EFFECT OF TEMPERATURE REGIME AND GROWTH STAGE INTERACTION ON PATTERN OF VIRUS PRESENCE IN TSWV-RESISTANT ACCESSIONS OF CAPSICUM CHINENSE

We studied the resistance to tomato spotted wilt virus in plant introd uction accession (PI)-151225 and PI-159236 under Mediterranean climati c conditions. Two temperature regimes were utilized, corresponding to early and late cultivation cycles. Inoculations were made at 2- and 4- leaf stages to determine the effect of early infection. The existence of interaction between temperature regime and developmental stage was also studied. When plants of both PIs were maintained at 30/18 degrees C (day/night), all plants at both growth stages when inoculated devel oped systemic infection. At 25/18 degrees C, only those plants inocula ted at 2-leaf stage became systematically infected; however, those ino culated at the 4-leaf stage behaved as resistant. Thus, there was an i nteraction between temperature regime and growth stage. There is poten tial for using this type of resistance in areas with mild climates, pr oviding seedling infections are avoided.