Comprehensive studies on school and root system development in cereal crops

用作者开发的新指标研究了水稻叶原基的形成和发育及叶片出苗。这些研究阐明了地上部发育的规律性，同时也揭示了根系发育的规律性，表明可能对产量有贡献的根系的大小和分布格局是在穗形成期以后形成的，并采用剪叶法进行试验，寻找地上部与根系发育的密切关系。结果表明，光合作用和水分对小麦生长发育可能有贡献。对小麦分蘖发育的研究表明，密度的影响是存在的。也证实了地上部发育与根系发育是同步进行的。小麦的根系由伸长到深层的种子根和分布在表层的节根组成。灌水等管理措施对种子根的分枝程度和节根的大小及分布均有较大影响。研究发现，从营养生长期到生殖生长期的过渡是决定整个植株组织结构的一个重要因素。叶片、茎和根的大小和形状反映了植物身体的发育，包括相变。根的分枝也被检测到。

Formation and development of leaf primordial and leaf emergence in rice were examined with the new index developed by the authors. Those studies clarified the regularity in the shoot development.At the same time, the regular development of root system.It was shown that dimension and distribution pattern of root system which have possible contribution to yield were formed after panicle formation stage.Also the leaf-cutting method was used for the experiments to find the intimate interrelation between shoot and roots development. Those results suggested the possible contribution of photosynthesis and water relation to growth and development.Studies on the development of tillers of wheat showed the existence the effect of the density. It was also confirmed that the shoot development proceeded with root system development synchronizedly. Root system of wheat was clarifed to be composed of seminal roots elongateing into deep soil layers and nodal roots distributed in surface soil layer. Management practices including irrigation and so on had great influences on both branching degree of seminal roots and the dimension and distribution of nodal roots.Development of maize was examined using the new index proposed by the authors. It was found that organization of the whole plant was determined with special references to transition from vegetative phase to reproductive phase. Size and form of leaf,stem and roots reflect the development of plant body including the phase transition.Branching of roots was also examined.