جستجوی مقالات مرتبط با کلیدواژه "breeding" در نشریات گروه "زراعت"

Coriander is one of the important medicinal plants in the world which has been used widely in medicinal, cosmetic and health care industries.

In order to investigate the genetic diversity of this plant in Iran, 20 Coriander populations were collected from different parts of the country and evaluated out using randomized complete block design with three replications in Karaj Vegetable Research Center of Horticultural Sciences Research Institute in 2018-2019 and 2019-2020 crop years. During the growth period, the phenological, morphological and physiological characteristics were recorded. Days to generation, Largest basal leaf length, Basal leaf number, Days to full flowering, Days to Maturity, Plant height, Umbel number per plant, Fertile umbel number per plant, Unfertile umbel number per plant, Umbellate number per umbel, Seed number per umbel, thousand seed weight, Grain yeild per plant, Biomass per plant, Harvest index per plant, Grain yield, Biomass and Harvest index traits were investigated. Data were analyzed using SAS and SPSS software and for Grouping of the population, the cluster analysis was performed by Ward’s method and factor analysis was done using the Variomax rotation method.

According to the results of analysis of variance, there were significant differences between the studied populations in terms of most traits include the largest basal leaf length, basal leaf number, plant height, umbel number per plant, fertile umbel number per plant, unfertile umbel number per plant, umbellate number per umbel, grain number per umbel, 1000-seed weight, seed weight per plant, biomass per plant, harvest index per plant, grain yield, biomass and harvest index. Phenotypic and genotypic coefficients of variation were high for most of the traits which indicated the high diversity of these traits in the studied populations. The heritability in broad-sense of the traits largest basal leaf length, basal leaf number, plant height, umbel number per plant, fertile umbel number per plant, umbellate number per umbel, seed number per umbel, 1000-seed weight, seed weight per plant, biomass per plant, harvest index per plant, grain yield, biomass and harvest index were high, which makes the response to the selection of these traits expected in breeding programs. Cluster analysis classified 20 studied populations into five groups.

According to the results, the Kermanshah population had the highest grain yield in two years. The higher yield of this populaion was due to having the highest number of umbels per plant, number of fertile umbels, number of umbels per umbel and weight of 1000 seeds. Also, the traits of the length of the longest basal leaf, the number of basal leaves, the number of umbels per plant, the number of fertile umbels per plant, the number of umbels per umbel, the number of seeds per umbel, the weight of 1000 seeds, the yield of seeds per plant, the biomass of a single plant, the harvest index of a single plant, seed yield, biomass and harvest index had high heritability, which indicates the high role of genetic factors and the low influence of environmental factors on the control of these traits.

In order to select suitable parents for breeding purposes, one must have sufficient knowledge of genetic diversity and germplasm classification. It was for this reason that a study was conducted in 2019 at the Seed and Plant Research Institute in Karaj in order to identify and classify 17 eggplant genotypes based on the randomized complete block design. This stud measured 19 morphological traits such as number of days to flowering, plant height, number of stems per plant, number of nodes, and internodes, weight, and fruit yield as well as total phenol content, total anthocyanin content and glico-aldeid solasonin. The results of the analysis of variance revealed a significant difference for all the traits (p≤0.01). The range of variation showed great genetic diversity among cultivars, which can be useful for different breeding purposes, lower plant height to prevent dormancy. Greater number of stems and flowers are important to achieve higher yield, wherein 13321 genotypes showed lower height among genotypes. Cluster analysis classified the studied genotypes into three groups, and separated white eggplants from colored ones correctly. The PCA also confirmed the results of cluster analysis, showing that the color eggplants had more fruit yield, lower levels of solasonine, and lower days to maturity than white eggplants. However, the color eggplants that were used in this research were breeding cultivars; therefore, the use of breeding methods would be important to improve the quality and quantitative of eggplant genotypes.

In order to evaluate and compare 15 different hybrid genotypes of greenhouse tomato (Solanum lycopersicum L) in Gorgan, Golestan, north of Iran, an experiment was carried out in randomized complete block design with 3 replications at two Golestan province greenhouses (greenhouse of Gorgan Agricultural and Natural Resources Research and Education Center and a private greenhouse in Gorgan).  Investigated traits were fruit yield per plant, number of fruits per plant, number of fruits per cluster, average fruit weight, fruit diameter, fruit height, stem length, total soluble solids, pH, pericarp thickness, total phenolics content and flavonoids content. Statistical analyses were suggestive of significant difference in all of the studied traits between different genotypes in both greenhouse experiments. In both of the greenhouse experiments, the highest fruit yield per plant was observed in 4129, Omagna, and then Izmono, 10161, Hirad and Sakhia genotypes. Dafnis and Hiva cultivars were intermediate in terms of fruit yield compared to other genotypes. In traits such as fruit number, fruit weight, fruit size, plant height, pericarp thickness, total soluble solids, pH, phenolics content and flavonoids great differences were observed between the studied genotypes. Positive correlations of fruit yield with number of fruits per plant, mean fruit weight and fruit diameter traits were observed in both greenhouse experiments. Therefore, selecting based on the latter three attributes may improve fruit yield of tomato in seed and variety breeding programs.

