The effect of loading rate, fruit size and loading direction on some of mechanical properties of tangerine (Citrus tangerina)

Taherkhani, Tofigh (2018) The effect of loading rate, fruit size and loading direction on some of mechanical properties of tangerine (Citrus tangerina). Doctoral thesis, University of Mohaghegh Ardabili.

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Text (تأثیر محرک¬ها و پیش ماده بر بیان ژن‌های دخیل در مسیر سنتز متابولیت‌های ثانویه در کشت سلولی گیاه زعفران (Crocus sativus)) Tofigh Taherkhani.pdf Download (1MB) | Preview

Abstract

Saffron with the scientific name of Crocus sativus is of flavor, aroma and color, which has many medicinal properties in addition to its nutritional use. These properties are created by secondary metabolites called crocin and safranal, and their biosynthesis is controlled by numerous genes. The purpose of this study is to investigate the effect of using ultrasound, sodium acetate, sucrose, Abscisic acid and chitosan on the expression of controlling genes of crocin and safranal and their amounts in saffron. In this study, a test with different combinations of BAP, 2,4-D, IBA and NAA hormones is carried out in order to determine the best hormonal composition in a ½MS medium. Then, a test in the culture medium with the best combination of hormones according to the results of the previous experiment in the liquid environment is carried out to determine the best time to apply treatments. Finally, saffron calluses are cultured in a cell suspension system under optimal growth conditions of calluses and treatments are applied. In 24 hours and 72 hours after applying the treatments, the samples are collected in three replications in separate experiments in a completely randomized design. Measurements of secondary metabolites and gene expression are performed using HPLC and a real time PCR assay, respectively. The results show that among the different callus induction environments, ½MS medium supplemented with 0.1 mg/L BAP and 0.5 mg/L 2,4-D is the most suitable hormone combination for callosing. Also, the results show that there is a significant difference between the genes on different days, so that the CsGT-2, CsLYC and CsBCH genes have the highest expression on the 12th day after cultivation in suspension. Measurements of crocin and safranal levels during 8-14 days after culture in saffron callus suspension also show that the highest accumulation of crocin and safranal is observed on day 12. Also, expression of genes in saffron cell suspensions treated with 100 and 150 mg/L chitosan and 15 and 45 g/L sucrose show that these stimuli altered the expression of CsLYC and CsGT-2 genes at both 24 and 72 hours after treatment, and the use of these stimuli with these doses does not affect the expression of the CsBCH gene. Also, the results of gene expression in saffron cell suspension treated with 0.5 mg/L abscisic acid show that this hormone has an effect on the expression of CsBCH, CsLYC and CsGT-2 genes at both 24 and 72 hours after treatment. Applying 1.5 mg/L of Abscisic Acid also has an effect on the expression of the two CsLYC and CsGT-2 genes, but does not affect the expression of the CsBCH gene. Statistical analysis of genes expression in saffron cell suspensions treated with sodium acetate 1 and 2 mM and 1 and 2 times under ultrasound for 2 minutes show that this stimulus change the expression of CsBCH, CsLYC and CsGT-2 genes in both time 24 and 72 hours after treatment. Comparison of the mean values of safranal and crocin by different levels of chitosan show that the amount of safranal and crocin is the highest in 72 hours after treatment with 150 mg/L chitosan, the mean comparisons show that the amount of safranal in 72 hours after treatment with 1.5 mg/L of Abscisic Acid has the highest value with an average of 66.55 micrograms per gram of callus, and also the amount of crocin in 72 hours after treatment with 1.5 mg/L of Abscisic Acid has the highest value with an average of 1732.13 microgram per gram of callus. Comparison of mean crocin values by different levels of sodium acetate treatment show that the amount of safranal is the highest in 72 hours after optimum growth using 1 and 2 mM Sodium acetate. The comparison of the mean values of safranal treated by ultrasonic waves for 2 minutes show that the amount of safranal 72 hours after 2 times application of the treatment is the highest with the mean of 0.035 mg of safranal per one grams of callus. Also, the mean comparison of crocin values using treatment with ultrasonic waves for 2 minutes show that the amount of crocin is the highest in 24 hours after 2 times application of the treatment. The comparison of mean show that the amount of safranal 72 hours after treatment with 45 g/L sucrose has the highest value with an average of 8.935 micrograms per gram of callus, and also the amount of crocin 72 hours after application of 45 g/L sucrose has the highest content with an average of 792.135 micrograms of crocin per gram of callus.

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