Ali Imani; Khosro Parvizi; Hamdollah Beyrami jam; Ebrahim Hadavi
Abstract
Introduction: Iron chlorosilicon caused by calcium carbonate can be controlled widely with iron chelate in nutrition management of gardens, but it has high costs and potential environmental hazards. Such constraints have led to alternative strategies for managing iron nutrition in relation to soil and ...
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Introduction: Iron chlorosilicon caused by calcium carbonate can be controlled widely with iron chelate in nutrition management of gardens, but it has high costs and potential environmental hazards. Such constraints have led to alternative strategies for managing iron nutrition in relation to soil and plant parameters. Almond rootstocks and almond x peach hybrids (GF 677) are widely used as the rootstock for almonds, peaches and nectarines in the Mediterranean basin, moreover, in addition to its drought resistance, has a high tolerance to iron chlorosis. Different references of almond tree have introduced this fruit tree as a chlorosis resistant, but it shows different ranges of chlorosis when grafted on almond x peach hybrids such as GF677 and GN15. Therefore, this study carried out to evaluate the effect of calcium bicarbonate on some physiological characteristics of selected almond cultivars on the GN15 rootstock.
Materials and Methods: This research was conducted during 2015 and 2016 to evaluate the resistance to bicarbonate and the amount of chlorosis produced in selected almond cultivars on the hybrid rootstock (peach and almond) as a factorial experiment with completely randomized design with three replications in greenhouse conditions. The first factor consisted of different concentrations of calcium bicarbonate (0, 20, 10, 30 and 40 mmol L-1) and the second factor included nine selected almond cultivars grafted to the GN15 rootstock and a GN15 (non-grafted) rootstock. Almond cultivars included 9 cultivars including Supernova, 25-1, 40-13, Mamaei, 16-1, Kaghazi, Sahand, 200A, 7-9, and GN15 rootstock. Each plot included a pot, where the rootstock planted. In the spring, the cultivars and GN15 rootstock planted in plastic pots with soil compositions including perlite (50%) and cocopeat (50%). After sufficient growth of these rootstocks in the pots, almond cultivars were grafted onto them and immediately after the transplantation, the calcium bicarbonate treatments began after proper growth of the scions. In order to apply bicarbonate treatment, 1.62, 3.23, 4.86 and 6.48 g L-1 calcium bicarbonate (Ca (HCo3) 2) were added to the pots. In addition, 10% of calcium bicarbonate added also to the pots because of the deficiency of 10% chemical purity. After applying the treatments, chlorophyll, chlorophyll a and b, carotenoids, chlorophyll fluorescence were measured in two stages at intervals of 30 and 90 days. After the end of the growth period, the length and diameter of the current season branches and the leaf length and width of each almond cultivar were measured and recorded in different treatments. Two-way ANOVA of the data was carried out using SAS software (v. 8.02, SAS Institute, Cary, NC) and the means were compared based on Duncan’s multiple range test.
Results and Discussion: Based on the ANOVA results, it was determined that the effects of calcium bicarbonate, cultivar and their interactions on the content of chlorophyll a and b were statistically significant (p≤0.01). The lowest decrease levels of chlorophyll a and b were found in the leaflets of Kaghazi, Mamaei, saplings, 25-1, and 40-13 cultivars, but the highest decrease was observed in Supernova cultivar, 7-9, and GN15. The reasons for decreasing the chlorophyll content of the leaf with the increase of bicarbonate levels can be related to iron deficiency and its deactivation and the role of iron in the synthesis of chlorophyll. Nevertheless, the difference for chlorophyll depletion at different levels of bicarbonate in different cultivars can be due to the capacity of these cultivars to tolerate higher levels of bicarbonate and the possibility of the synthesis of chloroplastic proteins in leaf cells even with a relative lack of iron. In all cultivars, as well as the GN15 rootstock, the level of carotenoids decreased with increasing concentrations of calcium bicarbonate. However, the response of the cultivars was different. Under bicarbonate conditions, reducing leaf iron concentration reduces chlorophyll and carotenoids. The results of the mean comparison showed that bicarbonate induced height growth reduction and branch diameter in the current season, while the reaction of the studied rootstocks were also different. So that the highest decrease in growth rate was observed in Supernova, 7-9 cultivars and GN15 rootstock and the lowest decrease of growth rate were found in the cultivars of Kaghazi, 1.25-1 and -40-13. High concentrations of bicarbonate, by disabling and decreasing iron absorption, indirectly reduces DNA synthesis, cell division, and thus decreases cell growth and plant biomass. The results of this study are in agreement with Ghasemi et al. (2010) in different responses of the rootstock to bicarbonate concentration on the height and diameter decreasing of current season branch. Mean comparison of data showed that the length and width of leaf area in all studied cultivars decreased with increasing concentration of calcium bicarbonate in irrigation water. Also, leaf length and width decrease in rootstock grafted cultivars had a significant difference, so that the lowest reduction in leaf length and width was in pepper, midwifery and 25-1, and the highest leaf area decrease in Supernova cultivars, 7-9 and GN15 base was observed. Leaf growth decreases in calcareous soils due to a decrease for iron in the symplast. The specific effects of high bicarbonate on leaf growth in almond cultivars and the different reaction of almond rootstocks in this study are in agreement with Tedaion et al. (2004) results in orange, as well as Wahom et al. (2001) in olive and peach.
