Plant Science & Physiology

Biography

Biography: Bahman Amiri Larijani

Abstract

Many higher plants, including rice, are composed of successive stem segments called phytomer. The phytomer concept has long been recognized among grass scientists. Each phytomer consists of an internode of the stem with one leaf, one tiller bud and several adventitious (nodal) roots. The coordinated development of stem, tiller bud, and adventitious roots in each phytomer corresponds to the phyllochronic time in rice. The phytomer concept has provided a sound botanical basis for understanding plant development, canopy architecture, and the dynamic nature of plant canopies in the field. The number of phytomers per axis decreased with branching order and rank. An analysis of plant dynamics showed synchronous emergence of the leaves on the main stem and on the tillers up to flowering. Axillary bud development into tillers depended on their topological location and plant developmental stage. Conclusions the timing and frequency of flowering tillers complied with rules of priority depending on their order, rank and emergence time. The tiller phyllochron differs from the main stem (MS) phyllochron during both the vegetative and reproductive phases. But leaf emergence on the MS and tiller development are nevertheless closely linked and result in synchrony between leaf emergence rates on the MS and tillers. Moreover, the final number of leaves on a rice tiller at a given position is strongly dependent on the MS leaf number. The probability of tillers reaching heading depended on their topological position and emergence time. There is synchronous appearance of tillers and leaves on the MS throughout plant development until flowering, and a relation between emergence time and tiller flowering. I found the idea of planting special ranked phytomer (internode) for faster heading and reduce the length of the growing period in rice.