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 ...
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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 ...
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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.
