JWSS - Journal of Water and Soil Science

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Immature embryo culture response of 28 durum wheat (Triticum turgidum var. durum) cultivars was studied using MS medium in Tissue Culture Laboratory of College of Agriculture, Isfahan University of Technology. Donor plants were grown in a recirculating hydroponic system and pots in a greenhouse. Regenerated immature embryos were recorded at 2, 4, 8 and 16 days after inoculation. Assessment of durum wheat cultivars for immature embryo culture was conducted by percentage and rate of regenerated embryo, using a split plot design arranged in completely randomized design with 5 replications. The analysis of variances showed that there were highly significant differences among cultivars for plant regeneration capacity. The highest potential and rate of embryo regeneration (two days after inoculation) were observed in “Shahivandi” which is a native cultivar of west Iran. “Awl1/Sbl4” with a mean of 48.5%, “Hagla” and “Ofen/Kil” with a mean of 80% have the poorest and the best mean of regeneration during the recording period, respectively. The high regeneration potential is important in view of reducing the time constrain and somaclonal variation in a breeding program.

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Potato is a valuable plant as a source of nutrition and as an industrial product. The modification and breeding of potato plants are very difficult, or even impossible, via the conventional plant breeding programs. However, plant biotechnology and tissue culture are reliable methods which can produce plant material for gene transformation using Agrobacterium as a vector. In this study, one-, two-, and three-step methods of plant regeneration from stem culture of potato cv. Delaware were tested. Among these only the one-step procedure using TDZ, a synthetic cytokinin, was the best for rapid plant regeneration. In this culture medium, several shoot buds and shoots were regenerated from stem culture, while the other methods using a culture medium supplemented with BAP, NAA, zeatin, 2ip, IAA produced white and green callus. Morphology and chromosome number of all regenerated plants were similar to the original plants. The results showed that the regeneration system was suitable for cv. Delaware and that the culture conditions prevented genetic variation of the regenerated plants.

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This study was conducted to evaluate the responses of Iranian commercial genotypes of maize (hybrids and their inbred lines) to callus induction and plant regeneration, using mature embryos. Twenty five genotypes comprising of 12 inbred lines, 11 single cross hybrids, 1 double cross hybrid and 1 composite cultivar were used. Mature embryos of the genotypes were plated on MS and N6 media. Callus induction rates were evaluated using relative growth rate of callus (RGR), callus fresh weight (CFW), callus dry weight (CDW) and callus growth rate (CGR).

The results indicated that genotypes highly varied in both callus induction and plant regeneration. IL8 inbred line, SC7 (IL4×IL8) and SC9 (IL6×IL10) hybrids had the highest callus production capacity (based on CFW and CDW), whereas the highest RGR and CGR were obtained for ILl inbred line and SC9 hybrid. The estimated heterosis based on superior parent showed the highest heterosis for CFW, CDW, RGR and CGR in SC9 hybrid. Genotype × medium interactions for CWD, RGR and CGR were significant. For instance, SC9 hybrid on MS medium and IL8 on N6 medium produced the highest CGR. There was a significant difference between the observation periods [8, 12, 16 and 20 days after planting (DAP)], so that CGR was the least at 8 DAP and increased gradually till 16 DAP, but declined afterward. CGR had a range of 0.51 in IL8 inbred line to 0.74 in SC9 hybrid. Comparisons of the genotype for plant regeneration percent indicated that ILl and IL10 inbred lines as well as SC2 and SC4 single cross hybrids had the highest regeneration rates. Considering plant regeneration as a critical and genotypic dependent factor, it can be concluded that ILl and IL10 inbred as well as SC4 (IL4×IL5, ‘single cross 301’), SC2 (IL2×IL3, ‘single cross 704’) and SC7 hybrids are recommended for use in tissue culture-based breeding programs in maize.

