M. Yousofi,
Volume 12, Issue 45 (10-2008)
Abstract
Freezing is one of the most important climatic factors affecting almond products in Isfahan province. Therefore, it is important to use a rapid method for assessing the resistant cultivars and wild species of these plants. Evaluation of electrolyte leakage (EL) from freezing damaged tissues of almond is an appropriate method for this purpose. In the present work, the effect of freezing on the rate of electrolyte leakage of 10 cultivated almonds (Amygdalus communis cultivars) and one wild species (A. scoparia) was evaluated in Isfahan province. The perfect and mature flowers of all samples were selected at random, and examined under natural (in nature) and artificial (in laboratory) freezing treatments in 3 replicates. All measurements were done using an Ec meter instrument and the mean of obtained data was analyzed statistically via ANOVA and Tukey's tests. In each treatment, increase in the rate of electrolyte leakage of treated samples in relation to the controls was taken as a criterion for comparison. Total Dissolved Solids (TDS) of the flowers of all samples were also measured, with an accuracy of 0.001, under natural freezing conditions. The mean of TDS was 390.8±33.5 mg/L among cultivated almonds (maximum in Safari cultivar with 439±29.3 mg/L and minimum in Kababi cultivar with 355±35.3 mg/L) and 362±55.8 mg/L in the wild almond (a little less than that of the cultivated ones). Linear regression test showed that there was no correlation between TDS and the rate of electrolyte leakage from freezing damaged tissues of the studied samples. Furthermore, the results showed that the cultivars of Tageri (with 7.47% increasing), Azar (with 19.2% increasing) and Rabie (with 22% increasing) are respectively more resistant than other cultivars under natural freezing, and the cultivars of Rabie (with 60.7% increasing), Tageri (with 67.6% increasing) and Hag Mirzaie (with 71% increasing) are more resistant than other cultivars under artificial treatment. These results are in agreement with the experimental observations in the studied area. The freezing tolerance of wild species (with 48.7% and 73% increasing, respectively) was moderate in both natural and artificial freezing treatments.
