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Showing 9 results for Correlation
Mohammad Ali Ebrahimi, Rahim Mohammadian, Marouf Khalili,
Volume 3, Issue 1 (9-2016)
Abstract
Estimation of genetic variation in crops, a very important role in the development of breeding programs and preservation of genetic resources through morphological characteristics, is possible. To identifying genetic variation and double haploid barley lines classification in relation to germination traits, 72 lines derived from the cross of Steptoe and Morex were evaluated in randomized complete block design (RCBD) with two replications, at three conditions including normal and two salinity levels of NaCl (100 and 200 mM NaCl). Investigated traits in this study were coefficient of velocity of germination, final germination percentage, mean germination daily, germination rate index and average germination speed. The results indicated that considerable genetic variation among genotypes in all traits. Genetical correlation based on average of the three environments indicated that high significant correlation exist (r= 0.85**) between the daily germination and final germination percentage. In this study, the highest value of phenotypic and genotypic variation coefficient, broad and narrow sense heritability and genetic gain were calculated for final germination percentag. Based on cluster analysis, barley genotypes were grouped into three categories and genotypes of the third cluster, were superior coefficient of variation of germination, germination percentage, germination rate and mean daily germination index, but had low a mount of germination rate. Therefore, the genotype of this group can be used in breeding for high germination percentage. Using principle component analysis; five traits were grouped in the form of two new variables that explained 99.061 percent of the total variance. Analysis biplot indicated that the genotypes of first group have a high percentage of germination index and germination index coefficients.
Seyede Minoo Mirarab Razi, Reza Shirzadian-Khorramabad2, Hossein Sabouri, Babak Rabiei, Hossein Hosseini Moghadam5,
Volume 6, Issue 1 (9-2019)
Abstract
Salinity is an important limiting factor in the production of more plants, including rice. Due to the limited amount of cultivated area, identification of tolerant genotypes to environmental stresses and especially salinity is very important. The aim of this study was to investigate the genetic diversity among 114 recombinant lines derived from the intersection of local Tarom × Khazar cultivars under non stress conditions and salinity levels of 8 dS/m in reproductive stage in a completely randomized design. Combined analysis of variance showed that the differences between lines was significant for all traits. Genotypic variation coefficients also showed that the highest genetic variation among the evaluated recombinant lines was related to the number of panicles per plant. In contrast, days to 50% flowering showed the least genetic variation among these lines. In non stress and stress conditions, the highest genotypic and phenotypic correlation coefficient was observed between grain yield and number of fill grain in seedlings. Based on the cluster analysis of grain yield, the lines were classified into four groups under normal conditions and were classified into three groups under salinity conditions. The third-party lines in both cases had a higher average than the overall average. In general, the results of this study showed that there is a significant genetic variation between the studied lines in terms of salt tolerance and this variety can be used in subsequent corrective programs. Accordingly, lines 83, 81, 56, 39, 37 and 89 were the most sensitive lines and lines 107, 101, 16, 100, 84, 98, 47, 32, 14, 29, 95, 63, 5, 49, 92 and 10 were the most tolerant lines to salinity stresses of 8 dS/m and they also had higher yields and yield components. Strained lines are proposed directly for cultivating saline or for transferring salt tolerance to commercial cultivars through future breeding programs.
Saman Valizadeh, Ahmad Ismaili, Hadi Ahmadi, Omid Ali Akbarpour, Bijan Bajalan, Ashkboos Amini,
Volume 6, Issue 2 (3-2020)
Abstract
Wheat is mostly cultivated at rainfed condition in Iran, so, water deficit stress has much effect on yield reduction. Hence, breeding activities are necessary for introduction of wheat tolerant genotypes to water deficit stress. In order to estimate the heritability and genetic correlation between traits of 36 wheat genotypes, an experiment was conducted in two separate conditions (water stress and non-stress) based on a randomized complete blocks design with three replications. Studied traits in wheat genotypes under water stress and normal condition showed significant differences for environment, genotype and genotype× environment interaction at 1 and 5% level of probability. The results of the factor analysis showed that the 6 first factor in normal condition explained 81.13% of total variance, and the 5 first factor in stress condition explained 74.96% of total variance. Estimation of genetic correlations based on REML approach revealed that biological yield, harvest index and number of grains per spike had the highest correlation with grain yield and these characteristics are of important for selecting the varieties with high yield under non-stress and stress conditions. Estimation of heritability based on REML approach showed that number of days to heading had the highest amount of heritability in both normal and stress conditions.
