Growing vegetables
Kazem Hokmabadi; Seyyed Hosein Nemati; Reza Tavakkol Afshari
Abstract
Breeding of nutty watermelon: evaluation and selection from among the populations of some landraces
Abstract
Introduction
Selecting desirable traits in plants and improving them for desired traits requires the existence of sufficient genetic diversity within the population or between them and on the ...
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Breeding of nutty watermelon: evaluation and selection from among the populations of some landraces
Abstract
Introduction
Selecting desirable traits in plants and improving them for desired traits requires the existence of sufficient genetic diversity within the population or between them and on the other hand, the use of genetic diversity within a population can be used as a suitable solution to deal with genetic vulnerability in plants. Usually, the genetic diversity of plants changes in time and place. Genetic diversity of a trait is the different value of individuals or genotypes for that trait. Usually, in the classical breeding program, varieties are identified based on the morphological characteristics of leaves, flowers and fruits. However, most cultivars cannot be identified based on these traits, especially if they are closely related. In addition, phenotypic identification based on morphology is affected by environmental changes. The success of breeding programs depends on the existence of diversity in germplasms in terms of the desired trait or traits. Collecting superior watermelons and examining their characteristics provides valuable resources to researchers for breeding programs. Watermelon (Citrullus lanatus) has great diversity in terms of shape, fruit size, fruit skin pattern, fruit flesh color, seed length and width, and number The seed in the fruit as well as the quality of the fruit is among its cultivars and varieties, therefore it seems that by examining the native cultivars and populations, it is possible to find desirable traits and use them in future commercial cultivars for breeding processes.
Materials and Methods
In order to evaluate the genetic diversity of 10 native stands of Iranian watermelon by examining the growth and seed-related traits, a research was conducted in Farouj city in 2019 in the form of a randomized complete block design with three replications. The seeds of Jabani, Sonbek and Kalaleh trees were collected from Joven, Kashan and Gorgan. After the selection in the first year, the desired traits were also checked in the selected populations in the second year.
Conclusion
In this research, it was found that the type of mass and the choice of generation had a significant effect on the yield of the product. The highest fruit yield, i.e. 65 tons per hectare, corresponds to Jabani 1 mass. After Jabani cluster 1, Kalaleh cluster 1 had the highest yield with a yield of 45 tons per hectare, which seems to have a direct relationship with the fruit weight per plant. There was a significant difference in the yield between the stands in terms of seed characteristics and yield, fruit flesh and skin yield, fruit length and width. In the breeding goals of nutty watermelons, the most important are the characteristics of the seeds. Coarseness of the seed and high percentage of the kernel compared to the skin of the seed and the softness of the seed texture are also among the other improvement goals in these watermelons. In the first year experiment, among these traits that determine the quality and quantity of seeds, the highest 1,000-seed weight (326.6 grams) in Jabani stand 1, the highest percentage of brain to seed weight (50%) in Sanbek stand 1, the longest seed (average 20 mm) and the widest fruit (average 11.7 mm) belongs to Jabani 1, while the lowest thickness of the seed coat (0.37 mm) is evident in Sanbek 3 mass. Therefore, Jabani mass and stigma are desirable for the cultivation of a nut watermelon. In the second generation of the first experiment, Jabani mass 1 with an average weight of 1000 seeds was 350 grams, seed length was 20.35 mm, seed width was 12.44 mm, seed diameter was 3.39 mm, and seed coat thickness was 0.86 mm. m and seed yield of 1.39 tons per hectare was the best group among the tested groups. Regarding fruit traits, Jabani 1 had the heaviest fruit weight (3.14 kg), the heaviest weight of fruit flesh (1.80 kg) and the highest fruit yield per hectare (62.80 tons per hectare).
The examination of traits that determine the quality and quantity of seeds, such as the weight of 1000 seeds, percentage of kernel weight to seed, length, width and diameter, thickness of the seed coat, showed that Jabani 1 and 3 are the most desirable types. In the second year, Jabani 1 and 3 have the highest quantity and quality of seeds and they are suitable for cultivation as nut watermelon. The comparison of two generations of each of the selected populations showed that most of the fruit and seed traits improved under the influence of the generation and the second generation produced heavier fruits with better seed yield. Also, this improvement of fruit traits in Jabani population 1 and the improvement of seed traits in Kalaleh population 1 is more significant than other populations.
Growing vegetables
Safdar Pourmombeini; Mahmud Lotfi; Hossein Ramshini
Abstract
Introduction Cantaloupes, are a group of Cucumis melo cultivars, that have round, fragrant fruits with netted skin. Our country, is one of the top five producers of cantaloupe, and melon in the world. Its original origin, is still debated, but one of the important centers of its diversity, is Iran. ...
