TRANSGENIC PLANTS OF CC 84-75 RESISTANT TO THE VIRUS ASSOCIATED WITH THE SUGARCANE YELLOW LEAF DISEASE

摘要

The virus associated with the yellow leaf disease of sugarcane (ScYLV) was detected in Colombia in 1998. Since then it has been found in several commercial hybrids, especially in CC 84-75 which occupies second place in cultivated area in the Colombian sugar industry. Due to the susceptibility of most commercial hybrids and to the importance of CC 84-75, the possibility of producing transgenic plants with resistance to the virus was studied. Embryogenic callus of hybrid CC 84-75 was bombarded with plasmids pFM395 and pFM396 containing a ScYLV coat protein DNA fragment. After geneticin selection, 69 regenerates were obtained. Fifty-seven plants were positive for NPT II by PCR amplification. Forty-six plants out of 69 regenerates contained the coat protein coding fragment as confirmed by both PCR and Southern blot assays. Digestions with Bam HI, cutting only once within transgene, indicated the presence of six independent transformation events. Transformed plants were inoculated with ScYLV by Melanaphis sacchari and tested for infection at monthly intervals, using TBIA and RT-PCR, for 10 months after challenge. Thirty-seven plants out of 66 tested negative for ScYLV. A field test of resistant lines versus the original variety is underway.