نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، بخش تحقیقات زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان کرمان، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرمان، ایران.
2 استادیار، پژوهشکده میوه‌های معتدله و سردسیری، مؤسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Kerman province has the second largest walnut growing areas in Iran, with significant genetic diversity that provides the opportunity for identification and selection of desirable genotypes. This study evaluated 35 local genotypes from various walnut-growing regions in Kerman province during 2020 to 2023, using 21 morphological and pomological traits. Kernel percentages ranged from 41% to 66.88%, with most genotypes showed easy to medium kernel separation from the shell. The highest coefficients of variation (CV) were related to adhesion of the two woody halves (26.59%) and the shape of the fruit tip (26.26%). The highet correlation coefficient was between ease of separation and adhesion of the woody halves (r=0.672). Cluster analysis (CA) grouped the walnut genotypes into four distinct groups, which did not correspond with their geographical locations. Principal component analysis (PCA) revealed that the first three components accounted for 58.9% of the total variation. Genotypes 1, 2, 3, 10, and 18 outperformed others in bearing type, leafing time, kernel percentage, fruit size, fruit yield tree-1, and kernel color intensity, make them suitable for further evaluation and used in walnut breeding programs.
Keywords: Walnut, bearing type, kernel percentage, fruit weight, kernel colour, yield tree-1.
Introduction
The Persian walnut (Juglans regia L.) is an important food and medicinal species, and Iran is the main center of its diversity and one of the leading walnut producer (Rezaei et al., 2018). Kerman province has a long history of walnut cultivation, ranking second in area and third in production at the national level (Anonymous, 2022). Due to using seed for propagation, there is significant genetic diversity among walnut populations in different regions, which are valuable sources for walnut breeding programs. Mozaffari, (2011) evaluated 33 walnut genotypes from Kerman province and reported that there were walnut genotypes with fruit weights of 12.5g, kernel weights of 5.6g, and kernel percentages of 43.25%. Multivariate analysis methods as CA and PCA have proven effective in understanding the relationship between morphological traits in walnut germplasm, enhancing breeding efficiency and horticultural management
(Liu et al., 2020). This study aimed to classify walnut genotypes from different regions in Kerman province based on morphological and pomological traits and to identify promising walnuts genotypes with higher fruit yield and quality.
Materials and Methods
This study was carried out during 2020 to 2023 on trees of 35 local walnut genotypes of almost the same age, from different regions in Kerman province. Information from horticultural experts of Baft and Rabor city agricultural administrations and local people, promoters and extension agents was obtained and used. The geographical coordinates of locations of the walnut orchards including longitude, latitude and altitude above the sea level was recorded using a GPS device. These areas mainly had an altitude of more than 2100 meters above sea level and included: Googher, Rabor, Esker, Baft, Bezenjan, Sirjan, and Bardsir.We assessed 21 nut-related traits using scoring methods based on national walnut DUS descriptor. Correlation coefficients were calculated and descriptive statistics were derived. The cluster cutting method using, with n represented the number of genotypes, and was implemented at points of significant distance between clusters. Statistical analyses were performed using Minitab 18 and SPSS Statistics version 26.
Results and Discussion
Walnut genotypes; 6 from Cheshmehsabz Googher, 13 from Genuieyeh Rabor, and 16 from Bagh-e-Fatk Bezenjan showed strong wood adhesion and difficulty
in separating the kernel from the shell. Genotypes 15 from Borkanan-e-Sofla Baft
and 20 from Ghanatzereshk Sirjan had dark kernel colour, while genotypes 1 from Godal-e-Seiffoddin Googher, 4 from Bondar-e-Hanza Rabor, and 9 from Tezerj Esker had very light kernel colour. The highest kernel weight percentage (66.88%) was in genotype 14 from Borkanan-e-Sofla Baft, and 29 from Hajiabad Baft (66.83%), respectively, while genotype 25 from Dehbala-e-Bidkhoon Bardsir had the lowest (41%). The average kernel percentage was 52.85%, which is lower than reported averages for walnuts from Albania and Turkey, and Neyriz-e- Fars, and Malayer regions (Zeneli et al., 2004; Rezaei et al., 2018). Cluster analysis, using Ward's method, grouped the 35 walnut genotypes into four distinct clusters: 13 genotypes in the first group, 12 in the second group, and five in each of the third and fourth groups. Genotypes; 1 from Godal-e-Seiffoddin Googher, 2 from Avask Googher, 3 from Bondar-e- Hanza Rabor, and 18 from Kahansiyah Sirjan from group 1, along with genotype 10 from Amirabad Googher from group 4, excelled in type of beaing, leafing time, hernel percentage, nut width and length, yield tree-1, and intensity of kernel ground color traits, and can be considerd for further evaluation and used in walnut breeding programs.
References
Anonymous, 2022. Agricultural Statistical Yearbook. 3rd Volume. Horticultural and Glasshouse Products. Ministry of Jihad-e-Agriculture, Tehran, Iran (in Persian). 401 pp.
Liu, B., Zhao, D., Zhang, P., Liu, F., Jia, M. and Liang, J. 2020. Seedling evaluation of six walnut rootstock species originated in China based on principal component analysis and cluster analysis. Scientia Horticulturae, 265, pp.109-212. DOI: 10.1016/j.scienta.2020.109212
Mozaffari, M. R. 2011. Comparison of Iranian and foreign walnut cultivars and clones, both quantitatively and qualitatively. Kerman Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Kerman, Iran (in persian). 46 pp.
Rezaei, Z., Khadivi, A., ValizadehKaji, B. and Abbasifar, A. 2018. The selection of superior walnut (Juglans regia L.) genotypes as revealed by morphological characterization. Euphytica, 214(69), pp.1-14. DOI: 10.1007/s10681-018-2153-z
Zeneli, G., Kola, H. and Dida, M. 2004. Phenotypic variation in native walnut populations of northern Albania. Scientia Horticulturae, 105, pp.91–100. DOI: 10.1016/j.scienta.2004.11.003
کلیدواژه‌ها [English]
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