scholarly journals Diversity of the Seedborne Fungi and Pathogenicity of Fusarium Species Associated with Intercropped Soybean

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 531
Author(s):  
Xiaoli Chang ◽  
Hongju Li ◽  
Muhammd Naeem ◽  
Xiaoling Wu ◽  
Taiwen Yong ◽  
...  

Maize/soybean relay strip intercropping has been widely practiced in Southwest China due to its high productivity and effective application of agricultural resources; however, several seedborne diseases such as seedling blight, pod and seed decay are frequently observed causing severe yield loss and low seed quality. So far, the population and pathogenicity of the seedborne fungi associated with intercropped soybean remain unexplored. In this study, seeds of 12 soybean cultivars screened for intercropping were collected from three growing regions in Sichuan Province of Southwest China, and the seedborne fungi were isolated from the surface-sterilized seeds. Based on sequence analysis of ribosomal DNA internal transcribed spacer (rDNA ITS), 148 isolates were identified into 13 fungal genera, among which Fusarium covered 55.0% as the biggest population followed by Colletotrichum. Furthermore, Fusarium isolates were classified into five distinct species comprising F. fujikuroi, F. proliferatum, F. verticillioides, F. asiaticum and F. incarnatum through sequence analysis of translation elongation factor 1 alpha (EF-1α) and DNA-directed RNA ploymerase II second largest subunit (RPB2). Among them, F. fujikuroi accounted for 51.22% (42/82) and was isolated from 91.7% (11/12) soybean varieties. Pathogenicity assay showed that five Fusarium species were able to infect the seeds of soybean cultivar “Nandou12” and caused water-soaked or rot symptoms, while F. fujikuroi and F. asiaticum had much higher aggressiveness than other species with significant reductions of seed fresh weight and germination percentage. Accordingly, this study indicates that Fusarium species are the dominant seedborne fungi in the intercropped soybean in Sichuan, China, and this provides some useful references for the effective management of seedborne fungal diseases as well as soybean resistance breeding in maize/soybean relay strip intercropping.

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 211
Author(s):  
Xiaoli Chang ◽  
Li Yan ◽  
Muhammd Naeem ◽  
Muhammad Ibrahim Khaskheli ◽  
Hao Zhang ◽  
...  

Fusarium species are the most detrimental pathogens of soybean root rot worldwide, causing large loss in soybean production. Maize/soybean relay strip intercropping has significant advantages on the increase of crop yields and efficient use of agricultural resources, but its effects on the occurrence and pathogen population of soybean root rot are rarely known. In this study, root rot was investigated in the fields of the continuous maize/soybean strip relay intercropping and soybean monoculture. Fusarium species were isolated from diseased soybean roots and identified based on sequence analysis of translation elongation factor 1α (EF-1α) and RNA polymerase II second largest subunit (RPB2), and the diversity and pathogenicity of these species were also analyzed. Our results showed that intercropping significantly decreased soybean root rot over monoculture. A more diverse Fusarium population including Fusarium solani species complex (FSSC), F. incarnatum-equiseti species complex (FIESC), F. oxysporum, F. fujikuroi, F. proliferatum and F. verticillioides, F. graminearum and F. asiaticum was identified from intercropping while FSSC, FIESC, F. oxysporum, F. commune, F. asiaticum and F. meridionale were found from monoculture. All Fusarium species caused soybean root infection but exhibited distinct aggressiveness. The most aggressive F. oxysporum was more frequently isolated in monoculture than intercropping. FSSC and FIESC were the dominant species complex and differed in their aggressiveness. Additionally, F. fujikuroi, F. proliferatum and F. verticillioides were specifically identified from intercropping with weak or middle aggressiveness. Except for F. graminearum, F. meridionale and F. asiaticum were firstly reported to cause soybean root rot in China. This study indicates maize/soybean relay strip intercropping can reduce soybean root rot, change the diversity and aggressiveness of Fusarium species, which provides an important reference for effective management of this disease.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 245 ◽  
Author(s):  
Naeem ◽  
Li ◽  
Yan ◽  
Raza ◽  
Gong ◽  
...  

