Computer Vision Techniques for Quality Assessment of Dates

Computer vision (CV) is a technique in which the image of an object is obtained through any imaging system and the image is analyzed to characterize the quality of the object objectively. The advancement in electronics has made this technique utilized in various fields. In North America, food industry is one of the top ten industries utilizing CV technique for quality monitoring. However, CV technique is not much utilized in the food industries in Asia. Dates is an important fruit crop in Oman and many other Arab countries. The quality assessment of dates during handling and processing are mainly carried out through manual inspection method. But this method has many challenges such as the efficiency of a worker, subjectivity, and so on. There are lots of opportunities to utilize CV technique for measuring and monitoring various quality aspects of dates. Through an Open Research Grant program funded by The Research Council (TRC), Oman, potential of CV technique for various internal and external qualities of dates was determined. This paper describes the efficiency of CV systems for variety identification, surface crack detection, texture and hardness determination

Global consortium for the classification of fungi and fungus-like taxa

The Global Consortium for the Classification of Fungi and fungus-like taxa is an international initiative of more than 550 mycologists to develop an electronic structure for the classification of these organisms. The members of the Consortium originate from 55 countries/regions worldwide, from a wide range of disciplines, and include senior, mid-career and early-career mycologists and plant pathologists. The Consortium will publish a biannual update of the Outline of Fungi and fungus like taxa, to act as an international scheme for other scientists. Notes on all newly published taxa at or above the level of species will be prepared and published online on the Outline of Fungi website (https://www.outlineoffungi.org/), and these will be finally published in the biannual edition of the Outline of Fungi and fungus-like taxa. Comments on recent important taxonomic opinions on controversial topics will be included in the biannual outline. For example, ‘to promote a more stable taxonomy in Fusarium given the divergences over its generic delimitation’, or ‘are there too many genera in the Boletales?’ and even more importantly, ‘what should be done with the tremendously diverse ‘dark fungal taxa?’ There are undeniable differences in mycologists’ perceptions and opinions regarding species classification as well as the establishment of new species. Given the pluralistic nature of fungal taxonomy and its implications for species concepts and the nature of species, this consortium aims to provide a platform to better refine and stabilise fungal classification, taking into consideration views from different parties. In the future, a confidential voting system will be set up to gauge the opinions of all mycologists in the Consortium on important topics. The results of such surveys will be presented to the International Commission on the Taxonomy of Fungi (ICTF) and the Nomenclature Committee for Fungi (NCF) with opinions and percentages of votes for and against. Criticisms based on scientific evidence with regards to nomenclature, classifications, and taxonomic concepts will be welcomed, and any recommendations on specific taxonomic issues will also be encouraged; however, we will encourage professionally and ethically responsible criticisms of others’ work. This biannual ongoing project will provide an outlet for advances in various topics of fungal classification, nomenclature, and taxonomic concepts and lead to a community-agreed classification scheme for the fungi and fungus-like taxa. Interested parties should contact the lead author if they would like to be involved in future outlines

Differential leaf gas exchange performance of mango cultivars infected by different isolates of Ceratocystis fimbriata

ABSTRACT Caused by the vascular fungus Ceratocystis fimbriata, mango wilt is considered to be one of the most serious threats in mango-producing regions worldwide. However, changes in leaf gas exchange level and the mechanisms underlying host responses to this fungal infection remain poorly described. This study aimed to evaluate potential changes in the leaf gas exchange of different mango cultivars (Ubá, Espada, Haden and Tommy Atkins) in response to two Brazilian isolates of C. fimbriata (CEBS15 and MSAK16) to non-invasively assess cultivar variability in relation to the basal level of resistance to mango wilt. Both isolates, regardless of the cultivar, caused reductions in stomatal conductance and, thus, a reduction in CO2 assimilation via diffusive limitations. Taking into account the full length of the internal lesion and the radial colonization of the stem tissues, both isolates showed equivalent aggressiveness when inoculated into the Haden and Tommy Atkins cultivars. Conversely, when compared to the CEBS15 isolate of C. fimbriata, the MSAK16 isolate was more aggressive in cv. Espada and less aggressive in cv. Ubá

Genetic analysis reveals diversity and genetic relationship among Trichoderma isolates from potting media, cultivated soil and uncultivated soil

