-Late blight caused by the oomycete Phytophthora infestans is a destructive disease of tomato in
In Egypt, the impact of high temperatures on tomato production during summer season has become an urgent issue. Where the day/night temperature rising above the optimal for flowering and fruit set, consequently, the fresh market tomato prices increase about 400 to 500% during this period with inferior quality of fruits. The objective of this work was to assay new genetic resources of a set of ex situ lines and cultivars for heat-tolerant. Furthermore, selection for promising parents that would be used in developing more adaptive cultivars to heat stress. All experiments were carried out during 2013 to 2015. Fifty tomato genotypes (Lycopersicon esculentum, Mill.) were evaluated in a randomized complete blocks design under the natural heat stress conditions. The following traits; plant height, number of branches, leave area, fruit set %, total chlorophyll, chl a/b ratio, chl T/carotenoid, in addition to yield and some fruit quality traits were estimated. Based on the phenotypic performance and the genetic divergence of these genotypes, 10 parental varieties were selected for a factorial mating design using 6 as males and 4 as females. High genetic variability was observed among the genotypes for all studied traits. Mean of fruit set % ranged from 12.7 % to 66.5%. Twelve genotypes gave more than 50kg/plot where the genotypes LA0535 and BGH-0226 recorded the highest mean values of 63.15 and 61.88 kg/plot, respectively. The mean squares of GCA as well as SCA were significant for the majority of studied traits indicting the importance of both additive and non-additive types of variation for all studied traits. Among the female lines, BGH-2004 exhibited maximum positive gi effect, while among the male lines, BGH-0226 displayed highest gi effect for plant height. The cross resulted from BGH-3474 x BGH-0226 gave the highest Sij effect for fruit set % indicating that the female line BGH3474 and tester BGH-0226 produced promising progenies for vegetative traits and fruit set improvement. While the female line BGH-3474 and male line BGH-7466 gave the highest gi effects for total yield per plot. According to the variation and diversity analysis, the genotype LA0535 from group I showed stable high yield across the two summer seasons 2014 and 2015 and was a good donor for fruit set, TSS and firmness however its poor fruit in lycopene. The hybrid 2x5 showed high adaptation against heat stress under field condition in 2015 with high total yield, leave area number of branches per plant, average fruit weight and fruit firmness but low lycopene. Therefore, for hybridization program, crosses among LA0535, BGH-0025, BGH-7466 for heat tolerance and yield could be effective and promising.
The genetic diversity, relationships and population structure of sixty Egyptian camels derived from four breeds (Baladi, Sudani, Somali, and Maghrabi) were investigated using 18 microsatellite (SSRs) loci. In addition, the four breeds were genotyped using 16 Start Codon Targeted (SCoT) primers. A total of 346 SSR alleles were detected across the four camel breeds with an overall mean of 9.3 ± 0.66 alleles / locus. The mean number of alleles (MNA) and effective number of alleles (Ne) ranged from 9.2 ± 1.45 in the Baladi to 9.5 ± 1.27 in the Maghrabi breeds and from 6.5 ± 0.82 in the Maghrabi to 7.1 ± 0.93 in the Somali breeds, respectively. The values of observed heterozygosity (HObs) and expected heterozygosity (HExp) per breed varied from 0.82 ± 0.07 in the Maghrabi to 0.87 ± 0.07 in the Sudani camel breeds, and from 0.75 ± 0.03 in the Sudani to 0.79 ± 0.03 in the Maghrabi breeds , respectively. The genetic diversity estimated as the Shannon's information index (I) revealed the highest value (1.88 ± 0.14) in the Maghrabi and the lowest value (1.78 ± 0.18) in the Sudani breed. The values for fixation indices (FIS, FST and FIT) were-0.07284, 0.12364 and 0.05981, respectively. Thus indicating a moderate level of differentiation among the four breeds and a random mating process within each breed. The genetic structure revealed that the three breeds (Baladi, Sudani and Maghrabi) were genetically distinct and look like pure breeds, while the Somali breed showed some degree of admixture. A total of 153 amplicons were generated by the 16 SCoT primers, with an average of 9.56 amplicon/ primer and a polymorphism rate of 49%. The phylogenetic tree based on microsatellite and SCoT markers revealed that Maghrabi was separated in one cluster while, the second cluster comprised two sub-clusters. Sudani and Somali formed one sub-cluster and Baladi was in the second sub-cluster. Thus, the closest phylogenetic relationship was between the Sudani and Somali breeds.
