جستجوی مقالات مرتبط با کلیدواژه "regression analysis" در نشریات گروه "باغبانی"

This study was conducted in order to evaluate the variation of blackberry accession of Iran in terms of antioxidant activity, phenolic components, fruit quantitative traits and photosynthesis pigments. For this regards, four accessions of wild blackberry including Babolsar, Naharkhoran, BandarGaz and NamakAbroud belongs to Rubus sanctus species, which collected from the northern area of Iran and has been kept in Blackberry Collection of Horticulture Department of Shiraz University were selected and subjected to factorial design based on randomized complete block designs with four replications in two consecutive years. Then, the fruit sanmples were collected in three fruit maturity stages (Black, Red and Green). The results indicated significant differences between accessions in terms of half maximal inhibitory concentration (IC50) (range, 46.25-65.50 %), total phenolic content (TPC) (range, 224.67-350.53 mg/100 g DW), flavonoid (range, 531.71-812.37 mg/100 g DW), flavanone (range, 18.47-75.55 mg/100 g DW), anthocyanin (range, 92.23-281.57 mg/100 g FW) along with other traits. Furthermore, the highest quantity of abtioxidant and phenolic compounds were observed in complete fruit maturity stages (Black) compared to other maturity stages. There was a positive and significant association between antioxidant activity and phenolic compounds. Babolsar genotype with highest quantity of phenol (350.53 mg/100 g DW), anthocyanin (281.57 mg/100 g FW), flavanone (75.55 mg/100 g DW), flavonoids (812.37 mg/100 g DW) and lowest amount of IC50 (46.25 %) identified as the best genotype in terms of nutritional value.

Peach (Prunus persica L.) is one of the most essential fruit in Iran and the world. This fruit is suitable for both fresh markets and industrial producer and it is quite favorable by consumers. The efficiency of production is strongly influenced by the chosen peach cultivars. New cultivars are constantly in development by breeders. However, all characteristics are required to be examined include their ecological adaptation ability, productivity, fruit quality, and market value before orchard establishment. Studying the new cultivars is practically essential for exact determination of morphological and phenological features of genotype which is important. However, there is limited information on the global evaluation of fruit quality in breeding progenies and their relationships with pomological traits. Furthermore, the cultivated peach area under Khorasan Razavi province is 1850 ha and the production of fruit is 11283 tons. Therefore, the selection of suitable cultivars for cultivation in the region is very important due to the high economic lifespan of peaches (20-30 years), which in some commercial orchards this period is reduced to 12-15 years. Therefore, this study aims to evaluate the pomological and morphological traits of 14 peach genotypes and cultivars in Khorasan Razavi province climatic conditions to select cultivars or genotypes compatible with high quantitative and qualitative performance. This study was performed in two-years (2016-17 and 2017-18) experiments based on a complete randomized block design with three replications on 14 peach cultivars and genotypes in Golmakan Agricultural and Natural Resources Research Station on 4-years-old trees with density planting system at a spacing of 4 ×5 m. The type of applied irrigation was drip irrigation, with common fertilizer. Trees were trained to an open center system. The vegetative (tree height, trunk cross-section, the crown of the tree), phenological (first bloom, full bloom, end of flowering, flowering period, and harvest time) and reproductive (fruit weight, stone weight, fruit length, fruit width, fruit yield, total soluble solids, titratable acidity, flavor index, and pH) traits were evaluated. It is necessary to explain the soluble solids content by Refractometer (Model 7887, Osk Japan) in terms of percentage and acidity by titration with NaOH (0.1 N) based on predominant peach acid, malic acid. The ratio of soluble solids to acidity was obtained by dividing soluble solids by acidity. The pH of the fruit juice was measured with a portable pH meter at room temperature (23–18 °C). Data analysis was performed using SAS software (version 9.2) and means were compared using Duncan's multiple range test. Stepwise regression and cluster analysis (Ward method) was conducted by Minitab software (version 19). Simple correlation (Pearson) between traits from the mean of two-year data was performed using SAS statistical software (version 9.2), in which positive correlation with blue color and negative correlation with red color was determined, which increased the color intensity indicates an increase in the correlation coefficient. The results showed that year and genotype had significantly different effects on all studied traits. ‘Anjiri Maliki’ and ‘Shindabad Hastejoda’ were the earliest and the most late-flowering genotypes, respectively. Among the studied genotypes, ‘Shindabad-5’ and ‘Spring Time’ were the earliest fruiting genotypes, and ‘Meshkinshahr Paeeze’, ‘Kajil’, and ‘Anjiri Zafarani’ were the most late-fruiting genotypes. ‘Haj Kazem’ genotype had the highest tree height (236.18 cm), trunk cross-section (181.83 cm2), and tree crown volume (73.34 cm3), which compared to the control genotype (‘G.H. Hill’) showed  38.62%, 79.9%, and 55.7% increases, respectively. In the second year of the experiment, the characteristics of fruit weight, stone weight, fruit length, fruit width, and fruit yield increased by 41.72%, 43.45%, 16.61%, 16.40% and 81.99%, respectively, compared to the first year. The highest amount of single fruit weight (165.28 g) in ‘Fayette’ genotype, stone weight (7.04 g) and fruit length (65.05 mm) in ‘Shinabad Hastejoda’ genotype, fruit width (66.04 mm) in ‘Shandabad-5’, and fruit yield in ‘Fayette’ and ‘Paeeze Meshkinshahr’ genotypes (with an average of 21.78 and 21.33 kg, respectively) were obtained. ‘Anjiri Zafarani’ genotype had the highest content of soluble solids (16.95%), flavor index (48.38), and acidity (4.65), which compared to control genotype were increased 0.1%, 69.38% and 25.8%, respectively. Fruit yield had a positive and significant correlation with trunk cross-sectional traits, tree crown volume, fruit weight, stone weight, and fruit width. According to this study, the tree height, trunk cross-section, and fruit weight traits were entered into the regression model, respectively, and finally, the traits entered in the model justified 53.23% of the fruit yield changes. Generally, ‘Fayette’ and ‘Shindabad Hastejoda’ genotypes can be recommended as the best genotype for cultivation in the Khorasan Razavi region due to their high quantitative and qualitative yield.

