KOYAMA Akio, YAMANOUCHI Hiroaki and MACHII Hiroaki
National Institute of Agrobiological Sciences
Ohwashi Tsukuba Ibaraki 305-8634, Japan
E-mail: [email protected]
Plant genetic resources are considered as an important property to human being in providing rich genetic diversity especially through wild types for their useful traits such as disease resistance which might get diminished in cultivated plants as results of on-going breeding practices. From this point of view, steps are being taken to strengthen the preservation and utilization of genetic resources in many countries. Moreover, with advancement in biotechnology, the importance of plant genetic resources is being paid more attention.
In order to conserve agricultural genetic resources, National Institute of Agrobiological Resources (at present National Institute of Agrobiological Sciences: NIAS) under the umbrella of the Ministry of Agriculture, Forestry and Fisheries, Japan started the Genebank Project in 1983 for plants, micro-organisms and animals as a central bank in coordination with sub-banks comprising of 14 other institutions. This Project has focused on exploration/collection, evaluation, preservation, data management and distribution/utilization of these genetic resources. At the same time, systematic management on mulberry genetic resources was also carried out within this project.
Mulberry is a generic term for the genus Morus of the family Moraceae. Koidzumi (1917) classified the genus Morus into 24 species and one subspecies. Most of mulberry varieties cultivated in Japan belong to Morus bombysis, M. alba and M. latifolia. Varieties belonging to M. bombysis are primarily cultivated in cold regions, such as Tohoku district, and varieties belonging to M. latifolia are mainly cultivated in warm places, such as Kyushu district. However, varieties of M. alba are cultivated in a wide area, from Kyushu district to Tohoku district, since it has intermediary traits of the above two species. Besides, M. acidosa shows natural growth in semi-tropical regions and is cultivated in south-west islands including Okinawa islands. M. kagayamae and M. boninensis are indigenous to remote islands of Izu and Ogasawara, respectively.
Mulberry genetic resources have been collected and maintained in several countries including Japan, China and India. In Japan, more than 1,000 accessions of both indigenous and exotic origin of mulberry species were maintained at the National Institute of Sericultural and Entomological Science (NISES)(Machii et al., 1999). In April 2001, NISES was reorganized and was merged with National Institute of Agrobiological Sciences (NIAS) which is now also responsible for maintaining and conserving the mulberry genetic resources. At present, 1,375 genotypes are being registered as the mulberry genetic resources in Genebank of NIAS. These genotypes are preserved on the campus field and greenhouse and are being used to dissect the morphological and agricultural traits to improve mulberry cultivars for beneficial uses.
