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Root-knot nematodes (Meloidogyne spp.) are serious pests of most food crops, causing up to 100% yield loss. Nevertheless, commercial nematicides are costly and harmful to the environment. While the nematicidal potential of crustacean and synthetic chitin has been demonstrated globally, research on the potential of insect-derived chitin for nematode control has received limited attention. Here, seven chitin-fortified black soldier fly frass fertilizer extracts (chFE) were assessed for their suppressiveness of Meloidogyne incognita and impacts on spinach growth in comparison with a commercial nematicide using in vitro and in vivo bioassays. The performance of chFE and control treatments was assessed by determining their effects on nematode egg hatchability; infective juvenile (J2) mortality and paralysis; number of galls, egg masses, and J2s per plant; and spinach root and shoot biomass. In vitro results showed that chFE and commercial nematicide suppressed nematode egg hatchability by 42% and 52%, respectively, relative to the control (sterile distilled water). Up to 100% paralysis was achieved when M. incognita J2s were exposed to either chFE or commercial nematicide. Further, the J2 mortality achieved using chFE (95%) was comparable to the value achieved using commercial nematicide (96%); in all treatments, mortality increased with exposure time. Similarly, up to 85% suppression of gall development was achieved when spinach plants were grown in soil drenched with chFE; up to 79% reduction in egg mass formation and 68% suppression of J2 development in the root system were achieved using chFE. Also, chFE application significantly increased spinach root and shoot biomass by 54%-74% and 39%-58%, respectively, compared to commercial nematicide. Our findings demonstrate the nematicidal potential of chFE and its benefits on crop production. Thus, chFE could be considered as a promising multipurpose, regenerative, and cost-effective input for sustainable management of plantparasitic nematodes and enhancement of crop yield. [ABSTRACT FROM AUTHOR]

Potato production faces major challenges from inadequate soil fertility, and nematode infestation, yet synthetic fertilizers and nematicides are costly and harmful to the environment. This study explored the potential of chitin-fortified black soldier fly-composted organic fertilizer (BSFCOF) as a multipurpose organic fertilizer amendment for enhancing potato yield and suppressing potato cyst nematodes (PCN). The BSFCOF was applied at a rate equivalent to 150 kg N ha-1 and fortified with chitin from black soldier fly pupal exuviae at inclusion rates equivalent to 0.5, 1, 2, 3, 4 and 5% chitin. Data were collected on potato growth characteristics, PCN population densities, and soil chemical properties for two growing cycles. Results showed that chitin fortified BSFCOF significantly improved potato growth parameters, chlorophyll concentration, marketable tuber yield and number of marketable tubers. The marketable tuber yield achieved using chitin-fortified BSFCOF was 70 - 362%, and 69 - 238% higher than the values achieved using unfertilized soil during the first and second growing cycles, respectively. Soil amendment with chitin-fortified BSFCOF significantly reduced the number of cysts per 200 g soil-1, number of eggs and J2 per cyst-1, eggs g-1 soil and reproduction rate by 32 - 87%, 9 - 92%, 31-98% and 31 - 98%, respectively. The PCN suppression increased with chitin inclusion rates. There were significantly higher values for soil pH, ammonium nitrogen, nitrate nitrogen, available phosphorus, calcium, magnesium, potassium, and cation exchange capacity in soil amended with BSFCOF compared to unamended soil. This study demonstrates that BSFCOF fortified with 5% chitin is an effective soil enhancer with multiple benefits, including improved soil fertility, potato performance, and effective management of potato cyst nematodes. [ABSTRACT FROM AUTHOR]

Author(s): Salim S. Abdool Karim 1,2,*, Segenet Kelemu 3, Cheryl Baxter 1 Introduction The Coronavirus Disease 2019 (COVID-19) pandemic has dramatically changed everyone's lives, highlighting the fragility of systems providing [...]