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This study was conducted to evaluate the response of 18 rice (Oryza sativa L.) genotypes to callus induction and plant regeneration from immature embryo culture, using three media (MS, LS and N6). To evaluate callus induction rate, the following criteria were used: callus diameter, callus fresh weight and callus dry weight. Percentage of callus water content was also measured. After transferring the produced calli from the induction media to a regeneration medium (MSR), percentage of plant regeneration was evaluated.

A highly significant difference was observed among genotypes for both callus induction and plant regeneration (P<0.01). In callus induction phase, “Nemat” and “Cheram-2” cultivars were superior for callus diameter, having 4.83 and 4.6 mm callus diameter, respectively. “Nemat”, “Cheram-2”, “Sepidrood” and “Taroum” cultivars as well as “33IRCTN91” and “IRFAON-30” lines were significantly superior to other cultivars for callus fresh weight. Among the genotypes “Nemat”, “Zayandehrood”, “33IRCTN91” had the highest percentage of callus water contents. Based on plant regeneration, “33IRCTN91” line and “Anbarbo”, “Nemat”, “Cheram-2” and “Taroum” cultivars showed highest rate of plant regeneration from callus. Significant differences were observed among media. While MS and N6 media did not showed any significant differences for callus diameter, callus fresh weight and rate of plant regeneration, they were superior to LS medium (P<0.01). According to percentage of callus water content, MS and LS media ranked the best and the most inferior medium, respectively. In the present study, MS and N6 media were considered as suitable in vitro culture media of rice immature embryos. Among genotypes, “Nemat” and “Cheram-2” cultivars were ranked the best for both callus induction and plant regeneration. Also, the used Japonica rice cultivars were superior for percentage of plant regeneration. The calculated correlation coefficients between traits showed a non-significant correlation between callus induction and plant regeneration, which, in turn, indicated that these traits were independent.

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In order to investigate the androgenic response of chickpea cultivars, two Iranian Chickpea cultivars, Pirooz and Karaj 12-60-31, were used in this study. After 7 to 10 days of cold pretreatment of flower buds, anther containing uninucleate stage of microspores were placed aseptically on MS medium supplemented with various combinations of growth regulators of 2,4-D (1,2 and 3 mg/l) and kinetin (0.1, 0.2 and 0.5 mg/l). Callus regeneration achieved using MS and modified Blayd’s media with various hormones and different sucrose concentrations. The results indicated that the callus initiation was significantly affected by 2,4-D and kinetin concentrations, and that increasing these hormones reduced callus induction. The best response obtained on media with the lowest concentration levels of 2,4-D and kinetin (1 and 0.2 mg/l, respectively). A highly significant genotypic effect and a genotype  2,4-D interaction were detected, which proved that Pirooz response was the best. Callus differentiation and organogensis occurred in MS medium supplmented with NAA, BA and 3% sucrose. Mature embryos also obtained in modified Blayd’s plus 0.5 mg/l kinetin and 10% sucrose. Cytological studies revealed the presence of haploid cells with chromosome variation in the anther derived callus. Therefore, optimizing the hormone levels of different basal media with a particular sucrose cocentration may improve haploid regeneration in chickpea. It seems a further study should be carried out to characterize calli from induction to regeneration and to determine the effect of cold pretreatment, the results of which could be used to improve anther culture response of chickpea.

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Optimizing regeneration of cotton plant in two variety (Sahel and Varamin) via shoot apex was done in order to Agrobacterium-mediated transformation. In this reaserch shoot apexes of two varieties were isolated from four or five day seedling and were placed on a special medium of shooting (modified MS without hormon).In order to select the best rooting media, The Statistical Analysis explants that produce shoot and leaves in a CRBD with 4 replicates and 4 rooting treatments: 1) modified MS without hormon, 2) ½ MS with 0.1 mg/lit IBA, 3) ½ MS with 0.1 mg/lit NAA, 4) ½ MS with 0.1 mg/lit IAA. The statistical analysis indicated that the best for both varieties, was medium with 0.1 mg/lit IBA and rooting percentage of Varamin is better than sahel in all of media.

