~ 517 ~ Journal of Pharmacognosy and Phytochemistry 2020; 9(5): 517-522 E-ISSN: 2278-4136 P-ISSN: 2349-8234 www.phytojournal.com JPP 2020; 9(5): 517-522 Received: 01-04-2020 Accepted: 02-05-2020 S Mallikarjuna Research Scholar, Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Guntur, Andhra Pradesh, India V Roja Assistant Professor, Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Guntur District, Andhra Pradesh, India I Sudhir Kumar Scientist, Department of Plant Breeding, Agricultural Research Station, Peddapuram, East Godavari District, Andhra Pradesh, India T Srinivas Professor, Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Guntur District, Andhra Pradesh, India Corresponding Author: S Mallikarjuna Research Scholar, Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Guntur, Andhra Pradesh, India Genetic diversity studies in newly developed maize inbreds S Mallikarjuna, V Roja, I Sudhir Kumar and T Srinivas Abstract Forty nine inbred lines of maize were evaluated for 14 parameters at the experimental field of Agricultural Research Station (ARS), Peddapuram, Andhra Pradesh, during 2018-19 to study the genetic divergence using multivariate analysis. The analysis indicated considerable genetic divergence among the 49 genotypes studied. D 2 analysis grouped the 49 maize genotypes into nine distinct clusters. Among those, cluster I was largest with 24 genotypes, while clusters IV, VI, VII, VIII, IX are smallest with single genotype in each. The intra-cluster distances in all the nine clusters were more or less low, indicating that the genotypes within the same cluster were closely related. The maximum inter cluster distance was observed between clusters II (KDML-115, PDML 15, VM 51, ADL 1619, PDML7470, CAL 1784, CAL 17834, VM 45, AL8127) and cluster VIII (CML 1505) indicating presence of maximum diversity among the genotypes falling within these clusters. Hence, the crosses VM51 × CML1505 is expected to result in heterotic hybrids and transgressive segregants. Keywords: Newly developed, maize inbreds Zea mays L. Introduction Maize (Zea mays L.) is a monoecious and cross pollinated crop. It is a versatile cereal crop next to wheat and rice in the world. Moreover it is one of the most important agricultural food crop for humans and livestock. It also serves as the basic raw material in numerous industrial products that include starch, oil, protein, alcoholic beverages, food sweeteners, pharmaceutical, cosmetic, film, textile, gum, package, paper industries and so on (Nikkhoy and Shiri, 2017) [5] . Maize breeders are consistently emphasizing on diversity among parental genotypes because it is a significant factor contributing for development of heterotic hybrids. Hence, characterization of genetic diversity of maize germplasm is of great importance in hybrid maize breeding aimed at development of high yielding hybrids. Magnitude of genetic diversity among germplasm can be estimated with the help of advanced biometrical techniques such as multivariate analysis based on Mahalanobis D 2 statistics which is a very useful technique in quantifying the degree of divergence between inbred lines or any biological population at genotypic level. It is also helpful in assessment of relative contribution of different components to the total divergence at both intra and inter-cluster level. Clustering method is used to separate the genotypes into sub groups in order to obtain homogeneity within the groups. Different clustering methods are used depending on the procedure that is most suitable for the data set. Data obtained from the clusters can then be used to select potential parents for production of heterotic hybrids in maize. In view of the above, the present investigation was taken up to assess the genetic diversity of 49 elite maize inbred lines towards identification of superior and divergent parents for the production of heterotic hybrids. Materials and Methods The present study was carried out during kharif 2018 at Agricultural Research Station (ARS), Peddapuram, Andhra Pradesh. The experimental material comprised of 49 inbred lines, including one check (BML-6) (Table 1). The genotypes were sown in Simple Lattice Design (SLD) with two replications. Each genotype was planted in two rows of 4m length each in each replication, with a spacing of 70 cm between rows and 20 cm within row. The crop was raised as per the recommended package of practices. Observations on various pre and post- harvest parameters were recorded on five plants selected at random from each entry in each replication for plant height (cm), ear placement height (cm), cob length (cm), cob girth (cm), kernel rows cob -1 , number of kernels row -1 , cob yield plant -1 , grain yield plant -1 , 100 grain weight and protein content (%).In contrast, observations for days to 50 per cent tasselling, days to 50 per cent silking, and anthesis silking interval were recorded on plot basis.