نشریه نهال و بذر
سال سی و هشتم شماره 4 (زمستان 1401)

The plateau of Iran has very high diversity of different species of the genus Pyrus that has not been evaluated at the species level and used in the national pear breeding programs. The present research was carried out with the aim of evaluating the variation in fruit, seed and the initial seedling growth characteristics of 10 native pear species and comparing them with three East Asian pear species during 2021-2022. The results showed that P. salicifolia and P. hyrcana species had the highest and lowest seed thickness that could be used to distinguish these species. The highest (226.5 g) and lowest (0.67 g) fruit weight was observed in the two Asian pear species, P. bretschneideri and P. betulifolia. The evaluation of the seedlings of pear species showed that the highest seedling height, stem diameter, number of internodes, number of leaves, number of leaflets and petiole length belonged to the seedlings of P. communis cv. Dargazi, and the lowest related to P. pashia. Cluster analysis based on morphological and pomological characteristics grouped pear species in two groups. The first group included P. communis cv. Dargazi and P. bretschneideri that were very similar for pomological characteristics. Considering the importance of breeding for devlepment of dwarf rootstocks, it is necessary to study the dwarf pear species especially P. pashia in future and for longer period.

Plum fruit moth Grapholita funebrana (Treitschke) is one of the important pests of plums. The aim of this study was to assess the antixenosis resistance of plum genotypes/cultivars and the effect of fruit physico-chemical characteristic on it. Twenty seven plum genotypes/cultivars in fruits tree genetic resources collection in Kemalshahr in Karaj, Iran, were considered and evaluated from 2019 to 2021 seasons. Antixenosis resistance indices were estimated by sampling larvae population during the seasons. The plum geneotypes/cultivars were grouped using cluster analysis, and the relationship between different fruit characteristics and antixenosis resistance was investigated using Pearson correlation. The antixenosis resistance indices had significant relationship with fruit length, width, diameter, engineering diameter, spherical index and fruit surface area. The minimum antixenosis index of larvae establishment ratio in Bukhara, Genotype 19 and Uromieh 20 was 0.02, and its maximum was 0.06 in Anjelo, Friar, G-98, Kh-Mashhad and Sosourmi. The minimum larval non-preference index was 91.96 in G-Melayer and its maximum was 98.81 in Bukhara. The minimum larvae preference was 0.03 in Sosourmi, and its maximum was 1.03 in Zojlo. The minimum larvae crowding index was 24.6 in Bukhara, and its maximum was 66.42 in G-98. Finally, Black Star, Queen Rosa, G99, G98, Qomi, Santa Rosa, Sosurmi, Anjelo, Black Amber, and GR-Rezaieh genotpes/cultivars were more resistant, and Kermanshah genotype was the most sensitive to plum fruit moth. The results of this research are part of the supplementary information for selection of suitable plum cultivars for development of plum orchards in Karaj and other similar envirmonetal conditions.

Soil salinity is one of the major environmental stresses which reduces the growth and yield of crops by affecting wide spectra of physiological and biochemical processes in plants. In this study, effect of foliar application of melatonin levels (0 and 200 μM) under salt levls (0, 30, 60, 90 and 120 mM NaCl) on sour orange rootstock was investigated. The experiment was carried-out as factorial arrangements in completely randomized design with four replications in 2020-21 at the research farm of Sari Agricultural Sciences and Natural Resources University, Sari, Iran. The results showed that most of morphological and physiological characteristics were affected by salinity and foliar application of melatonin. Salinity × foliar application of melatonin interaction effect was significant on most of studied traits including leaf length, leaf width, flush number, flush length, root length, leaf moisture and dry matter contents of leaf, ion leakage, stomatal conductance, transpiration rate, of assimilation rate, vapor pressure deficit and photosynthetic quantum yield. Foliar application of melatonin increased leaf moisture content, flush number, assimilation rate, stomatal conductance and photosynthesis quantum yield, while leaf ion leakage decreased. The highest photosynthetic quantum yield was recorded in 200 µM melatonin and salinity free treatment. Foliar application of melatonin under salinity stress conditions improved most of the physiological parameters. Foliar application of melatonin at different salinity levels caused significant increases in length and width of flush leaves compared to the control. Overall, the results of this study showed that foliar application of melatonin reduced negative effects of salinity stress on growth and physiology of sour orange rootstock, therefore, it can be considered as an effective approach to mitigate the adverse effect of soil and water salinity on sour orange rootstock.

