Many viruses infect cucurbits. One of the well-known symptoms is mosaic disease. Those that cause mosaic are cucumber mosaic virus (CMV), squash mosaic virus (SqMV), watermelon mosaic virus (WMV), zucchini yellow mosaic virus (ZYMV) and cucumber green mottle mosaic virus (CGMMV). WMV resistant GM squash was developed many years ago in the United States and it was on the market, but no further information was available by now pertinent to commercial aspect. Usually these viruses are not easily controlled by frequent applications of chemicals that target the insect as carriers of viruses. Therefore, it is necessary to develop commercial varieties possessing resistance against viral diseases. We have developed GM watermelon rootstocks called gongdae, using a coat protein gene of CGMMV as transgene. Those GM watermelon rootstocks showed highly resistant to CGMMV, and have been crossed to get the several BC and T generation. In order to obtain the virus resistant watermelon, watermelon lines were crossed to the selected GM watermelon rootstock. Here, we present the successful watermelon cultivars that show resistance to CGMMV. The resistance must have obtained by transferring the transgene from the GM watermelon rootstock to watermelon line

In Korea, CMV (cucumber mosaic virus) is the most frequently occurring virus with a single infection rate of 45%. However, a total occurrence of CMV by co-infection, either couple or multiple, with BBWV (broad bean wilt virus), PepMoV (pepper mottle virus) and PMMoV (pepper mild mottle virus) covers over 90% in the field cultivation of pepper. The PepMoV is transmitted by several aphid species, and it has been considered the most frequently detected potyvirus when it co-infects with CMV or PMMoV. Since F1 hybrid that resistant to PepMoV has not been developed, we have developed transgenic peppers using Agrobacterium-mediated transformation with a Hc-Pro gene of the PepMoV. A large number of T1 peppers were tested for resistance to the PepMoV, and T1 peppers tolerant of PepMoV were selected. After consequent self-crossing up to T4 generation, highly tolerant peppers to PepMoV were selected. So far, BC3F1 lines have been selected by back-crossing with 4 elite lines through a breeding program. The horticultural differences of the GM line comparing to inbred lines were investigated and no statistical significance between GM and non-GM lines was found. Based on molecular analysis, One of GM lines, 10-2, contained the transgene in the non-coding region indicating that this line would be a GM event.

Many viruses infect cucurbits. One of the well-known symptoms is mosaic disease. Those that cause mosaic are cucumber mosaic virus (CMV), squash mosaic virus (SqMV), watermelon mosaic virus (WMV), zucchini yellow mosaic virus (ZYMV) and cucumber green mottle mosaic virus (CGMMV). WMV resistant GM squash was developed many years ago in the United States and it was on the market, but no further information was available by now pertinent to commercial aspect. Usually these viruses are not easily controlled by frequent applications of chemicals that target the insect as carriers of viruses. Therefore, it is necessary to develop commercial varieties possessing resistance against viral diseases. We have developed GM watermelon rootstocks called gongdae, using a coat protein gene of CGMMV as transgene. Those GM watermelon rootstocks showed highly resistant to CGMMV, and have been crossed to get the several BC and T generation. In order to obtain the virus resistant watermelon, watermelon lines were crossed to the selected GM watermelon rootstock. Here, we present the successful watermelon cultivars that show resistance to CGMMV. The resistance must have obtained by transferring the transgene from the GM watermelon rootstock to watermelon line.