Ornamental plants
Behrooz Moradi Ashour; Khosro Parvizi; Mohammad Hossein Azimi
Abstract
Introduction
The evaluation of morphological, phenological and agronomical characteristics is one of the first steps for the initial study of germplasm. It can also be conferred as basic information for the breeder to study genetic diversity for particular purposes. Chrysanthemum (Chrysanthemum ...
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Introduction
The evaluation of morphological, phenological and agronomical characteristics is one of the first steps for the initial study of germplasm. It can also be conferred as basic information for the breeder to study genetic diversity for particular purposes. Chrysanthemum (Chrysanthemum morifolium) is a perennial herbaceous plant of the family Asteraceae with simple coniferous leaves and alternate arrangement on its branched stems and has composite flowers. The first stage in breeding programs is to study genetic variation of the selected plants. This study was conducted in order to evaluate the genetic variation of flower traits for selected Chrysanthemum genotypes for three years. Researchers use different methods to estimate genetic diversity of plants including DNA markers, isozymes and morphological traits. Use of morphological traits that are easily measured and have high heritability is a convenient tool to assess the level of genetic diversity of plants.
Materials and Methods
The origin of the tested genotypes was from the gene bank of the Research Institute of Flowers and Ornamental Plants. The results of random crosses between different chrysanthemum clones were evaluated. The research was conducted for four consecutive years. The aim of the first year experiment was positive selection of genotypes. In fact, the best genotypes were selected. In addition, negative selection of different genotypes was performed. During this selection period, similar genotypes were removed. Selected genotypes (20 genotypes) were evaluated based on a completely randomized design with three replications using seven morphological traits including number of flower per plant, period of flowering, flower diameter, number of petal row, petal length, Fresh weight and dry weight of flower. Statistical analyses including analysis of variance, correlation coefficient, and heritability, phenotypic and genotypic coefficient of variation were estimated using SAS 9.0 software.
Results and Discussion
After performing Bartlett test and confirming the uniformity of variances, combined analysis was performed for three years. The results of analysis of variance showed that the effect of the year was significant only for the number of flowers per plant and the flowering period. The results of three-year analysis of variance showed that there was significant difference among the genotypes for the number of flowers per plant, flowering period, number of petal rows, fresh and dry flower weight. There was a significant difference (p≤0.05) among the years only in flowering period and number of flowers per plant. The highest variation observed between flowering period and flower diameter. The highest coefficient of phenotypic and genetic variation obtained for the number of petal rows, flower fresh weight and petal length. The lowest coefficient of phenotypic and genetic variation obtained for fresh and dry flower weight and number of flowers per plant. The highest positive genetic and phenotypic correlation coefficient estimated between flowering period with flower diameter, number of rows of petals and fresh weight of flowers which is important for the simultaneous breeding of these traits. The results of this study showed that flower diameter, flowering period, petal length and number of petal rows showed high general heritability. Therefore these results indicate that the selection process for these traits is effective and can be used in the breeding programs. The results of this study showed that highest number of petal rows belonged to B136 genotype. Genotype 31 with forty-three days of flowering period had the highest flowering length compared to other genotypes. GenotypeC85 had 202 flowers per plant. These genotypes can be used as parents especially to increase the flowering period and the number of petal rows due to the general heritability of over fifty percent of these traits. It is also suggested that traits such as petal color and resistance to important pests (including black chrysanthemum aphid, flower thrips pest) and important diseases (including Fusarium wilt, verticillium wilt and leaf spot) should be studied. The superior genotype can be selected if statistically significant difference observed among of genotypes.
Conclusion
It is a fact that chrysanthemums has characteristics such as variation of flower shape and color, plant size, form and flowering period that is widely used in landscape. In this research significant difference observed among the genotypes. Also some of measured traits had a high general heritability due to the positive and significant correlation of these traits that can be used to improve other genotypes and their traits.
