Evaluation of medicinal plant germplasm in laboratory of seed technology in gene bank.

The main objectives of this project was evaluation of seed samples of medicinal plant with different provenances of different stats of Iran for different seed technology test including: physical purity, genuineness of seed (genetically purity), thousand weight , determination of seed moisture content, seed healthy test, seed germination and seed vigour test in standard germination test. These type of seed test were carried out for the all seed samples of medicinal plant with different provenance in laboratory of seed gene bank. Also some specially test like pre- cold test, determination model of seed storage behavior, effect of dry storage (room temperature) and cold room temperature on germination and vigour, accelerated ageing test were carried out for some special of medicinal plant seeds by experimental design. Regarding to seed healthy test, seed samples of some species collected from different regions of Iran, were chosen for seed health testing. After cleaning and determination of physical purity, the seed samples were analyzed for determination of seed borne mycelia (fungi) and insects. Damaging effects of seed borne pest were observed on the seed samples, but there were not any life cycles of insect (adult, larva and pupa). The infected seeds were separated from healthy seed. Also for determination of mycoflora (seed borne fungi), with the trace of damaging, shapes of symptoms on the seed and their color were used for identification of healthy seeds from non-healthy seeds. The infected seeds were cultured on Potato Dextroz Agar (PDA), after growing of fungi, four genera called Penicillium, Alternaria, Aspergilus, Rhizopus and Fusarium were isolated from the seed samples. Moreover, the seed quality (percentage of germination and speed of germination) of infected seeds to seed borne fungi were compared to healthy seeds . In other experiment, for model determination of seed storage behavior, the seed samples of some medicinal plants from different state of country were processed and analyzed. The processing of the seed samples included for physical and genetically purity, seed healthy test, thousand weight, moisture content determination, germination test, packaging and conservation of the seed samples in cold room of gene bank. Evaluation and determination of model of seed storage behavior was the main point of this research work. By determination of moisture content, the model of seed storage behavior of medicinal plant seeds was identified and most of them have orthodox seed storage behavior. Therefore their conservation should be done as ex situ conservation. By pre-chilling treatment comparing of normal condition, total speed of germination and vigor index of seeds of 9 medicinal plant species were studied by an experiment. The vigor indexes were calculated by following equation: percentage of germination * mean of total length of root and shoot. The results were a function of the results of percent of germination and total speed of germination. With an experiment, the seeds of two medicinal species (Eruca sativa Lam. and Anthemis altissima L.) under two cold room (4°C) and dry storage (room temperature) conditions were maintained over six months and tested by standard germination test. The physiological quality of the seed rocket plant had not any significance differences in two conditions. The reason might be due to non-physiological dormancy of the seed species. Whereas, percent of germination in the species of chamomile was significant in the two conditions. As it is clear the percent of germination of the chamomile from dry storage condition was higher from cold room condition and this due to physiological dormancy of plant seed which overcome by dry storage condition. The speed and vigor index of plant seed had no significant differences in two conditions. For evaluation of seed quality traits (germination percent, rate of germination and vigor index) in Moldavian balm (Dracocephalum moldavica L.) an experiment was conducted using accelerated aging test (AAT) under laboratory condition. The seed samples were subjected to 40 0C in 100% relative humidity for 0, 12, 24, 48 and 72 hours. A completely randomized design with 3 replications was used. The results showed significant differences among treatments for germination percent, rate of germination and vigor index. There were no significant differences between 0, 12 and 24 hours AAT treatments for germination percent and rate of germination, but AAT treatments for 48 and 72 hours significantly decreased germination percent and rate of germination compare to 0, 12 and 24 hours. Increasing the time of AAT treatments decreased all of the three seed quality characters. The vigor index was affected more than the two other quality characters. The effect of AAT duration treatments on vigor index reduction was as fallow: 0 18, 24 48, 72. It is concluded that under conditions of this experiment, the vigor index is more sensitive trait for seed quality evaluation of Moldavian balm (Deracocephalum moldavica L.) seeds. For determination and evaluation of percent of germination, total speed of germination and vigor index of the seed of 17 species of medicinal plants, according to the International Seed Testing Association, different tests including standard germination test and accelerated ageing test were used. Among those species, some species were resist and some species were not, nevertheless the percent and speed of germination, of those seed samples which is resist to accelerated ageing, are meaningful, comparing with non-aged seeds.