Shaghayegh Mehravi, Gholam Ali Ranjbar, Hamid Najafi-Zarrini, Ghader Mirzaghaderi,
Volume 7, Issue 1 (9-2020)
Abstract
Anise is an annual plant belonging to Apiaceae family and fruit essential oil of this herb is used in various pharmaceutical, cosmetic and beverage industries. Drought stress is one of the most critical limiting factors for anise production in worldwide. In this research, to finding interrelationships among different traits and performance, some anise genotypes were evaluated using the biplot method. In this study, 18 anise genotypes were evaluated in normal irrigation regime and drought stress conditions according to a randomized complete block design with three replications at the field of the Western Australia University (UWA), Australia. Fifteen phonological, morphological and physiological traits were measured. Results indicated the positive and significant correlations between yield and fruit number and fruit thousand weight in both conditions. Due to the negative correlation between phonological features with fruit yield in two different irrigation conditions, it could be concluded that to have genotypes with high fruit yield, selection for early ripening genotypes should be done in anise. In this study, a significant correlation was observed between fruit yield and relative water content in the stress condition. Therefore, this trait can be used as a physiological index to evaluate drought tolerance in anise. According to cluster analysis based on the measured traits, genotypes were divided into 3 groups in both non-stress and stress conditions. According to the results of the comparison of the means of the groups in non-stress and drought stress conditions, genotypes No. 1, 5, 6, 11, 12, 14, 15 and 16 were identified as the most drought-tolerant genotypes. These genotypes could be utilized in breeding programs for further improvement of drought tolerance in anise germplasm.
Abdul Karim Tahmasebi, Reza Darvishzadeh, Amir Fayaz Moghaddam, Esmaeil Gholinezhad, Hossein Abdi,
Volume 8, Issue 2 (3-2022)
Abstract
The selection of genotypes based on multiple traits is a fundamental issue and an important part of the process of plant breeding. In the present study, the efficiency of selection indices based on phenological, morphological and physiological traits was studied to improve sesame grain yield. The evaluation of 25 sesame populations was realized in a completely randomized design with 10 replications under Urmia conditions in 2017.The results showed that phenotypic and genotypic correlations between grain yield and No. of capsules per plant, No. of grains per capsule, No. of branches, leaf temperature, leaf index and biological weight were positive and significant. By regression and path analysis, the No. of capsules and No. of branches were identified as the variables of the first-order cause and biological weight, harvest index, leaf index, plant height and chlorophyll as the second-order cause variables, among which only plant height had a direct negative effect. In order to obtain selection indices, two optimal and basic methods and ten different vectors of economic values of traits were used. The vectors were based on the analysis of correlation, regression, path and broad sense heritability. The third and fourth indices, in which the first-order cause entered the model, showed high relative efficiency and in terms of these two indices, and the sesame populations with code number of 12, 17, 18 and 19 populations were identified as the most desirable populations. Finally, it is suggested that the efficiency of these selection indices be evaluated in the field
Kaveh Sadeghi, Mohammadhadi Pahlevani, Mohsen Esmeilzadeh Moghaddam, Khalil Zaynali Nezhad,
Volume 8, Issue 2 (3-2022)
Abstract
Identifying selection indices is the most important step of a breeding project that aims to improve grain yield. The definition of the selection index is usually done by evaluating the variables in multivariate statistical methods. In the present study, the relationship between grain yield and its components in bread wheat genotypes was determined by multivariate statistical methods. The experiment was conducted in a randomized complete block design with 3 replications in the research farm of Gorgan University of Agricultural Sciences and Natural Resources in the 2018-19 crop years. Ten commercial cultivars of bread wheat along with their offspring from direct and inverse crosses in a dialysis arrangement were evaluated for morphological and phenological traits, especially grain yield and its components. The results of genotypic and phenotypic correlation coefficients showed a positive and significant correlation (at 1% probability level) between grain yield and spike length, spike weight, number of fertile tillers, number of seeds per spike, number of spikes per spike, 1000-seed weight, biological yield and harvest index. Based on the results of stepwise regression analysis, biological yield, harvest index, number of grains per main spike and main spike weight were entered into the regression model, respectively, and explained a total of 98% of the variation in grain yield. Based on the results of path analysis, biological yield had the highest direct effect on grain yield. After biological yield, the most direct effect on grain yield was related to the weight of main spike. Also, by considering eigenvalues greater than one in factor analysis, 8 hidden factors were identified that explained a total of 75.18% of the data changes. In general, it can be concluded that biological yield, harvest index, number of seeds per spike and weight of spike compared to other traits can be used as appropriate indicators in breeding programs to select high-yield genotypes in field conditions. Genotypes Alo, Ehsan♂ × Gonbad♀ and Ehsan had the highest value for the studied traits, which can be used in future breeding researches.
