Ali Akbar Ghasemi-Soloklui; Ahmad Ershadi
Abstract
Freezing damage is a significant environmental challenge that limits both the geographic distribution and production of pomegranates in the world. The objective of this research was to search for useful correlations between freezing tolerance and soluble carbohydrate and proline content, as well as stomatal ...
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Freezing damage is a significant environmental challenge that limits both the geographic distribution and production of pomegranates in the world. The objective of this research was to search for useful correlations between freezing tolerance and soluble carbohydrate and proline content, as well as stomatal density in different parts of the leaves, to allow indirect selection of winter hardiness in pomegranate cultivars. Our results showed that freezing tolerance at the non-acclimated stage (August) was not strongly correlated with freezing tolerance during deep winter dormancy in January. Cold tolerance in summer was strongly correlated with leaf stomatal density; however, a moderate correlation was observed between cold tolerance in winter and leaf stomatal density. The results showed that 'Alak', the most cold-tolerant cultivar in summer and winter, had the highest leaf stomatal density. 'Agha Mohammad Ali' cultivar had the lowest leaf stomatal density and cold tolerance in summer; however, this cultivar showed considerable cold tolerance in winter. Moreover, with the except of 'Agha Mohammad Ali', stomatal density in summer was related to soluble carbohydrate concentration in the stems, which could justify the correlation between stomatal density and winter hardiness in pomegranate trees. It was found that LT50 values in January were negatively related to soluble carbohydrate concentration in stems. However, there was no statistical correlation between winter hardiness in January and proline content in the stems. These results suggest that soluble carbohydrates and stomatal density are suitable indices for predicting freezing tolerance of pomegranate cultivars throughout the year and growing season, respectively.
Ali Akbar Ghasemi Soluklui; Ahmad Ershadi; Zia eldin Tabatabaee; Esmaeil Fallahi
Abstract
Freezing injury is an important limiting factor in the production of pomegranate in Iran.The aim of the present study was to evaluate the effect of paclobutrazol (PBZ) on cold hardiness of pomegranate (Punica granatum L.) cv. ‘Malas Saveh’. Different concentrations of PBZ including 0 (control), ...
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Freezing injury is an important limiting factor in the production of pomegranate in Iran.The aim of the present study was to evaluate the effect of paclobutrazol (PBZ) on cold hardiness of pomegranate (Punica granatum L.) cv. ‘Malas Saveh’. Different concentrations of PBZ including 0 (control), 31, 62, 125 or 250 mg L–1 were sprayed on one-year-old plants in August and the electrolyte leakage of their stems was measured at three acclimation stages (November, January, and March). PBZ treatments, especially at 125 and 250 mg L–1 concentrations increased cold hardiness, and corresponding soluble carbohydrates and proline contents. The highest variation in freezing tolerance was observed between control and PBZ-treated plants in January, and the lowest found in November. Irrespective of PBZ treatment, correlations between cold hardiness and soluble carbohydrate concentrations were stronger, compared to proline. Soluble carbohydrates were higher in January, associated with deep dormancy, whereas the maximum proline content was detected in March, at deacclimation stage. Results suggest that PBZ application can reduce low temperature-induced dysfunction of cell membrane through increasing soluble carbohydrates and proline contents.
Babak Valizadeh Kaji; Ahmad Ershadi; Masoud Tohidfar
Abstract
In this study, an efficient Agrobacterium-mediated transformation method was developed forpomegranate (Punica granatum L.), a difficult-to-transform plant. In vitro shoot segments wereinoculated with Agrobacterium tumefaciens strain LBA4404 harboring the binary vectorpBI121 carrying the neomycin phosphotransferase ...
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In this study, an efficient Agrobacterium-mediated transformation method was developed forpomegranate (Punica granatum L.), a difficult-to-transform plant. In vitro shoot segments wereinoculated with Agrobacterium tumefaciens strain LBA4404 harboring the binary vectorpBI121 carrying the neomycin phosphotransferase (nptII) gene as a selectable marker and β-glucuronidase (gus) gene as a reporter. After 28 d in WPM selection medium containing 50 mgL-1 kanamycin, 59 new shoots proliferated. gus analysis was performed on these putativetransgenic shoots, of which 32 stained positive. Positive staining shoots were cut and culturedin selection medium for 2 subsequent subcultures until final gus analysis. After three months ofthe selection period, 6 putative transgenic shoots were obtained. Presence of the gus and nptIIgenes was confirmed by polymerase chain reaction. Southern blot analysis confirmed that TDNAwas stably integrated into the genome of three out of six PCR-positive plants. Thetransgenic plants were rooted and successfully acclimatized.
