Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2005 | Volume:12 | Issue:3|Papers Count:8

To evaluate 8 Damask rose genotypes, an experiment was conducted during 2003-2004 at the experimental field of Research Institute of Forests and Rangelands, Tehran, Iran. Genetic variation was studied for phonological traits, such as flowering date and duration, and morphological traits, including plant height and canopy coverage, thorn length and density, leaflet length and width, stipule size, branch angel, receptacle length and width. Simple and combined analyses of variance, mean comparison and phenotypic correlations were performed. The combined analysis showed significant differences (P<0.01) between genotypes for all the traits and for year and year x genotype interactions for most of the traits. Comparison of means classified the genotypes for flowering duration, and also in different groups for other characteristics. Significant correlations were observed between different traits. Also the phenotypic correlation coefficient (r= 0.90) between flower yield and flowering duration indicates a significant (P<0.01) positive relationship between these traits. According to the results of this investigation, a wide range of variation among the 8 genotypes was observed in terms of the traits under study. for an efficient breeding program, flowering duration could therefore, be one of the useful criteria for yield selection, though more genotypes, as well as further analyses, such as yield quantity and quality are necessary to be considered.

Most of the range and fallow lands in Iran are located in cold regions. Annual medic species are important forage plants for introducing to such regions. Low temperatures at late winter and early spring are a main preventive factor for enough forage production.Effects of chilling temperatures on vegetative growth were studied in nine genotypes of five annual medic species (Medicago rigidula, M. radiata, M. orbicularis, M. trancatula and M. polymorpha). The experiment was conducted in a split plot experimental design. The tempreture (0,5, 10, 15, 200e and glass- house 18-25oC) was the main factor and the nine annual medic genotypes were minor factors. The experiment was carried out in growth rooms at aqua culture condition.Plant height, shoot and root dry matter yields and root length were significantly different at various Plants showed better performance at glass-house. In growth rooms, plant height, shoot and root dry matter at 15oe and root length at woe had better performance than other temperatures. In gereral, M. trancatula was the most cold sensitive and M. rigidula, was the most cold tolerant species. No significant differences were observed among temperatures and genotypes after 15 day cold treatments.Regarding great number of accessions and annual medic species in Iran and, considerable inter- and intra- genetic variation among various characteristics are promising for improvement of appropriate varieties adapted to different environmental conditions.

To determine distribution, of Medicago during the years of 2000 and 2001, different parts of the Fars province in Iran were visited and 60 habitats of various species of Medicago were collected. For identification of the species, plant samples were collected from all habitats and finally 11 species were identified. Out of the 9 species including M. minima, M. polymorpha, M. coronata, M. laciniata, M. scutellata, M. rigidula, M. orbicularis, M. intertexta and M. radiata were annual medics and 2 species including M. lupulina and M. sativa were perennial. In order to determine the yield of species, seeds of 5 species were planted in the field. This experiment was carried out in a complete blocks design with four replications. Yield compared in the end of vegetative and the middle of flowering phases showed that there were significant differences between fresh and dry weight of the species. For example the fresh forage yield in M. polymorpha, M., scutellata and M. orbicular is from 30, to 4 grams per plant in the end of vegetative 58, to 32 grams per plant in the middle of flowering phase, respectively. The result showed 49, 87 and 87.5 percent increase in forage yield.

Oriental beech (Fagus orientalis Lipsky) is a timber producing species in Hyrcanian forests in north part of Iran. In order to increase seed germination capacity and seedling production of this species, in vitro embryo culture was carried out. Cold (four-week cold stratification) and non-cold treated seeds were disinfected. Endocarps of seeds were removed and isolated embryos transferred onto MS and 1 MS media. The results indicated that there is no 1/2. Significant difference between cold treated (4oC) and control seeds for embryo germination at p<0.05 level (72.33 and 77.5% respectively). Therefore, removal of endocarp layer from seed and in vitro embryo culture without cold treatment can cause breakage of seed dormancy. There was no significant difference e between MS and 1 MS medium for embryo 1/2 germination at 0.05 level (78/37 and 72/72% respectively). Produced seedlings were successfully acclimatized and transferred to the greenhouse

