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The aim of this study was to explore the characteristics essential for a maintainer line to effectively complement the A lines in hybrid rice production. The experiment was conducted at the Regional Agricultural Research Station, Jagtial and Telangana, India during kharif, 2016 (June-October). A total of 40 genotypes were raised in Randomized Block Design (RBD) with two replications. PCA identified five principal components (PCs) with Eigen values over 1, collectively accounting for approximately 75.50% of the total variance. PC1 predominantly representing yield and related features (number of tillers per plant, panicle length, length-to-breadth ratio, grain yield per plant), while the other PCs corresponded to unique aspects like grain numbers, morphological and quantitative traits. The study also utilized biplot analysis to elucidate the relationships among these traits, revealing significant correlations and interactions crucial for rice breeding. It indicated a negative correlation between 1000 grain weight, kernel breadth, and the number of grains per panicle, while showing positive correlations among traits influencing grain yield. This method also proved assistance in identifying superior genotypes for specific traits, as exemplified by genotypes JMS18B and JMS20B excelling in grain numbers per panicle and genotype B18 standing out in grain yield and other yield-related traits. [ABSTRACT FROM AUTHOR]

The present investigation was carried out during kharif, 2016 (June to October) at Regional Agricultural Research Station, Jagtial, Telangana, India to study the phenotypic coefficient of variation and genotypic coefficient of variation, heritability (bs), and genetic advance (GA) for yield contributing characters of 40 maintainer lines of rice. The experiment was designed in RBD replicated twice. Analysis of variance revealed significant differences among rice lines for 15 quantitative traits. The phenotypic coefficient of variation (PCV) value was higher than the genotypic coefficient of variation (GCV), indicating a negligible environmental influence in the phenotypic expression of traits. The PCV and GCV values were highest for the grains panicle-1 and moderate for bran oil percentage, indicating that these two characteristics have a higher variability within and between populations than other characteristics. All of the characters had high heritability. The range of bran oil content in the 40 maintainer lines used to assess the range of bran oil content was from 11.87% in line B11 to 19.35% in line JMS17B. The genetic advancewas greatest for number of grains panicle-1 (87.86%) and modest for bran oil %. The high and moderate estimations of genetic advance show that traits such as the number of tillers plant-1, test weight, L/B ratio, plant height, bran oil percentage, kernal breadth, grain yield plant-1 and kernal length were selected. The genetic advance obtained from the high and moderate estimates indicate that the selection for these characters can be used to improve the yield of the crop. [ABSTRACT FROM AUTHOR]

The study was conducted during kharif season ( June–October) of 2016 at the Regional Agricultural Research Station, Agriculture College, Professor Jayashankar Telangana State Agricultural University (PJTSAU), Jagtial, Telangana, India. Forty (40) maintainer lines of rice (Oryza sativa L.) were grown in randomized block design replicated twice to find the relationships between the yield and its components, as well as their direct and indirect effects on the rice grain yield. Observations were recorded for yield, yield attributing characters and quality traits on five randomly selected competitive plants for each entry in each replication for 15 characters. The results revealed that the analysis of variance was significant for all the characters investigated. Grain yield was significantly correlated with its component characters like number of tillers plant-1 (0.9191**), panicle length (0.3339**), milling percentage (0.3214**) and hulling percentage (0.2873**) whereas it showed a negligible positive correlation with days to 50% flowering, days to maturity, plant height, panicle length, number of grains per panicle, kernel length, kernel breadth, L/B ratio, test weight, hulling percentage, and head rice recovery percentage. Path coefficient analysis revealed that number of tillers plant-1 (0.9439) exerted maximum positive direct effect on plant yield followed by kernel breadth, L/B ratio, panicle length, milling percentage, days to flowering and head rice recovery percentage indicated their importance in determining the complex character and therefore should be kept in mind while practicing selection aimed at improving the grain yield. [ABSTRACT FROM AUTHOR]