Pomology
Seyed Asghar Mousavi; Akram Vatankhah; Ali Imani
Abstract
IntroductionAlmond (Prunus dulcis L.) is one of the valuable nut trees that is cultivated in many temperate regions and Mediterranean climatic conditions for domestic consumption and export. Almond belongs to the genus Prunus, from the Rosaceae family. Identifying and introducing genotypes and cultivars ...
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IntroductionAlmond (Prunus dulcis L.) is one of the valuable nut trees that is cultivated in many temperate regions and Mediterranean climatic conditions for domestic consumption and export. Almond belongs to the genus Prunus, from the Rosaceae family. Identifying and introducing genotypes and cultivars of late bloom is one of the most important goals of almond breeding programs. The correct choice of almond rootstock causes better management of the garden, compatibility with all types of soil and resistance to nematodes. Peach × almond hybrid has been the most widely used rootstock in both dry and irrigated conditions in the past years. Creating an orchard by selecting grafted genotypes on suitable rootstock for sustainable cultivation of almonds is particularly important. Cultivation of superior genotypes grafted on fruit trees has an effect on pomological characteristics, yield and quality of nuts. The requirement for the introduction and production of superior cultivars is an accurate selection between cultivars, which is possible through the identification of cultivars and their diversity. The purpose of this research is to investigate and evaluate the most important vegetative, phenological, quantitative and qualitative characteristics of nuts and kernels in 36 promising cultivars and genotypes grafted on GN15 rootstock, in order to introduce superior cultivars.Materials and Methods:In this research, 36 promising almond cultivars and genotypes on GN15 rootstock were investigated in garden conditions in terms of various vegetative traits, nut and kernel characteristics in order to obtain suitable commercial cultivars. This research was conducted at the Badam research station in Saman region affiliated to the Center for Research and Education of Agriculture and Natural Resources of Chaharmahal and Bakhtiari province as a randomized complete block design with three replications. Vegetative traits of tree height, canopy length, canopy width, and branch length were measured by meter in the garden, and rootstock diameter, scion diameter, and branch diameter were measured in the garden with calipers. In order to measure the nut and kernels, 100 fruits were harvested from each of the studied cultivars and genotypes at the time of fruit ripening, and their green shell was separated and dried. Measurement of traits such as length, width, diameter of nut and kernel was done by digital caliper and weight of nut and kernel was measured by digital scale with accuracy of 0.01. Coding of some traits was done based on almond descriptor (Gülcan, 1985) with some changes. The data obtained from the experiment were analyzed using SAS software (version 3.1.9). To compare the means, Duncan's multiple range test was used at the 5% probability level.Results and DiscussionAccording to the results of analysis of variance (ANOVA), there was a statistically significant difference at the level of 1% between the attributes of tree height, canopy width, rootstock and scion diameter, branch length and diameter, and the ratio of tree height to canopy length. (P<0.01). The results of variance analysis show that there is a significant difference between the investigated nut and kernel traits in promising cultivars and genotypes grafted on GN (Table 5). These differences show the diversity in the investigated traits and it is possible to choose cultivars for different values of the same trait. Based on the average comparison results of the vegetative traits, the highest height in genotypes GA4, GA3, GA35, The highest canopy width was observed in genotypes GA5, GA17, GA3, and GA20, GA15, GA5, the highest diameter of rootstock and scion, and the highest length and diameter of one-year branches were observed in genotype GA18. The results of the comparison of the average nut and kernel characteristics show that there is a significant difference in the cultivars and genotypes investigated in this research. The results of the comparison of the average nut and kernel characteristics show that there is a significant difference in the cultivars and genotypes investigated in this research. Based on the obtained results, cultivars and genotypes of GA5, GA24, GA12, GA9 and GA1 showed relative superiority in terms of nut and kernel traits. The results of this research showed that the GA35 genotype grafted on the GN15 rootstock had the highest length, width and diameter of the nut, and the highest weight of nut and kernel. The kernel color light, the without shrinking the kernel and the highest percentage of kernel and the highest ratio of kernel weight to nut weight.ConclusionThe results of this research showed that the examination of vegetative traits, nuts and kernels in the studied cultivars and genotypes could show the diversity between cultivars and genotypes. The results showed that the investigated cultivars and genotypes have significant differences in terms of all nut and kernel traits, which indicates the existence of diversity between the investigated cultivars and genotypes. This indicates that these cultivars and genotypes can be considered as a source of good germplasm for breeding programs. Cultivars and genotypes with higher percentage of kernels had thinner shell, more patterns on the skin, and light to medium kernel color. Based on the obtained results, cultivars and genotypes of GA5, GA24, GA12, GA9 and GA1 showed relative superiority in terms of nut and kernel traits. The results of this research showed that the GA35 genotype grafted on the GN15 rootstock had the highest length, width and diameter of the nut, and the highest weight of nut and kernel. The kernel color light, the without shrinking the kernel and the highest percentage of kernel and the highest ratio of kernel weight to nut weight.
