Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2007 | Volume:15 | Issue:2 (28)|Papers Count:11

In order to study of cytogenetic characteristics in Hedysarum, the karyotypes of six populations from four species were analyzed using image analysis system. The basic chromosome number was x=8 in all of the populations, but their ploidy level varied. According to Stebbins categories, all of the populations were grouped in symmetric class of 1A, indicating a symmetric karyotype. Variance analysis showed a significant difference (P<%1) among the genotypes for all of traits. Using principal components analysis, the first two components justified %99.50 of total variance. For the first component, the length of long arm, total length of chromosome, centromer index and the length of short arm with the highest coefficients of eigen vectors, were the most important traits. For the second component, the arm ratio had the most important role for total variation. Cluster analysis classified the genotypes into two groups. The highest distance were observed between H. coronarium (Gorgan) and H. criniferum (Kermanshah) indicating the least affinity between them. The lowest metric distance values were obtained between two accessions of H. kopetdaghi (Solgerd and Sharlogh). According to the dispersion diagram, based on first two components, the genotypes were grouped in two distinct classes, corresponding with the results of cluster analysis. According to the results of cluster analysis based on A1 and A2 parameters, the populations were grouped in two classes. The highest distance was observed between H. criniferum (Zanjan) and H. kopetdaghi (Solgerd), which implied the lowest affinity between them. Lowest distance was observed between H. criniferum (Kermanshah) and H. kopetdaghi (Solgerd).

The D genome of T. aestivum has an important role in agronomic traits of bread wheat. It has been inherited to bread wheat from A. tauschii. Moreover, two Iranian species A. cylindrica and A. crassa have received D genome from A. tauschii. 52 samples with 13 samples from each species were selected from different areas, to study homology between D genome of these species and possibility of transferring alien genes to bread wheat. Interspecific hybrids between Aegilops and bread wheat samples of each set were made in farm. The meiotic chromosomal pairing was studied in young spikes of F1 hybrids of Aegilops species and bread wheat. Results suggested that hybridization between them is possible however by embryo rescue. The genome of A. tauschii is very similar to D genome of bread wheat. Usually, homologues chromosomes of D genome in two species were paired to each other and average of chiasmata was 11.9 per cell. Lower homology was found between genome of A. cylindrica and bread wheat. The average of chiasmata was 7.37 per cell in these crosses. Homology between genome of tetraploid A. crassa and bread wheat was very low and average of chiasmata in this cross was just 3.42 chiasmata per cell. These species are very important in bread wheat improvement because transferring alien genes to bread wheat is possible even by a few chiasmata formations in hybrids.

A total of 126 accessions of v. ervilia (bitter vetch) from National Plant Gene Bank of Iran (NPGBI) were planted in the field in the visual design in March 2000. The accessions were evaluated for 42 agro-morphological traits according to descriptors. All of accessions showed the erect growth habit. The most important variation were obtained in the plant height (21 to 80 cm), days to flowering (55 to 88 days with the mean 69.8 days), number of flower per inflorescence (1 to 3), days to seed ripening (93 to 115 with the mean 100) and 1000- seed weight (30 g to 75 g with the mean of 45 g). The average of seed per pod and pod per plant were 3.5 and 55, respectively. Number of seed per plant correlated with pod length and width (r =0.81, P<0.01), pod shape (r =70, P<0.01) and number of leaflet per leaf (r= -0.33, P<0.01). Factor analysis revealed that 70.4 % of total variance is explained with the first 7 factors. The first factor was affected by traits such as branching pattern, days to flowering, number of flower per inflorescent, days to ripening and growth rate. Whereas the 2nd factor consisted of branching, standard size, standard color intensity and pod number per plant traits. Also distribution of accessions in the provinces based on two first factors in biplot was shown. Cluster analysis in Ward's method on mean of each quantitative trait per province produced 3 homogeneous clusters. The first cluster included the accessions from Markazi, Lorestan and Kurdestan provinces. The accessions from Ham, Hamedan and Isfahan were located in the second cluster. And the third cluster consisted of Kerman and East Azarbaijan.