This research was carried out to meet the need for development and introduction of new crops that can adapt to long periods of drought stress under changing climate. For this purpose the adaptability and seed yield stability of 10 autumn sown quinoa genotypes including; Red Carina, Titicaca, Giza1, Q12, Q18, Q21, Q22, Q26, Q29 and Q31 were studied using randomized complete block design with three replications in four location (Ahvaz, Iranshahr, Bushehr and Jiroft) in Iran in 2018-2019 and 2019-2020 cropping seasons. Seed of quinoa genotypes were sown in October 2017 and 2018 in Ahvaz and Jiroft, and in November 2017 and 2018 in Iranshahr and Bushehr. Genotypes with Q prefix have been received from Chile, cv. Titicaca from Denmark, cv. Giza1 from Egypt and cv. Red Carina from the Netherlands. Days to germination, days to flowering, days to physiological maturity, plant height, inflorescence length, stem diameter, seed yield, 1000-seed weight and seed saponin content were measured and recorded. Combined analysis of variance showed that effects of year, location and genotypes were significant (P ≤0.01) on all studied traits, except days to germination. Also, genotype × location interaction was significant (P ≤0.01) on all studied traits. Genotype Q12 (2350.2 kg ha-1) and Red Carina (1695 kg ha-1) had the highest and lowest mean seed yield, respectively. Jiroft (3147.5 kg ha-1) and Bushehr (1009 kg ha-1) had the highest and lowest mean seed yield, respectively. The results of AMMI analysis showed that Q18, Q22, TTKK and Q21 genotypes had the highest seed yield stability, respectively. Genotypes Q18 and Q22 had specific adaptation to Ahvaz, Iranshahr and Bushehr, and genotypes Q12, Q29 and Q26 showed specific adaptation to Jiroft. In conclusion, the results of this research showed that all studied quinoa genotypes were suitable for autumn sowing in target areas.

Selection of suitable pistachio rootstock and compatible cultivar are the fundamentals for establishing a pistachio orchard. The aim of this research was to investigate the effect of Pistacia vera L. rootstocks on leaf nutrients concentration and yield of two pistachio cultivars. The rootstocks included; Akbari, Badami Sefid, Badami Zarand, Barg Siah, Kaleghochi, and Sarakhs, and two pistachio cultivars;  Akbari and Barg Siah were evaluated as factorial split-plot arrangements in randomized complete block design with three replications in Feizabad pistachio research station in 2020-2021. Results showed that rootstock had significant (P<0.01) effect on the concentration of leaf nitrogen, calcium, magnesium, iron, zinc, copper and boron. Sarakhs rootstock caused the highest leaf copper concentration and the lowest boron concentration. Also, Akbari and Sarakhs rootstocks had the lowest Na: K ratio with 0.063 and 0.069, respectively. Badami Sefid rootstock had the highest Na: K ratio with 0.126. Akbari cultivar grafted on Barg Siah rootstock had the highest leaf boron concentration (337.8 mg kg-1), and cv. Akbari grafted on Sarakhs rootstock showed the lowest leaf boron concentration (221.2 mg kg-1). Sarakhs and Barg Siah rootstocks with 9.58 and 3.33 kg tree-1, respectively, had the highest and lowest effect on fresh yield. Furthermore, cv. Akbari grafted on Sarakhs rootstock had the highest number of flower buds on terminal shoot, and the highest fresh yield with 11.92 kg tree-1. In conclusion, cv. Akbari grafted on Sarakhs rootstock was identified as the most efficient rootstock-scion combination.

To evaluate effect of genotype and plantlet age on the yield and yield components of potato minitubers, this study was conducted under aeroponic system conditions in Ardabil agricultural and natural resources research station and Behparvar Sabalan Ardabil Company in Aradbil in Iran. Four potato genotypes including; promising clones C-397097-2, C-397081-1, cv. Agria and cv. Caesar, and three plantlet ages including; 30, 40 and 50 days were experimented as factorial arrangements in completely randomized design with three replications. The results showed that tuberization and development of minitubers was delayed in the aeroponic system. The effect of plantlet age on yield and yield components was more pronounced than genotype. The effect of plantlet age was significant (P≤0.05) on all traits. Genotype × plantlet age interaction was significant for yield and yield components, except for single minituber weight. Clone C-397081-1 of 30-day plantlet age produced the highest minitubers plant-1 (57.3 minitubers plant-1). For cv. Caesar and clone C-397097-2 of 40 days plantlet age were the best and produced on average 55.57 and 53.54 minitubers plant-1, respectively. There was no significant difference between plantlet ages of 30 and 40 days for clone C-397097-2. The cv. Agria had the best response at the plantlet age of 40 days and had on average 45.7 minitubers plant-1. Clone C- 397081-1, C-397097-2, cv. Agria and cv. Caesar produced on average 1203, 1235, 1113 and 1223 m-2, respectively. Forward stepwise regression analysis showed that the mean single minituber weight and minituber weight plant-1 was important in the selection of potato genotype for production of large number of minitubers. The mean weight of single minituber and plant height were inversely related to minituber number. In conclusion, the maximum economic minituber production for each potato genotype was affected by the plantlets age. The plantlet age between 30 and 40 days was identified as suitable for transferring potato plantlets to areoponic system.