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Maintenance of Cannabis germplasm in the Vavilov Research Institute Gene Bank - 1993

Nikolai Lemeshev¹, Lyudmila Rumyantseva¹ and Robert C. Clarke²

1. N.I. Vavilov Institute of Plant Industry, 42 Bolshaya Morskaya Street, St. Petersburg 190000, Russia
2. International Hemp Association, Postbus 75007, 1070 AA Amsterdam, The Netherlands

        Lemeshev, N., L. Rumyantseva and R. C. Clarke. Maintenance of Cannabis germplasm in the Vavilov Research Institute Gene Bank- 1993.  Journal of the International Hemp Association 1: 1; 3-5.
        The collection of Cannabis hemp germplasm at the Vavilov Research Institute (VIR) consists of 397 accessions from 3 different eco-geographical groups: Northern, Central and Southern.  Eighty-five collection accessions were sown in isolation at 4 locations in Russia in 1993 for the purpose of maintaining the gene pools and replenishing the reserves of seed for distribution.  Sixty accessions yielded from 10 to 2,000 grams of seed each.  The remaining 25 accessions yielded no seeds.

Figure 1.  N. I. Vavilov, courtesy VIR.

Introduction
        The most important project of the International Hemp Association is a grant of humanitarian aid to the N. I. Vavilov Institute of Plant Industry (VIR) in St. Petersburg, Russia.  The VIR was founded in 1924 by plant collector and geneticist N.I. Vavilov (Fig. 1), one of the first scientists to recognize the importance of plant genetic resources conservation.  The institute is the longest existing seedbank in the world and houses a priceless collection of over 400,000 seed accessions.
        The Department of Industrial Crops of the VIR maintains the largest Cannabis germplasm collection in the world.  Most of these accessions are either wild landraces or fiber hemp varieties, and many of them are found in no other gene banks.  Under normal storage conditions, hemp seeds can be kept for about 5 years before losing viability.  Maintaining a Cannabis collection therefore involves reproducing the accessions at least once every 5 years.  Since the dissolution of the Soviet Union, the funding of the VIR has dramatically decreased, threatening the maintenance of its collections.  If the Cannabis accessions of the VIR are not reproduced they will surely become extinct before their true value is ever realized and utilized.  Especially in light of the renewed interest in Cannabis, it would be very short-sighted to let this collection die.

Figure 2.  Locations of four VIR Experimental Stations.

        In 1993 the VIR, with the sole support of the IHA, began a 4 year program to preserve and evaluate its Cannabis germplasm.  The collection consists of 397 accessions of Cannabis seeds from three basic eco-geographical groups: Northern, Middle, and Southern, collected from 16 nations (Table 1).  The collection represents wild and traditional cultivated varieties as well as products of plant improvement programs.  The vast majority of the accessions are classified as low-THC chemotypes of Cannabis sativa L.  All of the accessions will be reproduced during the first three years, and in 1996 the entire collection will be grown in replicate gardens and each accession will be characterized.
        Two key requirements must be fulfilled before an accession can be considered adequately reproduced.  The primary goal of a germplasm preservation project is the conservation of the entire gene pool.  It is very important that the population size is large enough to ensure that nearly all of the genes within the gene pool are reproduced in the resultant seed.  We have set a minimum limit of 1,000 plants in each population.  This should ensure 99% preservation of the gene pool.   The second goal is to reproduce the accession in sufficient amounts to distribute seed to researchers worldwide.  We have set a minimum limit of 200 grams of seed for storage and later reproductions.  Two hundred grams is approximately 10,000 seeds and will allow 5,000 seeds to be stored in an active collection for reproduction and 5,000 seeds to be kept in long-term storage.  Seeds can only be released to the research community if more than 200 grams of seed from each accession are held by the VIR.
        This paper reports the results obtained in 1993.