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In this research the effect of ethinyl estradiol on somatic embryogenesis of Medicago sativa was investigated. Seeds were grown in vitro on MS medium containing 2,4-D, Kin and NAA for callus induction. Plant regeneration media with 14 different combinations of auxin, cytokinin and ethinyl estradiol were provided. Three to four-week old celli and stem or hypocotyl segments of Medicago sativa were transferred to regeneration media. Results showed that ethinyl estradiol (l mg/L) induced shoot, root and somatic embryo on calli. When the stem and hypocotyl segments were cultured on medium M12, only shoots and roots were produced with no somatic embryo. Finally, it was observed that ethinyl stradiol and auxin together could induce somatic embryogenesis and plant regeneration, while these hormones had no effect separately.

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The present research was conducted to find the influence of some topographic factors on distribution of large-leaved lime (Tilia platyphyllos Scop.) and its natural regeneration characteristics in "Vaz" forest (northern Iran). After identification of site and preparation of topography map, selective sampling method was carried out for tree inventory in plots. The sample plots were circular in 1000-m² areas with at least 2-3 dominant lime trees in each. In the plots, altitude, slope gradient, direction, forest storey, tree type and natural regeneration were investigated. Results indicate that in this habitat the average diameter at breast height and height of Tilia platyphyllos is 36.9 cm and 23 m, respectively. Tilia platyphyllos prefers 1200-1400 m altitude, 75-100% slope gradient and northeastern to eastern directions and benefits from denser trees in these environments. It consists of some tree types together with Fagus orientalis, Carpinus betulus and Parrotia persica, whereas the dominant type is Tilia platyphyllos-Fagus orientalis. In most of tree types, lime occurs in the upperstorey. Natural regeneration of lime is often observed as sprout (coppice shoot).

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In order to investigate the success of natural regeneration and to determine the best area for regeneration settlement, 12 gaps with the areas ranging from 50-100, 150-300, and 400-600 m² and 4 replicates equal elevation level were selected. For measuring frequency, height, and collar diameter of regenerated seedlings, a certain number of 2 m² subplots were carried out inside the gaps, along the bigger diameter, and related to each gap’s area. Results showed that the number of seedling varies from 5 (in big gaps) up to 28 (in small and moderate gaps) per square meter. Furthermore, there was not a significant difference between the number of seedlings in small and moderate gaps. In contrast, the number of seedlings in small and moderate gaps was significantly different from those in large gaps (at 1% Probability). This finding demonstrates that natural regeneration would be limited in large gaps (400-600 m²) but it shows a better result in smaller gaps, associated with single- tree harvests. The final result of this study shows that the most appropriate area for selective cuting in such an area is up to at most 300 m².

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  Parsi Zira, Bunium persicum (Boiss.) B. Fedtsch., which is called Mountainous or Black Zira, is one of the most important medicinal plants with high economic importance. Generally, there is a little information about in vitro culture of Bunium persicum. Fragmented embryo was used as an explant in Bunium persicum regeneration. In this method, a great callus induction and regeneration only on the same medium without any subculture occurred because of being young and having better interaction with medium, leading to reduction of tissue culture time, infection and chemical consumption. In this research, B5 media containing different concentrations of plant growth regulators, NAA and 2,4-D only or together with Kin, were used. The experiment was conducted using completely randomized design with 30 treatments and 10 replications per treatment. The highest callus number was obtained from the treatment containing 0.1 mg/l 2,4-D and 2 mg/l Kin or 1 mg/l NAA and 2 mg/l Kin. Regeneration occurred in some treatments without Kinetin, showing that Kinetin is not essential for Bunium persicum regeneration. The treatment containing 0.1 mg/l NAA and 4 mg/l Kin was the best one for regeneration. The best treatment for somatic embryogenesis was 2 mg/l 2,4-D.

