Early blight (EB) disease caused by fungus Alternaria solani is one of the world's most catastrophic Solanum lycopersicum L. diseases. This study was aimed to check the response of 29 different tomato genotypes toward EB disease with the help of phenotypic (percent disease index and growth inhibition index), physiological (total chlorophyll content and carotenoids) and biochemical attributes [total protein content (TPC), total phenolics (TP) and activities of catalase (CAT), peroxidase (POX), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL)] at 30 and 60 DAI (days after inoculation). The experiment consisted of all 29 inoculated and uninoculated genotypes of tomato which were placed in greenhouse. The results obtained from investigated parameters grouped eight genotypes as resistant, seven as moderately resistant, six as moderately susceptible and eight as susceptible to the infection of the pathogen. Moreover, from the findings of physiological and biochemical attributes in the grouped genotypes, possible resistance mechanisms activated in the host were also predicted. Activation of defense responses was revealed by elevated biochemical attributes in all inoculated genotypes and changes were more obvious in resistant and moderately resistant tomato genotypes due to the least reduction of health markers. Among antioxidant enzymes, CAT contributed maximum to resistance, as the enzyme activity was highest in resistant genotypes.

由真菌链格孢引起的早疫病（EB）是世界上最具灾难性的茄属茄属之一L.疾病。这项研究的目的是借助表型（疾病百分率和生长抑制指数），生理学（总叶绿素含量和类胡萝卜素）和生化特性[总蛋白含量（TPC）]，检查29种不同基因型的番茄对EB病的反应。在接种后30天和60天DAI（接种后天数）测定总酚（TP）和过氧化氢酶（CAT），过氧化物酶（POX），多酚氧化酶（PPO）和苯丙氨酸氨裂解酶（PAL）的活性。该实验由放置在温室中的所有29种接种和未接种的番茄基因型组成。从研究的参数获得的结果将八种基因型分为耐药型，七种中等耐药型，六种中等敏感型和八种对病原体感染的敏感型。此外，根据分组基因型中生理和生化属性的发现，还预测了宿主中可能激活的抗性机制。在所有接种的基因型中，生化特性的升高揭示了防御反应的激活，并且由于健康指标的降低最少，所以在抗性和中度抗性番茄基因型中变化更为明显。在抗氧化酶中，CAT对抗性的贡献最大，因为抗性基因型中的酶活性最高。在所有接种的基因型中，生化特性的升高揭示了防御反应的激活，并且由于健康指标的降低最少，所以在抗性和中度抗性番茄基因型中变化更为明显。在抗氧化酶中，CAT对抗性的贡献最大，因为抗性基因型中的酶活性最高。在所有接种的基因型中，生化特性的升高揭示了防御反应的激活，并且由于健康指标的降低最少，所以在抗性和中度抗性番茄基因型中变化更为明显。在抗氧化酶中，CAT对抗性的贡献最大，因为抗性基因型中的酶活性最高。