带菌砧木种子和灌溉方式对西瓜嫁接苗细菌性果斑病（BFB）发生的影响

摘要

细菌性果斑病（BFB）是西瓜上的毁灭性病害，育苗工厂因BFB的发生而导致的经济损失严重，本研究旨在探明西瓜嫁接育苗过程中带菌砧木种子和灌溉方式对嫁接苗BFB发生的影响。砧木种子人工接菌后，以带菌砧木幼苗和健康接穗为材料，采用不同的方法嫁接，结果发现， BFB病菌通过嫁接从砧木传递到接穗，导致嫁接苗BFB的发生，不同嫁接方法对BFB的发生无显著差异。发病嫁接苗移栽至健康嫁接苗群体，采用不同灌溉方式提供水分，结果发现，上部喷灌有利于BFB病菌传播，可加剧病情扩展，潮汐灌溉能有效地控制嫁接苗BFB的发生与扩展。%Bacterial fruit blotch (BFB) of cucurbits, caused by Acidovorax avenae subsp. citrulli (Aac), is one of the most devastating diseases for watermelon. In recent years, BFB has caused significant economic losses in the grafted seedling production. In this paper, we investigated the effects of contaminated rootstock seeds and irrigation methods on BFB occurrence in the production process of grafted watermelon seedlings. The rootstock seeds were inoculated Aac artificially, and healthy scions were grafted onto inoculated rootstocks by different grafting methods. The results showed that inoculated rootstock could spread BFB pathogens to scion through grafting, leading to BFB occurrence of grafted seedlings, and different grafting methods had no significant difference on BFB occurrence. After transplanting inoculated grafted seedlings with healthy grafted seedlings, we found that tidal irrigation could significantly reduce BFB occurrence of grafted seedlings compared with upper sprinkler irrigation.