ABSTRACT

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.

摘要

了解玉米杂种中氮稳定同位素的变化可能有助于获得有关不同玉米杂种中氮吸收和分布的信息。在这项研究中，我们通过实验室培养实验研究了玉米杂交种不同部位的氮同位素组成。结果表明，玉米杂交种及其亲本不同部位的δ15N值依次为：δ15Nstem>δ15Nleaf>δ15Nroot。玉米杂交种的根与叶之间的δ15N（Δδ15N根-叶）的变异模式与根与茎之间的δ15N（Δδ15N根-茎）的变异模式相同。因此，Δδ15Nroot-叶和Δδ15Nroot-叶的顺序如下：玉米杂种的Δδ15Nroot-叶>雌性亲本的Δδ15Nroot-叶（T4）> 雄性亲本的Δδ15N根茎（803）和玉米杂交体的Δδ15N根-茎>雌性亲本的Δδ15N根-茎（T4）>雄性亲本的Δδ15N根-茎。该顺序与杂种优势一致，表明δ15N的差异反映了杂种优势现象。本研究提供的数据支持使用同位素技术确定植物内的氮分布并指导杂交。