran(17.75 days) whereas control treatment took the longest duration (21.62 days). Rice bran produced the highest fresh mushroom yield (793.04g/bag) with highest biological efficiency (137.92%), which was statistically at par with control, molasses and wheat bran. Similarly, rice bran had least cropping duration (66.62 days) followed by control (67.88 days), molasses (69.14 days), wheat bran (70.12 days) and mustard oilseed cake (73.86 days). The lowest fresh yield (521.84 g/bag) with lowest biological efficiency (90.75%) and the longest cropping duration (73.86 days) was observed on mustard oilseed cake supplementation. This study revealed that molasses, rice bran and wheat bran accelerated spawn run whereas mustard oilseed cake supplementation produced lowest fresh mushroom yield with least biological efficiency and highest cropping duration showing that it was ineffective for increasing yield and productivity of oyster mushroom.

A large-scale study on the effectiveness of a Bacillus subtilis Ch-13-based biofungicide against green mould disease and mushroom yield improvement

The aim of this study was to test a biofungicide based on Bacillus subtilis Ch-13 and its effectiveness in the control of green mould disease of cultivated mushroom in comparison with the fungicide prochloraz. Biofungicide effectiveness in disease control and impact on yield were evaluated on Agaricus bisporus after its natural infection with Trichoderma aggressivum in a commercial mushroom growing facility. An assay for testing the microbial efficacy of the biofungicide was conducted in two different procedures involving either three or two split doses. The highest statistically significant effectiveness in green mould control was shown by the fungicide prochloraz (71.43%), followed by the biofungicide applied in tree split doses (53.57%), and finally its two doses (45.46%). The biofungicide significantly improved yield in comparison with an untreated control and the fungicide prochloraz. Three split applications of B. subtilis strain Ch-13 enhanced mushroom yield to a larger extent than its two split doses, although the same final amount was used in both procedures. Biofungicide application in three split doses increased the total mass of harvested mushrooms 8.41% compared to the untreated control, and 10.53% compared to the fungicide prochloraz. These results implied that the biofungicide should be applied in three split applications: 30 ml (second day after casing) + 15 ml (two weeks after casing) + 15 ml (after first flush, 20-25 days after casing). The biofungicide B. subtilis Ch-13 should be further investigated regarding its joint usage with chemical fungicides in different application procedures, as it showed remarkable characteristics both in terms of promoting mushroom yield and inhibiting the spread of mycopathogenic T. aggressivum.

Functional Analysis of a Novel ABL (Abnormal Browning Related to Light) Gene in Mycelial Brown Film Formation of Lentinula edodes

Lentinula edodes is a globally important edible mushroom species that is appreciated for its medicinal properties as well as its nutritional value. During commercial cultivation, a mycelial brown film forms on the surface of the sawdust growth medium at the late vegetative stage. Mycelial film formation is a critical developmental process that contributes to the quantity and quality of the mushroom yield. However, little is known regarding the genetic underpinnings of brown film formation on the surface of mycelial tissue. A novel causal gene associated with the formation of the mycelial brown film, named ABL (Abnormal browning related to light), was identified in this study. The comparative genetic analysis by dihybrid crosses between normal and abnormal browning film cultivars demonstrated that a single dominant allele was responsible for the abnormal mycelium browning phenotype. Whole-genome sequencing analysis of hybrid isolates revealed five missense single-nucleotide polymorphisms (SNPs) in the ABL locus of individuals forming abnormal partial brown films. Additional whole-genome resequencing of a further 16 cultivars showed that three of the five missense SNPs were strongly associated with the abnormal browning phenotype. Overexpression of the dominant abl-D allele in a wild-type background conferred the abnormal mycelial browning phenotype upon transformants, with slender hyphae observed as a general defective mycelial growth phenotype. Our methodology will aid the future discovery of candidate genes associated with favorable traits in edible mushrooms. The discovery of a novel gene, ABL, associated with mycelial film formation will facilitate marker-associated breeding in L. edodes.

Evaluation of some organic substrates for the growth and yield of oyster mushroom Pleurotus ostreatus (Jacq.Fr.) Kumm in southeast Nigeria

Four organic substrates; Mahogany Sawdust (MSD), Corn Cobs (CC), Oil Palm Fruit Fibre (OPFF) and Rice Bran (RB) were evaluated for their effects on growth and yield of Pleurotus ostreatus (Jacq.Fr.) Kumm. The completely randomized experimental design was adopted for the study with 4 treatments replicated 10 times. Results on mean number of days for spawn run, primordial formation and formation of fruit body were 19.90±0.28(CC)-25.20±0.29(MSD), 45.10±0.28(CC)-47.90±0.23(MSD) and 56.50±0.22(CC)-59.40±0.27(MSD), respectively. Similarly, height of stipe, diameter of stipe and diameter of pileus ranges were 3.28±0.13 (MSD)-3.51±0.06 (RB),1.26±0.06 (OPFF)-1.39±0.05(RB) and 4.08±0.05(CC)-4.70±0.04(OPFF), respectively. Fresh weights (g), dry weights (g) and biological efficiency were 10.20±0.31(OPFF)-11.05±0.14(MSD), 3.18±0.15(CC)-3.38±0.13(RB) and 4.14±0.14 (OPPF)-4.42±0.06(MSD), respectively. Results on mushroom growth showed that CC took the least duration for full mycelial colonization and the longest duration occurred on MSD. There were significant differences (P ≤ 0.05) between the durations required for primordia formation among the four organic substrates. The results on mushroom yield showed that mean fresh weights of harvested mushrooms varied from 10.20±0.31 g on OPFF to 11.05±0.14 g on MSD. There were no significant differences (P ≥ 0.05) in the biological efficiency of mushrooms grown on MSD, CC and OPFF substrates. Considering the growth and yield attributes RB was observed to be the best substrate and could be used for commercial production of P. ostreatus among the various organic substrates used in this study.