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In vitro regeneration of two cultivars of carnation, namely, ‘Nelson’ and ‘Impulse’ was studied through direct somatic embryogenesis. Somatic embryos were formed directly on petal explants cultured on Murashige and Skoog (MS) medium containing different concentrations (0.2, 0.5, 1, 2, 4, 6 mg 1^-1) of picloram. Maximum embryogenesis was obtained with 1 and 2 mg/l picloram. Globular shaped embryos were developed into cotyledonary-shaped embryos when they were transferred to the growth regulator-free media containing different concentrations (2, 4, 6, 8, and 10 %) of sucrose. Increasing sucrose concentrations in the culture media enhanced somatic embryos development. Cotyledonary somatic embryos developed plantlets when they were transferred to the half-strength MS culture medium containing 3% sucrose. Plantlets also continued to grow under greenhouse conditions.

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In this research, the logging and wood extraction damages caused by wood and paper companies was investigated. The average volume per hectare of compartments 17 and 28 of Waston watershed and Compartment 7 of Alandan watershed was more than 150 cubic meters. So, these compartments were selected as the suitable research sites. The systematic randomized sampling method with 1000 m2 circular plots was used to assess the damages to residual stands and 100 m2 circular plots was used to assess the damages to regeneration. Sampling in skid trail was done with one hundred percent inventory method with a width of 12 meter. Results of this study indicated that 3.2 percent of regeneration was damaged in felling and bucking operations and 4.8 percent of regeneration was also damaged after winching and skidding operations. Most of these damages occurred for thicket stage. The felling and bucking operations damaged 13.6 percent of the residual stand. The amount of damage to the stand after skidding including the whole logging damages equals 15.5 percent. Unnecessary damages to stand and regeneration could have been avoided by selecting the best harvesting method, skidding practices, adequate incentives/disincentives and appropriate supervision.

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This study was set up in the research station of Rice Research Institute of Iran (RRII) to determine the response of three hetrotic Indica × Indica rice hybrids (Bahar1, IR75221H and IR69688H) to anther culture on four induction media (N6, modified N6, chu and modified chu). To evaluate hybrids, the percentage of calluses which had been made from anthers in early uni- to mid- uninucleate stage and the number of regenerated plantlets of calluses in those media were determined. The results indicated that genotype, composition of callus induction medium and their interactions significantly affected callus percentage, total plant regeneration and production of green and albino plants. IR75221H hybrid was considerably superior for callus induction (1/64%) and Bahar1 hybrid was the most desirable for producing of green plants (3/43%) and total regeneration (12/24%). IR75221H hybrid produced higher albino plant (10/66%) and IR69688H hybrid produced lower albino plant (6/45%). The best medium culture in the case of callus induction was modified N6 (2%) and total regeneration (21/82%) produced green plant (5/6%), and albino plant (16/22%) was modified Chu among all media culture. However, genotypes showed different results in each media culture, and responses to hybrid of anther culture was low, but by changing the media culture we increased the response of culture.

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Forest future depends on forest stands regeneration. Soil is one of the principal capitals in the forest area. It is important to minimize damages to the forest ecosystem during logging operation. In forestry and forest management, it is significant to know the effect of forest logging damages on regeneration, sapling and soil compaction. This study was carried out in Asalem Beech forest area, in the north of Iran. The forest was harvested by selective cutting method. A systematic and randomized sampling method was used for data collection. Analysis of variance (ANOVA) techniques and binomial distribution were used for data analysis. The results showed 14.5 ± 0.99 percent of regeneration and saplings of forest stands were destroyed and damaged by logging operations with 20 m3/ha intensity per year. 9.12 ± 0.83 percent of saplings were totally destroyed and 5.3 ± 0.63 percent were damaged. These damages were caused due to felling, accumulating, skidding and landing. Soil bulk density in range of 0-10 cm depth, logging and skid trails areas were increased 17.54 and 35.61 percent, respectively. To reduce logging damages and soil compaction in forestry, and manage the forest, we need a suitable organization of timber extraction operation, careful designing and standard construction of skid trails on the basis of logging maps before felling the trees down.