Background\ud \ud Trichoderma is one of the most common fungi in soil. However, little information is available concerning the diversity of Trichoderma in soil with no previous history of cultivation. This study was conducted to investigate the most common species and the level of genetic relatedness of Trichoderma species from uncultivated soil in relation to cultivated soil and potting media.\ud Results\ud \ud A total of 24, 15 and 13 Trichoderma isolates were recovered from 84 potting media samples, 45 cultivated soil samples and 65 uncultivated soil samples, respectively. Analysis based on the internal transcribed spacer region of the ribosomal RNA (rRNA) and the translation elongation factor gene (EF1) indicated the presence of 9 Trichoderma species: T. harzianum (16 isolates), T. asperellum (13), T. citrinoviride (9), T. orientalis (3), T. ghanense (3), T. hamatum (3), T. longibrachiatum (2), T. atroviride (2), and T. viride (1). All species were found to occur in potting media samples, while five Trichoderma species were recovered from the cultivated soils and four from the uncultivated soils. AFLP analysis of the 52 Trichoderma isolates produced 52 genotypes and 993 polymorphic loci. Low to moderate levels of genetic diversity were found within populations of Trichoderma species (H = 0.0780 to 0.2208). Analysis of Molecular Variance indicated the presence of very low levels of genetic differentiation (Fst = 0.0002 to 0.0139) among populations of the same Trichoderma species obtained from the potting media, cultivated soil and uncultivated soil.\ud Conclusion\ud \ud The study provides evidence for occurrence of Trichoderma isolates in soil with no previous history of cultivation. The lack of genetic differentiation among Trichoderma populations from potting media, cultivated soil and uncultivated soil suggests that some factors could have been responsible for moving Trichoderma propagules among the three substrates. The study reports for the first time the presence of 4 Trichoderma species in Oman: T. asperellum, T. ghanense, T. longibrachiatum and T. orientalis

Effect of rootstock on muskmelon cultivar reaction to vine decline disease and yield under arid conditions

Monosporascus cannonballus, Rhizoctonia solani and Pythium aphanidermatum are the main causal agents of muskmelon vine decline disease in Oman. This study was conducted to examine the response of six cucurbit rootstocks grafted on four muskmelon scions to the causal agents and fruit quality and quantity. The response of 10 day old Palmira seedlings to artificial inoculation with R. solani pathogen alone revealed more damage to muskmelon seedling whereas P. aphanidermatum and M. cannonballus caused less damage when inoculated singly but more disease severity index when combined with R. solani. Artificial inoculation of different rootstocks produced significantly no damping-off and very low vine decline disease severity index on Mubyeongjangsoo, Titan, Tetsukabuto, Rsscih7458, Ezra and Strong Tosa rootstocks. All rootstocks produced high grafting success and low graft failure with the four selected muskmelon cultivars. Rootstocks enhanced early harvesting of grafted Tamara but had no effect on other scions. Fruit shape was almost not significantly affected by grafting except Samit grafted on Strong Tosa and Caramel grafted on Mubyeongjangsoo produced significantly different fruit shapes compared to ungrafted controls in the spring 2013 trial. Fruits from both grafted Shahd and Tamara showed no significant differences in rind brightness, redness and yellowness from the control. An various effect of rootstock was found on harvesting, fruit number and weight, chlorophyll content, and stem diameter of the scion. Rootstocks enhanced early harvesting and increased fruit number and fruit weight in grafted Tamara scions. There was no significant effect of grafting on fruit TSS. The study shows positive effects of grafting on tolerance to vine decline and on fruit quality and yield

Effect of rootstock on muskmelon cultivar reaction to vine decline disease and yield under arid conditions

