Source-sink Potential of Maize Inbreds Grown under Rainfed Condition in Bangladesh

The experiment was conducted at the Plant Breeding Research Field, Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during the period of November, 2018 to March, 2019. The experiment was conducted at randomized complete block design with three replications comprised fifteen inbred lines. The individual plot size and spacing were 2 m x 3 m and 40 cm x 60 cm respectively. Plant height (cm), cob length (cm), cob weight (g), cob diameter (cm), kernels/cob, 100-kernel weight (g) and yield/plant (g) were recorded from randomly selected ten plants/plot. To assess source (leaves) and sink (kernels), leaves/plant were counted at four crop growth stages, 30 DAP, 45 DAP, 60 DAP and 75 DAP (days after planting). Moreover, root lengths were measured four times at same interval and leaf length was measured at 75 DAP only. Four inbred lines, IL 15, IL 32, IL 33 and IL 35 appeared high yield potential as compared to other lines and the highest yield (477.02 g/plant) was obtained from IL35. Three lines, IL32, IL33 and IL35 produced high root length and leaves/plant so, these lines apparently found outstanding for synthesizing more starch and providing mechanical support against lodging. Two characters, cob diameter and 100-kernel weight had high heritability. Plant height showed negative correlation with yield/plant, hence short stature plant is suitable for maize cultivation. The character, cod diameter alone exerted maximum direct effect (0.86273), followed by cob length (0.82606) and kernels/cob (0.77719). The negative direct effect of plant height (-0.7021) was not counter balanced and compensated by other indirect effects. The inbred lines, IL32, IL33 and IL35 were promising for future breeding. The accumulation of starch in kernels was not uniform in rainfed condition which resulted average low kernel yield potential in maize inbred lines and may be improved through providing good agronomic requirements.