Pomology
Esmaeil Safavi; Mehrab Yadegari; Seyyed Asghar Mousavi; Bijan Haghighati
Abstract
Introduction
Water shortage is very frequent in many countries, and, together with the rising demand for industry, growth of human population, climate change and specifically the trend towards irrigated agriculture, has led to widespread problems of water scarcity, especially in Middle East countries. ...
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Introduction
Water shortage is very frequent in many countries, and, together with the rising demand for industry, growth of human population, climate change and specifically the trend towards irrigated agriculture, has led to widespread problems of water scarcity, especially in Middle East countries. This situation imposes the need to optimize water use in all human activities. Among the different productive uses of water, agriculture is by far the main water user in most water scarce regions and, consequently, any potential improvement in the use of the available water resources may play a significant role toward achieving a more sustainable use of water. Plant responses to water deprivation are usually monitored through selected morphological and physiological parameters which have been proven to be good indicators of drought in different studies. Some of the most important standards for evaluating plant genotypes under drought stress are measurements of morphological parameters such as height, leaf characters and root growth.
Materials and Methods
To compare the growth response of different almond cultivars to different levels of water stress, an experiment was conducted as a split plot in the base of randomized complete block design with three replications in the Agricultural and Natural Resources Research Center of Chaharmahal and Bakhtiari Province in two growing season 2019-2020 and 2020-2021. Different irrigation periods based on the percentage of usable soil moisture between filed capacity to wilting point, including 70% filed capacity (control or no stress), 50% filed capacity (mild stress), 30% filed capacity (medium stress) and 10% of field capacity (severe stress) were considered as the main factor of the experiment. The sub-factor included 14 commercial cultivars of almonds (Mamaei, Rabi, Saba, Araz, Eskandar, Aidin, Shahrood 6, 7, 8, 10, 12, 13 and 21 and GN vegetative rootstock), all of which were grafted on GN rootstock. In this study, uniformly grafted seedlings in terms of age, stem diameter and height were selected and planted. In the second year after planting the seedlings, in order to apply drought stress, tubes for hygrometer (TDR) were installed in each experimental plot and based on soil moisture content, irrigation cycle was determined for different treatments.
Results and Discussion
In both years, three months after applied water stress growth traits and nutrient concentrations in the leaves of treated seedlings were measured. Based on the results of analysis of variance, the morphological traits of almond seedlings were significantly affected by cultivar type and drought stress level. In all almond cultivars, the highest height was belonged to seedlings that were grown in non-stress conditions and with increasing the drought stress intensity, the height of almond seedlings was decreased. Under severe drought stress, GN and Mamaei cultivars had the highest (183.93 cm) and the lowest (94.60 cm) height, respectively. Seedling height in GN, Shahrood 12, Saba and Shahrood 10 cultivars showed the lowest decrement under severe drought stress. In all cultivars, drought stress caused a significant reduction in the length and width of the seedlings crown, and the greatest decreasing was recorded in severe drought stress (10% FC). Under severe drought stress, cultivar GN had the largest crown and cultivars Rabi, Shahrood 7 and Eskandar had the smallest crown. Increasing the drought stress intensity significantly reduced the branches growth of seeding in terms of number and length of sub-branches. As the intensity of drought stress increased, the length of sub-branches decreased however the number of intermediates in sub-branches increased. In non-stressed condition, the cultivar GN had the longest branch (55.95 cm), which was significantly higher than the other studied almond cultivars. The shortest branches were also observed in Saba (29.94 cm) and Eskandar (29.47 cm) cultivars. Increasing drought stress caused a significant reduction of leaf area in all studied cultivars and the highest decreasing was observed under severe drought stress. The GN (37.76 cm²) and Shahrood 10 (31.81 cm²) had the highest leaf area in non-stress and drought stress conditions. Under severe drought stress (10% FC) cultivar Shahrood 6 showed the lowest leaf area. The results of this study showed that increasing the intensity of dehydration significantly reduced the amount of nitrogen, phosphorus, manganese and zinc in the leaves of the studied cultivars of almonds, however, the amount of potassium and iron in stressed plants increased under drought stress. Based on the results of the present study, under severe drought stress the GN, Shahrood 8 and Shahrood 12 cultivars in terms of growth indices including seedling height, stem diameter, canopy growth, branch growth and concentration of macro and micro elements was superior compared with the other studied cultivars.
Conclusion
Based on the results of this study, drought stress significantly reduced growth indices and nutrient concentrations, although the reaction of almond cultivars to different levels of drought stress was different. In this study, among the studied almond cultivars GN, Shahrood 8 and Shahrood 12 cultivars in terms of growth characters including seedling height, stem diameter, canopy growth, branch growth and concentration of macro and micro elements showed higher tolerance to different level of drought stress. These cultivars less affected by the high intensities of dehydration. Therefore, GN, Shahrood 8 and Shahrood 12 cultivars can be used in future studies to evaluate the possibility of cultivating these cultivars in areas with water deficit.
