Latest News on Tomato Cultivar : Nov 2020

Latest News on Tomato Cultivar : Nov 2020

Comparative Transcriptomic Profiling of a Salt-Tolerant Wild Tomato Species and a Salt-Sensitive Tomato Cultivar

Wild halophytic tomato has long been considered as an ideal gene donor for improving salt tolerance in tomato cultivars. Extensive research has been focused on physiological and quantitative trait locus (QTL) characterization of wild tomato species in comparison with cultivated tomato. However, the global gene expression modification of wild tomato in response to salt stress is not well known. A wild tomato genotype, Solanum pimpinellifolium ‘PI365967’ is significantly more salt tolerant than the cultivar, Solanum lycopersicum ‘Moneymaker’, as evidenced by its higher survival rate and lower growth inhibition at the vegetative stage. The Affymetrix Tomato Genome Array containing 9,200 probe sets was used to compare the transcriptome of PI365967 and Moneymaker. After treatment with 200 mM NaCl for 5 h, PI365967 showed relatively fewer responsive genes compared with Moneymaker. The salt overly sensitive (SOS) pathway was found to be more active in PI365967 than in Moneymaker, coinciding with relatively less accumulation of Na+ in shoots of PI365967. A gene encoding salicylic acid-binding protein 2 (SABP2) was induced by salinity only in PI365967, suggesting a possible role for salicylic acid signaling in the salt response of PI365967. The fact that two genes encoding lactoylglutathione lyase were salt inducible only in PI365967, together with much higher basal expression of several glutathione S-transferase genes, suggested a more effective detoxification system in PI365967. The specific down-regulation in PI365967 of a putative high-affinity nitrate transporter, known as a repressor of lateral root initiation, may explain the better root growth of this genotype during salt stress. [1]

Cultivar, Maturity, and Heat Treatment on Lycopene Content in Tomatoes

Using high performance liquid chromatography, tomato cultivars which contain the Crimson gene (og) were usually found to have higher lycopene content (5086 to 5786 μg/100 g fresh weight) than those cultivars lacking the gene (2622 to 4318 μg/100 g fresh weight). A comparison of the color readings taken from tomatoes at the equatorial region with those of the homogenate prepared from the same region showed that the hue of tomato homogenate was a better indicator of lycopene content than tomato surface hue. The tomatoes’ lycopene content was not affected by ethylene treatment or cooking for 4, 8, and 16 min at 100 °C. [2]

Antihypertensive Effect of a γ-Aminobutyric Acid Rich Tomato Cultivar ‘DG03-9’ in Spontaneously Hypertensive Rats

This study aimed to investigate the effects of a γ-aminobutyric acid (GABA) rich tomato (Solanum lycopersicum L.) cultivar ‘DG03-9’ in comparison with ‘Momotaro’, a commonly consumed tomato cultivar in Japan, on systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR). In a single administration study, treatment with the GABA-rich cultivar elicited a significant decrease in SBP compared to the control group. In a chronic administration study, SHR were fed diets containing one of the tomato cultivars for 4 weeks. Both cultivars significantly reduced the increase in SBP compared to the control. The antihypertensive effect of the GABA-rich cultivar was higher than that of the commonly consumed cultivar in both the single- and chronic-administration studies. Treatment with a comparable amount of GABA elicited a similar response to treatment with the GABA-rich cultivar. These results suggest that the GABA-rich cultivar ‘DG03-9’ is a potent antihypertensive food and may be useful for treating hypertension effectively. [3]

Reproducible Agrobacterium-mediated Transformation of Nigerian Cultivars of Tomato (Solanum lycopersicum L.)

