Origin and genetic diversity of Tunisian grapes as revealed by microsatellite markers

Ten SSR loci, previously developed for grapevine, were analyzed to evaluate the genetic variability, cultivar relatedness, and parentage in a collection of 61 autochthonous Vitis vinifera cultivars from Tunisia.The number of alleles per locus ranged from 6 to 11, while the number of genotype patterns varied between 10 and 21. The expected heterozygosity varied between 0.621 and 0.855 and the observed heterozygosity was higher than 0.9 at 4 loci (VVMD28, VVMD5, VVIP31 and VVS2) indicating that the SSRs were highly informative.Cluster analysis using unweighted pair group method with arithmetic averaging (UPGMA) suggested 14 groups among studied cultivars and 53 grapevine denominations out of 61 were unequivocally distinguished, with all accessions showing at least one-specific combination of alleles.On the other hand, in order to overcome the existing confusion in Tunisian grapevine nomenclature, of the analyzed homonymous pairs of cultivars, only ‘Balta 2’ and ‘Balta 3’ have shown identical allelic profiles, consistent with their being the same genotype. Hence, nomenclature distinction is meaningless and only one denomination should be retained.Due to the high overall power of exclusion (Q) (greater than 99.99%) and to the absence of null alleles, the set of microsatellite loci used is appropriate to determine parentage in Tunisian grapevines beyond any reasonable doubt. The analysis of fingerprints indicated that the Tunisian grape vines have evolved through out crossing between five possible parents: Balta 1, Beldi Baddar, Beldi Rafraf, Beldi Local Rafraf and Khedhiri 3.     

A new look at the genus Crocus L. phylogeny and speciation: Insight from molecular data and chromosome geography

Genetic Resources and Crop Evolution - The genus Crocus of the family Iridaceae is a monophyletic genus with over 100 species. Due to the high degree of hybridization and the changes in the number...     

Genetic structure and differentiation among grapevines (<Emphasis Type="Italic">Vitis vinifera</Emphasis>) accessions from Maghreb region

Three gene pools representative of Vitis vinifera L. subsp. vinifera (=subsp. sativa Beger) growing in the Maghreb regions (North Africa) from Tunisia (44), Algeria (31) and Morocco (18) and 16 wild grape accessions (Vitis vinifera L. subsp. sylvestris (Gmelin) Beger) from Tunisia were analysed for genetic diversity and differentiation at twenty nuclear microsatellites markers distributed throughout the 19 grape chromosomes. 203 alleles with a mean number of 10.15 alleles per locus were observed in a total of 109 accessions. Genetic diversities were high in all populations with values ranging from 0.6775 (Moroccan cultivars) to 0.7254 (Tunisian cultivars). F _st pairwise values between cultivated grapevine populations were low but found to be significantly different from zero. High F _st pairwise values were shown between wild and cultivated compartments. Two parent offspring relationships, two synonyms and two clones of the same cultivar were detected. The rate of gene flow caused by vegetative dissemination of cultivated grapevine plants was not sufficient to genetically homogenise the pools of cultivars grown in different regions. The Neighbour Joining cluster analysis showed a clear separation according to geographical origins for the cultivated grapevines gene pools and revealed a high dissimilarity between cultivated and wild grapevine. However, three cultivars (Plant d’Ouchtata 1, Plant de Tabarka 3 and Plant d’Ouchtata 3) are very close to wild accessions and may result from a hybridisation between cultivated and wild accessions. The high level of differentiation between cultivated and wild accessions indicates that the cultivated accessions do not derive directly from local wild populations but could mostly correspond to imported materials introduced from others regions during historical times or derived from crossing between them.     

The true nature of Ganoderma in Iran: Taxonomy based on ITS and mtSSU rDNA

The genus Ganoderma Karst. has broad‐spectrum usage in biotechnology, medicine and the food industry. The complexity of the morphology within species has led to uncertain identification in the past, but recent advancements in molecular identification methods have provided scientists with the opportunity to better understand the taxonomy of the species. The present study attempts for the first time to elucidate the distinctiveness of the Ganoderma species growing in Iran concerning those elsewhere in the world based on mitochondrial small subunit ribosomal DNA (mtSSU rDNA) and internal transcribed spacer (ITS) sequence data. The results disclosed that the G. lucidum Karst. samples collected in Iran are more similar to the European Ganoderma species than to the Asian (Chinese) one used in this study.     

IMPACT OF USING LEACHED SPENT MUSHROOM COMPOST AS A PARTIAL GROWING MEDIA FOR HORTICULTURAL PLANTS

More than 10 million metric tons of spent mushroom compost (SMC), which is a by-product of Agaricus bisporus mushroom, is produced in the world. Adding the compost to the soil resulted in improving the nutritional status of the plants. This study aims experiment is to study the effect of SMC on cucumber plant growth. A basic property of SMC and high concentrations of soluble salts restricted its implementation in the agricultural arena. The SMC was leached in order to reduce its salinity. Leached spent mushroom compost has less salinity while carbon and nitrogen content as well as inorganic cation components did not change significantly when compared to non-leached SMC. To study the effects of SMC on plant growth, leached SMC in rates of 15, 25, 35, and 45% were added to a sandy-loam soil medium. Cucumber plant growth rate was evaluated based on fruit number and plant height. Results showed that additions of 15% and 25% leached SMC to growing media significantly improved the cucumber plants growth.     

