Report on visit to Japan of Dr P. Tzenov, BACSA president and Dr S. Cappellozza, Italy

Visit to Japan (25/2- 3/3/2007)

The BACSA president, Dr P. Tzenov and Dr S. Cappellozza, Sericulture Experiment Station, Padua, Italy were invited to visit Japan during the period 25 Feb. – 3 Mar. 2007 by Prof. Yutaka Banno, Genetic Resources Institute, Faculty of Agriculture, Kyushu University, in the framework of the national Japanese project on bio-resources, whose details can be red at the following web address: http://nbrp.jp//index.jsp ; travel expenses as well as board and lodging on Dr Tzenov's and Dr. Cappellozza's part were offered by the Japanese host, in the framework of the above-mentioned project. In fact, in the past, prof. Banno had the chance of visiting the Padua Section as well as of meeting Dr.Tzenov, so that he rightly evaluated the Bulgarian and the Italian germplasm banks as the most relevant ones in Europe . In the framework of a world discussion, which was also promoted in the past by the FAO, within the programme “Global Exchange of Sericulture Germplasm”, resulting in the meeting held in Bangkok , Thailand - September 2002, “Conservation Status of Sericulture Germplasm Resources in the World - II. Conservation Status of Silkworm ( Bombyx mori ) Genetic Resources in the World”, http://www.fao.org/docrep/005/AD108E/ad108e00.HTM, the Japanese seminar was focused on the status of preservation of the resources in countries which show similar structural problems: poor care of sericulture, scantiness of funds devolved to germplasm preservation, need of finding new methods of preservation and new means of using genetic resources to the best of their advantage.

In the first three days of staying at the Fukuoka University , the guests could inspect the facilities to rear the silkworm, where are reproduced 500 mutant strains every year. Mutant strains are populations selected on the basis of some phenotypic characters, concerning eggs, larvae, cocoons, pupae or moths or more than one of these developmental stages together; for example, the character “albinism” is shown both by the larva and in the eyes of pupae and moths. Mutants are not preserved for their quantitative characters, which are not considered in the selection process, but because their phenotypic traits are employed as “markers” in order both to carry out selection, and to map the genome.

During the visit it was possibile to find out substantial convergences in preserving methods and rearing problems; for example, it was assessed the same difficulty in maintaining a trained working staff, which, currently, is seasonally engaged in Japan too. Furthemore, a visit was performed to the mulberry field, which is used to produce leaf for reproduction rearing of strains. Training sistem of tree is low-cut pruning, so that the mulberry has the shape of a bush; this method is apt to the local climatic conditions (semi-tropical ones).

The prof. Banno's team explained their laboratory activity, performed in order to characterise strains and mostly concerning proteomics studies; informations and publications were exchanged. During the third day of staying in Japan , the seminar took place at the Fukuoka University , during which the Power Point presentations by the two foreign visitors, Dr. Tzenov and Dr. Cappellozza, were expounded.

The following morning, after leaving Fukuoka , foreign guests went to Kyoto , the Japanese imperial city, where the homonymous University is located, which is about 700 km away from Fukuoka . The distance was covered in about three hours thanks to the superfast train “Shin-kan-sen”, which connects the Kyushu island to Kyoto , by crossing the sea in a tunnel under the water. Kyoto is located more Northern than Fukuoka, so the climate is colder (corresponding to that of the Northern part of Italy). During staying in Kyoto, Dr. Sakano, belonging to the prof. Banno's team, took over the role of guide.

Once arrived to Kyoto, Dr. Tzenov and Dr. Cappellozza were accompanied to the Kyoto University, Textile Faculty, Institute of Technology, where they met prof. Ichida, who showed them facilities to rear the silkworm on artificial diet under sterile conditions. This kind of rearing is carried out with a different technique with regard to that developed at the Padua Section, where asepsis is not implemented. Prof. Ichida's artificial diet is characterised by a very high quality of its ingredients, and it contains a very high quantity (until 60-80%) of mulberry leaves, of remarkable nutritious value, because it comes from a very careful selection on the mulberry shoot (only top leaves are used) and finely ground to 20 micron meshes. The silk fiber which is spun by the larvae reared on this kind of food is very similar, with regard to its chemical and aminoacidic composition, as that obtained by feeding the silkworms on fresh mulberry leaves and, for this reason, it could be employed for some niche applications, with high added value, where the “natural” fibre is required. Nevertheless, both the type of diet and the type of rearing require expensive rearing rooms and equipment, and the costs are not comparable to that of rearing on leaves.

It was possible also to visit the laboratories and the experimental mulberry field, where different mulberry cvs are cultivated and to observe the layer propagation, which is an unusual kind of agamic propagation of the mulberry.

The discussion with prof. Ichida was particularly useful, with indications on the diet recipe and modalities to put the leaf into the silkworm diet. An English book on artificial diet was given to Dr. Cappellozza, of which she had known only the Japanese edition; this book, though very old, contains basic information. Dr. Cappellozza received also information about a new kind of disinfection technique which can substitute the traditional one with formaldehyde; this is a very innovative one because the end product is not dangerous (oxygen is produced in the final step), the time of application is very short (from half an hour to some hours, according to the volume of the rearing rooms), and, the most important thing, the larvae can stay inside the room during the disinfection process (they stand up to 0.5 p.p.m. concentration)

Equally interesting was the observation of the machinery used in order to automatically rear on leaves the last one-two larval instars; differently with regard to the Italian automatic machine, the Japanese one does not need bed cleaning, as it is a sort of mechanised branch rearing.

Also in the case of prof. Ichida, an exchange of scientific publications occurred.

The following day was partially spent in visiting Kyoto, and partially used for the transfer to the Kansai International Airport, from where the departure was foreseen on the 3 rd March morning.

The visit to Japan was particularly precious due to the collected information; this aspect is particularly remarkable due to the fact that Japanese specialised literature it is not simple to consult being mostly in the national language. However, much important was also exchanging ideas and discussing particular problems, which permitted to put a basis for future collaborations. In particular, with this visit, it was favoured the establishment of agreements with both the Japanese and Bulgarian germplasm banks, in order to exchange genetic material of reciprocal interest, for the silkworm and the mulberry. A bilateral agreement Italy-Bulgaria is enclosed with the report, as it was sent by Dr. Tzenov, at his coming back to Bulgaria. That one with the Japanese germplasm bank is being prepared.

Furthermore, Dr. Tzenov, proposed the Italian application for registration to BACSA ( Black, Caspian Seas and Central Asia Silk Association) which does not charge any entrance or yearly fee on the associated countries and, on the other hand, permits to take advantages, as the participation to meetings, Congresses, collaborative experiments, project implementation.

In addition, also thanks to the trip to Japan, it was possible to better settle the guide lines, of a project which will be presented within the mid of April to the EC Agricultural Commission, FP7, CAPACITIES programme, with the participation of Greece, Bulgaria, Romany, Italy, France.

On the other hand, with prof. Banno, chances of establishing a technological transfer (Japan à Europe) always in the FP7, were discussed, but the concrete possibility of starting this kind of scientific relationship should be better evaluated by an in-depth analysis of the communitary programmes.