ارزیابی سازگاری و پایداری عملکرد غده کلون‌های جدید سیب‌زمینی با استفاده از روش‌های آماری چند متغیره

To study the adaptability and yield stability of 19 selected potato clones along with four cultivars, Agria, Marfona, Savalan and Khavaran a field experiment was carried out in randomized complete block design with three replications in five locations; Karaj, Ardabil, Hamadan, Esfahan and Mashhad, in 2015 and 2016. GGE Biplot based on environment scaling showed that Isfahan, Ardabil and Hamadan, respectively, were closer to the ideal location and KSG23, KSG82, KSG31, KSG64 and KSG300 clones with mean tuber yield of 30.71, 29.76, 29.38, 27 and 26.68 kg plot^-1 (nine square meters), respectively, were more suitable for being grown in ideal areas. The relative superiority coefficient of KSG23, KSG302, KSG81 and KSG107 clones were 2.87, 6.98, 7.81 and 12.49, respectively, and they had relatively good tuber yield stability. The relative superiority coefficient of KSG31, KSG82 and KSG64 clones were 18.07, 15.76 and 13.67, respectively, and almost similar to the Agria control (17.22) and they were superior to the Agria (control) for tuber yield. AMMI analysis revealed that the genotypes reacted differently in different environments and the sum of squares of the genotype × environment interaction was 4.8 times larger than that of the genotypes. KSG81, KSG64, KSG300 and KSG107 clones, and cv. Agria (control) had reasonable tuber yield stability. Based on the adaptability and tuber yield stability, KSG302, KSG82 and KSG31 clones were identified suitable for spring planting in different regions of Iran, KSG23 and KSG57 for Khorasan, KSG64 and KSG48 for Hamadan and Ardabil, respectively, KSG81 for Isfahan and Ardabil. 
 
Keywords: Potato, tuber no. plant^-1, total tuber yield, marketable yield, storability.
 
Introduction
Evaluation of genotype × environment interaction and selection of genotypes adapted to target environment is very important for plant breeders. Cultivars that have high yield stability and adaptability to different environments are suitable (Gauch and Zobel, 1988). The multivariate statistical methods are necessary to understand the different aspects of genotype × environment interaction (Gauch and Zobel, 1988). To develop potato cultivars with high adaptability and tuber yield stability for different target environment, it is very important to increase the tuber yield stability and consider genotype × environment interaction (Hajibarat, et al., 2023). The aim of this research was to investigate the adaptability and tuber yield stability of new potato clones in different major potato production regions in Iran, and to select the superior clones adapted to the target environments for being released as new commercial potato cultivars.
 
Materials and Methods
In this research, 19 selected potato clones along with Agria, Marfona, Savalan and Khavaran commercial cultivars were evaluated in randomized complete block design with three replications in five regions of Karaj, Ardabil, Hamadan, Mashhad and Isfahan in Iran in 2015 and 2016. Each plot consisted of two rows with between row spacing of 75 cm and within row spacing of 25 cm, 75 and 25 cm. Tuber yield and yield components were measured and recorded. The adaptability and tuber yield stability were investigated using multivariable AMMI, GGE Biplot, and the relative superiority coefficient models. Potato genotypes were grouped using cluster analysis. Analyses were performed using SAS and GenStat softwares.
 
Results and Discussion
Combined analysis of variance showed that the effects genotype and location on total tuber yield were significant at the 5% level. The effect of year, genotype ×   location, genotype × year and interaction on tuber total yield were significant at the 1% probably level. Significant effect of genotype and environment and their interactions on tuber yield of potato have been reported by Hajibarat, et al., (2023), Khan, et al., (2011), and Hassanpanah (2011).
GGE Biplot analysis based on 10 environments (location and year) scaling showed that the first and second components explained 63.28% of the total variance. Ardabil 1 and 2, Isfahan 1 and 2, Hamadan 1 and Karaj 2 were closer to the ideal region and suitable for positive tuber yield selection. The results of GGE Biplot analysis for total tuber yield based on five environments (locations) scaling showed that the first and second components explained 58.13% of the total variance. Esfahan, Ardabil and Hamadan, respectively, were closer to the ideal region and suitable for positive tuber yield selection. Overall, two mega environments were identified for evaluating potato cultivars and clones. Mashhad 1 and 2 as one mega environment and Karaj 1 and 2, Ardabil 1 and 2, Isfahan 1 and 2 and Hamadan 1 and 2 were identified as another mega environment, which itself includes two smaller environments.
The results of the scatter GGE Biplot based on mean tuber yield and coefficient of variation showed that the tuber yield and variance of clones KSG82, KSG23, KSG31, KSG64 and KSG300 were higher than the grand mean with mean tuber yield of 30.71, 29.76, 29.38, 27 and 26.68 kg plot^-1 (9 square meters), respectively. The relative superiority coefficient of KSG23, KSG302, KSG81 and KSG107 clones were 2.87, 6.98, 7.81 and 12.49, respectively, and had good tuber yield stability. The relative superiority coefficient of KSG31, KSG82 and KSG64 clones were 18.07, 15.76 and 13.67, respectively, and almost similar to cv. Agria (17.22).
The results of AMMI analysis showed that 50.7% of the total sum squares are assigned to environmental effect, 8.5% to genotypic effect, and 40.8% to genotype × environment interaction. The sum squares of the genotype × environment interaction was 4.8 times larger than the sum squares of genotype, which indicates the different genotypic responses in different environments. KSG81, KSG64, KSG300 and KSG107 clones along with cv. Agria (control) had reasonable tuber yield stability. In this research, genotypes with high tuber yield in each environment usually had lower tuber yiled stability. KSG302, KSG82, and KSG31 clones wee identified suitable for spring planting in different potato growing regions in Iran, KSG23 and KSG57 clones for cultivation in Khorasan, KSG64 and KSG48 clones for cultivation in Hamedan and Ardabil, respectively, and KSG81 clone for cultivation in Isfahan and Ardabil regions. Hajibarat, et al., (2023) also identified superior potato clones by using multivariate statistical models.
 
References
Gauch, H.G. and Zobel, R.W. 1988. Predictive and postdictive success of statistical analyses of yield trials. Theoretical and Applied Genetics, 76(1), pp.1-10. DOI: 10.1007/BF00288824
Hajibarat, Z., Saidi, A., Mousapour Gorji, A., Ghafari, M.R. and Zeinalabidini, M. 2023. Stability analysis of potato yield using AMMI and GGE biplot under water deficit. Iranian Journal of Horticultural Science and Technology, 24(1), pp.83-94 (in Persian). DOR: 20.1001.1.16807154.1402.24.1.7.2
Hassanpanah, D. 2011. Analysis of G × E interaction by using the additive main effects and multiplicative interaction (AMMI) in potato cultivars. African Journal of Biotechnology, 2(10), pp.154-158. DOI: 10.5897/AJB09.633
Khan, A.A.­, Jilani, M.S., Khan, M.Q. and Zubair, M. 2011. Effect of seasonal variation on tuber bulking rate of potato. The Journal of Animal and Plant Sciences, 21(1), pp.31-37.