Abstract
Since ancient times, humans have bred several plants that we rely on today. However, little is known about the divergence of most of these plants. In the present study, we investigated the divergence of Mibuna (Brassica rapa L. subsp. nipposinica L. H. Bailey), a traditional leafy vegetable in Kyoto (Japan), by combining genetic analysis and a survey of ancient literature. Mibuna is considered to have been bred 200 years ago from Mizuna, another traditional leafy vegetable in Kyoto. Mibuna has simple spatulate leaves, whereas Mizuna has characteristic serrated leaves. The quantitative trait loci (QTL) and gene expression analyses suggested that the downregulation of BrTCP15 expression contributed to the change in the leaf shape from serrated to simple spatulate. Interestingly, the SNP analysis indicated that the genomic region containing the BrTCP15 locus was transferred to Mibuna by introgression. Furthermore, we conducted a survey of ancient literature to reveal the divergence of Mibuna and found that hybridization between Mizuna and a simple-leaved turnip might have occurred in the past. Indeed, the genomic analysis of multiple turnip cultivars showed that one of the cultivars, Murasakihime, has almost the same sequence in the BrTCP15 region as Mibuna. These results suggest that the hybridization between Mizuna and turnip has resulted in the establishment of Mibuna.
Highlights
Traditional indigenous vegetables are native varieties that have been grown or cultivated in a given region for a long time, and many of them have characteristic traits
The present study revealed that the Japanese subspecies of B. rapa Mizuna with serrated leaves was crossed with turnip in the late 1800s, resulting in the development of Mibuna with spatulate leaves, and the main reason for this leaf shape change was the downregulation of BrTCP15 on LG A07 (Fig. 4i)
Genome sequencing revealed that Murasakihime, a variety of turnip, has the same Mibuna-allele homo-SNPs around BrTCP15 (Fig. 5c)
Summary
Traditional indigenous vegetables are native varieties that have been grown or cultivated in a given region for a long time, and many of them have characteristic traits. Traditional vegetables have garnered attention owing to their regional revitalization and importance in maintaining crop biodiversity. To maintain and effectively use such vegetables, an indepth understanding of their origin and breeding history. Kyoto was the capital of Japan from 794 to 1868, when many varieties of vegetables were gathered and cultivated as offerings to the emperor[1,2]. Several types of Kyo-yasai are still being actively cultivated, including varieties of turnip (Brassica rapa L.), radish (Raphanus sativus L.), eggplant (Solanum melongena L.), pumpkin (Cucurbita moschata Duch.), and various other leafy vegetables[2]. Among the types of Kyo-yasai, Mizuna and Mibuna Mizuna was used to be eaten boiled, whereas nowadays, it is often used in salads
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
