Abstract
Cultivation of early-maturing lines of Perilla frutescens Britt. var. frutescens is important to avoid damages caused by typhoons and early-frost in the Shidara region of Aichi Prefecture, Japan. In the present study, the characteristics of Nagurazairai, a late-maturing native line cultivated in Shidara region, Kurotane, an extremely early-maturing line and their progeny lines (No. 1, No. 7 and No. 9) raised by the crossing between Nagurazairai and Kurotane were examined along with the effects of the cultivation area on their characteristics. The lines were cultivated at Inabu, a hilly and mountainous area, and Kasugai, a low-altitude flat area, in 2015 and 2016. All breeding lines, which flowered earlier in the order of No. 1, No. 7 and No. 9, flowered earlier than Nagurazairai which flowered in late September. There was little difference in flowering time of all lines between Inabu and Kasugai. No. 1 had the greatest number of seed-setting per flower cluster and the heaviest 1000-seed weight among all lines. All lines of Kasugai had lower yield per plant than Inabu , which was primarily due to the lighter 1000-seed weight in Kasugai than in Inabu. In kasugai, No. 1 and No. 7 showed markedly lower percentage of filled-seed in 2016, probably due to the continuously high temperature condition during the seed-filling stage. The seed oil concentration tended to be lower in early-maturing lines, and was lower in Kasugai than in Inabu, except for No. 1 and Nagurazairai. These results indicate that the lines for cultivation of Perilla in a low-altitude flat area, should have a seed-filling stage not coinciding with the high-temperature season or should be tolerant to high temperatures.
