Vol. 11, Issue 7 (2022)

Author(s):
K Vinothini, T Abdul Razak, N Balakrishnan and A Kavitha Pushpam

Abstract:
Field evaluation of 82 rice cultures along with the resistant and susceptible check, PTB 33 and TN-1 respectively was done at Rice Research Station, Ambasamudhram. Fourteen rice cultures viz., RMLT-21-102, RMLT-21-103, RMLT-21-105, RMLT-21-109, RMLT-21-207, RMLT-21-212, RMLT-21-213, RMLT-21-302, RMLT-21-303, RMLT-21-401, RMLT-21-402, RMLT-21-405, RMLT-21-602 and RMLT-21-608 were showed resistance at vegetative stage while ten rice cultures viz., RMLT-21-102, RMLT-21-103, RMLT-21-105, RMLT-21-109, RMLT-21-207, RMLT-21-212, RMLT-21-401, RMLT-21-402, RMLT-21-501 and RMLT-21-602 were showed resistance to yellow stem borer damage at reproductive stage. The number of trichomes/ cm2 was maximum on the upper surface of leaf blade than the lower surface. It ranged from 87.9/cm2/ leaf to 93.7/cm2/ leaf on the upper surface and 17.2/cm2/ leaf to 19.9/cm2 / leaf on the lower surface in the highly resistant cultures and were categorized as pubescent (scale 3). The highly susceptible entry was found to have minimum number of trichomes i.e., 15.3/cm2/ leaf on the upper surface and 8.6/ cm2/ leaf on the lower surface of leaf blade and categorized as glabrous (scale 1). The flag leaf angle of highly resistant cultures/ accessions ranged from 4.13° to 6.83° (decreased leaf attitude) and flag leaf attitude as erect (scale 1). The penultimate leaf angle of highly resistant cultures/ accessions ranged from 6.68° to 8.64° (scale 1 – erect leaf attitude). Resistant and susceptible entries had semi-erect and horizontal leaf attitude, respectively. The highly susceptible entries have the flag leaf angle of 72.17°. Correlation studies were carried out with biophysical parameters and yellow stem borer damage. Results revealed that the trichome density was significantly negatively correlated. While, plant height and leaf length were significantly negatively correlated and leaf breadth is significantly positively correlated.