Growing vegetables
Ali Mirhosseyni; Moazam Hassanpour Asil; Jamal Ali Olfati; Mohammad Bagher Farhangi
Abstract
Introduction
Cucumber (Cucumis sativus L.) is an annual plant in the Cucurbitaceae family, which has 90 genera and 750 species. Iran, with an under-cultivation area of 89,632 hectares and a production rate of 1,804,184 tons of cucumbers, yield of 201,289 tons per hectare, and it is the third largest ...
Read More
Introduction
Cucumber (Cucumis sativus L.) is an annual plant in the Cucurbitaceae family, which has 90 genera and 750 species. Iran, with an under-cultivation area of 89,632 hectares and a production rate of 1,804,184 tons of cucumbers, yield of 201,289 tons per hectare, and it is the third largest cucumber producing country in the world in terms of production. Use of fruits of these vegetable is different depending on the country and the consumer's taste and demand, and it is cultivated for fresh consumption as well as processing (pickled vegetables or cucumbers). The utilization of local genotypes or unmodified native reserves for production has led to very low yield of cucumbers in some countries of the world. The general objectives of cucumber breeding are resistance to diseases and pests, fruit quality and yield increase. Considering the history of cultivation of this product in Iran and due to the large under-cultivation areas of cucumber in the country, little breeding research has been done on this product and the country's required seeds are supplied annually through imports. Therefore, practical and applied research on the breeding of cucumber plant seems necessary. The present study was conducted to evaluate 27 cucumber plant lines using factor analysis and cluster analysis as a tool to identify superior genotypes and more effective traits.
Materials and Methods
This study was carried out in the research greenhouse of Department of Horticultural Sciences, Faculty of Agricultural Sciences, University of Guilan, with a longitude of 49 degrees and 36 minutes east and latitude 37 degrees and 16 minutes north with a height of 7 meters from the level of the open sea in February 2021. Overall, 35 cucumber inbred lines, available in the Germplasm Bank, University of Guilan, were selected and on completely randomized design, in three separate rows, and with three replications. A code was assigned to each of the lines in order to facilitate the naming of lines and easier evaluation. In the winter of 2019, the desired genotypes were first planted in the seedling tray and kept there until the second true leaves were observed. Then they were transferred to the greenhouse in the form of a completely randomized design with 27 lines of inbred cucumbers, in three separate rows with 3 replications and 3 observations. The length of the plant breeding period continued until the economic fruiting of the plant. During the growing season, various traits were checked and recorded according to the national guidelines for tests of differentiation, uniformity and stability in cucumber prepared by the Research Institute of Registration and Certification of Seeds and Seedlings. These traits are the Fruit diameter (mm), Fruit length (mm), Fruit number, Weight of single fruit (g), Total fruit weight (g), Number of female flowers in 15 nodes, Number of female flowers per node, Width of the end of the terminal leaf(cm), Length of the end of the terminal leaf(cm), Number of lateral branches in 15 nodes, Length of 15 internodes (cm).
Results and Discussion
Genetic diversity in plant genotypes is essential for a successful breeding program. Understanding the degree of variability in plant species is of importance because it provides the basis for selection. The results of variance analysis show that there is a highly significant variation between the studied lines at the level of 1%. The significant difference observed between genotypes for all traits indicates the existence of inherent genetic variation among genotypes.
The evaluation results show that the average fruit weight trait varied from 1371.7 grams (L57) to 157.71 grams (L35) among the examined lines. Furthermore, genotype L57 (117.56 grams) had the highest statistical position in terms of single fruit weight. The results of the mean comparison table showed that L34 line had the highest fruit length values (161.84 mm) and L49 line had the highest fruit diameter values (39.83 mm). Moreover, L55 and L34 lines had the lowest values of fruit length (92.46 mm) and diameter (24.61 mm), respectively. The leaf area variable varied from 426.52 cm2 (L57) to 204.24 cm2 (L31) among the studied lines. The results of chlorophyll index traits investigation and total soluble solids showed that L51 line had the highest values in both traits.