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Introduction Cantaloupes, are a group of Cucumis melo cultivars, that have round, fragrant fruits with netted skin. Our country, is one of the top five producers of cantaloupe, and melon in the world. Its original origin, is still debated, but one of the important centers of its diversity, is Iran. Although, native cultivars, such as, Saveh cantaloupe, Samsoori, Rish Baba, and various types of Tiles, are often of good quality, and taste, but they are sensitive to a variety of fungal and viral diseases and as a result, their yield is low. On the other hand, every year new cultivars and hybrids, are introduced by seed companies, which are welcomed by farmers, due to, their better agronomic characteristics, and resistance to a wider range of diseases. Continuation of this process, in addition to severe genetic erosion of native cultivars, and populations, and even the complete elimination of some of them, will have consequences such as, dependence of production on foreign companies, annual departure of currency from the country, and non-exploitation of the country's genetic resources. Therefore, it seemed that by creating a diverse population resulting from the crossing of superior native cultivars with cultivars of commercially resistant hybrid to diseases, and then, successive selections, new cultivars, with desirable traits of both parents, could be achieved. Thus, in this study, heritability, minimum and maximum mean values of parents, and F1 and F2 generations, aggressive segregation, and relative frequency of qualitative traits, in F2 generation, and selection of the best genotypes, in two dispersing NGF2 populations, were investigated. Materials and Methods Parental cross, was performed in the spring of 2017, between Samsoori cantaloupe cultivar (round, striped fruit, cream skin color, completely reticulate, green flesh, very early ripening fruit, poor transportability and durability, free pollinator and high homogeneity) as the selected native paternal parent, and commercial cultivar from Gallia group, that called Cory and as maternal parent (round fruit, completely reticulate, no striped skin, yellow to cream skin color, high transportability and durability, green and very sweet flesh, high resistance to various plant diseases and viral diseases) and produced by Seminis Company. The first-generation seeds, obtained from parental crosses, were planted in the greenhouse in the fall of 2017, and were self-sown. In the spring of 1397, 1000 seeds of F2 generation, along with parent seeds, and their first generation, were planted in a seedling tray, in the greenhouses of the Faculty of Agricultural Technology (Aborihan) of Tehran University, and transplanted to the ground, in the rental research production farm, located, in Filistan village-Golzar sector-Pakdasht. Controlled pollination, (isolation of male flowers, and manual inoculation) was performed, for all second-generation plants. Selection for subsequent generations, was done by pedigree method, all plants in F2 generation, were evaluated, and selected. Morphological traits, such as, plant form and phenological traits, such as, day to fruit harvest, were evaluated, and recorded. Plant health, was assessed against common and important fungal, viral and mites, under normal field conditions by scoring the severity of infections in four categories. Fruit quality traits were measured based on nominal, sequential and interval scales and quantitative fruit traits were also measured. Tables of minimum and maximum values, variances, general heritability, transgressive segregation, etc for quantitative traits, also relative frequency percentages and observed genetic ratios for quantitative traits, were calculated. Results and Discussion The results showed that all quantitative traits in the F2 population had a general heritability above 90%. The mean of all quantitative traits except soluble solids and fruit flesh thickness in F1 population was lower than the parental average. In F2 population, for all quantitative traits, positive transgressive segregation was observed, compared to, the superior parent, and negative transgressive segregation was observed, compared to, the less valuable parent. In the F2 population, nearly 80% of the genotypes, were completely reticulate, and 20% had less or no netting, on the fruit skin. These results were almost consistent with genetic ratios of 3.1. Also, 35% of F2 population genotypes, were striped and more than 80% of them had yellowish skin color and green flesh color. Due to, the fact that, selection based on traits with high heritability, will be more reliable, and successful in early generations, so, it is better, to select the best genotypes, in this population, based on fruit weight, soluble solids, and early maturity, respectively. ConclusionIn the F2 population, positive transgressive segregation was evident for all quantitative traits, favoring the superior parent, while negative segregation was observed for the less valuable parent. Traits exhibiting high heritability showcased a pronounced influence of genetic variance over environmental variance. Consequently, selecting cultivars based on these traits in early generations is expected to yield more reliable and successful outcomes. Therefore, it is better, to selection, the best genotypes in the early generations, in the F2 population, based on fruit weight, (with high genetic efficiency), soluble solids, day to fruit ripening, and with the pedigree management, of the populations, it is finally, possible to achieve lines, that have the desirable traits, of both parental cultivars. The resulting lines, can be used to produce, new hybrids, or provided, to the farmer, as a single cultivar.
