The report of the work of Natinal Bioresource Project: Seed resources of Kihara Institute for Biological Research

Tsuneo Sasanuma and Tetsuo Sasakuma

Division of Evolutionary Genetics, Kihara Institute for Biological Research, Yokohama City University, Maioka-cho 641-12, Totsuka-ku, Yokohama 244-0813, Japan

Corresponding author: Tsuneo Sasanuma

E-mail: sasanuma@yokohama-cu.ac.jp

In the first stage of National BioResource Project (NBRP), Kihara Institute for Biological Research (KIBR) has acted as a subcenter responsible for the conservation and multiplication of wheat “experimental lines” and “landraces”. During the five years of the first stage (2002-2006), a total of 1,849 accessions of wheat and its relatives, in which 428 accessions of experimental lines and 1,154 accessions of landraces were included, were multiplied in KIBR and stored as a genetic resource of NBRP (Table 1 and Figure 1).

The experimental lines include mutant lines, chromosome substitution lines, near isogenic lines (NILs), and recombinant inbred lines (RILs). These kinds of lines, especially the NILs and RILs, are powerful materials for genetic analyses, but the successive backcrossing or selfing for more than ten years were required to produce such lines, and once lost it is difficult to recover them. Therefore, the stable and authorized support of NBRP to the work of maintenance and supply of such materials is valuable and helpful for wheat researchers.

Landraces are the traditional cultivars, which have been grown in a local area for a long period and responsible for the regional climate and cultures. With respect to the agronomical traits such as grain yield and bread making quality, landraces are inferior to modern cultivars. The landraces, however, are thought to possess adaptation genes against environmental stress, such as drought or cold tolerant and disease resistant genes. As known well, the bread wheat is hexaploid originated in the hybridization between cultivated tetraploid wheat and wild diploid goatgrass (Kihara 1944, McFadden and Sears 1946). The characteristic of hybrid origin and hexaploidy gives the bread wheat several problems for breeding, that is, the lack of stably crossable wild species and difficulty of producing the drastically expressed mutation. From these reasons, the expansion of genetic resource of bread wheat is more difficult than other major cereal crops, such as rice and barley. Therefore, the hexaploid landraces, which have been grown under a strong selection of severe local climate and ethnic culture and consequently has come to contain a wide range of genetic variation, are considered to be the most important primary genetic resources of bread wheat.

In the NBRP program, KIBR multiplied and stored wheat landraces of Afghanistan, Uighur and Tibet, which were collected by successive explorations, as represented by Dr. Hitoshi Kihara’s historical expedition called KUSE (Yamashita 1965). In addition to the conservation and multiplication program, systematic survey of qualitative and quantitative morphological traits and molecular genotyping are being carried out for the purpose of using the genetic resources efficiently and applicatively. Furthermore, for the next stage, several accessions are selected from the large number of accessions based on the morphological and molecular data as representative collections, which are named “core collection”. The construction and utilization of core collection is progressing and more detailed data on our genetic resources is accumulating, which will certainly improve the scientific quality of our materials.

References

Kihara H (1944) Die Entdeckung des DD-Analysators beim Wiezen. Agric Hort 19, 889-890.

McFadden ES, Sears ER (1946) The origin of Triticum spelta and its free-threshing hexaploid relatives. J Hered 37: 81-89, 107-116.

Yamashita K (1965) Results of the Kyoto University Scientific Expedition to the Karakoram and Hindukush, 1955, vol. I. Cultivated plants and their relatives (edited by the author). The committee of the Kyoto University Scientific Expedition to the Karakoram and Hindukush, Kyoto University, Kyoto, Japan.