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Using immature embryos that undergo somatic embryogenesis, we studied the effects of different hormonal compounds and media on controlling secondary somatic embryogenesis (SSE) in Persian oak (Quercus brantii L.). To this end, we focused on the immature embryos that were subjected to several treatments including chilling (at 4 ℃) period and SH, MS, 2,4-D, IBA, BAP, and glutamine concentrations in 5 separate sequential experiments. The results showed that, by extending chilling period to 8-weeks, SSE induction was reduced (68.75%). In different MS concentrations or MS containing PGRs, the lowest globular embryo (66%) and the secondary embryo induction (87.5%) were observed in embryos treated with MS+IBA+BA. Adding 0.75 mg L^-1 glutamine to MS resulted in a decrease in the secondary somatic embryogenesis (56.25%). Among MS and SH media, 1/2 SH almost entirely controlled this phenomenon (6.25%). The highest maturation progression was obtained in the SH+glutamine treatment, which had the highest conversion to plantlet percentage (100%) and vigor index of plantlets (51.93) compared to the use of SH alone. We found that nutrient and PGR concentration were critical in embryo maturation and conversion percentage and stop the embryo induction cycle that plays a major role in secondary embryogenesis.
 

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There is little information about the genetic resources of Persian walnut (Juglans regia L.), an important edible and one of the most important plants in pomology and economy in Iran. Germplasm identification and conservation are important and fundamental issues in breeding programs. Six regions in BoyerAhmad and Dena Counties were chosen, and 82 walnut genotypes were selected randomly. Annual growth period was short in Setangun and Ganjegun Regions (190-200 days), but in other investigated regions was long and more than 230 days. Maximum fruit and kernel weights were 63.44 and 8.35 g, respectively. The number of observed alleles ranged from seven (ISSR7A) to 14 (ISSR3A) for primers, and the Number of effective alleles (Ne) in the primers used was between 1.19 to 1.45. The highest Ne alleles belonged to the ISSR1A primer (1.445). Walnut genotypes showed the highest genetic diversity based on the information derived from ISSR1A and ISSR2A with PIC index of 0.44 and 0.41, respectively. The Nei's gene diversity ranged from 0.13 to 0.24, and the Shannon's index was from 0.23 to 0.44. In general, increase in the altitude and decrease in the temperature delayed phenological characteristics.Suitable genetic diversity was found among the genotypes, based on the morphological and phenological characteristics and the ISSR markers. Overall, the results are useful in walnut breeding and conservation programs, and by choosing late leafing and flowering genotypes from Setangun and Ganjegun Regions, it would be possible to reduce the risks of late spring frost.