Comparison of Detached Leaf Evaluations in Different Age of Transgenic Tomato Expressing Antimicrobial Peptide Gene (Ace-AMP1) Resistant to Early Blight Disease Caused By Alternariasolani
Tomato cultivar Arkavikas were transformed with Ace-AMP1 gene, regenerated plants were screened for the presence of gene and T1 transgenic leaves were used for detached leaf bioassay evaluations. Three different stages of transgenic tomato leaves were evaluated for resistance to early blight caused by the fungus Alternariasolani. Evaluations were conducted in three replications in growth chambers using detached leaves under controlled conditions. Leaf samples were plated on sterile blotting paper with 3 mm fungal plug along with respective control. Percentage of lesion diameter were calculated and compared with control for disease resistances. Forty day old leaf developed chlorotic lesions in 3 days and were more susceptible to disease when compared to 60 and 90 day old leaves and the correct age for detached leaf bioassay evaluation is 90 day old leaf. Transgenic line 10-7 was highly resistant towards Alternariasolani and moderate levels of resistance were observed in 7-2, 13-19 and 1-3. The detached leaf bioassay offers an early, compact and relatively fast method to detect resistance levels in transgenic plants when compared to other screening methods.