نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار، پژوهشکده میوه‌های معتدله و سردسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
2 استادیار، بخش تحقیقات علوم زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان سمنان، سازمان تحقیقات، آموزش و ترویج کشاورزی، شاهرود، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Pear genotypes in Shahroud collection are among the historical Iranian cultivars that their horticultural and commercial values have not been previously assessed. In this study, 25 native and introduced pear genotypes and cultivars from this collection were evaluated for authenticity, and subsequently eight cultivars including: Astaneh, Kuzeh Kalaghi, Chini, Tashkandi, Ghosi, Hassan Kondori, Kadu Anbari, and Malachi, and cv. Dargazi (control) were selected for further assessments. The evaluated traits were tree vigor and dwarf growth habit, leaf and blossom characteristics, fruit morphology and sensory attributes. Among the studied genotypes, cv. Chini, cv. Hassan Kondori, and cv. Malachi exhibited weak growth vigor. Comparison of leaf chlorophyll index revealed that just Kadu Anbari had mean value higher than cv. Dargazi. Sensory attributes based quality assessments highlighted the superiority of cv. Dargazi and cv. Tashkandi. Considering the dwarf growth habit of cv. Chini, cv. Hassan Kondori, and cv. Malachi, it is necessary to evaluate their seed germination attributes, precocity of grafted cultivars on their seedlings, and rooting ability to assess their potential for use in pear breeding programs.
Keywords: Pear, chlorophyll, fruit quality, leaf blade chlorosis, dwarfing.
Introduction
The common pear (Pyrus communis L.), and ranks second in importance among pome fruits (Abdollahi, 2010). Globally, the pear is the third most important fruit in terms of fruit production, within the temperate fruit category (FAO, 2025). Furthermore, the plateau of Iran is a major center of diversity for the genus Pyrus, and from the 20 to 22 recognized species of this genus, at least seven to eight species, are distributed across various regions of Iran (Abdollahi, 2010; Bell and Itai, 2011).
Iranian pear germplasm, regardless of their origins, are preserved in the collections of the Temperate Fruit Research Center of the Horticultural Science Research Institute and the Shahroud Agricultural and Natural Resources Research Center, as well as scattered collections in the Isfahan, West Azerbaijan, and Khorasan Razavi Agricultural and Natural Resources Research and Education Centers (Abdollahi, 2010). These collections comprise approximately 40 native cultivars.
The preliminary evaluations of this germplasm was carried out by Manee (1994) during the 1960s and 1970s. Subsequently, superior cultivars were developed in initial nurseries. Atefi (1990) conducted a more comprehensive study and documented some information about quantitative traits of native pear cultivars. Some imported cultivars such as cv. Coscia, cv. Williams (Bartlett), cv. Duchesse d'Angouleme, cv. Louise Bonne de Jersey, and cv. Spadona were also evaluated in his research.
There is very limited information about native pear cultivars from Shahroud collection. Therefore, the present research was carried out, as first evaluation, for determination of their authenticity, and subsequent assessment of specific horticultural and fruit quality traits.
Material and Methods
For identification and preliminarily evaluation of pear cultivars and accessions from the pear collection of Shahroud Agricultural and Natural Resources Research Center, fruit samples of 25 pear genotypes and cultivars were harvested in 2010 and transferred to the Temperate Fruit Research Center of the Horticultural Science Research Institute. The fruit traits of all 25 accessions were compared with key characteristics and starred fruit traits of introduced and native cultivars from the Karaj pear collection.
Eight cultivars including: cv. Astaneh, cv. Kuzeh Kalaghi, cv. Chini, cv. Tashkandi, cv. Ghosi, cv. Hassan Kondori, cv. Kadu Anbari, and cv. Malachi, together with cv. Dargazi (control), were selected and grafted on seedling rootstocks in 2011.
The grafted saplings were transplanted, at distance of 4 × 5 meters, using randomized complete block design with four replications in the pear collection orchard in Kamalshahr Horticultural Research Station in Karaj, Iran, in the winter of 2013. The trees were trained to a modified central leader system, and maintained in the following years.
Morphological and pomological traits were evaluated using the national guideline of distinctness, uniformity and stability (DUS) tests of common pear (P. communis L.) (Sadeghi et al., 2008). To quantify leaf chlorosis, in upper and lower sections, of current-season shoots, the SPAD index was scored using a chlorophyll meter. In addition, fruit quality properties, including appearance and marketability, flesh aroma, flesh flavor, flesh juiciness, and flesh firmness (sensory), were evaluated by five panelists using one to five scale.
Analysis of variance was performed for data of quantities traits using SAS ver. 9.4 . Duncan’s Multiple Rage Test was used for mean comparisons.
Results and Discussion
Among the studied pear cultivars, cv. Chini, cv. Hassan Kondori, and cv. Malachi showed weak growth vigor. Comparison of leaf chlorophyll index with revealed that only cv. Kadu Anbari had mean value higher than cv. Dargazi. Other traits such as blossom shape, leaf color, fruit dimensions including fruit length and diameter, fruit length: diameter ratio, fruit maximum diameter position, and sensory tests of flesh tissue, indicated that these cultivars have a strong resemblance to wild pear genotypes from forests in the north of Iran. These native germplasm are potential genetic resources for use in pear breeding programs (Bell and Itai, 2011).
Sensory attributes based quality assessments highlighted the superiority of cv. Dargazi and cv.Tashkandi. In addition, cv. Malachi appears to be an interspecific hybrid between the Syrian pear (Pyrus syriaca Boiss.) and the common pear. The results showed that cv. Chini, cv. Kadu Anbari, cv. Hassan Kondori, cv. Astaneh, and cv. Kuzeh Kalaghi had low in quality, indicating their unsuitability for commercial use (Abdollahi, 2010).
However, considering the dwarf growth habit of cv. Chini, cv. Hassan Kondori, and cv. Malachi, it is necessary to evaluate their seed germination attributes, precocity of grafted cultivars on their seedlings, and rooting ability to assess their potential for use in pear breeding programs for development of new dwarf rootstocks for commercial pears cultivars.
References
Abdollahi, H. 2010. Pear: botany, cultivars and rootstocks. Iranian Agricultural Ministry Publications, Tehran, Iran. 210 pp. (in Persian).
Atefi, J. 1990. Primary evolutions of the pear cultivars in Iran. Technical Handbook of Horticultural Research Department, Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran. 95 pp. (in Persian).
Bell, L. R. and Itai, A. 2011. Pyrus. Pp. 147–177. In: Kole, C. (ed.). Wild Crop Relatives: Genomic and Breeding Resources. Springer-Verlag, Berlin, Germany.
Manee, A. 1994. Growing of pear and quinces. Iran Technical Publishing Corporation, Tehran, Iran. 113 pp. (in Persian).
Sadeghi, L., Abdollahi, H. and Fakhraee Lahiji, M. 2008. National guideline for the conduct of tests for distinctness, uniformity and stability in pear. Seed and Plant Certification and Registration Institute. 37 pp. (in Persian).
کلیدواژه‌ها [English]
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