Development of plants resistant toPapaya leaf distortion mosaic virusby intergeneric hybridization betweenCarica papayaandVasconcellea cundinamarcensis.
In this study, we confirmed thatVasconcellea cundinamarcensisresistsPapaya leaf distortion mosaic virus(PLDMV), and used it to produce intergeneric hybrids withCarica papaya. From the cross betweenC. papayaandV. cundinamarcensis, we obtained 147 seeds with embryos. ThoughC. papayais a monoembryonic plant, multiple embryos were observed in all 147 seeds. We produced 218 plants from 28 seeds by means of embryo-rescue culture. All plants had pubescence on their petioles and stems characteristic ofV. cundinamarcensis. Flow cytometry and PCR of 28 plants confirmed they were intergeneric hybrids. To evaluate virus resistance, mechanical inoculation of PLDMV was carried out. The test showed that 41 of 134 intergeneric hybrid plants showed no symptoms and were resistant. The remaining 93 hybrids showed necrotic lesions on the younger leaves than the inoculated leaves. In most of the 93 hybrids, the necrotic lesions enclosed the virus and prevented further spread. These results suggest that the intergeneric hybrids will be valuable material for PLDMV-resistant papaya breeding.
Okinawa Prefectural Agricultural Research Center, 820 Makabe, Itoman, Okinawa 901-0336, Japan; Department of Bioscience and Textile Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
Kazuhiko
K
Tarora
Okinawa Prefectural Agricultural Research Center , 820 Makabe, Itoman, Okinawa 901-0336 , Japan.
Ayano
A
Shudo
Department of Agriculture, Forestry and Fisheries, Yaeyama Agriculture, Forestry and Fisheries Promotion Center , 438-1 Maezato, Ishigaki, Okinawa 907-002 , Japan.
Shinji
S
Kawano
Okinawa Prefectural Forest Resources Research Center , 4605-5 Nago, Nago, Okinawa 905-0012 , Japan.
Keiji
K
Yasuda
Department of Bioscience and Textile Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan; Institute of Vegetable and Floriculture Science, NARO, 360 Kusawa, Anno, Tsu, Mie 514-2392, Japan.
Hiroki
H
Ueno
Gene Research Center, Shinshu University , 3-15-1 Tokida, Ueda, Nagano 386-8567 , Japan.
Hideo
H
Matsumura
Okinawa Prefectural Agricultural Research Center , 820 Makabe, Itoman, Okinawa 901-0336 , Japan.
Naoya
N
Urasaki
embryo rescue; flow cytometric analysis; monodehydroascorbate reductase gene; trnD-trnY