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The success of green revolution led to the introduction of high yielding and semidwarf genotypes in rice to a great extent. However, lodging remains a problem in many of the improved rice cultivars causing a significant reduction in grain yield and quality. With this aspect in mind, Keerthiraj et al. (2019) conducted a study to identify the lodging resistant genotypes among twenty-one different rice genotypes at Department of Plant Breeding and Genetics (PBGN). Three lodging resistant genotypes and four lodging prone genotypes were identified and they were crossed in Line × Tester design for the development of hybrids. Lodging resistance (LR) evaluation was carried out among the hybrids developed to identify the best lodging resistant hybrids. The evaluation of segregating generations would provide more insight into the lodging resistant character and higher yield of the hybrids developed.

The present study was therefore conducted as two experiments to identify the best segregants for LR in F2 and F3 generations of two hybrids H8 (Vaisakh × Gouri) and H5 (Prathyasha × Gouri) having intermediate LR at Agricultural Research Station (ARS), Mannuthy. Observations were recorded for qualitative, quantitative and biochemical characters. The qualitative characters included flag leaf angle, culm angle, culm strength, panicle type and panicle axis. Quantitative observations consisted of plant height (cm), flag leaf length (cm), flag leaf width (cm), internodal length (cm), number of tillers, number of productive tillers, culm diameter (mm), culm thickness (mm), panicle length (cm), panicle weight (g), number of seeds per panicle, 1000 seed weight (gm), seed yield (g) and lodging percentage. Biochemical characters included silicon and potassium content. Correlation and path analysis were carried out to identify the effect of the characters towards grain yield.

The F2 population of both the crosses showed high mean performance, range and variance over the parents, indicating higher variability among the segregating population. Correlation study revealed that grain yield per plant exhibited a significant positive association with number of tillers, number of productive tillers, panicle weight, number of seeds per panicle, culm diameter and culm thickness. Path analysis


revealed that number of productive tillers and 1000 seed weight had the highest positive direct effect towards grain yield. Based on the observation recorded for quantitative characters individual plants were ranked for each character effecting lodging resistance. A selection criterion was fixed based on quantitative characters for selecting best lines to be forwarded to F3 generation. Six lines from F2’ s of H8 family and four lines from F2’s of H5 family were identified to be the best and forwarded to next generation. Silicon and potassium content were analyzed among the selected plants and parents, it was found to be high in selected plants indicating strong culms for the plants which to a great extent signifies lodging resistance of the selected plants.

In experiment 2, the selected F2 plants were grouped into families consisting of 50 plants each and were evaluated for lodging resistance in F3 generation to identify the best segregants. Similar as in experiment 1 the observations recorded include qualitative, quantitative and biochemical characters. The mean performance and variability in F3 generation were found to be lower than F2 generation. Correlation studies revealed that grain yield per plant exhibited a significant positive association with number of tillers, number of productive tillers, panicle weight, number of seeds per panicle, culm diameter and culm thickness. Path analysis revealed that number of productive tillers and panicle weight had the highest positive direct effect towards grain yield in F3 generation. The selection criteria were fixed based on the quantitative observations recorded for lodging related traits in F3 generation. Based on this criterion and ranking of individual plants seven lines from F3’s of H8 family and three lines from F3’s of H5 family were identified as the best lodging resistant segregants from the evaluation and shall be forwarded to next generation for evaluation.