Amir Gholizadeh, Hassan Amiri Oghan, Valiollah Rameeh, Kamal Payghamzadeh, Behnam Bakhshi, Bahram Alizadeh, Seyed Alireza Dalili, Shahriar Kia, Farnaz Shariati,
Volume 9, Issue 1 (9-2022)
Abstract
Genetic diversity is key to breeding programs and increasing selection efficiency. In this study, 19 promising advanced lines (F7 generation) along with two cultivars, Dalgan and, RGS003 were evaluated in a randomized complete block design with three replications in three experimental field stations (Gorgan, Sari and, Zabol) during the 2020–2021 growing season. The highest phenotypic and genotypic coefficient of variations was found for number of lateral branches and number of pods per plant, respectively. The highest broad sense heritability was estimated for days to end of flowering, and days to start of flowering and the lowest broad sense heritability was estimated for the plant height. The genotypes G16, G18, G15, G1, G2, G5, and G20 with a higher SIIG values as well as a higher seed yield above average were introduced as superior genotypes with respect to yield and other agronomic traits. Therefore, these genotypes can be used for further testing, including adaptation tests. Also, the results of factor analysis and genetic correlation coefficients indicated a positive relationship between number of lateral branches, number of pods per plant and number of seeds per pod with seed yield and seed yield. Generally, it can be concluded that number of lateral branches, number of pods per plant and number of seeds per pod traits could be used as the appropriate criteria to select for increasing seed yield in rapeseed breeding programs.
Mostafa Khodadadi, Behzad Sorkhilalehloo, Seyed Mohammad Mahdi Mortazavian, Jahangir Abbasi Kohpalekani, Mahmoud Bagheri, Milad Karbasi,
Volume 10, Issue 1 (9-2023)
Abstract
Eggplant is a highly nutritious vegetable that is widely consumed. The aim of this study was to evaluate the genetic diversity between eggplant accessions from the National Plant Gene-Bank of Iran. In the first year, a preliminary evaluation was conducted using 168 accessions. Based on preliminary evaluation results, 40 accessions were selected for complementary evaluation in the second year. The evaluation was based on 23 quantitative and qualitative traits. The results of the preliminary evaluation showed statistically significant (P<0.01) differences between accessions for all traits. Fruit shape frequencies were rounded (35.89 percent), elongated (32.18 percent), oval (13.67 percent), Semi-elongated (13.15 percent), and mace-shaped (5.11 percent). In the complementary evaluation, there were significant differences between accessions for all traits. Qualitative traits such as flower color (1.56) and fruit shape (1.53) exhibited the highest genetic variation, while fruit color (0.5) showed the lowest. Cluster analysis analysis results revealed four groups for accessions and the highest (22.34) and least (0.12) genetic distances between 1 and 2 and between 7 and 21accessions, respectively. Factor analysis showed that the first three factors explained 68.06 percent of total variation in data. The first and second factors were related to yield and yield components, respectively. Also, fruit yield traits showed high heritability and there was significant genetic correlation between these traits. Therefore, high heritable and high-scoring traits in these factors should be considered when selecting progenies in segregating populations for improvement in terms of fruit yield and shape.
Hosein Astaraki, Mahmoud Lotfi, Sasan Aliniaeifard, Ali Izadi-Darbandi, Payman Sharifi, Hossein Ramshini,
Volume 10, Issue 2 (2-2024)
Abstract
In order to select the most tolerant genotypes of melon to drought stress, 30 landraces and cultivars were evaluated at Broujerd Agricultural Research Station in 2018. Under normal and drought stress conditions genotypes were evaluated in a randomized complete block design with three replications. Drought stress was started when fruits appeared. Based on the rate of evaporation in class A evaporation pan (normal conditions: 50 mm, stress conditions: 100 mm), irrigation was carried out. The results of this study showed that Yield under drought stress and normal conditions showed high correlations with stress tolerance indices such as MP (Mean Productivity), GMP (Geometric Mean Productivity) and STI (Suitability Tolerance Index). The broad sense hereditary under drought stress condition varied from 81% for yield per plant to 97% for the fruit lenght. Under drought stress condition, the highest percentage of genetic coefficient of variation (GCV) was observed for Weight of flesh and skin (49 percent) and the lowest for days to maturity (4 percent). Based on the PCA biplot, the genotypes of Mamaghani, Rish-baba, Garmak and Japuni melon were identified as tolerant and Mazandrani, Uzbak1 and Ginsen Makuwa were classified as sensitive to drought stress. These results could be useful for breeding purposes and the genotypes can be crossed with each other to produce segregating populations and selection of the best plants.
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