Anthracnose is a very limiting disease affecting production, as well as postharvest quality of numerous fruit crops in Colombia. The current management practices for this disease are partially effective due to limited information about the etiology, the inoculum sources, population structure and variation of the pathogen. A total of 293 Colletotrichum isolates were obtained from symptomatic tissues collected from Tahiti lime, tamarillo and mango orchards. To determine the Colletotrichum species causing the symptoms, amplification, and PCR product analysis for intergenic regions of the ribosomal DNA were conducted. Genetic diversity of the fungal population was assessed with Random Amplified Microsatellites (RAMS). Results of this study indicated that anthracnose in Tahiti lime and tamarillo are caused by Colletotrichun acutatum whereas symptoms on mango were induced by the species Colletotrichum gloeosporioides, which was also fund in fewcitrus samples. RAMS data analysis indicated the existence of two distinct species groups, with a low similarity index (35%). RAM profiles also showed a clear host differentiation of isolates. The C. acutatum population originated from tamarillo exhibited a narrow and homogeneous genetic base, while the C. acutatum population from Tahiti lime was more heterogeneous and genetically complex, as determined by the analysis of molecular variance (AMOVA) and of Ni-Li coefficient. The C. gloeosporioides population originated from mango and Tahiti lime was heterogeneous and highly diverse, with clear host differentiation according to RAM profiles. Collectively, the results from this study provide new insight into the general characteristics of Colletotrichum populations on various hosts; this type of knowledge will prove useful in designing more effective management practices.

Two sets of independently regulated pectate lyase isozymes capable of macerating plant tissues were produced by Erwinia chrysanthemi EC16. Mutant CUCPB5012, which directs mutations in all the known enzymes in all clearing alpha-1,4 galacturonosyl linkages, is constructed to seek the unknown components of the pectolytic activity of E.chrysanthemi EC16. A novel set of pel isozymes in inoculated chrysanthemum cuttings and in minimal medium supplemented with crysanthemum cell walls is produced by the mutant which retains some ability to macerate chrysanthemum tissues.

Black soldier fly frass fertilizer (BSFFF) is increasingly gaining momentum worldwide as organic fertilizer. However, research on its performance on crop production remains largely unknown. Here, we evaluate the comparative performance of BSFFF and commercial organic fertilizer (SAFI) on maize (H513) production. Both fertilizers were applied at the rates of 0, 2.5, 5, and 7.5 t ha-1, and 0, 30, 60, and 100 kg nitrogen (N) ha-1. Mineral fertilizer (urea) was also applied at 0, 30, 60 and 100 kg N ha-1 to establish the N fertilizer equivalence (NFE) of the organic fertilizers. Maize grown in plots treated with BSFFF had the tallest plants and highest chlorophyll concentrations. Plots treated with 7.5 t ha-1 of BSFFF had 14% higher grain yields than plots treated with a similar rate of SAFI. There was a 27% and 7% increase in grain yields in plots treated with 100 kg N ha-1 of BSFFF compared to those treated with equivalent rates of SAFI and urea fertilizers, respectively. Application of BSFFF at 7.5 t ha-1 significantly increased N uptake by up to 23% compared to the equivalent rate of SAFI. Likewise, application of BSFFF at 100 kg N ha-1 increased maize N uptake by 76% and 29% compared to SAFI and urea, respectively. Maize treated with BSFFF at 2.5 t ha-1 and 30 kg N ha-1 had higher nitrogen recovery efficiencies compared to equivalent rates of SAFI. The agronomic N use efficiency (AEN) of maize treated with 2.5 t ha-1 of BSFFF was 2.4 times higher than the value achieved using an equivalent rate of SAFI. Also, the AEN of maize grown using 30 kg N ha-1 was 27% and 116% higher than the values obtained using equivalent rates of SAFI and urea fertilizers, respectively. The NFE of BSFFF (108%) was 2.5 times higher than that of SAFI. Application rates of 2.5 t ha-1 and 30 kg N ha-1 of BSFFF were found to be effective in improving maize yield, while double rates of SAFI were required. Our findings demonstrate that BSFFF is a promising and sustainable alternative to commercial fertilizers for increased maize production. [ABSTRACT FROM AUTHOR]

