Molecular characterization and incidence of new tospovirus: Soybean Vein Necrosis Virus (SVNV) in Egypt

Field survey study was conducted season (2017). Soybeans and weeds were weekly sampled randomly. Thrips adults were identified and counted. Detection of the virus isolate and the natural incidence was determined using; Mechanical transmission, host range, DAS-ELISA, RT-PCR. The natural incidence thrips individuals was detected depending on the SVNV% in thrips individuals and weeds hosts. Ten thrips species were associated with soybean plants in the field. The most abundant species was T. tabaci, average 256.5 average no.of individuals, followed by F. occidentalis (142.5 average no. of individuals), then N. variabilis (86.6/ average no. of individuals). Fourteen thrips species occurred on 5 legumes field crops and 41 weed plant species within soybean field. The highest average number 40.6.of individuals were recorded on Ammi majus. While the lowest one 3.3 average no. of individuals were on Urtica urens. Only 21diagnostic plant species were susceptible to infection with SVNV. G. max and Vigna radiate, were the highest percentage of infection 80% followed by V. unguilata & N. benthamiana, 75%. Egyptian isolate of Soybean vein necrosis virus (SVNV) in this study showed a high degree of similarity and it is closely related to TSWV from Egypt (DQ479968) and TCSV from USA (KY820965) with nucleotide sequence identity of 78%. Four thrips species transmitted SVNV (F. fusca 4.0%, F. schultzei 4.3%, F. tritici 3.3% and N. variabilis 68.0% transmission). Both C. phaseoli and M. sjostedti can acquire the virus but unable to transmit it. The following species; T. tabaci, F. occidentalis, S. dorsallis and T. palmi cannot acquire or transmit SVNV. The incidence of SVNV in the field started by the end of July then increased gradualy from 12.7 to 71.3% by the end of the season. In conclusion, few thrips individuals invaded soybean crops are enough to transmit high rate of SVNV within the crop. Furthermore, several vector species are also abundant on weeds, which are the major sources of soybean viruses transmitted to the crops. This information might be important for control and reduce the incidence of SVNV infection.

Importance of the Natural Incidence of the Fusarium Genus in Food Crops Established in Northern México

The incidence of the Fusarium genus causing root rot is reviewed in crops showing high importance for food supply and to obtain regular income by farmers in the highlands of Northern México. Pathogen incidence was evaluated under field conditions in multiple sampling locations for common beans (Phaseolus vulgaris L.) and several chili peppers (Capsicum annuum) local cultivars (landraces and bred cultivars). Five commercial plots for registered and certified seed were also evaluated in common beans to be used in the ‘seed refreshing program’ implemented for the cultivar Pinto Saltillo, considered as the main variety sown in the highlands of México. High Fusarium genus incidence and its interactions with other fungi species, such as Rhizoctonia solani and Pythium spp., cause high losses in plant population, commercial yield and seed quality in food crops grown in Northern México. The natural incidence of plant disease caused by the Fusarium genus and its negative effect on crop survival and the reduction of commercial yield and seed quality is fully reviewed. Plant disease resistance, crop breeding and the influence of the environmental conditions were also considered.

Variation of Deoxynivalenol Levels in Corn and Its Products Available in Retail Markets of Punjab, Pakistan, and Estimation of Risk Assessment

This study investigated the natural incidence of deoxynivalenol (DON) in corn and corn products from corn-producing districts of Punjab, Pakistan. The analysis was carried out using high performance liquid chromatography (HPLC) with UV detector and immunoaffinity cleanup columns. The detection limit (LOD) and limit of quantification were 25 and 50 µg/kg, respectively. A total of 1220 samples of corn and corn products were analyzed to detect DON, and 539 (44.2%) samples were observed to be contaminated with DON (n ≥ LOD). Furthermore, 92 (7.5%) samples of corn and corn products had DON levels that were higher than the proposed limits of the EU. The data are significantly different from a normal distribution of DON in samples of corn and corn products from different locations (p < 0.05) for Shapiro–Wilk and Kolmogorov–Smirnov values. However, a significant difference in DON levels was found between corn and corn-derived products (p ≤ 0.05). The lowest and highest exposures, and hazard quotient (HQ) values of 0.92 and 9.68 µg/kg bw/day, were documented in corn flour samples.