This study was carried out to develop transformation protocol for the possible improvement of local cultivars of tomatoes in Nigeria using complete randomized design (CRD). The research was conducted at the Plant Biotechnology Centre, International Institute of Tropical Agriculture (IITA), Ibadan, Oyo State, Nigeria between May 2009 and December 2009. Seeds of three promising farmer preferred varieties of cultivars of tomatoes namely Ibadan local, Ife and JM94/46 were selected and cultivated in-vitro. Sterile cotyledon and leaf explants were transformed using Agrobacterium tumefaciens strain LBA4404 with plasmid (pOYE153). Transformed plants were analyzed using GUS assay and PCR methods. Results showed that leaf explants had higher transformation efficiency than cotyledon explants in the three cultivars. Ife cultivar had the best transformation efficiency in both explant types – leaf 42.5% and cotyledon 8.89%. Histochemical GUS assay of transgenic plants showed blue coloration in leaves, stems and roots. PCR analysis showed amplification of 600 bp fragments of GUS and nptII genes in the transgenic plants on 1.0% agarose gel. The GUS and nptII genes were successfully integrated into the three cultivars of tomatoes thereby providing a reliable transformation protocol for the genetic improvement of local cultivars of tomatoes for desirable traits such as longer shelf-life, pest and disease resistance, enhanced nutrients, higher soluble solids, etc. [4]

Effect of Postharvest Application of Different Concentrations of 1-Methylcylclopropene on Quality and Shelf-life of Two Tomato (Solanum lycopersicum) Cultivars

Two tomato cultivars harvested at the mature-green stage were studied to determine the effect of postharvest application of different concentrations of 1-Methylcyclopropene (1-MCP) on their quality and shelf-life. A 2 x 3 factorial arrangement in Completely Randomized Design (CRD) with three replications were used. The two cultivars ‘Eva’ and ‘Power’ were each treated with 1 ppm and 2 ppm of 1-MCP concentrations and the untreated were considered as control (0 ppm).The fruits were placed inside air-tight plastic barrels with different 1-MCP concentrations at an average temperature of 29.5°C and relative humidity of 60-75%. The 1-MCP gas was allowed to circulate in the airtight barrels with the aid of a mini fan which was attached to the lid of the barrel for 24 hours before the fruits were brought out, displayed and physico-chemical properties and shelf-life monitored. The results showed that higher concentrations of the 1-MCP (2 ppm) significantly (P≤0.01) delayed ripening as measured by changes in colour, total soluble solids and total titratable acidity. Generally, between the cultivars, ‘Eva’ fruits were significantly (P≤0.01) firmer irrespective of the 1-MCP concentration. Significantly (P≤0.01), untreated fruits (0 ppm) of both cultivars recorded higher moisture and vitamin C contents than treated fruits (1 and 2 ppm). Tomatoes treated with 1 ppm and 2 ppm of 1-MCP concentrations had delayed ripening (longer green-life) and as a result had a longer shelf-life (89 and 104 days, respectively) compared to untreated tomatoes (77 days). Clearly, the results of this research has established that the use of 1-MCP have marketable prospect for growers and traders to delay the ripening of tomatoes. [5]

Reference

[1] Sun, W., Xu, X., Zhu, H., Liu, A., Liu, L., Li, J. and Hua, X., 2010. Comparative transcriptomic profiling of a salt-tolerant wild tomato species and a salt-sensitive tomato cultivar. Plant and Cell Physiology, 51(6), pp.997-1006.

[2] Thompson, K.A., Marshall, M.R., Sims, C.A., Wei, C.I., Sargent, S.A. and Scott, J.W., 2000. Cultivar, maturity, and heat treatment on lycopene content in tomatoes. Journal of Food Science, 65(5), pp.791-795.

[3] Yoshimura, M., Toyoshi, T., Sano, A., Izumi, T., Fujii, T., Konishi, C., Inai, S., Matsukura, C., Fukuda, N., Ezura, H. and Obata, A., 2010. Antihypertensive effect of a γ-aminobutyric acid rich tomato cultivar ‘DG03-9’in spontaneously hypertensive rats. Journal of Agricultural and Food Chemistry, 58(1), pp.615-619.

[4] Ajenifujah-Solebo, S. O. A., Ingelbrecht, I., R. Isu, N. and Olorode, O. (2014) “Reproducible Agrobacterium-mediated Transformation of Nigerian Cultivars of Tomato (Solanum lycopersicum L.)”, Journal of Experimental Agriculture International, 4(7), pp. 797-808. doi: 10.9734/AJEA/2014/5927.

[5] Amoateng, M. E., Kumah, P. and Yaala, I. (2018) “Effect of Postharvest Application of Different Concentrations of 1-Methylcylclopropene on Quality and Shelf-life of Two Tomato (Solanum lycopersicum) Cultivars”, Journal of Agriculture and Ecology Research International, 14(1), pp. 1-11. doi: 10.9734/JAERI/2018/38407.

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