Pathogenic, cultural, morphological and molecular variability among eight isolates of Alternaria solani, causing early blight of tomato

Among the fungal diseases infecting tomato crops, early blight caused by Alternaria solani (Ellis and Martin) Jones and Grout is one of the most catastrophic disease causing accountable losses. Further, all of the tomato cultivars presently under cultivation have succumb more or less to early blight disease. Therefore, the present studies were undertaken for the pathogenic, cultural, morphological and molecular variability among the isolates of A. solani. The results reveal all of the eight isolates of A. solani as pathogenic to tomato (Cv. Pusa Ruby) and showed variability amongst them. The test isolates could grow better on the basic culture medium potato dextrose agar; however, highest mycelial growth was recorded on the isolate AsLt (88.50 mm), followed by AsBd (82.36 mm) and AsHl (78.40 mm), with excellent sporulation. All of the eight test isolates exhibited a wide range of variability in respect of their mycelial and conidial dimensions and septation. RAPD-PCR analysis of the four most virulent A. solani isolates, using 13 OPA primers revealed that the isolates AsBd (Beed) and AsLt (Latur) were closely related with 85% genetic similarity whereas, the isolates AsHl (Hingoli) and AsJl (Jalna) were closely related with 50% genetic similarity, but distinct from that of AsLt and AsBd isolates. Key words: Tomato, Alternaria solani, isolates, pathogenic, molecular variability, virulent, primers

Development and validation of high-performance thin layer chromatographic method for ursolic acid in Malus domestica peel

Ursolic acid, a pentacyclic triterpenoid possess a wide range of pharmacological activities. It shows hypoglycemic, antiandrogenic, antibacterial, antiinflammatory, antioxidant, diuretic and cynogenic activity. It is commonly present in plants especially coating of leaves and fruits, such as apple fruit, vinca leaves, rosemary leaves, and eucalyptus leaves. A simple high-performance thin layer chromatographic method has been developed for the quantification of ursolic acid from apple peel (Malus domestica). The samples dissolved in methanol and linear ascending development was carried out in twin trough glass chamber. The mobile phase was selected as toluene:ethyl acetate:glacial acetic acid (70:30:2). The linear regression analysis data for the calibration plots showed good linear relationship with r 2 =0.9982 in the concentration range 0.2-7 ΅g/spot with respect to peak area. According to the ICH guidelines the method was validated for linearity, accuracy, precision, and robustness. Statistical analysis of the data showed that the method is reproducible and selective for the estimation of ursolic acid