Salahuddin Ahmed
Principal scientific officer
Plant breeding division
BARI, Gazipur
Genetic diversity among 50 inbred lines of maize were estimated by using Mahalanobis D2 statistic for eleven characters. The genotypes were grouped into eight clusters. The inter-cluster distances were larger than intra-cluster distances suggesting wider genetic diversity among the genotypes of different groups. Cluster VII contained the highest number of genotypes. The highest mean values for yield /plant (g), rows/ear and ear diameter was observed in cluster V. The lowest mean value for days to tasseling, days to pollen shedding, and days to silking and husk cover were found in cluster III The highest intercluster distance was observed between cluster I and IV and lowest between V and VIII. The highest intra-cluster distance was noticed in cluster I and lowest for cluster VI. Crossing between the genotypes of high inter cluster values would produce high performing crosses.
Genetic, Diversity, Inbreed
Variety and Species
Maize yield has dramatically boosted by the use of hybrids in many parts of the world. Genetic diversity in maize is a valuable natural resources and plays a key role in future breeding program. Knowledge of germplasm diversity and of relationships among elite breeding materials has a significant impact on the improvement of crop plants. In maize, this information is useful in planning crosses for hybrid and line development, in assigning lines to heterotic groups, and in plant variety protection. The present study was therefore undertaken to analyze the genetic divergence of maize inbreds.
Fifty maize inbreds were grown in a alpha lattice design with three replications at Bangladesh Agricultural Research Institute (BARI), Joydebpur during rabi 2008-2009. Seeds were sown on 23 November in single row of 5 m long plot. Spacing adopted was 75x 20 cm between rows and hills, respectively. One healthy seedling per hill was kept after proper thinning. Fertilizers were applied @ 120,80,80,20 and 5 kg/ha of N, P205, K20, S and Zn, respectively. Standard agronomic practices were followed and plant protection measures were taken when required. Data on days to 50% tasseling, days to pollen shedding and silking were recorded on whole plot basis. Ten randomly selected plants were used for recording observations on yield/plant (g), plant height(cm), ear height(cm), rows/ear, kernels/row, ear length(cm), ear diameter and husk cover (1-5 scale). The data were then subjected to Mahalanabis D2 analysis using GENSTAT 5.0 program
Research Report 2008-09
The crosses involving parents belonging to the maximum divergent clusters were expected to mainfest maximum heterosis and also wide genetic variability. Genotypes included in cluster III was important for early maturity and cluster I for shorter plant height. Cluster V was found important for yield/plant , rows/ear and ear diameter. High inter cluster distances were observed between cluster I and cluster IV followed by cluster I and cluster V. So, crossing of inbreds between this two inter cluster groups have the chance to produce better performing hybrids.
Report/Proceedings