LISIANTHUS LEAF CURL A NEW DISEASE OF LISIANTHUS CAUSED BY TOMATO YELLOW LEAF CURL VIRUS

In 1992 viruslike symptoms appeared on lisianthus plants grown at diff erent locations in Israel. The symptoms included distortion of the gro wing tips, cup-shaped leaves, and swelling of veins on the lower surfa ce of the leaves. Plants infected at an early stage did not yield flow ers, but late infections did not impair flowering. The viral causal ag ent of the disease was purified from infected plants and identified wi th a molecular probe prepared from cloned tomato yellow leaf curl viru s (TYLCV) DNA and a specific antiserum against the virus. Purified pre parations were infectious to healthy lisianthus in transmission experi ments with Bemisia tabaci. These data confirmed that lisianthus leaf c url is caused by TYLCV. This devastating disease has become a limiting factor in the expansion of lisianthus cultivation in Israel.