Behrouz Moradi Ashour; Mohammad Rabiei; Behrooz Shiran; Sadollah Hooshmand
Abstract
Introduction: Pomegranate (Punica granatum L., Punicaceae family), a native Iranian horticultural plant, is used as fresh fruit and also for other products and has special economic position in the world. It is estimated that pomegranate fruit production in Iran was about 900000 tons in 2016 which provinces ...
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Introduction: Pomegranate (Punica granatum L., Punicaceae family), a native Iranian horticultural plant, is used as fresh fruit and also for other products and has special economic position in the world. It is estimated that pomegranate fruit production in Iran was about 900000 tons in 2016 which provinces of Fars, Markazi, Khorasan, Yazd and Isfahan had the highest production respectively. Iran is the center of diversity and most probably center of origin of Pomegranate, so during the years, many attempts have been done to collect different genotypes. The National Research Station of Pomegranate of Saveh has three set collections including 760 genotypes collected from all around of Iran. Assessment of genetic variation among these genotypes to use in breeding programs should be considered as first priority. Researchers use different methods to measure genetic diversity of plants including DNA markers, isozymes and morphological traits. Using morphological characteristics that are easily measured and have high heritability is a convenient tool to assess the amount of genetic diversity of plants.
Material and Methods: In order to determine genetic variation and heritability on morpho-pomological traits, pomegranate genotypes were selected from different habitats of Iran that are already planted in the collection of National Research Station of Pomegranate of Saveh in 2016. Genotypes that had similar descriptor or genotypes that had not sufficient fruit to get involved in the experiment, were excluded. Selected genotypes (156 genotypes) were evaluated based on a completely randomized design with three replications using nine morphological traits including length of calyx, width of calyx, number of seed in 100-gram aril, thickness of peel, weight of fruit, length of fruit, width of fruit, weight of peel, weight of aril. Biochemical characteristics of fruit including total soluble solids, titrable acidity, maturity index, pH, EC, anthocyanincontain and absorbable color of juice were measured for each genotype without replication (five fruit were selected randomly for each genotype). Statistical analyses including analysis of variance, correlation coefficient, and broad sense heritability, phenotypic and genotypic coefficient of variation were estimated using SAS 9.0 software.
Results and Discussion: Analysis of variance showed that the effect of genotypes in each trait is highly significant (p-value=0.01), indicating a wide variation among these genotypes. Considering range for each trait reveals remarkable differences between genotypes especially for number of seed in 100-gram aril and anthocyanin content. Results showed that among 9 morphological traits, aril seed (g 100 aril-1) and peel thickness, also among 7 chemical traits, anthocyanin content, absorbable color of juice and maturity index had the highest variation. The most positive and significant correlation coefficients was observed between fruits weight with length and diameter of fruit, length and diameter of calyx, aril weight, seed number (g 100 aril-1) and peel thickness. Correlation between qualitative and quantitative traits were not significant. The highest phenotypic and genotypic coefficient of variation was observed on fruit weight, peel thickness, seed number (g 100 aril-1) and aril weight. A high broad sense heritability was observed for aril weight (g 100 aril-1), fruit weight and peel thickness.
Conclusion: Based on the results of this study, there was a high genetic variation among genotypes for most traits. As it was expected, Iranian collection of pomegranate is a rich source for this plant and highly supporter for other breeding researches. High correlation coefficient of fruit weight with other morphological traits is useful for early selection of high performance genotypes. For instant, genotypes with high diameter of calyx most probably will produce high yield. There was not statistically significant correlation between morphological and biochemical characteristics. That is to say genotypes with low yield should not be excluded in further research programs because of their beneficial biochemical traits; they can be involved in crosses with high yield genotypes to improve their biochemical characteristics. Pomnograte genotypes with good quality traits are also useful for industrial, pharmaceutical and nutraceutical purposes. Results of our experiment indicate that due high broad sense heritability of aril weight, fruit weight, peel thickness and aril weight, environmental effect on these traits is less than genetic effect. Therefore, selection based on these traits could successfully be used to improve genetic base of pomegranate genotypes in the next generations. Also based on the results of this research Hasteriz- Shahdad and Domaze- Izeh genotypes were the best for soft seed, color and flavor fruit.