RESUMO-o objetivo foi avaliar o potencial produtivo de cultivares de morangueiro em região representativa do Alto Jequitinhonha. o experimento foi conduzido na fazenda Mape Frutas ltda., localizada no município de datas-MG, em delineamento em blocos ao acaso, com oito cultivares de morangueiro em quatro repetições, para verificar a produção de mudas e de frutos. A contagem da produção de estolões e de mudas foi realizada aos 180 dias após o plantio. A avaliação das variáveis relacionadas à produção de frutos foi feita duas vezes por semana, no período de maio a outubro de 2012. das cultivares de dias curtos (Festival, Campinas, toyonoka, dover, oso Grande e Camarosa) e dias neutros (diamante e Aromas), apenas toyonoka foi a que apresentou menor desempenho para as variáveis. A significativa superioridade das cultivares Camarosa e Festival, para praticamente todas as variáveis avaliadas, permite recomendá-las para regiões com características edafoclimáticas semelhantes às da região onde o experimento foi conduzido. dentre as cultivares avaliadas, as mais precoces tenderam a apresentar maior desempenho para variáveis relacionadas à produção de frutos. Termos para Indexação: Fragaria x ananassa duch, colheita, rendimento. PRODUCTIVE POTENTIAL OF STRAWBERRY CULTIVARSABSTRACT -this study was conducted in order to evaluate the productive potential of strawberry cultivars in a representative region of Alto Jequitinhonha -Brazil. the experiment was conducted at farm Mape Frutas ltda, located in the municipality of dates, MG, in randomized block design with eight strawberry cultivars in four replications to verify the production of seedlings and fruit. Counting of production of stolons and seedlings was performed at 180 days after planting. the assessment of variables related to fruit production was done twice a week from May to october 2012. Cultivars of short days (Festival, Campinas, toyonoka, dover, oso Grande and Camarosa) and day neutral (diamante and Aromas), only Toyonoka showed the lowest performance for the variables. The significant superiority of the cultivars Camarosa and Festival for virtually all variables allows recommends it for regions with similar climatic edaphic characteristics of the region where the experiment was conducted. Among the cultivars, the earlier tended to have higher performance for variables related to fruit production.
Two field experiments were conducted during two successive winter seasons of 2012/2013 and 2013/2014 at El-Baramoun farm, Mansoura Horticulture Research station to study the effect of spraying by ATP (100ppm), amino acids (2.5ml/l), glycinebetaine (50ppm), salicylic acid (20ppm), Zinc (100ppm) and Boron (50ppm) compared with tap water (control treatment) on vegetative growth parameters, photosynthetic pigments, mineral constituents, yield components and fruit quality of tomato cv. Super strain B grown under low temperature conditions. Significant increases in vegetative growth parameters and photosynthetic pigment contents were recorded relative to corresponding control treatment. ATP treatment was more pronounced in these increments. Marked increases were observed in N, P, K, Ca, Mg and Zn percentages as a result of all applied treatments. However, Zn treatment decreased N and P percentages and gave the highest percentage of Zn during both seasons. B treatment at 50ppm had the highest fruit set percentage, while ATP treatment had the highest yield per plant, early yield and total yield per feddan. In addition, all spraying treatments significantly enhanced tomato fruit quality characters (TSS, TA, VC and lycopene), except for salicylic acid treatment which had no effect on TA (tetratable acidity) relative to control plants. The behavior of most studied traits was not changed from season to other except Chl A, N%, Ca%, F set%, YP, TSS and lycopene indicating the magnitude of the environmental factors on the genetic expression of these traits as controlled by more than one gene. In view of the obtained results, it was found that vegetative growth, yield and fruit quality of tomato plants cv. Super strain B could be enhanced under cold stress condition by spraying by anti-stressor under study (ATP, amino acid, glycinebetain, salicylic acid, Zn or B). It is worthy to mention that ATP spraying treatment at 100 ppm was the most optimum treatment.
In this study we used ISSR molecular markers to evaluate the genetic variability of 96 tomato accessions from Banco de Germoplasma de Hortaliças (BGH) of Universidade Federal de Viçosa, Minas Gerais, Brazil. Ten ISSR primers were individually amplified to allow the differentiation of the material. All ten primers generated 144 DNA bands, 53 being polymorphic, with an average of 14.4 per primer. The profiles generated by primer 840-(GA) 8 YT contained the largest number of polymorphic bands (13 bands). The primer 855-(AC) 8 YT detected the greatest differentiation of the accessions (12 accessions) while the primer HBH-884(AG) 7 did not detect any. The evaluation of the dendrogram obtained by UPGMA and Tocher' grouping method allowed the differentiation of all the accessions. Accession BGH-980 was located in a separate group, being the most divergent amongst the accessions tested by both methods. DNA profiles based on ISSR markers revealed the potential of the digital fingerprints in the diagnosis of all the accessions. From the results obtained in this study, ISSR markers have a high efficiency to differentiate the germplasm of wild species, besides origin studies.
Two polyploid hybrids between cassava (Manihot esculenta) cultivar 307-2 and its wild relatives M. glaziovii and M. anomala, were studied to examine the relationship between ploidy level and the production of seeds without fertilization. A clearing method was applied to assess ovule sizes as an indication of multiembryony. The diploid cultivar 307-2 had regular 18 bivalents at meiotic metaphase 1 while the polyploid types showed chromosome configurations varying from 3 to 4 quadrivalents and 28 to 30 bivalents. A total of 14% of studied ovules of the polyploid hybrid involving M. glaziovii were multiebryonic, while the percentage of multiembryony was as low as 2% in the polyploid hybrid M. anomala×M. esculenta. Diploid hybrid types did not show any multi embryony. Adventitious embryos were found and documented for the first time in polyploid hybrids M. esculenta×M. glaziovii. The association of multiple embryo formation with ovary size and pollination showed that apomictic embryos form independently from fertilization. Simple iodized carmine stain for measuring pollen viability proved as efficient as the sophisticated Alexander method.
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