The results of statistical analyses pertaining to genotypic and phenotypic variance, as well as general heritability, revealed that the trait with the highest heritability, at 99.44%, was fruit weight. With the exception of five traits-length of 15 primary internodes, leaf surface, length and width of the terminal leaf, and single fruit weight-whose heritability values were 87.35%, 73.83%, 63.59%, 61.27%, and 26.23%, respectively, the heritability exceeded 90% for the remaining traits. These findings indicate that most of the traits examined exhibited high heritability, suggesting they were less influenced by environmental factors. Factor analysis, an essential multivariate technique, was employed to explore trait relationships and assess the genetic diversity among genotypes. The results of factor analysis for 27 evaluated cucumber genotypes show that eight factors were identified. They were 23.52, 12.63, 11.81, 9.95, 8.6, 7.34, 6.27, 4.21 percent. in total explained 88% of the total diversity of traits in the studied population. In total, they justified 88% diversity of total traits in the studied population. The results of the cluster analysis placed the studied genotypes in four different groups based on the mean of traits. To ensure the cut-point in the dendrogram and to determine the actual number of groups, the discrimination function analysis method was used. The results of discrimination function analysis showed that the success of cluster analysis in grouping genotypes was 100%. Since the genotypes in each of the clusters have a greater genetic affinity with the genotypes in the same cluster and, conversely, a greater genetic distance with the genotypes in different clusters, hybridization can be done among the genotypes in different clusters according to the value of traits average for each cluster for more productivity of phenomena such as heterosis and transgressive segregation. On this basis, it seems that it is possible to produce hybrids that are superior to their parents in terms of various traits by hybridization between the genotypes in the first and second clusters with the genotypes in the third and fourth clusters.
Conclusion
According to the results obtained from this study, L57 and L54 genotypes had higher values than the rest of the genotypes in terms of fruit number and total fruit weight. Also, according to the results of cluster analysis, L57 line had higher total mean values in traits of total fruit weight, single fruit weight, diameter of the tail of the fruit, fruit, kernel diameter, fresh and dry weight of leaves and leaf area. In this study, the genotypes of the second and third groups in the fruit number trait, and the genotypes of the first and third groups in the fruit weight trait, due to having the maximum difference, were found suitable for use in crosses in order to create more diversity. In general, the results of this research showed that there was a suitable diversity among the studied lines in terms of all measured traits. In addition to the fact that the results obtained from this research can be used in future breeding programs, the results of multivariate statistical methods also show solutions for the scientific crossing of genotypes in future research. So that the genotypes placed in different groups in cluster analysis (Group 1: L57, Group 2: L54, L52, L47, L32, L49, and L27, Group 3: L43 and L35, Group 4: L59, L53, L51, L34, L26, L55, L25, L39, L31, L30, L33, L28, L29, L36, L24, L44, L22, and L20) and had superior characteristics in terms of different components, can be crossed together to create recombinant genotypes.
Ghahraman Bagheri; Bahman Zahedi; Reza Darvishzadeh; Ahmad Hajiali
Abstract
Introduction: Pepper is one of the most important vegetables in the world that belongs to the family of Solanaceae. It is used as a food flavoring, coloring agent and a pharmaceutical ingredient in different innovative ways. Capsicum annuum is one of the five cultivated species in the genus and the ...
Read More
Introduction: Pepper is one of the most important vegetables in the world that belongs to the family of Solanaceae. It is used as a food flavoring, coloring agent and a pharmaceutical ingredient in different innovative ways. Capsicum annuum is one of the five cultivated species in the genus and the others are C. baccatum L., C. chinense, C. frutescens and C. pubescens. While C. pubescens and C. baccatum are morphologically quite distinct, C. annuum, C. chinense and C. frutescens show evidence of parallel evolution for a variety of plant and fruit morphological characteristics as a result of similar regimens of human selection. The near continuous overlapping in morphological traits among these three species led various authors to recognize them as a complicated species. Within complex, taxa are differentiated from one another based primarily on differences in corolla color, the presence or absence of a calyx constriction and the occurrence of multiple pedicels/node.
Materials and Methods: This research was conducted to evaluate genetic diversity in pepper genotypes. Morphological traits of 42 genotypes were investigated in rectangular lattice 6×7 with three replications in two separate experiments at West Azerbaijan research institute. Analysis of variance was conducted by using SAS, SPSS and MINITAB softwares. 14 traits including length and width of fruits, thickness of fruit wall, width of plant canopy, length of shoots, length of corolla, fruits fresh and dry weight, SPAD, photosynthesis, yield, vitamin C, TSS and pH were assessed according to the International Board for Plant Genetic Resources (IBPGR) descriptor. Solid contents (TSS) were assessed by using refractometer, pH by using pH meter, and fruits fresh and dry weight by using a digital scale. For measuring vitamin C content, 3-10 g of the fruit tissue (pericarp and pulp) was homogenized and 100 mL of distilled water were added. Then 10 mL of sulfuric acid 20%, 1 mL of 0.01 N potassium iodide, 1 mL of 1% starch were added to the solution and then for titrating, 0.01 N potassium iodide was used.