This study aimed to investigate the genetic parameters of ten Cucurbita pepo L. hybrid cultivars, including seven foreign hybrid cultivars (F1 Shiraz, F1 Khaleej, F1 Samar, F1 Roham, F1 Daphne, F1 Asma and F1 Oto) and three domestic hybrid cultivars (F1 Peronesh, F1 BL and F1 CL) in the form of a randomized complete block design with 3 replications at the Pest Investigation Research Station and the Shahid Fozveh Research Station of Isfahan, central Iran, in 2019. The bed preparation operation was done and the seeds were sown in the mid-June. The results showed that the highest fruits/plant was observed in CL and Shiraz genotypes and the highest yield/plant in four harvests was observed in Peronesh genotype. Roham and Otto genotypes showed the lowest total yield/plant. BL genotype showed the highest mean fruit diameter in four harvests and the highest fruit weight of the seed sample. The highest seed weight was obtained in Shiraz and Asma genotypes and the highest seed-to-fruit weight ratio was obtained in Samar genotype. BL, Asma and Shiraz genotypes showed the highest seed dry weight. The highest seed length and the highest dry weight of 100 seeds were observed in Peronesh and BL genotypes. A positive and significant correlation was also observed between some traits. Among the investigated genotypes, Peronesh and BL genotypes outranked the other genotypes in most of the traits. Also, Shiraz genotype had a significant advantage in some seed traits compared to other genotypes. According to the presented results, different genotypes of the pumpkin plant were significantly different from each other in terms of various traits, indicating that the ground is prepared to employ these resources for improving the yield of this plant species.

Introduction:

Genetic diversity is one of the major goals of plant breeding. Mutation induction is a method to increase genetic variety that is used in plant breeding along with selection, recombination or a combination of the both. Rosa persica Michx can serve as a valuable genetic resource for breeding programs, especially due to the market demand for variety in rose cultivars as well as its drought resistance.  In two independent experiments, this study examined the effect of ethyl methane sulfonate (EMS) as a chemical mutagen on seed germination and seedling characteristics of Rosa persica. 

Materials and Methods:

 The seeds of Rosa persica Mich.seeds were collected from an adult shrub on the Arak University campus, Karbala St., Sardasht (34° N, 49.6° E) and an altitude of 1872 m above sea level during mid-summer. The seeds were separated from the hips by a sharp scalpel and the damaged and abnormal seeds were removed. Before applying the cold stratification, the seeds were washed for several hours and then placed in layers of wet sand at 4 ° C for 60 days.First, the effects of 0, 0.2, and 0.3% EMS at 4, 8 and 12 hours on seed germination characteristics were examined. Second, 0, 0.2, and 0.3 concentrations of EMS at 4 and 8 hours were studied on reproductive buds. Seed germination characteristics such as final germination percentage, germination rate index, coefficient velocity germination, germination rate, mean daily germination, daily germination speed, mean germination rate, germination index, seed vigor, seed dormancy and seedling vegetative traits such as stem lengths, root lengths, and leaf number are evaluated at first experiment. In second experiment, flower diameter, flower opening rate, number of necrotic buds and the number of seeds in each hip were measured. 

Results and Discussion:

The results showed that increasing the concentration of EMS and the time of seed treatment caused a further decrease in germination indices. In 0.3% EMS treatment for 8 hours on seeds, traits such as germination percentage, germination rate index and daily germination were reduced to zero. According to the results of the second experiment, leaf and seedling lengths were longer at 0.2 and 0.3% EMS concentrations and at 4 h incubation. There was a decline in the number of seeds per hip and an increase in necrotic buds with increasing concentration and time of EMS application. In order to succeed in a breeding program using mutagenic methods, the appropriate concentration and time must first be optimized. To determine the best concentration of mutagens, there are two important factors to consider: first, that the concentration should not be so high as to destroy plants, and second, that the applied concentration should be selected moderately. Although, that the frequency of mutations occurs sufficiently. 