Abstract: Maize (Zea mays) emits volatile terpenes in response to insect feeding and egg deposition to defend itself against harmful pests. However, maize cultivars differ strongly in their ability to produce the defense signal. To further understand the agroecological role and underlying genetic mechanisms for variation in terpene emission among maize cultivars, we studied the production of an important signaling component (E)‐caryophyllene in a South American maize landrace Braz1006 possessing stemborer Chilo partellus egg inducible defense trait, in comparison with the European maize line Delprim and North American inbred line B73. The (E)‐caryophyllene production level and transcript abundance of TPS23, terpene synthase responsible for (E)‐caryophyllene formation, were compared between Braz1006, Delprim, and B73 after mimicked herbivory. Braz1006–TPS23 was heterologously expressed in E. coli, and amino acid sequences were determined. Furthermore, electrophysiological and behavioral responses of a key parasitic wasp Cotesia sesamiae to C. partellus egg‐induced Braz1006 volatiles were determined using coupled gas chromatography electroantennography and olfactometer bioassay studies. After elicitor treatment, Braz1006 released eightfold higher (E)‐caryophyllene than Delprim, whereas no (E)‐caryophyllene was detected in B73. The superior (E)‐caryophyllene production by Braz1006 was positively correlated with high transcript levels of TPS23 in the landrace compared to Delprim. TPS23 alleles from Braz1006 showed dissimilarities at different sequence positions with Delprim and B73 and encodes an active enzyme. Cotesia sesamiae was attracted to egg‐induced volatiles from Braz1006 and synthetic (E)‐caryophyllene. The variation in (E)‐caryophyllene emission between Braz1006 and Delprim is positively correlated with induced levels of TPS23 transcripts. The enhanced TPS23 activity and corresponding (E)‐caryophyllene production by the maize landrace could be attributed to the differences in amino acid sequence with the other maize lines. This study suggested that the same analogous genes could have contrasting expression patterns in different maize genetic backgrounds. The current findings provide valuable insight not only into genetic mechanisms underlying variation in defense signal production but also the prospect of introgressing the novel defense traits into elite maize varieties for effective and ecologically sound protection of crops against damaging insect pests. [ABSTRACT FROM AUTHOR]

Microsatellite sequences are one of the best options for the study of genetic diversity in plant species. However, because of the high cost of their development, it is important to test whether existing sequences from related species can be exploited. Enset (Ensete ventricosum(Welw.) Cheesman) has remained largely unimproved partly due to lack of its genetic information, thus there is a need to study the genetic diversity of current accessions and build on it to develop new cultivars/varieties with desired agronomic traits. Transferability of 71 SSR loci from banana (Musa accuminata) to enset was investigated using 220 Enset accessions. Among the 71 SSRs tested, 12 (16.9%) were successfully transferable to enset. Eleven (16.9%) of these were used to examine the diversity of the 220 enset accessions that had been collected from eight different zones in Ethiopia. [ABSTRACT FROM PUBLISHER]

Abstract: Acremonium implicatum is a seed-transmitted endophytic fungus that forms symbiotic associations with the economically significant tropical forage grasses, Brachiaria species. To take advantage of the endophyte''s plant protective properties, we developed an efficient Agrobacterium-mediated transformation system for Acremonium implicatum, using green fluorescent protein (GFP) expression and vector pSK1019 (trpC promoter) or pCAMBIA1300 (CaMV35S promoter). We found that transformation efficiency doubled for both mycelial and conidial transformation as the co-cultivation period for Agrobacterium tumefaciens and Acremonium implicatum was increased from 48 to 72h. Significantly, optimal results were obtained for either mycelial or conidial transformation with Agrobacterium tumefaciens strain AGL-1 and vector pSK1019 under the control of the trpC promoter. However, mycelial transformation consistently generated a significantly higher number of transformants than did conidial transformation. The mitotic stability of the transferred DNA was confirmed by growing ten transformants in liquid and agar media for six generations. In all cases, resistance to the selection pressure (hygromycin B) was maintained. Fluorescence emission was retained by the transformants and also expressed in Brachiaria tissues from plants inoculated with GFP-transformed A. implicatum. This technology will help in the transfer and expression of agronomically important genes in host plants. [Copyright &y& Elsevier]

