اثر دو پایه بذری به و زالزالک بر رشد و باردهی ژنوتیپ‌های امیدبخش و ارقام جدید به (Cydonia oblonga Mill.) در شرایط محیطی ارومیه

Isfahan quince cultivar is the most popular cultivar in Iran. Although this cultivar has desirable fruit quality, but it is susceptible to fire blight and has lower fruit yield in comparison with some other quince genotypes in Iran. Morphological and pomological traits were evaluated in cv. Vidoja, cv. Behta and cv. Isfahan, and Isfahan2, Isfahan3, Isfahan5 promising genotypes grafted on two quince and hawthorn seedling rootstocks as factorial arrangements in randomized complete block design with three replications at Saatloo Agricultural Research Station in Urmia in West Azerbaijan province, Iran, in 2017, 2018 and 2019. The results showed that rootstock had significant effect on all vegetative traits, except internode length. Therefore, quince rootstock compared to hawthorn rootstock, increased tree height, grafting diameter, cultivar diameter, shoot number, annual shoot growth and width of tree canopy. Sucker number in hawthorn rootstock was less than that in quince seedling rootstock. The highest vegetative growth was observed in Isfahan5 genotype on quince rootstock. The correlation coefficient between vegetative traits showed that quince cultivars/genotypes with more shoots had shorter internode length. Internode length had significant negative correlation with rootstock diameter, grafting diameter and cultivar/genotype diameter. The highest fruit yield (5.7 and 5.4 kg tree^-1) was recorded in cv. Vidoja and Isfahan5 genotype, respectively, grafted on quince seedling rootstock.
 
Keywords: Quince, vegetative traits, tree height, annual shoot growth, internode length, fruit yield.
Introduction
Iran with production of 82,000 tons of quince fruit is among importance quince producers in the world (FAO, 2022). Isfahan cultivar, cv. Gorton, cv. Neishabur and cv. Torsh are the main quince cultivars in Iran. Isfahan quince cultivar is the most popular, due its high fruit quality. However, this cultivar is susceptible to fire blight and has lower fruit yield in comparison with some other quince genotypes in Iran. In the past decade, two quince cultivars; Vidoja and Behta, have been release by quince researchers, which have high fruit yield compared to the cv. Isfahan (Abdollahi, 2023).
The rootstock in fruit trees have great effects on disease resistance, vegetative growth, bearing, nutrition, tolerance to cold and drought and other environmental stresses (Abdollahi, 2023). Quince cultivars are grafted on quince seedling, quince C, B, A, and BA29 in many regions of the world. In Iran, cultivars are grafted mostly on quince and hawthorn seedling rootstocks. Hawthorn species are tolerant to drought and salt stresses. These species have higher efficiency in iron uptake in calcareous soils. Hawthorn species as rootstock decrease vegetative growth of quince and pear cultivars (Mohammadi and Rabiei, 2024).
The purpose of this research was to investigate the effect of two quince and hawthorn seedling rootstocks on growth and bearing of new quince cultivars/promising genotypes under climatic conditions of Urmia in Iran.
 
Material and Methods
In this research, cv. Vidoja, cv. Behta, cv. Isfahan and promising genotypes of Isfahan2, Isfahan3 and Isfahan5 grafted on two quince and hawthorn seedling rootstocks were studied for three years (2017-2019). Grafted seedlings were planted in an experimental orchard with planting density of 3 × 4 meters, with three trees in each plot, in early April 2016 at Saatlo Agricultural Research Station in Urmia in West Azerbaijan province, Iran. Factorial arrangement in randomized complete block design with three replications was used for evaluation of quince cultivar/genotypes.
The growth, rootstock diameter, grafting diameter, cultivar diameter, shoot number, tree height, annual shoot growth, internode length, width of tree canopy and sucker number tree^-1 at the end of season were studied. To estimate the effects of rootstocks on bearing of cultivars/genotypes in the third year (2019), fruit number and yield were counted and measured. Combined analysis of variance was performed using MSTATC software. Means were compared using Duncan's multiple range test at the 5% probability levels. Correlation coefficients between vegetative traits was calculated using SPSS software.
 
Results and Discussion
Combined analysis of variance revealed significant effect of rootstocks on vegetative growth traits, except internode length. Mean comparison showed that quince seedling rootstock increased vegetative growth in quince cultivars/genotypes in comparison with hawthorn rootstock. The rootstock can affect the remobilization of nutrients, carbohydrates and growth regulators between roots and shoots and the vegetative growth of quince tree (Tatari et al., 2016). The results showed that quince seedling rootstock increased tree height by 23 centimeters in comparison with hawthorn rootstock, grafting diameter by 0.7 centimeters, cultivar diameter by 0.7 centimeters, shoot number by 4 shoot, annual shoot growth by 7 centimeters and width of tree canopy by 20 centimeters.
Quince cultivars/genotypes significantly differed in tree height, shoot number, internode length, and width of tree canopy. The tallest tree height with 1.8 meters, the highest shoot number with 17.6 shoots, the longest internode length with 2.28 centimeters and the widest tree canopy with 90 centimeter was measured in cv. Behta cultivar, Isfahan5 genotype, cv. Isfahan and Isfahan5 genotype, respectively. The rootstock × cultivar interaction effect showed that the highest vegetative growth was recorded in Isfahan5 genotype grafted on quince seedling rootstock. The results showed that in 2019, fruit number tree^-1 and fruit yield tee^-1 increased in all cultivar/genotypes grafted on quince seedling rootstock.
 
References
Abdollahi, H. 2023. A review on cultivation history, genetic resources, selection of cultivars and improvement of tree and fruit characteristics of quince (Cydonia oblonga Mill.) cultivars in Iran. Seed and Plant, 39, pp. 445-493 (in Persian). DOI: 10.22092/spj.2024.365780.1372
FAO. 2022. Statistical Yearbook 2022. World Food and Agriculture. Food and Agriculture Organization. Rome Italy. 368 pp. DOI: 10.4060/cb4477en
Mohammadi, S. and  Rabiei, V. 2024. Effects of quince A and hawthorn rootstocks on some morphological and pomological properties of Esfahan local quince cultivar. Pomology Research, 8, pp. 11-19 (in Persian). DOI: 10.30466/RIP.2021.53275.1153
Tatari, M., Ghasemi, A. and Rezaeib, M. 2016. Evaluation of vegetative and reproductive traits of some commercial pear cultivars on quince clonal rootstocks in Isfahan climatical conditions. Seed and Plant, 32, pp.45-62 (in Persian). DOI: 10.22092/SPPJ.2017.110578