Black root rot (BRR) is a major seedling disease in cotton in Australia. BRR is caused by a soilborne fungus Thielaviopsis basicola, recently re-described as Berkelyomyces spp., that was reported for the first time in 1990 in northern New South Wales (NSW), Australia. The disease is now prevalent across NSW. Since the first detection, much research has been focused exclusively on management; however, little has been investigated to understand the BRR pathogen population. Isolation and collection of pure fungal cultures are essential for investigation of the pathogen diversity and pathogenicity. However, isolation of T. basicola is recalcitrant. In this study, T. basicola were successfully recovered from BRR diseased cotton seedlings in the past three seasons by using a simple 5% carrot agar amended with 100 ppm streptomycin. T. basicola was recovered within three days with the percentage of recovery ranging from 55–76% during the first isolation attempt. This carrot medium provided a simple and vigorous means for isolation of T. basicola.

黑根腐烂病（BRR）是澳大利亚棉花的主要苗木病害。BRR是由土壤传播的真菌Thielaviopsis basicola（最近被重新描述为Berkelyomyces spp。）引起的，该病在1990年首次在澳大利亚新南威尔士州（NSW）报道。该病现在在新南威尔士州普遍流行。自从首次发现以来，很多研究都专门针对管理。然而，很少有人了解BRR病原体种群。分离和收集纯真菌培养物对于调查病原体的多样性和致病性至关重要。但是，分离巴氏杆菌是顽强的。在这项研究中，T。basicola在过去的三个季节中，通过使用简单的5％胡萝卜琼脂和100 ppm链霉素修饰，成功地从BRR病害的棉苗中回收了大豆。T. basicola在三天内被恢复，在第一次隔离尝试中，恢复百分比为55-76％。这种胡萝卜培养基为分离T. basicola提供了一种简单而有力的方法。