Abstract: The tropical forage legume Clitoria ternatea (L.) has important agronomic traits such as adaptation to a wide range of soil conditions and resistance to drought. It is resistant to a number of pathogens and pests. These important traits gave us reasons to look more closely at the plant. A highly basic small protein was purified from seeds of C. ternatea to homogeneity by using ultrafiltration with Centricon-3 membrane tubes and preparative granulated-bed isoelectric focusing (IEF). A single protein band was obtained on both sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and IEF gels. The protein, designated ‘finotin’, has broad and potent inhibitory effect on the growth of various important fungal pathogens of plants, namely Rhizoctonia solani, Fusarium solani, Colletotrichum lindemuthianum, Lasiodiplodia theobromae, Pyricularia grisea, Bipolaris oryzae and Colletotrichum gloeosporioides. It also inhibits the common bean bacterial blight pathogen Xanthomonas axonopodis pv. phaseoli. Moreover, finotin has powerful inhibitory properties against the bean bruchids Zabrotes subfasciatus and Acanthoscelides obtectus. [Copyright &y& Elsevier]

Brachiaria is a pan-tropical genus of grasses with about 100 species. The fungus Acremonium implicatum can develop an endophytic association that is mutually beneficial with Brachiaria species. We developed a polymerase chain reaction (PCR)-based method by first amplifying DNA from A. implicatum isolates using the Random amplified polymorphic DNA (RAPD) technique with arbitrary 10-mer primers. A 500-bp PCR product, amplified with primer OPAK-10 and common to A. implicatum isolates, was selected for further evaluation. The fragment was digoxygenin-labelled and used to probe a dot blot containing genomic DNA from isolates of A. implicatum and non-endophytic fungi, and from Brachiaria species free of endophytes. Strong signals were obtained only for DNA from A. implicatum isolates. This fragment was cloned and subsequently sequenced. Based on the sequence data, two primers were selected and synthesized: P1 (5'-TTCGAATGATAAGGCAGATC-3') and P4 (5'-ACGCATCCACTGTATGCTAC-3'). The primer pair amplified a single fragment of about 500 bp from DNA of A. implicatum isolates, whether from pure culture or in association with Brachiaria plants. No amplification product was detected in DNA from endophyte-free plants, pathogenic fungi, the bacterium Xanthomonas campestris pv. graminis, or non-pathogenic fungi associated with Brachiaria. This assay thus allows the precise and rapid detection of endophytes in Brachiaria plants and permits a differentiation between endophytic and non-endophytic fungi. [ABSTRACT FROM AUTHOR]

The need for easily biodegradable and less toxic chemicals in drug development and pest control continues to fuel the exploration and discovery of new natural molecules. Like certain plants, some insects can also respond rapidly to microbial infections by producing a plethora of immune-induced molecules that include antibacterial and antifungal peptides/polypeptides (AMPs), among other structurally diverse small molecules. The recent recognition that new natural product-derived scaffolds are urgently needed to tackle life-threatening pathogenic infections has been prompted by the health threats posed by multidrug resistance. Although many researchers have concentrated on the discovery of AMPs, surprisingly, edible insect-produced AMPs/small molecules have received little attention. This review will discuss the recent advances in the identification and bioactivity analysis of insect AMPs, with a focus on small molecules associated with the microbiota of selected African edible insects. These molecules could be used as templates for developing next-generation drugs to combat multidrug-resistant pathogens. [ABSTRACT FROM AUTHOR]