Conclusion: Totally, the results of this study indicate that cultivar and rootstock cause the amount of chlorosis tolerance induced by calcium bicarbonate. In general, in terms of morphological and physiological traits studied in this research, Kaghazi and 25-1 cultivars are the most tolerant, while 7-9 and supernova are the most sensitive cultivars to bicarbonate.
Mahdieh Razaei; Abbas Safarnejad; Mostafa Arab; Seyyedeh Bibi Leila Alamdari; Marzieh Dalir
Abstract
Introduction: Thyme is an important medicinal plant in cosmetic, pharmaceutical and food industries. The genus Thymus L. (Lamiaceae) consists of about 300 species of herbaceous perennials and subshrubs. This genus is mainly distributed over Mediterranean country, northern part of Africa and Southern ...
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Introduction: Thyme is an important medicinal plant in cosmetic, pharmaceutical and food industries. The genus Thymus L. (Lamiaceae) consists of about 300 species of herbaceous perennials and subshrubs. This genus is mainly distributed over Mediterranean country, northern part of Africa and Southern Greenland. Thymus species are commonly used as spices, herbal tea, insecticide and flavoring materials. Also, Thymus have been most frequently used in traditional herbal medicine due to its antiseptic, carminative, expectorant, antispasmodic, anti-inflammatory properties. Recent studies have showed that this genus have strong antifungal, antibacterial and antioxidant activities. Because of these medical features of this genus, Thymus is cultivated all over the world. The aromatic and medicinal properties of the genus thymus have made it one of the most popular plantsthroughout all of the world.
Materials and Methods: In order to study genetic variations, 22 populations of endemic species of Thymus include thirteen populations from species of T. daenensis, four populations of T. migricus and one population from each of the following species: T. fedtschenkoi, T. vulgaris, T. transcaspicus, T. pubsence and T. kotschyanus were used for assessment of morphology and essence value. Populations in completely random block design with three replications at the Razavi-khorasan Agriculture and Natural Resources Research Center were planted. Morphological measurement was taken on five random individuals of each replicate and average traits were analyzed. Clevenger unit was used to measure the essence amount. Morphological traits were included leaf length, leaf width, leaf number of year stem, maximum diameter of canopy, minimum diameter of canopy, canopy area, height flowering stem, height inflorescence, number of stems per plant, number days to starting of flowering, number days to 50% of flowering, fresh yield, dry yield, height of stem than inflorescence, and essence weight and volume. A balanced completely randomized design with three replications was used. Biometric measurement was applied to study the selected thyme populations. SAS, SPSS and NTSYS softwares were used for calculating the statistics indicators, normality tests, analysis of variance, means of traits, correlation coefficients, stepwise regression analysis and principal component analysis.
Result Discussion: A wide range of morphological variety was observed by biometric measurements. The results showed that there were highly significant differences between thyme populations. Mean comparison was carried out using Duncan method at 5% level. Population No.18 and population No.4 were showed the highest and the lowest diameter of canopy, respectively. Population No.18 and population No.4 exhibited maximum and minimum canopy area, respectively. Maximum and minimum stem lengths were related to populations No.12 and No.4, respectively. Maximum and minimum numbers of stems at each plant were seen in populations No.12 and No.2, respectively. Inflorescence length of population No.6 was maximum and population No.5 was minimum. The maximum and minimum average of the number of leaf per stem were observed in population No.17 and population No.12, respectively. Maximum and minimum of the leaf length were seen in populations No.10 and No.16, respectively. Population No.4 and population No.22 exhibited the highest and the lowest leaf width, respectively. For inflorescence length/ stem length ratio, population No.6 and population No.21 were showed maximum and minimum, respectively. The maximum number days to stating of flowering and 50% flowering, were seen in populations No.2 and No.8 and populations No.6 and No.4 had minimum of these. Population No.13 and population No.4 exhibited maximum and minimum dry weight, respectively. Populations No.13, No.17, No.18 and No.20 had the maximum of fresh yield and population No.4 had the minimum of fresh yield. For essence value characteristics, the most volume and weight of essential oil was observed in populations No.2, No.9, No.10 and No.18 and the least volume and weight of essential oil was observed in populations No.4, No.5, No.6 and No.12.
Conclusion: ANOVA showed that there was significant difference between thyme accessions for morphological traits which it is important for plant breeding. High variation increases selection of desirable traits for breeding. In order to crossing and hybridization, parents must be genetically distant to gain the most variation. In this study, relationship between thyme accessions using morphological and essence value traits was investigated so plant breeder can use it for production desirable hybrid.
