مجله فنآوری زیستی در کشاورزی
سال دهم شماره 2 (زمستان 1390)

Spinach is one of edible leafy vegetable in many countries worldwide and is the most prime and informative plant species for studying plant chloroplast. A main advantage of spinach which makes it remarkable among other plants is that its leaf possesses abundant number of chloroplasts and each chloroplast sustains a very large genomic molecule. This characteristic of spinach makes it a unique crop that can serve as a valuable genetic model for studying chloroplast manipulation at the molecular genetic level. Therefore, implementing a technique which can lead to identify an appropriate way to induce adequate plant regeneration from explants has become significantly important with a great demand. A study was conducted to examine optimization of callogenesis and regeneration of two spinach cultivars; Orai and Viroflay using MS based medium with various combination of plant growth regulators (PGRs); IAA, 2,4-D and GA3 at different concentration rates in order to evaluate regeneration induction of leaf, hypocotyl and cotyledon explants under three separate experimental studies. The results indicated that leaf explants from both cultivars were capable of producing the highest callogenesis on growth media which supplemented with 0.5 mg/l 2,4-D and 2 mg/l Kinetin. When calli was transferred into medium containing concentration of 0.1, 2 and 1 mg/l of 2,4-D, Kinetin and GA3 respectively, only the explants of Orai cultivar was able to induce regeneration. Also, hypocoyl drived calli from Viroflay cultivar showed the best regeneration when transferred on medium containing 2 mg/l IAA and 3.4 mg/l GA3. There was no regeneration from cotyledon explants of both cultivars on all media.

Gami Almasi is a dwarf rootstock of apple (Malus domestica Bork) that originated from North West of Iran and has some good horticultural characteristics. Agrobacterium mediated gene transformation is a method that perform for introducing of gene into plant species and need for developed to new varieties. Present study performed for first time in this cultivar. Optimizing of factors that affected on transformation is necessary in transformation programs. In this research some factors that affected on transformation such as, Agrobacterium strain, bacteria suspension ‍‍concentration, infection time, Co-cultivation period and Agrobacterium infection medium type, were evaluated byinsertion of b-glucoronidase gene. In transformation experiments, infection by bacterial suspension in 0.5 OD at 600 wavelengths for 5 minutes, showed better results than other treatments. All regenerated shoots on selective medium tested by histochemical GUS assay and PCR. Agrobacterium tumefaciens strain GV3850, with 2 days co-cultivation period were better than GV3101 strain with 3 days, co-cultivation for transformation performance. LB medium had better effect than AB medium as Agrobacterium infection medium. Under the most suitable condition, 2% transformation ratio was observed.

In vitro culture of plants offers high capacity for multiplication, maintenance and manipulation of modern cultivars. Five commercial cut rose cultivars in Iran (Cherry Brandy, Cool Water, Full House, Maroussia and Super Green) were evaluated in this study. Nodal stem segments (2 cm) were surface sterilized with commercial bleach (10-50%) for 20 min and 70% ethanol (v/v) for 2-5 min and cultured on MS medium. Various concentrations of 6-benzyladenine (BA) (0 -0.55 -1.11 -2.22 µM) and naphthalene acetic acid (NAA) (0- 0.054- 0.27- 0.54 µM) were used for shoot proliferation of new establishments. Two types of auxin, NAA (5.4 µM) and IBA (9.9 µM) were tested for root induction. Higher percentage of aseptic shoots was obtained by 50% commercial bleach and 5 minute of 70% ethanol pretreatment. Significant difference was observed between shoot proliferation rates (0.0- 82%) of cultivars and all cultivars had satisfactory multiplications on 2.22 µM BA and 0.27µM NAA combinations. The rate of produced root (0- 71.4%) differed between cultivars.

The genetic diversity of 44 apple genotypes from all over part of Iran was evaluated using 16 pairs of SSR primers. In Total, 45 alleles were detected. The number of alleles per locus varied from 2 to 5 with an average of 2.8. The average number of effective alleles was 2.2, the average of expected and observed heterozygosity were 0.52 and 0.45, respectively. According to Chi-square test, population was out of Hardy–Weinberg equilibrium. The Polymorphism Information Content (PIC) ranged from 0.18 to 0.76 implying the high detecting potential of some studied primers. Based on Jaccard’s coefficients similarity matrix for all studied apple genotypes, the highest similarity was observed between "Salmas4" and "Dirras-e Mashhad" and the The lowest one was found between "Meshki-e Damavand 2" and "Sifeshirin". Cluster analysis by using UPGMA algorithm revealed two main groups. Considering to long juvenile period in fruit trees such as apple, it seems that the application of markers with high degree of polymorphism and linked to appropriate trait would be useful in apple genetic diversity studies and breeding activities.

This study carried out on commercial primrose (Primula acaulis L.). The aim of the present study was to establish an efficient and reproducible protocol for in vitro propagation of P. acaulis from shoot tips. First of all seeds were cultured on MS (Murashig & Skoog) medium without plant growth regulators. Afterwards, the seedling-derived shoot tips were cultured on MS basal medium, containing various concentrations of 6-benzylaminopurine (BA) and thidiazuron (TDZ) in combination with various concentrations of 1-naphthaleneacetic acid (NAA). The experiments was carried out in two factorial design on the basis of completely randomize design. The result showed that the frequency of shoot regeneration was 0 to 100% in the first experiment and 30 to 100% in the second one. The highest shoot regeneration in first and second experiments, considerably affected by MS media containing 1 mgL–l BA and also 0.4 mgL–l TDZ, respectively. Regenerated shoots easily rooted without the necessity for transfer to a rooting medium. Number of roots significantly affected by media supplemented with 3 mgL-1 BA + 0.8 mgL-1 NAA and 0.4 mgL-1 TDZ + 0.8 mgL-1 NAA. Finaly, plantlets were hardened-off and transferred to soil for further growth.

In order to identify fungi associated with weeds in Hamedan Province, samples were collected from different geographic regions during spring and summer in 2009. Species were identified using morphological characteristics and sequences of ITS regions (ITS1, ITS2, 5.8S gene) of ribosomal DNA. Five isolates related to Taraxacum officinale and three isolates related to Chenopodium murale were identified as Phoma herbicola and Phoma medicaginis var medicaginis, respectively. This is the first report of Phoma herbicola on Taraxacum officinale and Phoma medicaginis var medicaginis on Chenopodium murale in the World.

In order to investigate response of rapeseed genotypes (Brassica napus L.) to drought stress, an experiment was carried out with 16 genotypes and 5 level of drought induced via polyethylene glycol 6000 (0, 10, 20, 30 and 40% corresponding to osmotic potentials of control, -0.15, -0.49, -1.03 and -1.76 MPa) as a factorial arrangement in CRD template with three replications. Hypocotyl calli derived from cultures on callus induction medium (MS medium supplement with 0.5 mg/l NAA + 0.5 mg/l 2,4-D and 0.5 mg/l BAP) were subjected to different levels of drought stress. Some traits such as relative growth rate (RGR), relative water content (RWC), INTOL index, callus growth rate (CGR) and proline content (PC) were measured in calli. The results of ANOVA in vitro showed that there was a significantly difference between all genotypes for the traits. Results of means comparison revealed that the genotype No. 7 (Dante) had the highest amounts of RWC, CGR, RGR and INTOL, therefore this genotype is introduced because it had drought tolerant calli.