Globally, there is growing interest to integrate insect-derived ingredients into food products. Knowledge of consumer perception to these food products is growing rapidly in the literature, but similar knowledge on the use of oils from African edible insects remains to be established. In this study, we (1) compared the chemistry of the oils from two commonly consumed grasshoppers, the desert locust Schistocerca gregaria and the African bush-cricket Ruspolia differens with those of olive and sesame oils; (2) compared the proximate composition of a baked product (cookie) prepared from the oils; (3) identified the potential volatiles and fatty acids contributing to the aroma and taste; and (4) examined acceptance and willingness to pay (WTP) for the baked product among consumers with no previous experience of entomophagy. Our results showed that the insect oils were compositionally richer in omega-3 fatty acids, flavonoids, and vitamin E than the plant oils. Proximate analysis and volatile chemistry revealed that differences in aroma and taste of the cookies were associated with their sources of oils. Consumers' acceptance was high for cookies prepared with R. differens (95%) and sesame (89%) oils compared to those with olive and S. gregaria oils. Notably, cookies prepared with insect oils had more than 50% dislike in aroma and taste. Consumers' willingness to pay for cookies prepared with insect oils was 6–8 times higher than for cookies containing olive oil, but 3–4 times lower than cookies containing sesame oil. Our findings show that integrating edible insect oils into cookies, entices people to "take the first step" in entomophagy by decreasing insect-based food products neophobia, thereby, contributing to consumers' acceptance of the baked products. However, future research should explore the use of refined or flavored insect oils for bakery products to reduce off-flavors that might have been perceived in the formulated food products [ABSTRACT FROM AUTHOR]

The pan-tropical grass genus Brachiaria comprises about 100 species, several of which are forages of economic importance, particularly in tropical America. Acremonium implicatum is a fungus that forms an endophytic association with at least some of these economically important grasses. To ascertain whether A. implicatum can be seed transmitted in Brachiaria species, we vegetatively propagated, under greenhouse conditions, 20 tillers from an endophyte-infected mother plant obtained from each of 14 Brachiaria hybrids and species. Ten tillers of each genotype were treated with the fungicide tebuconazole to eliminate the endophyte, and the other 10 were left untreated. Seeds were then harvested individually from all 20 of these genetically identical plants, germinated, and the seedlings grown. A previously developed polymerase chain reaction-based method used a pair of endophyte-specific primers to amplify a diagnostic 500-bp DNA fragment. The seedlings generated from seeds harvested from endophyte-infected plants also tested positive, whereas those from seeds of endophyte-free plants showed no amplification products. This is the first report of A. implicatum being transmitted through seeds of Brachiaria grasses. [ABSTRACT FROM AUTHOR]

The article discusses education and profession in plant pathology based on the studies initiated by the American Phytopathological Society (APS). Undergraduate students enrolled in plant pathology courses were driven by factors like work experience, words from families and friends, and initial interest. The attributes of a graduate student that employers look for include work experience in molecular biology and biotechnology. Attracting students in plant pathology is a major challenge to face.

The pan-tropical grass genus Brachiaria comprises about 100 species, several of which are forages of economic importance, particularly in tropical America. Acremonium implicatum is a fungus that forms an endophytic association with at least some of these economically important grasses. To ascertain whether A. implicatum can be seed transmitted in Brachiaria species, we vegetatively propagated, under greenhouse conditions, 20 tillers from an endophyte-infected mother plant obtained from each of 14 Brachiaria hybrids and species. Ten tillers of each genotype were treated with the fungicide tebuconazole to eliminate the endophyte, and the other 10 were left untreated. Seeds were then harvested individually from all 20 of these genetically identical plants, germinated, and the seedlings grown. A previously developed polymerase chain reaction-based method used a pair of endophyte-specific primers to amplify a diagnostic 500-bp DNA fragment. The seedlings generated from seeds harvested from endophyte-infected plants also tested positive, whereas those from seeds of endophyte-free plants showed no amplification products. This is the first report of A. implicatum being transmitted through seeds of Brachiaria grasses.