Banana (Musa spp.) is one of the world's most important fruits. In 2011, 145 million metric tons, worth an estimated $44 billion, were produced in over 130 countries. Fusarium wilt (also known as Panama disease) is one of the most destructive diseases of this crop. It devastated the 'Gros Michel'-based export trades before the mid-1900s, and threatens the Cavendish cultivars that were used to replace it; in total, the latter cultivars are now responsible for approximately 45% of all production. An overview of the disease and its causal agent, Fusarium oxysporum f. sp. cubense, is presented below. Despite a substantial positive literature on biological, chemical, or cultural measures, management is largely restricted to excluding F. oxysporum f. sp. cubense from noninfested areas and using resistant cultivars where the pathogen has established. Resistance to Fusarium wilt is poor in several breeding targets, including important dessert and cooking cultivars. Better resistance to this and other diseases is needed. The history and impact of Fusarium wilt is summarized with an emphasis on tropical race 4 (TR4), a 'Cavendish'-killing variant of the pathogen that has spread dramatically in the Eastern Hemisphere.

CiteSpace信息可视化软件工具是由华人学者陈超美博士于2004年开发的,凭借其强大和先进的功能,该软件在国内外得到了广泛的应用和关注。国外对该软件的应用主要分布在信息科学、生命科学等领域,国内则主要应用于管理学和技术科学领域。从应用领域来看,主要包括图书情报学、管理学、科技政策、教育学以及具体的技术科学(纳米科学与技术、能源技术、新材料技术、电子信息技术等);从使用功能来看,主要是基于知识图谱的研究前沿与研究热点分析,科学计量学与引文分析,关键词共词网络分析,作者共被引与作者合作网络分析等。最后,针对当前的应用状况,本文对CiteSpace的应用前景和趋势进行了分析和展望。

为深入了解根系分泌物研究进展及发展趋势，以Web of Science核心合集数据库2002—2022年根系分泌物的相关文献为数据源，采用文献计量学方法，借助软件VOSviewer和CiteSpace对年发文量、高产发文国家间合作关系、发文机构、期刊分布、文献共被引和高频关键词等进行可视化处理，并对不同研究阶段主要研究内容进行分析。结果表明，近20年根系分泌物研究领域年发文量总体呈上升趋势，在国际范围内受重视程度越来越高。中国、美国合作关系密切且合作发文最多，中国科学院与美国科罗拉州立大学致力于该领域研究并做出突出贡献，《Plant and Soil》和《Soil Biology & Biochemistry》为主要载体。生态系统、根际微生物、有机酸、基因、胁迫和植物适应性为根系分泌物研究的核心主题；不同研究阶段主要研究内容由早及近表现为信号传导—养分获取—化感作用—植物修复—植物与微生物互作。在分子水平上揭示植物与根际微生物的互作机理、根系分泌物与根际微生物在植物生长过程中的调控功能及分子机制等更为细化的研究将会成为未来一段时间的新兴研究热点。

Fusarium wilt of banana (also known as Panama disease) has been a problem in Australia since 1874. Race 1 of the pathogen ( f. sp. ) is responsible for damage to 'Lady Finger' (AAB, Pome subgroup) and other less widely grown cultivars such as 'Ducasse' (Pisang Awak, ABB). Subtropical Race 4 (STR4) also affects these cultivars as well as Cavendish cultivars (AAA) in southern Queensland and northern New South Wales where cold temperature predisposition is involved. Tropical Race 4 (TR4) has led to the demise of the Cavendish industry in the Northern Territory, and its presence was confirmed in a North Queensland plantation in 2015, which warranted destruction of all banana plants on the property; as of this writing (April 2019), TR4 has spread to two adjacent properties. This review, which was commissioned by Biosecurity Queensland in response to the 2015 TR4 outbreak, considers the key epidemiological factors associated with the onset of a Fusarium wilt epidemic. Resistance to TR4, which is mediated by events following entry by the pathogen into the xylem, is not present in any commercially acceptable banana cultivar. Also, there is no effective chemical agent that can be used to manage the disease. Besides prevention, very early recognition and rapid containment of a disease outbreak are necessary to prevent epidemic development. A good understanding of the key factors responsible for disease development is required when devising practical protocols for the destruction of infected plants, treatment of surrounding infested soil, and reduction of inoculum in plant residues and soil.Copyright © 2019 Pegg, Coates, O’Neill and Turner.

In the last century, the banana crop and industry experienced dramatic losses due to an epidemic of Fusarium wilt of banana (FWB), caused by f.sp. () race 1. An even more dramatic menace is now feared due to the spread of tropical race 4. Plant genetic resistance is generally considered as the most plausible strategy for controlling effectively such a devastating disease, as occurred for the first round of FWB epidemic. Nevertheless, with at least 182 articles published since 1970, biological control represents a large body of knowledge on FWB. Remarkably, many studies deal with biological control agents (BCAs) that reached the field-testing stage and even refer to high effectiveness. Some selected BCAs have been repeatedly assayed in independent trials, suggesting their promising value. Overall under field conditions, FWB has been controlled up to 79% by using spp. strains, and up to 70% by several endophytes and spp. strains. Lower biocontrol efficacy (42-55%) has been obtained with arbuscular mycorrhizal fungi, spp., and non-pathogenic strains. Studies on spp. have been mostly limited to conditions so far, with very few pot-experiments, and none conducted in the field. The BCAs have been applied with diverse procedures (e.g., spore suspension, organic amendments, bioformulations, etc.) and at different stages of plant development (i.e.,, nursery, at transplanting, post-transplanting), but there has been no evidence for a protocol better than another. Nonetheless, new bioformulation technologies (e.g., nanotechnology, formulation of microbial consortia and/or their metabolites, etc.) and tailor-made consortia of microbial strains should be encouraged. In conclusion, the literature offers many examples of promising BCAs, suggesting that biocontrol can greatly contribute to limit the damage caused by FWB. More efforts should be done to further validate the currently available outcomes, to deepen the knowledge on the most valuable BCAs, and to improve their efficacy by setting up effective formulations, application protocols, and integrated strategies.

Banana (Musa spp.) is a staple food for more than 400 million people. Over 40% of world production and virtually all the export trade is based on Cavendish banana. However, Cavendish banana is under threat from a virulent fungus, Fusarium oxysporum f. sp. cubense tropical race 4 (TR4) for which no acceptable resistant replacement has been identified. Here we report the identification of transgenic Cavendish with resistance to TR4. In our 3-year field trial, two lines of transgenic Cavendish, one transformed with RGA2, a gene isolated from a TR4-resistant diploid banana, and the other with a nematode-derived gene, Ced9, remain disease free. Transgene expression in the RGA2 lines is strongly correlated with resistance. Endogenous RGA2 homologs are also present in Cavendish but are expressed tenfold lower than that in our most resistant transgenic line. The expression of these homologs can potentially be elevated through gene editing, to provide non-transgenic resistance.