Monosporascus cannonballus, Rhizoctonia solani and Pythium aphanidermatum are the main causal agents of muskmelon vine decline disease in Oman. This study was conducted to examine the response of six cucurbit rootstocks grafted on four muskmelon scions to the causal agents and fruit quality and quantity. The response of 10 day old Palmira seedlings to artificial inoculation with R. solani pathogen alone revealed more damage to muskmelon seedling whereas P. aphanidermatum and M. cannonballus caused less damage when inoculated singly but more disease severity index when combined with R. solani. Artificial inoculation of different rootstocks produced significantly no damping-off and very low vine decline disease severity index on Mubyeongjangsoo, Titan, Tetsukabuto, Rsscih7458, Ezra and Strong Tosa rootstocks. All rootstocks produced high grafting success and low graft failure with the four selected muskmelon cultivars. Rootstocks enhanced early harvesting of grafted Tamara but had no effect on other scions. Fruit shape was almost not significantly affected by grafting except Samit grafted on Strong Tosa and Caramel grafted on Mubyeongjangsoo produced significantly different fruit shapes compared to ungrafted controls in the spring 2013 trial. Fruits from both grafted Shahd and Tamara showed no significant differences in rind brightness, redness and yellowness from the control. An various effect of rootstock was found on harvesting, fruit number and weight, chlorophyll content, and stem diameter of the scion. Rootstocks enhanced early harvesting and increased fruit number and fruit weight in grafted Tamara scions. There was no significant effect of grafting on fruit TSS. The study shows positive effects of grafting on tolerance to vine decline and on fruit quality and yield.

Effect of rootstock on muskmelon cultivar reaction to vine decline disease and yield under arid conditions

Monosporascus cannonballus, Rhizoctonia solani and Pythium aphanidermatum are the main causal agents of muskmelon vine decline disease in Oman. This study was conducted to examine the response of six cucurbit rootstocks grafted on four muskmelon scions to the causal agents and fruit quality and quantity. The response of 10 day old Palmira seedlings to artificial inoculation with R. solani pathogen alone revealed more damage to muskmelon seedling whereas P. aphanidermatum and M. cannonballus caused less damage when inoculated singly but more disease severity index when combined with R. solani. Artificial inoculation of different rootstocks produced significantly no damping-off and very low vine decline disease severity index on Mubyeongjangsoo, Titan, Tetsukabuto, Rsscih7458, Ezra and Strong Tosa rootstocks. All rootstocks produced high grafting success and low graft failure with the four selected muskmelon cultivars. Rootstocks enhanced early harvesting of grafted Tamara but had no effect on other scions. Fruit shape was almost not significantly affected by grafting except Samit grafted on Strong Tosa and Caramel grafted on Mubyeongjangsoo produced significantly different fruit shapes compared to ungrafted controls in the spring 2013 trial. Fruits from both grafted Shahd and Tamara showed no significant differences in rind brightness, redness and yellowness from the control. An various effect of rootstock was found on harvesting, fruit number and weight, chlorophyll content, and stem diameter of the scion. Rootstocks enhanced early harvesting and increased fruit number and fruit weight in grafted Tamara scions. There was no significant effect of grafting on fruit TSS. The study shows positive effects of grafting on tolerance to vine decline and on fruit quality and yield

Native and Non-Native Bemisia tabaci NAFME Haplotypes Can Be Implicated in Dispersal of Endemic and Introduced Begomoviruses in Oman

Irrigated agriculture and global trade expansion have facilitated diversification and spread of begomoviruses (Geminiviridae), transmitted by the Bemisia tabaci (Gennadius) cryptic species. Oman is situated on major crossroads between Africa and South Asia, where endemic/native and introduced/exotic begomoviruses occur in agroecosystems. The B. tabaci ‘B mitotype’ belongs to the North Africa–Middle East (NAFME) cryptic species, comprising at least eight endemic haplotypes, of which haplotypes 6 and/or 8 are recognized invasives. Prevalence and associations among native and exotic begomoviruses and NAFME haplotypes in Oman were investigated. Nine begomoviral species were identified from B. tabaci infesting crop or wild plant species, with 67% and 33% representing native and exotic species, respectively. Haplotypes 2, 3, and 5 represented 31%, 3%, and 66% of the B. tabaci population, respectively. Logistic regression and correspondence analyses predicted ‘strong’- and ‘close’ virus–vector associations involving haplotypes 5 and 2 and the exotic chili leaf curl virus (ChiLCV) and endemic tomato yellow leaf curl virus-OM, respectively. Patterns favor a hypothesis of relaxed virus–vector specificity between an endemic haplotype and the introduced ChiLCV, whereas the endemic co-evolved TYLCV-OM and haplotype 2 virus–vector relationship was reinforced. Thus, in Oman, at least one native haplotype can facilitate the spread of endemic and introduced begomoviruses. © 2023 by the authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]