Efficacy of Grain Spawn and Lime/Gypsum Ratio
on Mycelial Growth of Oyster Mushroom
Rukhsana Afzal1*, Abida Akram1, Rehmatullah Qureshi1, Zahid Akram2 and Kishwar Nazir Sultana3
1Department of Botany, Arid Agriculture University, Pakistan
2Department of Plant Breeding and Genetics, Arid Agriculture University, Pakistan
3Institute of Biochemistry and Bioinformatics, Arid Agriculture University, Pakistan
Submission: February 21, 2019; Published: April 17, 2019
*Corresponding author: Rukhsana Afzal, Department of Botany, Arid Agriculture University, Rawalpindi, Pakistan
How to cite this article: Rukhsana A, Abida A, Rehmatullah Q, Zahid A, Kishwar N S. Efficacy of Grain Spawn and Lime/Gypsum Ratio on Mycelial
Growth of Oyster Mushroom. Adv Biotech & Micro. 2019; 13(5): 555871. DOI: 10.19080/AIBM.2019.13.555871
Efficacy of six differential grain spawn i.e. wheat, sorghum, pearl millet, barley, rye and maize were assessed against mycelial growth (mm) of eighteen samples of oyster mushroom collected from hilly areas of Sub-Himalayan range. Grains of pearl millet and sorghum revealed paramount range 2.4-6.95 mm and 2-5.75mm respectively. Five doses of lime Gypsum for spawn production technology against eighteen samples of oyster mushroom exemplified best mycelial growth of 5.5-9mm in 1:1 ratio. Thus, best quality spawn of oysterr mushroom was produced on pearl millet and sorghum with 1:1 lime, gypsum ratio.
Mushroom, a macro-fungus considered as indispensable and cherished food globally owing to its distinctive flavor. They have been stimulated historically by several nations as Romans acknowledged as the “God’s Food” and Chinese as “solution of existence.” They are deliberated as beneficial and profitable diet because of obvious organoleptic worth, therapeutic values and monetary significance . Almost more than 14000 varieties of mushrooms belonging to miscellaneous families have been discovered encompassing 2000 edible mushroom species. Merely five to six edible mushroom species have been commercially cultivated including button and oyster mushrooms respectively [2,3]. Oyster mushroom, member of class basidiomycetes is a ubiquitous second edible mushroom having fleshy, gilled appearance like oyster’s shell termed it “oyster mushroom” . It comprised 40 edible species including P. ostreatus (Jacq. Ex Fr.) P. Kumm., P. citrinopileatus Singer, P. pulmonarius (Fr.) Quel, P. eryngii (DC.) Quel and P. florida (Eger.) as protuberant one [5,6]. All of them contain esteemed nutrients, therapeutic assets and other imperious possessions [7,8]. Oyster mushrooms are cultivationally applicable in both tropical and temperate environments  and its culture attained attractiveness throughout the world due to varied temperature propagation as well as consumption of lignocellulosic wastes [10, 11].
Spawn has prodigious importance in mushroom cultivation technology, which prepared on any agricultural crop substrate or
grain. It has an equivalency to plant seed . Mushroom spawn is a propagating medium comprised of mushroom mycelium along with subsidiary medium indispensable for fungal proper development. Suitable spawn substrate played a fundamental role in crop production and grain spawn possess advantage over other substrate spawn having mushroom mycelium equally distributed on all grain surface and preserved for a long period. Different spawn grains such as corn, wheat, millet have been employed for their impact on different edible mushrooms . Grains retained moisture and aid in quick prevalence of fungal mycelium but it time depends on type and size of grain used . Several additives such as lime and gypsum sustenance in enhancement of fungal mycelium proliferation and expansion by providing essential nutrients. Different doses of these additives affect the fungal mycelial running and spawn production. Therefore, the present study was planned to study the efficacy of different grains and ratio of lime and gypsum on mycelial growth of oyster mushroom.
Eighteen samples of oyster mushroom collected from selected hilly areas of Sub-Himalayan Range during 2012-2014. Pure cultures of these edible mushroom samples were maintained using tissue culture technique . Small tissue portion was taken by an inoculation needle and positioned in the center of petriplates comprising PDA medium and incubated at 25 °C. This
yielded fungal mycelia. Small mycelial plugs of each sample was
taken and placed on the medium under a laminar flow cabinet.
The process was frequently carried out and until hygienic and
uncontaminated mycelial cultures were obtained and preserved
for further studies.
Grains of wheat (Triticum aestivum L.), sorghum (Sorghum
bicolor L.) Moench), pearl millet (Pennisetum glucam (L.) R. Br.),
barley (Hordeum vulgare L.), rye (Secale cearale L.) and maize
(Zea mays L.) were collected from their corresponding sources
at National Agricultural Research Centre, Islamabad, Pakistan.
The grains were cleaned and soaked in water for 24 hours and
spreaded on newspaper to eradicate unnecessary moisture. The
grains were mixed with lime (Calcium carbonate) and gypsum
(Calcium sulphate) in the ratio of 1:1, which helped in balancing
of grain pH. The treated grains were taken in bottles, plugged with
cotton wool, covered with aluminum foil and autoclaved at 15 psi
for 1 hour .
The grain-filled bottles were kept under laminar flow cabinet,
inoculated with 5mm plug of pure cultures of oyster mushroom
and incubated at 27 °C. The data were chronicled after two weeks
on the development of mycelium of oyster mushroom .
