Abstract
The Persian walnut is one of the most important horticultural crops grown in Iran. In the current study, a walnut germplasm from the six regions of Fars, located in the southwestern part of Iran, was evaluated to determine the variability and to identify promising types. A total of 232 genotypes were evaluated using 30 phenological and pomological characteristics. Considerable genetic variation in the measured traits was found in native trees which were of seedling origin. Variability found in nut weight was between 8.00 and 23.00 g, in kernel weight between 4.00 and 14.00 g, in shell thickness between 0.10 and 3.00 mm, and in kernel percentage between 40.00 and 72.22 %. Also, bud breaking, flowering, and nut maturity times showed wide variation among genotypes. Results from simple correlation analysis showed significant positive and negative correlations for certain important characteristics. Nut dimensions and weight were in significant positive correlation with kernel weight. The kernel percentage was in positive correlation with kernel weight, kernel filled, and kernel plumpness and in negative correlation with shell thickness. Cluster and principal component analyses showed a considerable diversity in the studied germplasm. The results indicated that most of genotypes were suitable in terms of consistent leafing date, lateral bearing, kernel weight, kernel percentage, and kernel color which can be singled out for cultivation. Furthermore, they could be useful as a parent to be crossed to generate appropriate populations or improve cultivars. These data collectively demonstrated large phenotypic diversity among the selected genotypes that can be considered as a valuable gene pool for breeding programs.
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References
Akca YS, Ozongun S (2004) Selection of late leafing, late flowering, laterally fruitful walnut (Juglans regia L.) types in Turkey. R Soc N Z J Crop Hortic 32:337–342
Arzani K, Mansouri Ardakan H, Vezvaei A, Reza Roozban M (2008) Morphological variation among Persian walnut (Juglans regia) genotypes from central Iran. N Z J Crop Hortic Sci 36:159–168
Aslantas R (2006) Identification of superior walnut (Juglans regia) genotypes in north-eastern Anatolia, Turkey. N Z J Crop Hortic Sci 34:231–237
Atefi J (2001) Comparison of some promising Iranian walnut clones and foreign varieties. Acta Horticult 544:51–59
Cosmulescu S, Botu M (2012) Walnut biodiversity in south-western Romania resource for perspective cultivars. Pak J Bot 44:307–311
Ebrahimi A, Fatahi R, Zamani Z (2011) Analysis of genetic diversity among some Persian walnut genotypes (Juglans regia L.) using morphological traits and SSRs markers. Sci Hortic 130:146–151
Ercisli S (2004) A short review of the fruit germplasm resources of Turkey. Genet Resour Crop Evol 51:419–435
Eskandari S, Hassani D, Abdi A (2005) Investigation on genetic diversity of Persian walnut and evaluation of promising genotypes. Acta Horticult 705:159–166
FAO (2012) FAOSTAT production crops. http://faostat.fao.org/site/567/default.aspx#ancor (accessed 16.01.2014)
Fjellstrom RG, Parfitt DE (1994) Walnut (Juglans spp.) genetic diversity determined by restriction fragment length polymorphisms. Genome 37:690–700
Forde HI (1979) Walnut. In: Janick J, Moore JN (eds) Advances in fruit breeding. Purdue University Press, West Lafeyette, pp 439–455
Germain E (1997) Genetic improvement of the Persian walnut (Juglans regia L.). Acta Horticult 442:21–32
Hammer O, Harper DAT and Ryan PD (2001) PAST: paleontological statistics software package for education and data analysis. Palaeontol Electron 4(1):9. http://palaeoelectronica.org/2001_1/past/issue1_01.htm
Iezzoni AF, Pritts MP (1991) Applications of principal components analysis to horticultural research. HortSci 26:334–338
IPGRI (1994) Descriptors for walnut (Juglans spp.). International Plant Genetic Resources Institute, Rome
Kazankaya A, Koyuncu F, Koyuncu MA, Yarilgaric T, Sen SM (2001) Some nut properties of walnuts (Juglans regia L.) of Edremit Country. Acta Hort 544:97–100
Khadivi-Khub A, Ebrahimi A, Sheibani F, Esmaeili A (2015) Phenological and pomological characterization of Persian walnut to select promising trees. Euphytica. doi:10.1007/s10681-015-1429-9
Martinez ML, Labuckas DO, Lamarque AL, Maestri DM (2010) Walnut (Juglans regia L.): genetic resources, chemistry, by-products. J Sci Food Agric 90:1959–1967
McGranahan GH, Forde HI (1985) Relationship between clone age and selection trait expression in mature walnuts. J Am Soc Hortic Sci 110:692–696
McGranahan G, Leslie C (2009) Breeding walnuts (Juglans regia). In: Jain SM, Pryadarshan PM (eds) Breeding plantation tree crop: temperate species. Springer Science + Business Media, New York, pp 249–273
McGranahan GH, Leslie C (2012) Walnut. In: Badenes ML, Byrne DH (eds) Fruit breeding. Springer, New York
Nenjuhin VN (1971) Selection of plus trees of the walnut in Ukraine. Plant Breeding Abstract 41:187
Rohlf FJ (2000) NTSYS-pc numerical taxonomy and multivariate analysis system, version 2.1. Exeter Software, Setauket
Sefc KM, Lopez MS, Lefort F, Botta R (2000) Microsatellites variability in grapevine cultivars from different European regions and evaluation of assignment testing to assess the geographic origin of cultivars. Theor Appl Genet 100:498–505
Serr EF (1962) Selecting suitable walnut varieties. Davis, California, California Agricultural Experiment Station, pp 144
Sharma SD, Sharma OC (1998) Studies on the variability in nuts of seedlings of walnut (Juglans regia L.) in relation to the tree age. Fruit Var J 52:20–23
Sharma OC, Sharma SD (2001) Genetic divergence in seedling trees of Persian walnut (Juglans regia L.) for various metric nut and kernel characters in Himachal Pradesh. Sci Hortic 88:163–171
Yang LX (2005) Effect of water extracts of larch on growth of Manchurian walnut seedlings. J For Res 16:285–288
Yarilgac T, Koyuncu F, Koyuncu MA, Kazankaya A, Sen SM (2001) Some promising walnut selections (Juglans regia L.). Acta Horticult 544:93–100
Yucel C, Baloch FS, Ozkan H (2009) Genetic analysis of some physical properties of bread wheat grain (Triticum aestivum L. em Thell). Turk J Agric For 33:525–535
Zeneli G, Kola H, Dida M (2005) Phenotypic variation in native walnut populations of Northern Albania. Sci Hortic 105:91–100
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Communicated by A. M. Dandekar
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Khadivi-Khub, A., Ebrahimi, A., Mohammadi, A. et al. Characterization and selection of walnut (Juglans regia L.) genotypes from seedling origin trees. Tree Genetics & Genomes 11, 54 (2015). https://doi.org/10.1007/s11295-015-0882-x
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DOI: https://doi.org/10.1007/s11295-015-0882-x