Response of teosinte derived maize lines towards banded leaf and sheath blight (BLSB) disease caused by Rhizoctonia solani

Banded leaf and sheath blight (BLSB) is one of the most important fungal diseases of maize causing substantial yield reduction. For disease management, resistance breeding is one of the best possible ways and wild relatives are a valuable source of resistance. Teosinte, the progenitor of maize, is known to carry BLSB resistance. Therefore, attempts were made to cross teosinte with maize to have resistance introgression. In total, one hundred sixty-nine teosinte derived maize BC 1 F 5 lines were evaluated under an artificially inoculated environment in a Randomized Complete Block Design with two replications in two different dates of sowing i.e. 9 July, 2018 (DE1) and 23 July, 2018 (DE2). The same sets of genotypes were also planted in two replications on 9 July 2018 under an un-inoculated situation to record 14 yield and other plant traits and identify their association with the disease. Nine lines (MT-25, MT-90, MT-99, MT-128, MT-136, MT-144, MT-145, MT-148, and MT-152), exhibiting disease score ranging between 3.1 and 5.0 and PDI values between 33.34 and 55.55%, were categorized moderately resistant to BLSB. Plant height (r = − 0.178*), ear length (r = − 0.711***), ear diameter (r = − 0.743***), kernel rows per ear (r = − 0.746***), kernels per row (r = -0.680***), test weight (r = -0.718***), yield per plant (r = − 0.657***) were negatively correlated whereas flag leaf angle (r = + 0.7061***) was positively correlated with PDI. Among nine moderately resistant lines MT-145 was ranked first with maximum score of 41 followed by MT-36, MT-152, MT25 = MT99, MT-144, MT-128, MT-148, MT-90 in decreasing order. By comparing disease severity on two different dates of sowing, the third week of July is recommended for sowing of maize for reducing BLSB severity.