RÉSUMÉ
The present work aims to isolate and characterize the bacterial endophytes associated with different maize genotypes varying in resistance to disease reaction against Macrophomina phaseolina. A total of 50 endophytic bacteria were isolated from root and stem of healthy maize plants at 30 DAS, 60 DAS by using two different media like TSA, NA medium and maximum number of endophytic bacterial population were recovered from root followed by stem in all the genotypes and TSA medium was found to be the most suitable medium for deciphering maximum endophytic bacterial diversity. The isolated bacterial endophytes were characterized on the basis of morphological parameters viz., size, shape, colour, margin and texture, elevation, gram staining reaction and it was observed that Gram positive bacteria (68.0 %) formed the dominant group. The colony characterization revealed that circular forms (38.0 %) were dominated. Among the colony features the colonies with entire margins (66.0 %) and convex elevation (44.0 %) were found to be dominating.
RÉSUMÉ
Combining ability of inbred lines is the ultimate factor determining future usefulness of the lines for hybrid development while, an idea about the nature of gene action controlling the yield and yield contributing characters is important for development of fruitful breeding programme. Owing to this, the present study was carried out to investigate the General Combining Ability (GCA) and Specific Combining Ability (SCA) effect of parental lines and hybrids respectively, and to deduce the type of gene action regulating the grain yield and its components. The 30 single cross hybrids were generated by crossing 6 lines with 5 testers in line x tester mating system and evaluated along with four checks at three locations for the estimation of combining ability effects. Significant differences were observed among the inbred lines, testers, hybrids and parents vs. hybrids for most of the studied traits. The non-additive gene action was predominant for all studied traits except plant height. PFSR 145 found to be good general combiner for traits such days to 50% tasselling, days to 50% silking, days to maturity, plant height and ear height. GP 329 is best general combiner for ear girth, number of kernel per ear, number of kernels per row, 100 kernel weight and grain yield. These parents could be used in future breeding programme for the accumulation of favourable genes and thereby improve maize yield with desirable traits. Hybrid GP 82×GP 83 found to be the best specific combiner for days to 50% tasseling, days to 50% silking, days to maturity, number of kernels per ear and grain yield. The hybrid GP 82×GP 83 can be further tested extensively for the development of potential early maturing hybrids.
RÉSUMÉ
Aim: This study was aimed to find resistance sources against FAW. Study Design: Randomised Block Design. Place and Duration of Study: The Present study was conducted at Maize Research Centre, Hyderabad with promising germplasm during Kharif-2021, Rabi-2021-22 and Kharif-2022. Methodology: Field-collected FAW egg masses were reared using maize leaf- and stalk-based diet at 27 ± 1 °C, 60 ± 5% relative humidity and 12 h day length. The resulting neonates were used to infest the seedlings of 34 diverse tropical maize inbred genotypes. Results: A total of 15 genotypes were found to have recorded a leaf damage score of less than 5 with the least score recorded in BML 2 (3.24), followed by BML 11 (3.34), BML 7(3.37), BML 5 (3.37), BML 8 (3.49), CM 201 (3.60), BML 32-2 (3.91), CM 132 (3.97), BML 10 (4.01), BML 6 (4.02), BML 13 (4.34), CM202 (4.34), CM 131 (4.68), BML 90 (4.82), BML 45 (4.95) and displayed moderate resistance. Conclusion: Out of 34 inbred lines studied 15 were found to be moderately resistant to fall armyworm based on LIR and cob damage score under artificial infestation.