Genebank managers are part of an international network of scientists who as a whole are trying to comprehensively conserve global genetic resources. The MAFF genebank system participates in the major forums for discussion of international crop genetic resources issues, such as the FAO and IPGRI regional network for East Asia. MAFF also has promoted international dialogue through an annual International Workshop on Genetic Resources, two of which have been devoted to crop genetic resources.15,16 In addition, active international collaboration on collecting, training, in situ conservation and database development among other areas is ongoing.
The experience of developing and improving the MAFF genebank project has led to collaboration in helping to develop, through the Japan International Cooperation Agency, genebank systems in many countries, such as Chile, Bangladesh, Myanmar, Pakistan and Sri Lanka.
Table 12.1. Examples of conserved germplasm used in prebreeding and breeding in Japan
Crop Useful trait
Rice Jukkoku, a native variety from Kyushu island has been the principal semi-dwarf gene source for rice in Japan.
Exotic varieties of rice have mainly been used in Japan to breed for pest and disease resistance, for instance Modan, a Pakistan variety which furnished resistance to rice stripe virus.
Food legumes The Japanese soybean variety Keburi has an altered protein content, and a wild soybean from Kumamoto prefecture was found to be a group A acetyl saponin-deficient mutant. These varieties have been used to study soybean chemical composition so that soybeans with improved quality can be produced.40,41
Cereals A search among about 2000 wheat accessions found that one variety,
'Bai-huo' from China, lacked the Wx protein on the D genome. Using the haploid breeding method, the first waxy bread wheat has been developed from the cross between 'Kanto 107' and 'Bai-huo'.42 The wheat variety Nobeokabozu has polygenic resistance to scab (Gibberella zeae (Schw.) Petch). This variety has been used as a parent in breeding.43
The barley variety Mokusekko 3, from China, has two resistance genes to barley yellow mosaic disease (Ym, Ym(t)). This variety is being used to breed for resistance to the disease.43,44
Tuber crops The Japanese sweet potato variety Hichi-fuku, which is resistant to black and stem rot and has excellent storage ability, has been used in breeding many varieties, including the variety 'Hi-Starch' popular in Japan.45 An accession of the wild relative of sweet potato (Ipomoea trifida), from Mexico, has been used to increase starch production. This wild species also has resistance to root knot nematode and root lesion nematodes. These traits have been transferred to improved varieties.46
Forage/lawn Japanese accessions of the lawn grass Zoysia japonica have been found grasses which stay green longer in autumn. The commercial use of this germplasm is being exploited.
Apomictic Guinea grass (Panicum maximum) from Africa has been used to develop a new variety of Guinea grass forage called "Natsukaze."
Small grains/ Japanese native buckwheat has been found with a high rutin content industrial crops The sesame cultivar H65 from China has higher anti-oxidation activity than Japanese cultivars and is being used as a parent in breeding.
Japanese pear (Pyrus pyrifolia) is not resistant to scab disease (Venturia nashicola). However, resistant clones have been found in Pyrus aromatica. This resistance is being analyzed to determine its value in breeding.
Table 12.1. (cont'd) Examples of conserved germplasm used in prebreeding and breeding in Japan
Tea One Japanese accession (MAK ZAI 17-1) has been used to produce lower caffeine type tea and an Indian accession (MAK IND 113) has been a source of high caffeine.
Vegetables Late bolting Chinese cabbage, Brassica campestris, has been an objective of breeders in Japan. The Japanese local variety, Oosakashirona, has been a source of this trait. 47
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