Variation of Deoxynivalenol levels in Corn and Its Products Available in Retail Markets of Punjab, Pakistan and Estimation of Risk Assessment

The study focused on investigating the natural incidence of deoxynivalenol (DON) in corn and products from corn producing districts of Punjab, Pakistan. The analysis was carried out using HPLC with UV detector and immunoaffinity cleanup columns. The detection limit (LOD) and limit of quantification were 25 and 50 &micro;g/kg, respectively. Total 1220 samples of corn and products were analyzed to detect the DON, and 539 (44.2%) samples were observed to be contaminated with DON (n &ge; LOD). Furthermore, 92 (7.5%) samples of corn &amp; products have DON levels, elevated than the proposed limits of the EU. The data is significantly different from a normal distribution for DON in corn and products samples and from different locations (p &lt; 0.05) for Shapiro-Wilk and Kolmogorov-Smirnov values. However, a significant difference in DON levels was found between corn and corn derived-products types (p &le; 0.05). The lowest and highest exposure &amp; hazard quotient (HQ) of 0.92 and 9.68 &micro;g/kg bw/d were documented in cornflour samples.

Influence of Bioregulators on Latex Yield and Proteolytic Activity of Papain Extracted from Field-grown TNAU Papaya CO. 8 under the Natural Incidence of Papaya Ring Spot Virus

The cultivation of papaya for both fruits and commercial papain extraction drastically suffers often due to the devastating incidence of papaya ringspot virus disease. The present study aimed to find out whether the papain yield and quality are influenced when bioregulators are applied to manage papaya ring spot virus (PRSV) incidence or as a measure to limit the height of the crop in TNAU Papaya CO.8 variety grown in the open field with the natural incidence of PRSV. Three growth retardants [250 ppm of prohexadione calcium (G2), 500 ppm of mepiquat chloride (G3) and 500 ppm of chlormequat chloride (G4)] and three stress tolerance promoting bioregulators [100 ppm of methyl jasmonate (S2), 100 ppm of salicylic acid (S3) and 0.6 g/ l of strobilurins (S4)] were employed in the study. Water spray (G1 and S1) was kept as control. The treatments were imposed at 4th and 8th months after planting. The growth retardants were initially sprayed and, in the subsequentweek ,the stress tolerance promoting bioregulators were sprayed as per the recommended doses. Among the combinations tried, spraying 250 ppm of prohexadione calcium followed by water spray (G2S1) a week later recorded the lowest plant height (140.79 cm) at the time of fruiting. The treatment combination G 2S2 involving 250 ppm of prohexadione calcium and 100 ppm of methyl jasmonate registered a higher number of fruits (42.17). The combination of 250 ppm of prohexadione calcium along with 100 ppm of salicylic acid (G2S3) was found to be the most effective combination to manage PRSV without compromising papain production and to enhance the proteolytic activity significantly (44378.36 TU g-1) as compared to other combinations. The treatment combination of 500 ppm of mepiquat chloride and 100 ppm of salicylic acid (G3S3) favored higher dry latex yield apart from a significant reduction in PRSV symptoms. Both these treatment combinations (G2S3 and G 3S3) merit due consideration in PRSV management for commercial fruit and papain production in papaya

NATURAL INCIDENCE OF ENTOMOPATHOGENIC FUNGUS Nomuraea rileyi ON Spodoptera frugiperda INFESTING CORN IN BENGKULU

Natural incidence of entomopathogenic fungus Nomuraea rileyi on Spodoptera frugiperda infesting corn in Bengkulu. Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a new invasive pest in corn. The intensive use of synthetic insecticides for pest control causing various problems such as resistance, pest resurgence, and environmental damage. To solve these problems, entomopathogenic fungi could be used as an alternative in pest management. Therefore, this study was aimed to determine the natural incidence of Nomuraea rileyi (Farlow) Samson (Hypocreales: Clavicipitaceae) entomopathogenic fungus on S. frugiperda in Bengkulu. The research was carried out by exploring the corn producing areas in Bengkulu for N. rileyi incidence. The results showed that the N. rileyi was occurred naturally infected S. frugiperda larvae reached 79.0%. Meanwhile, the percentage of crops damage due to S. frugiperda was ranged from 40.0 to 96.0%. The highest natural incidence of N. rileyi were found in the Village of Bukit Barisan and Tugu Rejo (79.0%), followed by Pulo Geto Baru (25.0%), and Taba Mulan (5.3%) while the lowest incidence was in Sidomulyo (1.0%). The infected larvae were not found in the Napal, Beringin Raya 1, and Beringin Raya 2, despite the percentage of S. frugiperda attacks was reached 50.0; 50.0 and 74.0%, respectively.