Chronic Aerobic Exercise Decreases Lectin-Like Low Density Lipoprotein (LOX-1) Receptor Expression in Heart of Diabetic Rat

Background:

Overexpression of lectin-like low density lipoprotein (LOX-1) receptor plays an important role in hyperglycemia-induced vascular complications such as atherosclerosis. Based on the beneficial effects of exercise on preventing cardiovascular complications of diabetes, we aimed to examine the protective effects of aerobic exercise on expression of LOX-1 receptor and production of free radicals in the heart of diabetic rats.

Methods:

Four groups of rats were used: (n = 5 per group): sedentary normal, trained normal, sedentary diabetes and trained diabetes. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg). The exercise protocol was consisted of swimming 30 min/day, 5 days/week for eight weeks. Plasma glucose was evaluated at initiation, weeks 4 and 8 of experiment. At the end of experiment, rats were sacrificed and the heart was removed for determination of nitrate, malondialdehyde, and LOX-1 gene expression.

Results:

In normal non-diabetic rats, the blood glucose level was <150 mg/dl; however, the induction of diabetes resulted in levels more than >400 mg/dl. Gene expression of LOX-1 was increased in the heart of diabetic rats. Exercise reduced the gene expression of this protein in diabetic states without reducing the blood glucose. Finally, swimming exercise decreased the malondialdehyde and nitrate levels in heart tissue both in control and diabetic rats.

Conclusion:

Swimming exercise reduces heart expression of the LOX-1 receptor in accompany with reduction of free radicals production. Since these parameters are important in generation of diabetic complications, swimming exercise is a good candidate for reducing these complications. Key Words: Hyperglycemia, Diabetic complications, LOX-1 receptor, Exercise, Free radicals     

Use of zoophytophagous mirid bugs in horticultural crops: Current challenges and future perspectives

In recent years, the use of predatory mirid bugs (Hemiptera: Miridae) in horticultural crops has increased considerably. Mirid bugs are zoophytophagous predators, that is, they display omnivorous behavior and feed on both plants and arthropods. Mirid bugs feed effectively on a wide range of prey, such as whiteflies, lepidopteran eggs and mites. In addition, the phytophagous behavior of mirid bugs can activate defenses in the plants on which they feed. Despite the positive biological attributes, their use still presents some constraints. Their establishment and retention on the crop is not always easy and economic plant damage can be caused by some mirid species. In this review, the current strategies for using zoophytophagous mirid bugs in horticultural crops, mainly Nesidiocoris tenuis, Macrolophus pygmaeus and Dicyphus hesperus, are reviewed. We discuss six different approaches which, in our opinion, can optimize the efficacy of mirids as biocontrol agents and help expand their use into more areas worldwide. In this review we (i) highlight the large number of species and biotypes which are yet to be described and explore their applicability, (ii) present how it is possible to take advantage of the mirid‐induced plant defenses to improve pest management, (iii) argue that genetic selection of improved mirid strains is feasible, (iv) explore the use of companion plants and the use of alternative foods to improve the mirid bug management, and finally (vi) discuss strategies for the expansion of mirid bugs as biological control agents to horticultural crops other than just tomatoes. © 2020 Society of Chemical Industry     

Functionalization of graphene nanosheets and its dispersion in PMMA/PEO blend: Thermal,electrical, morphological and rheological analyses

Graphene nanoplatelet (GnP) was chemically functionalized by amine groups for improvement of compatibility in poly(methyl methacrylate) (PMMA)/poly(ethylene oxide) (PEO) blend. PMMA/PEO (90/10) nanocomposites with non-functionalized GnP and functionalized GnP (FGnP) were prepared by solution casting method. Successful grafting of amine groups on the GnP surface was confirmed by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The Transmission electron microscopy (TEM) images showed that the dispersion state of FGnP was better than that of GnP in PMMA/PEO nanocomposites. The effects of FGnP and GnP on rheological, thermal and electrical properties of PMMA/PEO nanocomposites were investigated by various methods. The results indicated that the FGnP-based nanocomposites had higher storage modulus, glass transition temperature and thermal stability as compared to the GnP-based nanocomposites. The electrical conductivity of the nanocomposites with FGnP was better than that of GnP-based nanocomposites. The higher conductivity was attributed to homogeneous and well dispersion state of FGnP in PMMA/PEO nanocomposites.     

Characterization of single nucleotide polymorphism in Tunisian grapevine genome and their potential for population genetics and evolutionary studies

In this study, two gene fragments corresponding to the VvMYBA1 and VvMYBA2 loci were sequenced on a sample of grapes including cultivated and wild accessions originating from Tunisia, Germany and France. A total of 42 SNPs were detected in the sequenced fragments giving an average of 1 SNP every 33 bp. High level of polymorphism was observed in the samples either in cultivated or wild accessions. Pattern of nucleotide diversity indicates a non departure from neutrality expectations for wild grapevine sample for gene VvMYBA1 and VvMYBA2 and for cultivated sample for gene VvMYBA1. However, a linkage to a selective sweep was revealed for cultivated grapevine gene pool in gene VvMYBA2. A genetic structure of the studied sample according to accession taxonomic status was revealed by the UPGMA clustering with a considerable overlap. This result was confirmed by significant but low genetic differentiation values between cultivated and wild sample. The number of migrants Nm based on sequence data information between Tunisian cultivars and Tunisian wild accessions showed a low level of gene flow between those germplasms. This finding indicates that Tunisian cultivars do not derive directly from local wild populations but could mostly correspond to imported materials introduced during historical times. However, the possibility that some cultivars derived from ancestral events of local domestication or cross hybridization with native wild plants was not completely excluded for Tunisian grapevine accessions.