SHARMA, V. K.KIRTI, SIMRAN2023-11-042023-11-042022D/AB/410/18-19https://krishikosh.egranth.ac.in/handle/1/5810200367A study was conducted for characterization of baby corn inbred lines using agronomic characters and microsatellite markers to determine the molecular level genetic polymorphism and divergence among these baby corn inbred lines for construction of heterotic groups based on comparative analysis of amplification pattern of targeted microsatellite sites. The basic experimental material comprised twelve inbred lines and three inbred testers of baby corn, which were crossed to generate thirty-six single cross hybrids. The inbred lines and hybrids were evaluated in randomized block design with three replications during two seasons (rabi and kharif seasons). The degree of divergence and separation among inbred lines of baby corn was quantified and inbred lines were then divided into various heterotic groups based on the examination of focused microsatellite sites. Analysis of parental lines and heterosis in experimental hybrids was done statistically using nine quantitative agro-morphological characters based on the measurements and assessments of plant height, ear height, days to 50% tasseling, days to 50% silking, cob yield per plant, green fodder yield, baby corn length, baby corn girth and cob weight. Stastical analysis of nine quantitative characters using numerical taxonomic approach was employed and the inbred lines were classified into three clusters. Young seedlings were grown in almuninum container to extract genomic DNA for microsatellite primers based amplification of targeted genomic regions. Amplified products were produced using a set of 38 microsatellite sites specific primer pairs that covered every chromosome in the genome. Microsatellite-based allelic diversity was used for further classification and creation of various heterotic groups of the inbred lines. Statistically significant differences were revealed amongst inbred lines and crosses for nine quantitative morphological charactersrecorded during both the seasons. Among inbred lines, BCL-08 outperformed over all other inbred lines in respect of cob yeild per plant, followed by tester BCL-12, which was statistically equivalent to inbred lines BCL-05, BCL-07, BCL-10 and BCL-04 over the environments. Among 36 crosses, 14 crosses were found to have significantly greater mean performance as well as significantly positive heterosis. The cross BCL-10×BCL-12 was observed as high yielding cross followed by BCL-04 × BCL-03, BCL-09 × BCL-03, BCL-05 × BCL-03, BCL-07 × BCL-15, BCL-06 × BCL-15and BCL-14 × BCL-15 for cob yield per plant. By the use of 38 primer pairs, 279 allelic variant were investigated as amplified products. The value of the number of alleles varied from 4 for the primer phi011 to 11 in case of Nc130 having range between 75bp to 580 bp.The sum of total value of shared alleles was 166, which varied from 3 to 8 alleles per primer pairs. Similarly, the sum total of unique allels was 113, which ranged from 1 to 7 alleles per primer among the 15 inbred lines. Taking into the consideration the number of alleles and polymorphic status, the primers UMC1425, Phi024, UMC1407, UMC1159, Phi046, UMC1587, UMC1241, UMC1858, UMC1638 and UMC1370 seemed to be more informative on the basis of polymorphism level. On the basis of molecular level classification, BCL-15 and BCL-01 seemed to be highly diverse genotypes. Contrarily, BCL-03 and BCL-04 appeared most closely related to each other in same group. The inbred lines BCL-12 and BCL-13 were closely associated to each other. Both molecular and morphological attributes dependent cluster based data manifested that among the three testers, namely, BCL-03, BCL-12 and BCL-15 two testers excluding BCL-03 were included in same cluster. However, the cluster analysis used to group inbred lines using data from quantative characters and microsatellite markers did not show a perfect match. Results of genetic structure analysis based on repeat sequence length variation in primer specific genomic regions revealed that the genetic compositions with refrence to the targeted genomic regions of the inbreds are basically the admixtures of various combinations of three ancestral components. Analysis of the heterotic groups compositions using the hybrid index value and the hybrid mean value revealed that BCL-04, BCL-06, BCL-07, BCL-09, BC-L10, BCL-11 and BCL-14 were found in same group i.e in Group 1, BCL-01 and BCL-05 were found in Group 2 and BCL-02, BCL-08 , BCL-13 were found in Group 3.A comparative analysis of amplification pattern of targeted microsatellite sites was found effective in discriminating the inbred lines of various heterotic groups and therefore the employed panel of primer was found moderately efficient in discrimination of inbreds into heterotic groups.EnglishThesis