Conclusion:

In order to induce a positive mutation and diversity in Iranian roses for the purpose of introducing a new cultivar, seed treatment with a concentration of 0.3% EMS and an incubation time of 4 h is recommended. It is also recommended to apply a concentration of 0.2% EMS on the reproductive buds for 4 h to induce mutations. Keywords: Seed, breeding, germination, mutation, ornamental plant

Humans have long sought to select the desirable traits for agriculture and domestication of important and economical crop species around the world. In fact, the human selection is a factor that plays a key role in determining the fate of plant breeding lines, especially cereals. Therefore, the study of genetic diversity and the study of germplasm storage of breeding lines on the one hand and the study of the role and effect of choices made by plant breeders, on the other hand, are key factors in investigating the fate of improved seeds and lines. To conduct such studies, molecular studies using markers that act neutrally and randomly are important. Accordingly, the present study aimed to investigate the effect of selection on seeds of an important crop that has long been under domestication and crop breeding programs. Sixteen pure lines of sorghum grown in the research farm of Agricultural and Natural Resources Research and Training Center of Khorasan Razavi were assessed using retrotransposon-based molecular markers plus desirable morphological traits used in breeding crop sorghums.

A total of 80 individuals belonging to the first to ninth generations of breeding sorghums were randomly selected, and molecular studies were performed using 8 IRAP primer combinations. Morphological studies were also performed using the measurement of traits related to leaf biomass (the number of leaves at 60 days of plant growth).

The observations showed relatively high intergroup genetic diversity (between breeding generations) (63.5%) in the study group. Among the studied generations, the fifth generation and afterward the seventh and eighth generations showed the highest hereditary diversity, the highest heterozygosity, and the highest number of unique alleles. The first and ninth generations with the highest homozygosity, respectively, were the purest lines studied.

The results of dendrogram trees also confirmed the existence of three completely different clusters in the study group. Accordingly, the existence of gene flow between the breeding lines of sorghum and its occurrence among the individuals of the fifth, sixth and seventh generations was confirmed. However, its decline and decrease in the seventh generation onwards indicated the instability of observed recombination. Finally, it was concluded that the selection of superior and desirable phenotypes during the purification process always acts as a selective sweep and as a directional selection eliminates the variations created by gene flow and thus reduces the genetic diversity in the pure lines of crop sorghum.

Kiwifruit is one of the important exportable horticultural crops in Iran. international customers tend to buy novel kiwifruit with different flesh and taste has increased. Therefore, for persistence in exporting and success in export rank of Iranian kiwifruit, it is necessary to have new cultivars. One of the main limitations in kiwifruit breeding program, juvenility period is long time and it is dioecy which there is no distinguishable differences between male and female plants until flowering time. Therefore, sex determination in seedling and separation male and female plants as soon as possible is very important for accelerating kiwifruit breeding. In this study, validation of some molecular sex related markers for determination males and female plants results from open pollination.

In this study, we used two different yellow flesh kiwifruit genotypes (known as Khorshid and Navab) and one red flesh genotype, which all were belong to Actinidia chinensis with diploid. Extraction of genomic DNA from young leaves was carried out by CTAB method with few modifications. spectrophotometer (Biophotometra, Plus Eppendorff) is used for determine the exact concentration of each sample DNA, and DNA concentration was measured at a wavelength of 260 nm. Polymerase chain reaction (PCR) was performed in a volume of 10 μL for each sample. For each primer program (PCR), agarose gel concentration and optimum loading time was optimized. Finally, the validation of some sex related markers includes 3 SCAR markers (SmY, SmX, SmY1) and 3 SSR markers (A00I, A00II, A00II) in the DNA extracted from the leaves of the tested genotypes was investigated.

The results of current study showed that among different SCAR and SSR markers which previously reported, some of them were not able to separate correctly male and female seedlings. Among three SCAR markers (SmY, SmX and SmY1) were evaluated, just two markers; SmY1 (770 bp) and SmX (950bp) markers could able to separate correctly male (without band pattern in female) and female (without band pattern in male) kiwifruit seedlings respectively. According to polymorphic bands were obtained from three tested SSR markers (A00I, A00II, A00II) for determination males and females plants, only A00II with specific bands 232bp in male and 219bp in female plants could able to separate kiwifruit seedlings. The two A00I and A00III markers exhibited the similar banding patterns in males and females which were not able to separate individuals from gender.

Overall, the results of this study showed that simultaneously application of SmY1, SmX and A00II are able to separate correctly male and female seedlings of kiwifruit during the early juvenile phase.