Results and Discussion: Analysis of variance showed significant differences (at 1% level) among pepper genotypes, in terms of width of fruits, fruit wall thickness, yield, plant height, shoots diameter, length of shoots, and dry weight of fruit, TSS and vitamin C. But there were no significant difference between pH, SPAD and photosynthesis. The highest heritability was observed in length and width of fruits, fruit wall thickness, fruit pedicel length, yield, dry and fresh weight of fruits, and the lowest heritability obtained in SPAD and pH. Phenotypic variation coefficient was higher than genotypic variation coefficient for all traits, indicating the significant effects of environmental conditions. The maximum phenotypic correlation obtained between fruit fresh and dry weight (r=0.95) and also observed between fruit fresh weight and fruit wall thickness. Cluster analysis with Ward method classified studied landraces into six different groups. The highest distance was observed between groups four and five. This result showed that the maximum expected heterosis could achieve from crosses between genotypes from groups four and five.
Conclusions: High genetic variation was observed among pepper genotypes that could be helpful for morphological traits studies and to improve superior genotypes in next breeding programs.
Ahmad Hajiali; Bahman Zahedi; Reza Darvishzadeh; Jahangir Kohpalekani Abbasi
Abstract
Introduction: Watermelon (CitrulluslanatusThunb)belongs to Cucurbita genus and Cucurbitaceaefamily. Some people know Watermelon native to India and othersthought of it as native to African countries. The greatest diversity can be seen in West Africa, China and parts of India. Near East and Mediterranean ...
Read More
Introduction: Watermelon (CitrulluslanatusThunb)belongs to Cucurbita genus and Cucurbitaceaefamily. Some people know Watermelon native to India and othersthought of it as native to African countries. The greatest diversity can be seen in West Africa, China and parts of India. Near East and Mediterranean countries are also good places to find relatives and ancestors of watermelon. Like all Cucurbita genuscrops,, Watermelon has a variety of flowers including base, male and female separately located on one slip. In terms of production atglobal level, China is located in the first place followed by America, Iran and the Republic of Korea, respectively.
Materials and Methods: In order to evaluate genetic diversity among Iranian watermelon landraces by morphological traits, 16 landraces alongwith two commercial watermelon cultivars were planted in completely randomized block design with three replications inAgricultural Research Center of Urmia in 2013.
Morphological markers can be an effective means to determine genetic relationsamong cultivars and among selections used in watermelon breeding programs. 18 traits including cotyledon length, fruit length, fruit weight, fruit mass, fruit skin, rind thickness, flesh thickness, yield, seed length, seed width, weight of 100 seeds, vitamin C, pH, TSS, EC, chlorophyll content and plant length were assessed in the studied genotypes. During the fruit ripening,four fruits were selected randomly from each plot and according to the International Institute germplasms (IBPGR / IBGRI),solidscontent (TSS)was measured by using refractometer, pH by using pH meter, and fruit and seed weight by using digital scale. The amount of vitamin C (milligram per 100 grams) was measured using iodometry.
Results and Discussion: Results of variance analysis showed that there were significant differencesamong watermelon cultivars in terms of cotyledon length, fruit length, fruit weight, flesh weight, yield, seed length, seed width, seed weight, vitamin C, soluble solids and EC at the 1% level, while the level of significance with respect toskin weight, chlorophyll content and photosynthetic rate was5%.The results also showed that there were not significant differences among the cultivars in terms of pH, skin and flesh thickness, and plant length, suggesting that there is no diversity among the masses. Based on the means comparisontable,the highestfruit length (39 cm), fruit weight (8.03 kg), fleshweight(4.3 kg), skin weight (3.36 kg) and performance rate (24926 kg in hectare) were observed in Charleston Gray.Isfahan 808 mass showed the minimum fruit length (23.66 cm);Khorasan 806 mass had the least fruit weight (3.33 kg) andskin weight (1.8 kg); and East Azerbaijan 800 and Hamedan 817masses showed the lowest fruit flesh weight (1.5 kg) and performance (13444 kg per hectare), respectively.The highest positive phenotypic correlation (0.968) was observed between fruit mass and fruit weight,whilethe highest negative correlation (-0.815) existedbetween TSS and seed length. The highest positive (0.987) and negative (-0.990) genetic correlation was foundbetween fruit weight and fruit length, and between flesh thickness and photosynthesis, respectively. The greatestheritability was related to 100-seed weight, whereas minimum heritability was due to ph. The studied accessions were classified into three different groupsby using Cluster analysis based on Ward method. Based on the intervaltable,the highest space rate was observed between groups one and three (8.985).The resultsalso showed that the maximum expected heterosis obtained in crosses between genotypes one and three.
Conclusion: Based on the results of this research, improved varieties (Charleston Gray and Crimson Sweet) had the highest level of performance, TSS, fruit weight and flesh weight compared to the native masses.