Intercropping has been considered as a kind of a sustainable agricultural cropping system. In southwest China, maize/soybean strip intercropping has commonly been practised under local limited agricultural land resources. However, heavy rainfall in combination with high humidity and low temperatures cause severe pod and seed deterioration in the maturity and pre-harvesting stages of intercropped soybean. Numerous Fusarium species have been reported as the dominant pathogens of soybean root rot, seedling blight, as well as pod field mold in this area. However, the diversity and pathogenicity of Fusarium species on soybean pods remain unclear. In the current study, diseased soybean pods were collected during the cropping season of 2018 from five different intercropped soybean producing areas. A total of 83 Fusarium isolates were isolated and identified as F. fujikuroi, F. graminearum, F. proliferatum, and F. incarnatum-equiseti species complex based on morphological characteristics and phylogenetic analysis of the nucleotide sequence of EF1-α and RPB2 genes. Pathogenicity tests demonstrated that all Fusarium species were pathogenic to seeds of the intercropped soybean cultivar Nandou12. Fusarium fujikuroi had the maximum disease severity, with a significant reduction of seed germination rate, root length, and seed weight, followed by F. equiseti, F. graminearum, F. proliferatum, and F. incarnatum. Additionally, the diversity of Fusarium species on soybean pods was also considerably distinct according to the geographical origin and soybean varieties. Thus, the findings of the current study will be helpful for the management and resistance breeding of soybean pod decay in the maize/soybean intercropping system.


2021 ◽  
Vol 12 ◽  
Author(s):  
Kaifei Xi ◽  
Liuying Shan ◽  
Yini Yang ◽  
Guoqing Zhang ◽  
Jun Zhang ◽  
...  

Maize stalk rot caused by Fusarium species is one of the most important fungal diseases of maize throughout the world. The disease is responsible for considerable yield losses and has also been associated with mycotoxin contamination of the crop. In this study, a survey of maize stalk rot was performed in seven locations of Yunnan Province in China during the cropping season of 2015 and 2016. Based on morphological and molecular characteristics, 204 isolates belonging to 12 Fusarium spp. from symptomatic stalks of maize were identified. Among the isolated strains, 83 were identified as Fusarium meridionale (40.5%), 46 as Fusarium boothii (22.5%), 34 as Fusarium temperatum (16.5%), 12 as Fusarium equiseti (5.9%), 10 as Fusarium asiaticum (4.9%), six as Fusarium proliferatum (3.0%), four as Fusarium verticillioides (2.0%), four as Fusarium incarnatum (2.0%), two as Fusarium avenaceum (1.0%), one as Fusarium cerealis (0.5%), one as Fusarium graminearum (0.5%), and one as Fusarium cortaderiae (0.5%). Fusarium cortaderiae was the first report on the causal agent of maize stalk rot disease in China. These isolates were divided into five chemotypes: nivalenol (NIV), deoxynivalenol (DON), beauvericin (BEA), zearalenone (ZEN), and fumonisin (FUM). Phylogenetic analysis based on partial sequences of the translation elongation factor 1α (TEF1-α) showed a high degree of interspecific polymorphisms among the isolates. Pathogenicity analysis on maize stalks indicated that all the 12 species of Fusarium were able to cause the disease symptoms with different aggressiveness. This study on population, pathogenicity, and toxigenic chemotypes of Fusarium species associated with maize stalk rot in Yunnan Province of southwest China, will help design an effective integrated control strategy for this disease.


Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 463
Author(s):  
Amal Rabaaoui ◽  
Chiara Dall’Asta ◽  
Laura Righetti ◽  
Antonia Susca ◽  
Antonio Logrieco ◽  
...  

In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.


Plant Disease ◽  
2021 ◽  
Author(s):  
Terry Torres-Cruz ◽  
Briana Whitaker ◽  
Robert Proctor ◽  
Kirk Broders ◽  
Imane Laraba ◽  
...  

Species within Fusarium are of global agricultural, medical, and food/feed safety concern and have been extensively characterized. However, accurate identification of species is challenging and usually requires DNA sequence data. FUSARIUM-ID (http://isolate.fusariumdb.org/) is a publicly available database designed to support the identification of Fusarium species using sequences of multiple phylogenetically informative loci, especially the highly informative ~680 bp 5' portion of the translation elongation factor 1-alpha (TEF1) gene that has been adopted as the primary barcoding locus in the genus. However, FUSARIUM-ID v.1.0 and 2.0 had several limitations, including inconsistent metadata annotation for the archived sequences and poor representation of some species complexes and marker loci. Here, we present FUSARIUM-ID v.3.0, which provides the following improvements: (i) additional and updated annotation of metadata for isolates associated with each sequence, (ii) expanded taxon representation in the TEF1 sequence database, (iii) availability of the sequence database as a downloadable file to enable local BLAST queries, and (iv) a tutorial file for users to perform local BLAST searches using either freely-available software, such as SequenceServer, BLAST+ executable in the command line, and Galaxy, or the proprietary Geneious software. FUSARIUM-ID will be updated on a regular basis by archiving sequences of TEF1 and other loci from newly identified species and greater in-depth sampling of currently recognized species.


