Development of basic technologies for improvement of breeding and cultivation of Japanese gentian

Abstract

Japanese gentians are the most important ornamental flowers in Iwate Prefecture and their breeding and cultivation have been actively conducted for half a century. With its cool climate and large hilly and mountainous area, more than 60% of gentian production in Japan occurs in Iwate Prefecture. Recent advances in gentian breeding and cultivation have facilitated the efficient breeding of new cultivars; disease control and improved cultivation conditions have led to the stable production of Japanese gentians. Molecular biology techniques have been developed and applied in gentian breeding, including the diagnosis of viral diseases and analysis of physiological disorders to improve gentian production. This review summarizes such recent approaches that will assist in the development of new cultivars and support cultivation. More recently, new plant breeding techniques, including several new biotechnological methods such as genome editing and viral vectors, have also been developed in gentian. We, therefore, present examples of their application to gentians and discuss their advantages in future studies of gentians.

The Host Stomatal Density Determines Resistance to Septoria gentianae in Japanese Gentian

“…Maxim. ), and their interspecific hybrids are mainly used as cultivars or lines in Japan (Nishihara et al 2018;Yoshiike 1992). Several gentian fungal diseases, including gentian leaf blight, gentian brown leaf spot, and gentian sclerotial flower blight, have been reported (Nekoduka et al 2013;Ohno et al 1996;Saito and Kaji 2006).…”

Morphological and cytological observations of corolla green spots reveal the presence of functional chloroplasts in Japanese gentian

“…Furthermore, the roots and rhizomes of gentians are used in traditional medicine for skin diseases caused by wind-heat or damp-heat [4]. To date, more than 300 gentian cultivars derived from G. scabra, G. triflora, and their hybrids have been bred and selected for ornamental purposes [5]. Generally, Japanese cultivated gentians have green spots on the corolla adaxial surface, irrespective of flower color (S1 Fig).…”

Production of interspecific hybrids between Japanese gentians and wild species of <i>Gentiana</i>

“…The F 1 hybrid cultivar 'Iwate' (G. triflora) was first developed in 1977. Since then, more than 300 F 1 and clonal cultivars have been produced mainly by conventional crossbreeding using intra-specific and inter-specific crosses of two cultivated species of G. scabra and G. triflora (Nishihara et al 2018). In Europe, other endemic gentian species have been ornamentally used in rock gardens and garden borders.…”