Development and establishment of practical tissue culture methods for production of virus - free garlic seed bulbs,, a novel field cultivation system and convenient methods for detecting garlic infecting viruses

摘要

Garlic (Allium sativum L.) is an important plant widely used for culinary and medicinal purposes because of its ability to improve the taste of food and its biological activities that include antibiotic, antitumor, cholesterol lowering, and antithrombic effects on animal cells (Fujiwara and Natata, 1967). Garlic traditionally has been cultivated vegetatively because of its sexual sterility; therefore, viral disease is very serious problem (Mohamed and Young, 1981; Walkey and Antill, 1989; Walkey, 1990; Lot et al., 1994). Most unselected commercial garlic cultivars have been shown to be infected with a complex of two or more viruses and many reports have described the causative viruses of garlic diseases (Cadilhac et al., 1976; Bos et al., 1978a, b; Delecolle and Lot, 1979; Lee et al., 1979; Sako, 1976, 1978). However, identification of the viruses that infect garlic is complicated, and the pertinent literature is confusing (Walkey et al., 1987; Van Dijk, 1991, 1993a, b; Conci et al., 1992). In Japan, two types of rod-shaped flexuous viruses have been detected in garlic plants (Lee et al., 1979; Abiko et al., 1980a, b). Each of these viruses has been classified into the potyvirus and carlavirus groups based on their morphological and cytopathological properties. The potyvirus, which is termed garlic mosaic virus (GMV), is thought to be the causative agent of garlic viral disease, whereas the carlavirus, termed garlic latent virus (GLV), can infect garlic systemically, but causes no apparent symptoms of disease (Lee et al., 1979; Sako, 1989). However, GMV and GLV have not been biochemically or physically analyzed, and there is no information about their interrelationship. The relatively restricted host ranges and the lack of sensitive methods for detecting the individual viruses have led to confusion in differentiating garlic viruses.