In order to study the genetic variation for seed yield and its components among 9 accessions of strawberry clover (Trifolium fragiferum L.), a randomized complete blocks design was conducted during 2001-2003 in Karaj, Iran. The data were collected for leaf lamina area. Intemodes length, petiole length, canopy height, stand density, growth habit (prostrate), number of inflorescences per stolon, number of inflorescences per area, number of stolons per area, number of floret per pod, number of seeds per pod, thousand seed weight, seed yield and dry matter yield. The data were subjected to analysis of variance for each year and combined over two years. The data also were subjected to principal components and cluster analyses. The results showed significant differences between genotypes for all traits except thousand grain weight. The accessions 20258, 134 and 1608 were the best genotypes for both seed and forage production. Genotype 2580 originated from Australia had more prostrate growth habit than other Genotypes.Using principal components analysis, the most important variables for seed yield characters were identified. First three independent components accounted for 85% of total variation. The first principal component indicates that forage dry matter yield, petiole length, leaf lamina area, canopy height were important characters for classification. Internodes lengths, growth habit (prostrate), number of stolons per area, number of inflorescences per stolon, number of floret per pod were important characters in the second component. For third component, number of stolons per area, number of inflorescences per area, numbers of seeds per pod and seed yield were determined. The results indicated that 1, 2 and 3 components were known as dry matter yield, prostrate habit growth and seed yield components respectively.Based on Wards cluster analysis, entries were divided into three groups. Accessions in clusters 2 including genotypes 134 and 20258 averaged well above the overall mean for all of traits. In cluster number 3 genotype 720 originated from Tabriz had the lowest values for both dry matter yield and seed yield. Distribution of genotypes based on the first two components scores was in agreement with cluster analysis.

In order to study the genetic variation among Poa prathensis populations collected from Zanjan province, an experiment was conducted in Agricultural and Natural Resources Research Center of Zanjan during years 1382 and 1383. Seedlings of 10 genotypes were transplanted in the field using a completely randomized design with four replications. Each row plot was consisted of four spaced plants. Forage dry matter yield, ear emergence date, stem height, leaf length, leaf width, basal cover and etc. were recorded. Data was analysed using analysis of variance, combined and separately for each year, principal components analysis and cluster analyses.Analysis of variance showed significant differences among populations for all of the characters, indicating genetic variation in Poa prathensis populations collected from the Zanjan province. Using principal components analysis, the first three components determined 88.3% of the total variation. Ear emergence date, pollination date, seed maturity date and seed weight with positive sign and stem number with negative sign were the most important traits in first components. Flag leaf length, leaf weight and spike length were the important traits in second component and in third component, leaf width, canopy and flag leaf distance were the important traits. The 10 populations were grouped into 4 clusters based on multivariate analysis of 19 classification variables. Population in cluster 1 averaged well above the plant height and leaf length. In cluster 2 that had high ratio of leaf to stem and the most canopy populations. The populations in cluster 3 had average forage yield. Finally, principal components analysis was in agreement with cluster analysis.

The effect of water deficient stress on total non-stractural carbohydrates in two sainfoin species (Onobrychis radiata & Onobrychis viciifolia) was surveyed. Experimental design was a RCBD with 4 replication. The plants were grown in the greenhouse conditions with the maximum temperature of 38oC and the minimum temperature of 14oC. Forty days after the cultivation, both types were put under the care of water deficient stress based on the subtraction from the rate of moisture in the farm 75% field capacity (FC) and 50% FC. Samplings were carried out in germination and reproduction stages, with irrigation level of 100%FC being taken as control. The biochemical surveys showed that root and shoot sugar contents in both species increase under stress conditions as compared to that of control. However the amount of starch decreased under stress conditions, as compared to that of control. O. radiata contained higher osmosis metabolites, such as soluble sugars than O. viciifolia, under stress