A new black seeded soybean [Glycine max] variety "Iwaikuro" [Japan]

A new soybean (Glycine max (L.) Merr.) variety "Iwaikuro" was developed by the Hokkaido Central Agricultural Experiment Station. It was registered as "Soybean Norin No.107" in the Ministry of Agriculture, Forestry and Fisheries of Japan, and was released as a recommended variety for central area, southern area and Tokachi area of Hokkaido in 1998. The new variety is a selection formerly named "Chuiku No.39", which was derived from progeny of the cross of 'Bansei-Hikarikuro" and "Chuiku No.21". Parental "Bansei-Hikarikuro" is a local variety which has excellent seed quality such as large seeds (over 45 gram per 100 seeds) and black seedcoat and hilum, but matures late. Another one "Chuiku No.21" is a breeding line which resists to soybean dwarf virus disease (SDV) and has excellent seed quality such as large seeds (over 40 gram per 100 seeds) and yellow hilum. The objective of this cross is to combine resistance to SDV with black seedcoat variety which has excellent seed quality. "Iwaikuro" has a determinate growth habit, relatively short stem, brown pubescence, broad leaves, white flowers and large seeds (46.1 grams per 100 seeds) with black seedcoat and black hilum. The seeds of "Iwaikuro" have protein content of 39.2% and oil content of 19.5%. The inspection grade of the seeds is usually higher than the check variety "Chuusei-Hikarikuro". "Iwaikuro" matures 7 days earlier and its yield is 10% lower than the check variety. But its weight per 100 seeds is heavier by about 15% than the check variety. Therefore its standardized yield as "Hakoguro" brand is higher than check variety, the yield means the one from which small seeds passing through the 9.1mm sieve are removed. The existing black soybean varieties in Hokkaido have shiny seedcoat luster, but "Iwaikuro" has medium one. "Iwaikuro" is resistant to SDV but susceptible to soybean cyst nematode (Heterodera glycines Ichinohe)