Identify Some Harmful Factors Associated with Seeds of Acer monspessulanum sub. Turcomanicum and Tilia begonifolia in Golestan Province, Iran

Montpellier maple (Acer monspessulanum sub. Turcomanicum) is one of the five subspecies of Acer monspessulanum in Iran that has been distributed in the north-east of the country, from Gorgan to North of Khorasan. The lack of a revival in natural habitats and the problems due to the drought caused the loss of many maple trees in Iran. Furthermore, a high percentage of seeds are hollow and injured after maturing. Also, viability of seeds is very low due to seed dormancy that will be less after a period of cold stratification. Regeneration of linden species (Tilia begonifolia) also is faced with many problems in the province forests. In many cases, collected seeds from the forest floor seem to be healthy and mature despite of spending necessary stratification treatments, and having suitable viability but are not able to reach to the healthy and successful seedlings. This study aims to investigate and identify factors causing damages the seeds of these species in order to control them in the future.
Montpellier maple Seeds were collected from 11 native trees with superior morphological characteristics from Siahmarz-kouh located about 18 km from southeast of Gorgan and Zarrin Gol located at 17 km from southeast of the Aliabad city, Golestan province, Iran from outer part of the crown and in different ways. Then, the primary characteristics of seeds were calculated. Seeds viability was determined using tetrazolium after collecting and six months after cold stratification. Flotation test (24 hours immersion in water) was used to determine the value of the pure seeds and empty and infested seeds. Seeds pest of Montpellier maple was identified before leaving the pest from the seeds, by trapping 3 weeks on 20 trees and storing collected seeds in desiccators and using valid identification keys. Seeds were cultured on the PDA medium and after sterilizing with sodium hypochlorite 5% and removing the infected parts and fungi were identified. In order to identify harmful factors, seeds of linden tree were collected randomly from Touskestan forest at an altitude of 700 meters above sea level and then, their surface were sterilized in sodium hypochlorite 5% for 3 minutes. After washing and drying, the seeds were cultured in the dishes containing PDA medium (20g agar, 20g sugar, 300 g potato extract and distilled water 1000 cc) in 5 replications and were incubated for 24 to 48 hours at 25 °C. Examples of grown fungi were transferred on water agar medium (containing 20 g agar, 1000 cc distilled water), and were placed at incubator for 24 to 48 hours, then, the end of the grown hyphae of fungi was removed and were re-cultured in PDA media in order to purify and identify fungi completely.
The results of this study showed that rotted and hollow seeds of Montpellier maple are 50-75%. Anthonomus Eugenii pest was identified from Curculionoidea family that its damage has been evaluated 35-50%. Investigations showed that viability of the remaining seeds was remarkably reduced (2-12%) after period stratification. Also, Fusarium oxysporum and Alternaria alternata fungus were identified on Montpellier maple seeds that cause rot, reducing seed viability and damping-off diseases. Associated fungi with Tilia begonifolia seeds were identified through contamination test including Fusarium oxysporum, Penicillium implicatum and Alternaria alternata that can potentially reduce the viability and cause severe damage to the seeds in later steps i.e. seedlings.