The purpose of this study is surveying the genetic diversity between oilseed sunflower genotypes and relationships between traits and grain yield, so 12 genotypes cultivated in a completely randomized block design with three replications. Based on the results of analysis of variance, traits were observed among genotypes at a probability level of 1% for the traits of 100 seeds and at 5% probability for the traits of diameter and grain yield of diversity. The results of simple correlation coefficients of traits showed that the diameter of the plant had the highest correlation with plant height and 100 seed weight. The results of simple correlation coefficients of traits showed that the diameter of the plant had the highest correlation with plant height and 100 seed weight. The results of path analysis showed that the highest direct effect on seed yield was observed on seed width and plant height. Using factor analysis by principal component analysis, four factors justify 82.5% of the data variation. The first factor justified 34.2% of the total variance of the data, that named seed yield, the second factor justifying 21.9% of the variation factor that named length factor ,the third factor, justifying 14.5% of the data changes as the factor of 100-grain weight and the fourth factor justified 11.7% of the total data variance, was named dimeter factor.

The present study was aimed to investigate the response of the growth and physiological parameters of stevia (Stevia rebaudiana Bertoni) medicinal plant to salinity stress using a pot experiment in 2014. Ten levels of salt stress (0, 30, 60, 90, 120, 150, 180, 210, 240 and 270 mM of NaCl) were arranged in randomized complete block design with three replicates. Regression analysis of data indicated that some measured parameters such as stem diameter, plant height, green leaf number in plant, relative water content (RWC), chlorophyll a, b, leaf greening (SPAD value), leaf fresh weight, root and shoot dry weights linearly decreased when NaCl amount increased in the growing media. Green leaf number in plant and leaf greening (SPAD value) were more sensitive than other mentioned parameters. However, the response of some determined parameters such as electrolyte leakage, chlorophyll a/b ratio, stem, root, shoot and total fresh weights along with leaf, stem and shoot fresh weights were described by a segmented model. In conclusion, stevia plant could tolerate salt stress up to 80 mM and then its growth and physiological parameters significantly and adversely affected. Results, also, revealed that physiological parameters were more sensitive to salt stress than morphological parameters.

Wheat (Triticum aestivum L.) is a major staple food crop for more than one third of the world population and is the main staple food of Asia. Over 800 million hectares of land throughout the world are salt affected. Salinity is a major obstacle to food production because it substantially reduces the average yield of major crops. This study was conducted to evaluate the response of 24 cultivars and genotypes of wheat (Triticum aestivum L.) to NaCl salinity at early seedling growth and correlation between affected morphophysiological traits and molecular markers. Genotypes grew in hydroponic nutrient solution, under control (tap water) and salt stress (45 and 90 mM NaCl) conditions. Results of ANOVA analysis showed that there are significant difference (in one percent P-value) between genotypes and all of measured traits in different levels of salinity. A total of 20 RAPD and 34 ISSR primers were tested to investigate genetic diversity in 24 wheat genotypes. Of these, only 15 ISSR and 6 RAPD primers produced polymorphic bands and were further used for genetic diversity and regression analysis. Cluster analysis was performed based on jaccard coefficient and all genotypes were divided into 4 groups. Average genetic distance between genotypes was 0.486, showed that there is considerable variation among these genotypes. Regression analysis, also, revealed that there are significant relations between measured traits and using markers were investigated.

In order to evaluation of the relationship among protein markers and traits such as proline content variation، quantum efficiency of photosystem II and field viability index، 20 genotypes of barely were studied in a randomized complete block design in the greenhouse experiment. Plants were transferred to springhouse at the four leaf stage and were located at the temperature of 4°C for three weeks. The leaves were sampled، before and after the adaptation phase، to measure proline amount and quantum efficiency of photosystem II (Fv/Fm). Then freezing treatments were applied by temperatures of -4، -7، -10، -13 and -16. Also، these genotypes were planted in the field to determine the parameters of LT50 and FSI. According to our findings، some significant relations between protein markers and freezing resistance in hordeum vulgar was determined. According to A-PAGE technique، The obtained results showed decreasing trends in quantum efficiency of photosystem II، respectively، during adaptation phase. It was found significantly negative correlations between FSI and LT50 (-0. 601). Cluster analysis classified by FSI، LT50، proline، Fv/Fm، the genotypes of F-A1-1، F-A1-2، F-A2-11 and F-GRB-85-5 and cultivars of Sahra، Sahand، Dasht and Makooii were located in group that had a high value of FSI and LT50. In this recearch، Makooii knowened as the most resistant veriety because of LT50= -17. 66 and high FSI value. Based on regression analysis، there are relationship among four markers and LT50. Our results showed that we can introduce these markers as selection of the resistant lines.