ISSN 2375-1231
African Journal of Crop Science ISSN: 2375-1231 Vol. 12 (9), pp. 001-009, September, 2024. Available online at https://internationalscholarsjournals.org/journal/ajcr/table-of-contents © International Scholars Journals
Full Length Research Paper
Genetic variation and multivariate analysis of late maturing maize inbred lines using phenotypic and disease related traits
F. Foncha1,2*, P. T. Touna4, E.B. Kouam1, A. Mewounko3, A.S. Owona4, P. S. Alioum5 W. Ajambang2, E. Tembo6, E. Gasura7, C. Suh8, H.N.A. Mafouasson9
1Faculty of Agronomy and Agricultural Sciences (FASA), University of Dschang, P.O Box 222, Dschang, Cameroon. 2Institute of Agricultural Research for Development (IRAD), Bambui, P.O Box 51 Bamenda, Cameroon.
3Institute of Agricultural Research for Development (IRAD) Bertoua, P.O Box 203 Bertoua, Cameroon.
4Institute of Agricultural Research for Development (IRAD) Mbalmayo, P.O Box 2067 Yaoundé, Cameroon.
5Institute of Agricultural Research for Development (IRAD) Garoua, P.O Box 415 Garoua, Cameroon.
6Seed Co Limited, P.O Box CH142, Chisipite, Harare, Zimbabwe. 7Department of Crop Production and Technologies, University of Zimbabwe, Box MP 167, Mount Pleasant, Harare, Zimbabwe. 8International Institute for Tropical Agriculture (IITA), P.O Box 4163, Goma, Kinshasa, Democratic Republic of Congo. 9Institute of Agricultural Research for Development (IRAD), P.O Box 2123 Yaoundé, Cameroon. *Corresponding Author. Email: fonlix@yahoo.com
Received December 6, 2023; Accepted August 21, 2024 and Published September 08, 2024
Abstract
The determination of diversity among maize inbred lines is important for heterosis breeding. To estimate the genetic diversity amongst the 33 maize inbred lines used, cluster and principal component analyses were carried out for sixteen different morphological and Aspergillus ear rot disease related traits. The field experiments were carried out under field artificial infection with Aspergillus flavus inoculum following standard procedures. The trials were carried out during the 2020-2021 cropping season at two locations in Cameroon, namely, Bangangte from the Western highlands and Mbalmayo from the Bimodal humid forest zone. In each trial site, the experiment was laid out in an 11 x 3 alpha lattice design with two replications under similar conditions. The PCA identified six principal components (PCs) with Eigen value greater than 1.00 and accounted for 72% of total variation. Cluster analysis based on Ward’s minimum variance procedure distributed the maize inbred lines into 7 clusters indicating their broad genetic base of which cluster VII was the largest containing eleven inbred lines and maximum inter-cluster distance was recorded between clusters IV and VI (196.66) suggesting their use in breeding programmes for the exploitation of heterosis for the desirable ear rot and yield traits. Out of all the clusters, cluster I showed highest mean value for grain yield, indicating the importance of this cluster genotypes (87036, 88094, 90156, 90188 and 90301) in maize yield improvement programmes. Similarly, cluster IV showed the lowest mean values for Aspergillus ear rot disease incidence (21.28%) and Aspergillus ear rot disease severity (6.9%) revealing the importance of this cluster genotype (89291) in maize ear rot disease resistance improvement programmes. The distribution of genotypes in the study revealed that the geographical origin did not have any bearing on clustering pattern. These results showed that the inbred lines having widely divergent clusters can be utilized in hybrid breeding programmes.
Keywords: Genetic divergence, Hierarchical cluster analysis, Maize, Principal Component Analysis.