Fungal communities associated with the lenticel damage of avocado cv. Hass. Characterization of the lenticel damage of avocado cv. Hass and its associated fungal communities

The lenticel damage reduces the quality of avocado cv. Hass, leading to high fruit rejection rates and losses for the growers. The causes of this affectation are not fully understood, but mechanical stress and phytopathogens have been associated with the damage, suggesting that abiotic and biotic factors are involved. This study evaluated several aspects of the lenticel damage of avocado cv. Hass to unravel the nature of its causality. Precisely, we followed the lenticel damage in two Colombian farms for two years and found that spatiotemporal factors influence the damage as it is non-uniform and progressive. Then, we used NGS to characterize fungal communities of fruits with severe and mild injuries and found that these communities varied between farms. We also found that the damage severity influenced the composition of the fungal communities as some taxa were more common in avocados with severe damage. Finally, we isolated different fungi from necrotic lenticel to see whether we found some of these enriched taxa. Still, the isolated fungi did not coincide, showing that standard culturable techniques fail to capture the complexity of the fungal communities associated with the lenticel damage.

皮孔损伤会降低哈斯鳄梨（avocado cv. Hass）的品质，导致果实拒收率居高不下，给种植者带来显著经济损失。目前学界尚未完全明确该损伤的致病成因，但已有研究将机械胁迫与植物病原菌与该损伤关联起来，提示非生物与生物因素均参与了损伤的发生发展过程。本研究针对哈斯鳄梨皮孔损伤的多个维度展开系统性评估，以阐明其致病成因的本质。具体而言，研究团队在哥伦比亚的两座农场中对皮孔损伤情况进行了为期两年的跟踪监测，结果发现该损伤呈不均匀且渐进式发展的特征，时空因素对其存在显著影响。随后，本研究通过下一代测序（Next-Generation Sequencing, NGS）技术，对损伤程度轻重不一的鳄梨果实的真菌群落进行表征分析，发现不同农场间的真菌群落结构存在显著差异。研究同时发现，损伤严重程度会影响真菌群落的组成，部分分类单元在重度损伤的鳄梨果实中更为常见。最后，本研究从坏死皮孔中分离得到多种真菌，以验证是否能获取到前述富集的分类单元。但最终分离得到的真菌类群与前述富集类群并不匹配，这表明传统可培养技术无法完整揭示与皮孔损伤相关的真菌群落的复杂性。