Five dissimilar treatments were used i.e. To (0:0, no lime
and gypsum), T1 (1:0, 1 percent lime and 0 percent gypsum), T2
(0:1, 0 percent lime and 1 percent gypsum), T3 (1:1, 1 percent
lime and 1 percent gypsum), T4 (1.5:1.5, 1.5 percent lime and 1.5
percent gypsum). In this, grains of Pearl millet (P. glucam) were
soaked in water for 24 hours and spreaded on the newspaper
to remove unnecessary moisture. After checking grain moisture,
the grains were treated with lime and gypsum in diverse ratios in
bottles, plugged with cotton wool, covered with aluminum foil and
autoclaved at 15 psi for 1 hour. The bottles were further cooled and
inoculated with mycelium of oyster mushroom in decontaminated
circumstances the bottles were incubated at 27 °C and data was
recorded after two weeks in term of mycelial growth (cm) on each
of the treatment .
All grains demonstrated a substantial impression on
progression of all mushroom samples (df= 44, S. S= 195.664,
M. S= 1.918). It was experiential from the conclusions that two
grain substrates i.e. pearl millet and chickpea had a superior
influence as in term of linear growth followed by the sorghum, but
mycelium appeared thin and light in chickpea as related to pearl
millet. Sorghum grains considered as outstanding grains for the
spawn preparation as conveyed by various researchers. In case of
maize, mycelial growth was between 1.5-4.9 mm and maximum
was perceived in Pl-11 and Pl-2. In rye, range of linear growth
was 2.35-4.5 mm with preeminent in Pl-6. In barley, growth was
1.4-3.4 mm with superior in Pl-15. In case of wheat, light growth
was perceived, and this acquired numerous days for execution
of running. The range was 1.35-3.65 with dominant in Pl-2. In
chickpea, Pl-7 showed best linear growth and range in all was
1.95-7.25 mm. In sorghum, 2-5.75 was observed with condensed
mycelial texture in minimum days and best sample was Pl-9. Pearl
millet determined fastest running rates well as compact growth
ranged 2.4-6.95 mm with superlative in Pl-15. Though chickpea
maximum value is maximum but numbers of days for preparation
of spawn were greater than pearl millet and light mycelium.
Both lime and gypsum act as a buffer for the mycelial expansion
of oyster mushroom. Calcium from both of them oxidized the oxalic
acid produced by the fungal mycelium. Five different treatments
were experienced to assess the best lime to gypsum ratio such
as T0, 0:0; T1, 1:0; T2, 0:1; T3, 1:1 and T4, 1.5:1.5 (df= 68, S.S=
445.707, M.S= 6.55). The lime to gypsum ratio 1:1 was preeminent
for spawn manufacturing process and its long-term preservation.
In T0, having no lime and gypsum displayed augmented mycelial
growth on grains but had sticky presence in the future and there
was no pH maintenance. The T1 and T2 revealed slight rise in the
mycelial growth whereas T3 and T4 respond well to the mycelial
advancement of oyster mushroom. In the T0, pragmatic linear
growth was 2-8.5 mm with paramount samples were Pl-6 and Pl-
10. In T1, superlative growth was in Pl-11 tracked by Pl-7. In T2,
maximum growth was seen in Pl-18 followed by Pl-17. In T3, the
range was 5.5-9 mm with supreme increased by all samples. In T4,
Pl-18 had maximum one and range was 2-7.8 mm. Though T0 had
a worthy growth percentage but grain adhesiveness was observed.
So, for the paramount spawn production, 1:1 lime and gypsum
ratio was employed in the future. Both chemicals demonstrated a vibrant fragment in spawn preparation and storage eventually
resulted in better mushroom production. It was determined that
lime/gypsum ratios and samples both momentously influenced
the mushroom progression rate and their collaborations exhibited
inordinate importance over the fungal mycelium (Table1),
In mushroom cultivation, spawn is regarded as fermented
provision of mushroom seeds on a proper grain or crop substrate
under aseptic conditions. Spawn incorporates fungal mycelium
and supportive medium primarily from pure mushroom culture
. Due to the capability of substrate strengthening and easiness
of planting grain spawn is in common practice. In this, Pearl millet
and sorghum grains revealed superlative mycelium running rate.
Spawn running on diverse grains related to their size as extreme
inoculation points was provided by small grains for completion,
however larger grains with great reserved food have an capacity
to maintain fungal mycelium in traumatic condition for longer
period [20,21]. Quality of diverse grain and additives ratio
significantly affected the spawn running [22,23]. Millet grains are
best carbohydrate source certifying suitable nutritive supremacy
for mycelium propagation . Millet grain for spawn production
of mushroom was also determined [25,26]. Extensive oyster
mushroom production can be conquered using collective grain
substrate of millet and sorghum in 1:3 ratios [27,28].
Improved fungal mycelium rate was observed on red sorghum
followed by blending of red and white sorghum . Four
different grains (wheat, barley, sorghum and millet) subsidized
equally in quality spawn production of oyster mushroom [30,31].
Enhancement of spawn structure and inadequacy of pH was
carried out by suitable lime and gypsum ratio as unnecessary lime
causes decline in fungal mycelial growth as well as nutrients taking
capacity [32,33]. Mushroom mycelium can flourish efficaciously at
explicit pH level, due to proper uptake of substrate’s nutrients by
fungal mycelium . Greatest spawn running was perceived at
1:1 lime, gypsum ratio. Accrual of lime improved the lignocellulytic
enzyme production owing to neutral pH and crucial minerals,
Sulphur and calcium existence .