Effects of colonization by endophytic fungi of Cunninghamia lanceolata leaves on litter decomposition and associating microbial activities

Abstract:

[Background] Plant endophytic fungi begin to play an important role in litter decomposition with the death of plant tissues into the saprophytic process. However, this effect may vary with plant species and endophytic fungi species. [Objective] in order to analyze the effects of endophytic fungi with different dominance on litter decomposition and associating microbial activity. [Methods] Leaf litters of Cunninghamia lanceolata were selected in this study as the decomposition substrate with litterbag method. [Results] The colonization of endophytic fungi or their combinations almost significantly accelerated litter decomposition at the former stage of decomposition process, but at the later stage this acceleration effect was weakened, and even their colonization inhibited the decomposition process except Irpex lacteus and Colletotrichum sp. The responses of each variable of microbial activity to endophytic colonization were not completely consistent with the mass loss, and these responses depended on decomposition stage. CO2 releasing showed a poor correlation to mass loss at the former stage of decomposition, but a close correlation at the later stage. Carboxymethyl cellulose (Cx enzyme) greatly contributed to mass loss at the former stage of decomposition, but the contributions of laccase and peroxidase to mass loss were improved at the later stage. In a word, the colonization of endophytic fungi had a great influence on litter decomposition and associating microbial activities. [Conclusion] The colonization effect of endophytic fungi will contribute to the understanding of the mechanism on supporting soil carbon pool balance and nutrient cycle of forest ecosystem, and is of great significance for studying the restoration of soil fertility in barren plantation.