Materials and methods
        Eighty-five accessions of hemp contained in the germplasm collection of the Department of Industrial Crops at the VIR were sown with the purpose of germplasm maintenance, replenishment of seed stocks for distribution, and installation in long-term storage.  The accessions were planted at 4 VIR Experiment Stations in Russia (Fig. 2): Pavlovsk (59°N) near St. Petersburg, Ekaterinino (53°N) in Tambov Province, Kuban (44°N) near Krasnodar, and Volgograd (48°N).
        At the Pavlovsk Experiment Station 15 collection accessions belonging to the Northern and Central groups were sown in isolated plots.  Each plot contained one hemp accession, the distance between the plots being 3-4 kilometers.  The accessions were sown according to their ripening period, with early-ripening varieties planted nearer to late-ripening varieties to avoid stray pollination.
        Agrometeorological conditions during 1993 were unfavorable for the growth and development of hemp.  The spring was late and cold.  Air and soil temperatures in May and early June were lower than average by 4-5 °C.  Because of this the spring sowing was delayed by 15 days compared to the average sowing date.   The plots were planted on June 10-13.  The seed was sown in densely planted rows spaced 20 cm apart.  The size of the plot varied from 8-12 m² depending on the number of seeds available.
        The absence of rainfall in late May and strong winds dried out the soil.  The first seedlings appeared 10-12 days after sowing and continued to appear for several days.  During the course of the whole vegetative period the air temperature was well below average, while the rainfall was above average.  Therefore, the development of the plants was delayed.
        Sowing of the seed and maintenance of the plants in the isolation plots were performed according to the methods developed by the Department of Industrial Crops.   Maintenance of the plots consisted of hoeing the soil when needed, thinning the rows where seedling density was too high, weeding, applying fertilizer, removing male plants after they finished flowering, covering the female plants with gauze nets at the time of ripening to protect the seeds from birds, and harvesting of the seed plants.
        The remaining 70 collection accessions of the Central and Southern eco-geographical groups were sown at the Ekaterinino, Kuban and Volgograd Experiment Stations.  At the former two stations accessions were sown in isolated plots.   At the Volgograd Station isolation was achieved by using wooden and gauze isolation chambers.  In 1993 the agrometeorological conditions there were as described for the Pavlovsk Station, especially the dry and cold spring.  This caused a delay in sowing, sporadic germination of the seeds, and poor condition of the seedlings.  During the course of the vegetative period the rainfall was 2-3 times the average for many years.   This also impeded the development of the plants.

Results
        At the Pavlovsk Experiment Station, complete flowering was observed in early August. Seed formation occurred in late August and early September. Frosts arrived in the end of September and the temperature fell to minus 5 °C. These frosts killed the plants that had not matured and been harvested. Thus out of the 15 collection accessions planted at the Pavlovsk Station, 10 accessions yielded from 10-1,000 grams of mature seed, two accessions did not ripen, two accessions were stolen, and one yielded only immature seeds (Table 2).

        Twenty accessions were planted at the Ekaterinino Station; 14 of the accessions yielded from 10-1,200 grams of seed and 6 accessions failed to germinate because they were from old reproductions (Table 3).  Twenty accessions were planted at the Kuban Station; 17 accessions yielded from 10-2,160 grams of seed and three accessions were stolen, (Table 4).  Thirty accessions were planted at the Volgograd Station and 19 accessions yielded from 5-790 grams of seed, three accessions failed to germinate, and 8 accessions were stolen (Table 5).

***, Bold Face: see table 2.

Discussion and conclusions
        In the introduction to this paper we defined two key requirements which must be fulfilled before an accession can be considered adequately reproduced: at least 1,000 plants have to produce a total quantity of at least 200 g of seed.
        Due to poor weather conditions, poor germination, limited space and theft, only 14 of the 60 accessions reproduced were of sufficient population size (more than 1,000 plants).  Of these 14 accessions only 10 were reproduced in sufficient quantity to allow distribution (more than 200 g seed).  This means that although 60 of the 85 accessions were reproduced, only 10 were reproduced with sufficient population size and in sufficient quantity to satisfy our criteria.
        Eighty-five Cannabis seed accessions were sown, 60 Cannabis seed accessions were reproduced, and 10 seed accessions were reproduced in sufficient quantity for distribution.  Although the 1993 Cannabis germplasm reproductions yielded minimal tangible results, we must remember that this is the first time any Cannabis reproductions have been attempted during the confusing period since the dissolution of the Soviet Union.  The extensive VIR system for germplasm preservation has been partly reactivated and the future is now much brighter.  Our limited success is encouraging, considering that this is only the first year of the VIR/IHA Cannabis germplasm preservation project.  We feel that the project should certainly be continued.   However, persistence and considerable additional financing will be required to complete the reproduction and evaluation of the entire Cannabis germplasm collection of the VIR within the remaining three years of the project.  Only one thing is certain, we will never succeed if we do not focus our most concerted efforts on Cannabis germplasm conservation.