This is a draft schedule. Presentation dates, times and locations may be subject to change.
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Microbial Community Structure of Conventional and Brown Midrib Corns Ensiled at Low Dry Matter Concentrations with and without a Combo Inoculant
Microbial Community Structure of Conventional and Brown Midrib Corns Ensiled at Low Dry Matter Concentrations with and without a Combo Inoculant
Tuesday, July 11, 2017
Exhibit Hall (Baltimore Convention Center)
We evaluated the effects of an inoculant on the microbial community structure of 4 corn hybrids ensiled at low DM concentration. Treatment design was the factorial combination of 4 corn hybrids (HYB) ensiled with (INO) and without (CON) inoculant. HYB were TMF2R737, F2F817 (A and B, 30.5 and 26.3% DM, respectively), P2089YHR, and P1449XR (C and D, 31.1 and 31.5% DM). B and D were brown midrib mutants. The inoculant contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 105 and 1 × 105 cfu/g of fresh corn). Experimental design was a complete randomized design with treatments replicated 6 times. Corn was chopped, treated or not with inoculant, packed into 7.6L bucket silos, and stored for 100 d. At d 0, bacterial relative abundance (RA, %) of Enterobacteriaceae was lower in D vs. the other hybrids (~51.3 vs 58.4, respectively) and lower for CON vs. INO (54.8 vs. 58.5±1.83, respectively; P < 0.04). For fungi, A and C had a higher RA vs. B and D for Tremellales (~25.8 vs. ~13.9±3.91) and lower RA for Mucoraceae (~3.64 vs. ~7.51 ±1.18; P < 0.04). At d 100 for bacteria, INO had higher RA vs. CON for Lactobacillaceae (99.2 vs. 75.7±3.08) and lower RA for Enterobacteriaceae (0.28 vs. 9.93±1.32) and Lachnospiraceae (0.03 vs. 1.71±0.60; P < 0.05). INO had a lower RA of Leuconostocaceae vs. CON only for D (0.21 vs. 14.5) but not for other HYB (~0.21 vs. ~2.70±1.87; HYB × INO, P < 0.05). For fungi, INO had a lower RA vs. CON for Monascaceae (12.6 vs. 44.7±7.30), and increased incertae sedis Tremellales (8.0 vs. 1.2±2.31) and Saccharomycetales (6.4 vs. 0.3±1.72). INO had less OTUs for bacteria (66 vs. 226±10.7) and more for fungi (45.6 vs. 20.1±3.59; P < 0.01; d 100) vs. CON. PCoA plots showed a separation in the structure of bacterial and fungal communities at d 0 and 100, and within d 100 between the CON and INO. The results indicate that epiphytic microbial composition differ depending on HYB. In addition, INO favored the dominance of the Lactobacillaceae, compared to a more diverse CON, and reduced the dominance of Monascaceae, increasing fungal diversity relative to CON.