2021 ◽  
Vol 13 (2) ◽  
pp. 735-743
Author(s):  
Umesh Hiremath ◽  
Basave Gowda ◽  
Lokesh G.Y . ◽  
B. S. Ganiger

The continuous rise in global population demands more food production under limited land resources accompanied by climate change. More oversupply of quality seeds to meet ever-growing food demand is a highly challenging task. Seeds with low vigour level limit the growth and yield of crops at varied field conditions. Hence, an experiment was conducted to develop a technique for the fast and homogeneous growth of kabuli chickpea seeds. The priming treatments evaluated in the present study enhanced the various seed quality parameters of kabuli chickpea significantly when compared to control. Hydro-priming for 4 hours (at 20°C) and air drying for 72 hours showed better results compared to rest of the treatments both in fresh seeds which recorded higher first count (66.38%), germination (92.50%) root length (11.85 cm), shoot length (6.16), mean seedling length (18.01), dry seedling weight (747 mg), seedling vigour index-I (1665), higher speed of emergence (0.3992) and old seeds with higher first count (61.88%), germination (74.13%) root length (8.15 cm), shoot length (5.85 cm), mean seedling length (14.00 cm), seedling dry weight (611 mg), seedling vigour index-I (1056), higher speed of emergence (0.3814). The aged seeds have recorded 29 % increase in germination percentage in contrast to 8 percent increases in fresh seeds. Kabuli chickpea seeds could be subjected to hydropriming, an affordable, alternative, and eco-friendly technique for improving seed and seedling vigour of kabuli chickpea.


Author(s):  
Esteban Valverde-Bogantes ◽  
Andreia Bianchini ◽  
Stephen Wegulo ◽  
Heather Hallen-Adams

Fusarium head blight (FHB) is an economically important disease caused by several Fusarium species affecting wheat and other small grain cereals. In recent years, reports of shifts in populations of FHB pathogens around the world have shown that these populations are dynamic and change continuously, often resulting in increased yield losses or changes in the mycotoxins produced in the grain, which highlights the need for increased vigilance. The objective of this research was to identify the species and trichothecene genotypes of FHB pathogens in Nebraska in order to monitor their populations and the major toxigenic risks in the state. A total of 74 single-spore Fusarium isolates were obtained from 42 FHB symptomatic wheat spikes collected from Nebraska fields during the growing seasons in 2015-2018. Most of the isolates were identified as F. graminearum (n=67) based on translation elongation factor 1α (TEF1), trichothecene 3-O-acetyltransferase (TRI101), and reductase (RED) sequences. Additional species included F. boothii (n=3), F. poae (n=2), F. acuminatum (n=1), and one isolate was an F. graminearum × F. boothii interspecific hybrid. All F. graminearum and F. boothii isolates had the 15-ADON trichothecene genotype. This study shows that F. graminearum is not the only pathogen causing FHB in Nebraska and helps expand knowledge on the worldwide distribution of F. boothii. The information obtained from this survey will be useful in developing effective FHB management strategies in Nebraska, since different pathogen populations can cause varying levels of disease intensity and can be selectively sensitive to management tactics.


1977 ◽  
Vol 89 (1) ◽  
pp. 107-112 ◽  
Author(s):  
D. Nangju

SummaryField experiments were made in both 1974 rainy seasons in Ibadan, Nigeria, to evaluate the effect of harvest time on seed quality and viability of soya beans (Glycine max (L.) Merr.). The first harvest was made when about 85% of the pods had ripened and subsequent harvests were made at 7-day intervals. Delaying harvest increased the percentage purple-stained, cracked and black seeds in the first season, and of cracked seed in the second season. In the second season soya-bean seeds showed neither purpling nor dark discoloration on the seed coat; the crop matured during sunny, dry weather. However, in both seasons the reduction in seed quality was accompanied by a corresponding decrease in germination percentage. Varietal differences were noted in that the small-seeded Improved Pelican was least affected, and Hardee was the most affected by field weathering in both seasons. Kent and Bossier were intermediate between the two extremes. The results point out the importance of proper timing of harvest of soya beans in rainy seasons, and the need for screening soya beans for resistance to weathering in the tropics.


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