Microbial Community Structure, Diversity, and Succession During Decomposition of Kiwifruit Litters with Different Qualities

Abstract

There are differences in the litter quality and decomposition rate of kiwifruit varieties, but it is not clear whether these differences are related to microbial communities. The leaf litters of two kiwifruit varieties (A. chinensis cv 'Hongyang' and A. chinensis cv 'Jinyan') were taken as objects, and the structure, diversity, and succession of the soil microbial communities were analyzed using an in situ decomposition experiment. Moreover, the contents of C, N, P, and K in the litters during decomposition were analyzed. The results show that there were variety differences in community structure at the generic level. Lophotrichus, Acaulium, and Fusarium were relatively more abundant in the microbial community of the 'Hongyang' kiwifruit litter, and Humicola and Tausonia were relatively more abundant in the microbial community of the 'Jinyan' kiwifruit litter. Subgroup_6 and Sphingomonas were the dominant bacteria. The bacterial community diversity of 'Jinyan' kiwifruit was higher than that of the 'Hongyang' kiwifruit litter. The community diversity was higher in the middle and later periods. The contents of C and N in the litters were the main factors affecting microbial communities. The abundances of Humicola and Apiotrichum were negatively correlated with the contents of C and N, and the abundances of Sphingomonas and SC-I-84 were positively correlated with the content of C. There were variety differences in the microbial communities corresponding to the decomposition processes of the 'Hongyang' and 'Jinyan' kiwifruit litters. The mechanisms of the variety differences were related to litter quality and the initial soil microbial community.

Keywords: kiwifruit; litter decomposition; litter quality; microbial community; orchard ecosystem; variety difference.

Figure 1

Meteorological conditions of study site and kiwifruit litter. (a) shows daily mean temperature and daily precipitation of study site during decomposition experiment. (b) shows ‘Hongyang’ kiwifruit litter. (c) shows ‘Jinyan’ kiwifruit litter.

Figure 2

Microbial community compositions during kiwifruit litter decomposition. (a,b) show community compositions of fungi at phylum level and generic level, respectively. (c,d) show community compositions of bacteria at phylum level and generic level, respectively. HYIP, HYEP, HYMP, and HYLP represent microbial communities at initial, early, middle, and later periods of litter decomposition of ‘Hongyang’ kiwifruit. JYIP, JYEP, JYMP, and JYLP represent microbial communities at initial, early, middle, and later periods of litter decomposition of ‘Jinyan’ kiwifruit. Same in below figure.

Figure 3

Dominant biomarkers of kiwifruit litters based on linear discriminant analysis effect size (LEfSe). (a,b) show LEfSe results of fungi and bacteria, respectively. HY represents ‘Hongyang’ kiwifruit, and JY represents ‘Jinyan’ kiwifruit. To enhance readability of this figure, legend only retains microorganisms at phylum and genus classification levels.

Figure 4

Venn diagram for number of ASVs during kiwifruit litter decomposition. (a) shows number of ASVs in fungi. (b) shows number of ASVs in bacteria.

Figure 5

Microbial community diversity index during kiwifruit litter decomposition. (a,b) show Chao1 and Shannon diversity indexes of fungal community, respectively. (c,d) show Chao1 and Shannon diversity indexes of bacterial community, respectively. Different uppercase letters indicate significant differences in varieties, and different lowercase letters indicate significant differences in decomposition periods (p < 0.05).

Figure 6

Microbial community succession based on PCoA (principal coordinate analysis) during kiwifruit litter decomposition. (a,b) show PCoA results of fungi and bacteria, respectively.

Figure 7

Microbial community succession based on composition heat maps during kiwifruit litter decomposition. (a,b) show composition heat maps of fungi at phylum and generic levels, respectively. (c,d) show composition heat maps of bacteria at phylum and generic levels, respectively.

Figure 8

Co-occurrence and co-exclusion relationships between microorganisms based on network analysis. (a,b) show network analysis results of fungi and bacteria, respectively. Hum (Humicola), Lop (Lophotrichus), Aca (Acaulium), Fus (Fusarium), Bot (Botryotrichum), Acr (Acremonium), Tau (Tausonia), Asc (Ascobolus), Api (Apiotrichum), Asp (Aspergillus), Pen (Penicillium), Mor (Mortierella), Tre (Trechispora), Par (Paraphaeosphaeria), Pse (Pseudogymnoascus), Pur (Purpureocillium), Sai (Saitozyma), Myc (Mycoarthris); Sub6 (Subgroup_6), Sph (Sphingomonas), SCI (SC-I-84), Hal (Haliangium), KD4 (KD4-96), Bra(Bradyrhizobium), SBR (SBR1031), Gem (Gemmatimonas), Sub17 (Subgroup_17), RB41 (RB41), JG30 (JG30-KF-AS9), MND1 (MND1), Aci (Acidibacter), Nit (Nitrospira), A4b (A4b), Rok (Rokubacteriales), Gai (Gaiella).

Figure 9

Response of microorganisms to litter nutrient content based on redundancy analysis (RDA). (a,b) show RDA results of fungi and bacteria, respectively. IP, EP, MP, and LP represent microbial communities at initial, early, middle, and later decomposition periods. Hum (Humicola), Lop (Lophotrichus), Aca (Acaulium), Fus (Fusarium), Bot (Botryotrichum), Acr (Acremonium), Tau (Tausonia), Asc (Ascobolus), Api (Apiotrichum), Asp (Aspergillus); Sub6 (Subgroup_6), Sph (Sphingomonas), SC (SC-I-84), Hal (Haliangium), KD4 (KD4-96), Bra(Bradyrhizobium), SBR (SBR1031), Gem (Gemmatimonas), Ell(Ellin6067), Sub17(Subgroup_17).