Morphological structure of rice

Morphological structure of rice

The Rice plant consists of two main organs. They are vegetative organs and reproductive organs. The vegetative organs include roots, stems, leaves, sheaths, auricles, and ligules. The reproductive organs are the panicles, flowers, and grains. 

Vegetative structures

Roots - 95% of the roots can be found in the top 0.2m of the soil (Wopereis et al, 2009) and the roots are always under flooded conditions. Roots help in anchoring rice plants to the soil and for the absorption of nutrients from the soil.

Stems – stem is composed of nodes and internodes. Internodes are hollow structures with smooth surfaces. The internodes located at the lower part of the stem are shorter than the internodes at the top leading to more resistance to lodging.

Leaves – The leaves are located alternatively on the stems and always one leaf for one node. They capture solar radiation and contribute to photosynthesis. The solar radiation absorption of different rice varieties differs depending on the leaf architecture.

Sheaths - This is the leaf part that wraps the leaf. There are two elements that can be found between the joints of the collar and the leaf: namely auricle and ligule.

Auricle – This structure is covered with hair and has a crescent shape.

Ligule – The shape and the length of the ligule depend on the variety and rice is the only Poaceae plant with both auricle and a ligule.

Reproductive structures

Panicle – The rice inflorescence is carried by the panicle and it is the top part of the rice plant and the last internode. The studies have shown that one panicle can bear around 50 – 500 spikelets. But the spikelets of cultivating rice varieties range from 150 – 350.

Flowers – Rice flowers are self-fertile. The flower contains both male reproductive structures and female reproductive structures.

Grains – This is comprised of three structures. One is the rice envelope known as glume and there are two husks known as palea and lemma.