1- AREEO
Abstract: (164 Views)
Tomato (Solanum lycopersicum L.) is one of the most important crops in the world. So that the cultivated area of this plant in Iran is 103 thousand hectares and its production amount is more than 5 million tons, which indicates the importance of this plant. In plant breeding, different methods are used in genotypes selection. To select the best genotypes, a method is needed that can consider all the traits based on desirability and undesirability in selections. The ideal genotype selection index (SIIG) is one of the methods that can determine the distance between genotypes in addition to selecting ideal genotypes. In this method, it is possible to identify genotypes with special characteristics. For example, with the SIIG method, genotypes with high yield and early maturity can be identified and selected. The aim of this study was to evaluate tomato genotypes through quantitative and qualitative traits and to select the best ones for the southern Kerman climatic conditions.
Materials and Methods
In order to evaluate and select the best tomato lines in Jiroft region, an experiment with 11 genotypes (10 promising lines and Karoon variety) based on a randomized complete blocks design with three replications during two crop years (2021-2022 and 2022-2023) was carried out in the research farm of the Southern Kerman Agricultural and Natural Resources Research and Education Center. Cultivation was carried out under plastic on the 20 February. Drip irrigation was done and weeds were controlled by hand. During the growing season and after harvesting (May), qualitative traits including uniformity, growth crack, green shoulders, type of inflorescence and having a abscission layer were recorded for each genotype. Brix, pH, tissue firmness, Number of locules, fruit length, fruit width, fruit weight and yield of each plant were measured in the laboratory. The traits of day to flowering, day to ripening and number of inflorescences were also recorded in each plot. Statistical analyzes were performed using SAS software (9.4) and calculations related to the SIIG method were performed using the relevant matrices.
Results:
Compound variance analysis during the two years of the experiment showed that the effect of the year on all studied traits was significant except for the number of locules trait. This subject shows the different conditions during the two years of experiment and the influence of the studied traits on the experiment conditions. The effect of genotype and the interaction of genotype in year on all studied traits except the number of inflorescences were significant. This result shows the diversity between the used genotypes in terms of the studied traits. The mean comparison results of genotype effect showed that lines No. 14 and 6-33 were able to reach maturity earlier due to early flowering. Genotypes No. 8 and 32 had the highest fruit yield and the lowest amount in terms of this trait was related to lines 33-6 and 22-7. Mean comparison among genotypes showed, since traits are compared separately, it is not possible to select the best based on all traits. If the selection is based only on yield, they will be placed in the top group 2 lines number 8 and 32. Grouping based on cluster analysis placed four lines (8, 7-22, 11 and Karoon variety) in the top group. Grouping tomato lines based on SIIG index placed 6 lines in the top group. The superiority of the SIIG method compared to other methods is the grouping of lines based on the desirability of the traits (for example, low average genotypes in the traits of days to flowering and days to ripening are desirable). Therefore, the lines selected through the SIIG index are introduced as superior lines considering all traits in the south of Kerman. The SIIG method considers only quantitative traits and non-parametric traits are not involved in this selection, Therefore, Karoon cultivar due to the fruits growth crack and line number 7 due to the lack of uniformity and lack of abscission layer are not suitable for selection in the south of Kerman.
Conclusions:
Finally, by using the SIIG method and using all the traits, lines No. 33-4, 11, 13 and 8 were selected as the best lines in Jiroft conditions.
Materials and Methods
In order to evaluate and select the best tomato lines in Jiroft region, an experiment with 11 genotypes (10 promising lines and Karoon variety) based on a randomized complete blocks design with three replications during two crop years (2021-2022 and 2022-2023) was carried out in the research farm of the Southern Kerman Agricultural and Natural Resources Research and Education Center. Cultivation was carried out under plastic on the 20 February. Drip irrigation was done and weeds were controlled by hand. During the growing season and after harvesting (May), qualitative traits including uniformity, growth crack, green shoulders, type of inflorescence and having a abscission layer were recorded for each genotype. Brix, pH, tissue firmness, Number of locules, fruit length, fruit width, fruit weight and yield of each plant were measured in the laboratory. The traits of day to flowering, day to ripening and number of inflorescences were also recorded in each plot. Statistical analyzes were performed using SAS software (9.4) and calculations related to the SIIG method were performed using the relevant matrices.
Results:
Compound variance analysis during the two years of the experiment showed that the effect of the year on all studied traits was significant except for the number of locules trait. This subject shows the different conditions during the two years of experiment and the influence of the studied traits on the experiment conditions. The effect of genotype and the interaction of genotype in year on all studied traits except the number of inflorescences were significant. This result shows the diversity between the used genotypes in terms of the studied traits. The mean comparison results of genotype effect showed that lines No. 14 and 6-33 were able to reach maturity earlier due to early flowering. Genotypes No. 8 and 32 had the highest fruit yield and the lowest amount in terms of this trait was related to lines 33-6 and 22-7. Mean comparison among genotypes showed, since traits are compared separately, it is not possible to select the best based on all traits. If the selection is based only on yield, they will be placed in the top group 2 lines number 8 and 32. Grouping based on cluster analysis placed four lines (8, 7-22, 11 and Karoon variety) in the top group. Grouping tomato lines based on SIIG index placed 6 lines in the top group. The superiority of the SIIG method compared to other methods is the grouping of lines based on the desirability of the traits (for example, low average genotypes in the traits of days to flowering and days to ripening are desirable). Therefore, the lines selected through the SIIG index are introduced as superior lines considering all traits in the south of Kerman. The SIIG method considers only quantitative traits and non-parametric traits are not involved in this selection, Therefore, Karoon cultivar due to the fruits growth crack and line number 7 due to the lack of uniformity and lack of abscission layer are not suitable for selection in the south of Kerman.
Conclusions:
Finally, by using the SIIG method and using all the traits, lines No. 33-4, 11, 13 and 8 were selected as the best lines in Jiroft conditions.
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