Banded leaf and sheath blight (BLSB) of maize is an emerging disease in the northwest region of India. The present study investigates the potential role of defense-related enzymes in imparting resistance against Rhizoctonia solani in seven inbreds, viz., LMDR-2, CM-143, CM-600, LM-11, LM-12, LM-13 and LM-14, and four maize hybrids, viz., PMH1, PMH2, PMH4 and JH3459. The enzyme activities were determined from the leaf sheaths collected at 0, 24, 48, 72, 96, 120 and 144 h post-inoculation. The results indicated a spike in the expression of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POX) and catalase (CAT) at 72 h post-inoculation following pathogen challenge in different maize inbreds/hybrids. The moderately resistant group (LMDR-2 and JH3459) showed significantly higher activities than the susceptible group (LM-11, LM-12, CM-600, PMH4 and PMH2). A strong positive correlation was observed between different enzymes at 72 and 96 h after inoculation. Lesion length showed negative correlation with the activities of enzymes studied. Our results indicated that PAL, PPO, POX and CAT played key roles in providing BLSB resistance in maize inbreds/hybrids.

玉米带状叶纹枯病（BLSB）是印度西北部地区的一种新兴病害。本研究调查了防御相关酶在7 个近交系（即LMDR -2 、 CM-143、CM-600 、LM-11、LM-12、LM-13 和 LM-14，以及四种玉米杂交种，即 PMH1、PMH2、PMH4 和 JH3459。从接种后 0、24、48、72、96、120 和 144 小时收集的叶鞘测定酶活性。结果表明，在不同玉米自交系/杂种中，在病原体攻击后 72 小时，苯丙氨酸解氨酶 (PAL)、多酚氧化酶 (PPO)、过氧化物酶 (POX) 和过氧化氢酶 (CAT) 的表达出现峰值。中度耐药组（LMDR-2 和 JH3459）的活性显着高于敏感组（LM-11、LM-12、CM-600、PMH4 和 PMH2）。在接种后 72 和 96 小时观察到不同酶之间存在强正相关。病变长度与所研究的酶活性呈负相关。我们的结果表明，PAL、PPO、