Characterisation And Development Of Propagation Spawns For Selected Wild Edible Mushrooms From Aberdare National Forest, Kenya

ABSTRACT

Characterization and identification of mushrooms at the species level is an important first step in systematic exploitation in specific applications. Mushrooms industry is growing rapidly in Kenya, importation of cultures and propagation spawns is growing too. The imported strains are susceptible to pest and diseases, and are low yielding. This study aimed at characterising selected wild edible mushrooms using morphological and molecular characteristics and developing of propagation spawns of the selected Kenyan wild edible species of mushrooms. Mushrooms samples were collected with assistance of a taxonomist and local forest dwellers. Structured questionnaires were used for ethno-mycological study. Dominant phenotypic features of the fruiting bodies and spores were observed for morphological analysis. The Ribosomal DNA Internal Transcribed Spacer and Large Sub-Unit regions (rDNA-ITS and nLSU) were amplified and amplicons sequenced for molecular identification. Phylogenetic trees constructed using Neighbour-joining method in MEGA5. Pure cultures were grown in 3 different media potato dextrose agar (PDA), yeast extra agar (YEA) and malt extra agar (MEA) for 10 days for culture morphology studies. The spawning experiment was arranged in completely randomized design with three replicates raised on optimal condition studied from cultures. Ethno-mycology findings at p≤0.05 showed no significant difference among respondents. Collected accessions had numerous striking phenetic features. Based on the basidiomata and spores morphology data, the accessions were classified as members of genus Macrolepiota. The ITS sequences revealed identity (homology percentage from GenBank data base) of Macrolepiota dolichaula [KAB03, RMK04 and RMK08, % identity 100 (AF482839.1)], [MAT06, MAT08 and ZAI02, % identity 100 (AF382839.1)], [KAB07, % identity 100 (HM125516.1)]. The nLSU sequences revealed identity (homology percentage from GenBank data base) of Macrolepiota procera [KAB01, KAB03 KAB07 and ZUT06, % identity 100 (JN940269.1)], Macrolepiota dolichaula [MAT06, RMK04, RMK08 and ZAI02, % identity100 (AF482883.1)], [MAT08 % identity 100 (DQ411537.1)] and Galerina sp. For ZUT016 both ITS and nLSU sequences [% identity 99 (HQ60475.1)]. Nine out of 10 mushrooms could be identified up-to species level. Cultural studies revealed MEA at 25°C and pH 7 was most optimal for the mushrooms samples. Spawn production showed that 100 % sorghum grains can be successfully colonized by mycelia to produce high quality spawn. The ethno-mycology findings in this study envisage the purposeful strengthening of wild edible mushrooms exploitation. Characterization provides additional information enriching GenBank database. Successful development of propagation spawns suggest samples can be cultivated. Diversity studies and cultivation trials are recommended.