The differences in the nitrogen isotope composition between a maize hybrid and its parents.

Understanding of nitrogen stable isotope variation in maize hybrids might help obtaining information on nitrogen absorption and distribution in different maize hybrids. In this study, we examined the nitrogen isotopic composition of different parts of maize hybrids under a laboratory culture experiment. The results showed that the δ15N values of different parts of the maize hybrid and its parents were ordered as follows: δ15Nstem>δ15Nleaf>δ15Nroot. The variation pattern of δ15N between the roots and leaves(Δδ15Nroot-leaf) of the maize hybrid was the same as that of δ15N between the roots and stems (Δδ15Nroot-stem). Therefore, the order of Δδ15Nroot-leaf as well as Δδ15Nroot-stem was as follows: Δδ15Nroot-leaf of the maize hybrid>Δδ15Nroot-leaf of the female parent (T4)>Δδ15Nroot-leaf of the male parent (803) and Δδ15Nroot-stem of the maize hybrid>Δδ15Nroot-stem of the female parent (T4)>Δδ15Nroot-stem of the male parent (803). This order is consistent with heterosis, indicating that differences in δ15N reflect the phenomenon of heterosis. The present study provides data in support of using the isotope technique to determine nitrogen distributions inside a plant and guide crossbreeding.