Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2005 | Volume:13 | Issue:3 (21)|Papers Count:11

Genetic variation was evaluated in 27 genotypes of Haloxylon aphyllum from several arid zones of Iran, during 1998-2003. Experiment was carried out in Hossein-Abad station in Qom province, using a randomized complete blocks design with three replications. Variance analysis and compound analysis were done. Heritability of traits was assigned annually and for important traits total mean years were considered, that were low or middle. In first year, correlation coefficient of each trait was significant (p<0.05), except for survival. In second year, correlation coefficient of each trait was significant. Correlation coefficient of plant height in 5th year with plant height and stem diameter in former years was positive and significant (p< 0.05). Plant height in first year had positive and significant correlation with plant height and stem diameter in other years. Correlation coefficient of plant survival in first year with plant survival and diameter of long and small canopy cover in other years (except for stem diameter in 5th year) was positive and significant. To select trees with long height in 5th year, selection on base of this character in 1st and 2nd years and to select trees with longer diameter canopy cover, selection on base of stem diameter in 1 st year is recommended.

Trigonella belpngs to Papilionaceae. According to Flora Iranica, 32 species of it have grown in different parts of Iran. It is a medicinal, range and cultivated plant with many applications and uses in the traditional medicine and as a forage crop. Considering the different reproduction problems of this species through seed and importance of rehabilitation of its natural habitats, in this investigation, germination of the Trigonella was studied by different factors, such as chilling, hot water, seed wash, treatment with sulfuric acid and scarification. An experiment was conducted as split plot factorial in completely randomized design with 3 replications (each replication contains 50 seeds). Germination percentage, average time for germination, value of germination and germination rate were calculated. Comparing the averages had done with Duncan's test in 5% level. The results showed that these factors expect scarification with emery paper, had not effect on seed germination but scarification (2 minutes) for T. monspeliaca, T. uncata, T. stellata, T. anguina, T. astroits and (3-4 minutes) for T. elliptica and T. spruneriana showed considerable effects on the seed germination. Germination percentage for T. monspeliaca, T. uncata, and T. stellata reached to 100%, for T. anguina reached to 95%, for T. astroits achieved to 95% and for T. elliptica and T. spruneriana achieved to 75%. It seems that the hard coat of the seeds may be responsible for the lack of germination in native species.

The genus Latium belongs to Poaceae (Festuceae). It has natural distribution in Iran and found in rangelands of North and West parts of the country. This study was performed in order to investigate genetic variation and taxonomic relationships of the Lalium species in Iran. Seeds of 18 populations, which collected from different parts of the country or received from genebanks of research institutes, were used in this study. First, 0.2 g of bare seeds were ground and their proteins were extracted. Extractions were run on polyacrylamid gel by SDS - PAGE methods. Twenty-one bands were detected. Each band was considered as a taxonomic character. The data (population x band number) were analyzed, using factor and cluster analyses. Results showed that species of the genus were distinct and isolated from each other. Inbreeding species were, also, isolated from outbreeding.

To study relationships among morphological traits an experiment was conducted on different Haloxylon aphyllum genotypes at Semnan province Agricultural and Natural Resources Research Center. Twenty nine genotypes were collected from different parts of the country (Qhom, Semnan, Sistan and Bluchestan, and Yazd). The genotypes were investigated in a randomized complete block design with three replications. Six individual plants were planted 5m apart on the experiment unit rows. Plant height, canopy cover, collar diameter, the first sympodial interval, seed production, survival, infection to termite, pesylla and trips were recorded on the individual plants. Statistical analyses were conducted on the data collected from five year old plants. Correlations among traits were estimated. Path analysis was performed on the data to obtain direct and indirect effects of the dependent characters on canopy cover. The results showed that percentage of termite infection, first sympodial interval and plant height had the values - 0.744,- 0.516 and 0.352 for direct effects, respectively. It was concluded that plant height was the most important trait to improve varieties of Haloxylon aphyllum for canopy cover.

Dendrostellera lessertii is a bushy plant, growing in rangelands of Iran. This is not a plant species for grazing, because of unplatability. Its leaf extraction contains toxic substances which prevents progressive division of canceral cells. The pure leaves extraction of D. lessertii affects on alkaline phosphase enzyme of four types of human canceral cells. It is necessary to know its reproduction potential through seed germination. The seeds of D. lessertii were collected from rangelands of Isfahan and Markazi provinces of Iran in 2002. A range of treatments, including prechilling, KNO3 0.2%, GA3 100 and 200 PPM, H2SO4 95%, potting sand and control were performed. Seeds were disinfected with Vitavacs solution for 10 min. against surface infections. The germination experiment was carried out at two temperature treatments, constant (25°C) and alternative (15- 20°C) temperatures. Seed germination percentage was analysed in a randomized complete blocks design and the means were compared with Duncan tests at a =5%. The best treatment for germination was sulfuric acid (95%) for 5 minutes. Germination difficulties may be caused by hard seed coat which may be overcome by chemical or mechanical scarification processes. It should be noted that hard seed is necessary for protecting such species in a harsh area such as arid and semi-arid environment in Iran.

Condensed tannins (CTS) are flavonoid oligomers, many of which have beneficial effects on animal (safe bloat) and human health. The functions of CT are due to their ability to form reversible complex with proteins, the formation of these protein-tannin complexes making protein unavailable for microbial enzyme and activate other mechanisms like deprivation of metal ions and inhibition of oxidative phosphorylation which also results in the prevention of foam formation and bloating. Anthocyanins are flavonoids that contribute to the red, violet or blue pigmentation of both seeds and flowers. The BAN gene encodes anthocyanidin reductase (ANR), an enzyme proposed to convert anthocyanidins to their corresponding 2, 3-cis -flavan - 3-ols ((+)-catechin). Transformation of leaf explants from Medicago sativa var. Rgsy27 and M.sativa var. PI genotypes was carried out with the plasmid pBI121.BAN (binary vector containing the BAN gene) by two strains of Agrobacterium tumefadens (LBA 4404 & ERA 105). Leaf explants of Rgsy27 produced more than 90% proembryogenic calli, but in PI produced about 30%. More than 65% of regenerated embryos were changed to whole plants in both genotypes. The efficiency of transformation in Rgsy27 and PI plants was depended on Agrobacterium strains, so that the strain LBA 4404 was efficient more than ERA 105 for transformation of both genotypes. Ectopic expression of the BAN in Alfalfa transgenic foliage resulted in accumulation of CTs. Thus, it has been assumed that the BAN gene also acts as starter units in tannins condensation in alfalfa. Loss of the BAN gene function increases the amount of red pigment, suggesting that the BANYULS protein might be a negative regulator of pigment production.BANYULS activity is limiting factor for CT production, making this enzyme an attractive target for induction of over expression in forage plants, such as alfalfa (Medicago sativa) with the goal of inducing CT production in their foliage. The condensed tannin percentage in dry matter of transgenic Rgsy27 and PI plants was 0.474 and 0.600, respectively and 0.259 and 0.408 in control plants.