Salvia leriifolia (Lamiaceae) is an endemic plant to Khorasan and Semnan provinces. In recent years, the different pharmaceutical properties of the seeds, leaves and roots of the plant, such as antimicrobial, antifungal hypoglycemic, antispasmodic and anti-inflammatory were evaluated. Since germination of the seeds is restricted in nature, it is important to consider micropropagation. The aim of this study to examine the embryo culture in micropropagation of Salvia leriifolia. For this purpose, the effects of different concentrations of plant growth regulators on embryo culture were investigated. Different concentrations of 2,4-D (0 ,1 ,1/5 ,2 ,2/5 and 3 mgl-1), kinetin (0, 0/1 and 0/3 mgl-1) and their combination were applied in MS medium. The embryos were cultured and incubated at 25°C in dark for 1 week and then transferred to light for 3 weeks. According to the results MS medium supplemented with 2 mgl-1 2 ,4-D and 0.1 mgl-1 kin had a significant effect on growth of embryos and plant regeneration.

Micropropagation of E. gongylocarpa Blakely through bud culture was investigated. Different treatments of sterilization, establishment, shooting and rooting were studied. The best sterilization treatment for seeds was 0.5% Benomyl solution for 15 min, washing with detergent and then under running water for two hours, 70% ethanol for 20 seconds and 2% Naocl for 20 min. MS medium containing half strength of nitrate, 0.1 mg-1 BAP, 0.2 mg-1 Kin, 0.01 mgr-1 IBA and 0.25 mg-1 GA3 with 100 mg-1 PVP were selected for shoot establishment and multiplication. The best rooting, observed in MS medium including 1 mg-1 IBA with 2.5 g-1 activated charcoal. The micropropagated plantlets established in the greenhouse successfully.

The recovery of physiological quality of Bromus (Bromus inermis L.) aged seeds was evaluated, using cytokinin, auxin and gibberell in with 25, 50 and 100 ppm concentrations. Percentage of germination, rate of germination, length of radicle and plumule, seedling length and vigor index was decreased significantly by ageing. Auxin at 25 and 100 ppm increased germination percentage of aged seeds. All of plant growth regulators at same concentration showed different effects on germination percentage. Type of plant growth regulators had no significant effect on rate of germination, but increase in concentration of plant growth regulators, significantly decreased germination rate. Seed ageing inhibited growth of radicle more than plumula ones. Radicle seems to be one of susceptible structures to ageing in seed. Auxin some what recovered radicle growth of aged seed. Type of plant growth regulator did not affect radicle length, but plumule growth was promoted by cytokinin and gibberellin. In spit of decreasing Root/Shoot ratio in aged seeds, ageing had no significant effect on it, however, auxin increased this ratio in both aged and non-aged seeds. R/S decreased with increase in plant growth regulator concentration: Frequency of abnormal seed lings decreased by aging but dead seeds increased.

Germination percentage and seed vigor are among important characters affecting the seed quality. Effects of bracts in seeds of Haloxylon aphylum on seed germination percentage and vigor have been evaluated. The seeds were collected from man-made forests of Haloxylon aphylum in Ashkezar (Yazd province) in autumn 2004. At the harvest time, the plants aged 18 and had been pruned and scattered at age of 12. Screened seed samples were divided in two parts, a sample with bracts and the second without as bracts. Both seed samples were compared for germination percentage and seed vigor. Significant differences were obtained in germination percentage and seed vigor for the tree numbers per unit area treatment. It means that with reduction of tree accumulation, germination percentage and seed vigor also decreased. The seeds sampled from pruned and non pruned trees showed no difference, but differences were found among seeds with and without bracts in measured characteristics. Therefore, bractless seeds could present better germination percentage and seed vigor in Haloxylon aphylum. Thus, use of bract-free seeds is a feasible and advisable way for reproduction of Haloxylon aphylum.