Maize, also called “Indian corn,” is a strong annual plant that is grown during the rainy season for its grains. In some parts of India, it is the main food. The roots are of a type called fibrous adventitious. After the seed germinates, the primary root dies, and new, fibrous roots grow from the base of the stem.
The stems are thick and solid, and they have clear nodes and internodes. The leaves are simple and have full margins. They are quite large, linear, and are arranged in pairs. The arrangement is 2-ranked or distichous. They have a leaf base that wraps around a part of the internode above it (Figure 1).
At the point where the base and the blade meet, there is a membraneous ligule. Venation is parallel. All of the organs have a rough surface because silica is mixed in with them. There are two kinds of inflorescences: the terminal staminate compound raceme or panicle, and the axillary pistillate spadix.
The male inflorescence is made up of numerous spikelets. The spikelets grow in pairs, with the lowest one sessile and the higher stalked. Every spikelet has two flowers. They include four glumes.
The first and second glumes are sterile, while the third, known as the flowering glume, and the final, the two-nerved palea, surround a flower. Flowers are clearly unisexual. Lodicules are fleshy scale-like entities that resemble the perianth. Androecium is made up of three free stamens with distinctive long linear anthers.
Figure 2: Maize 1) Dissected male flower, 2) Carpel of female flower.
A spadix, or female inflorescence, grows from the axil of a lower leaf. A significant number of spikelets are placed densely along the fleshy axis, creating cob. It is still encircled by a few big hyaline bracts known as spathes.
Like the male spikelets, each spikelet bears two flowers and protecting glumes. The higher blossom is normally viable, whereas the lower one aborts. Lodicules are not present. Gynoecium is a monocarpellary organ. The ovary is superior, one-chambered, and oval in form, containing a single anatropous ovule. The hair is long and smooth. Persistent styles hang out in tufts from the cob’s apex. Stigma is feathery and lengthy (Figure 2).
Figure 3: Cob (Pistillate in Florescence) of maize
Wind pollinates flowers. Small powdery pollen grains are readily captured by the carpel’s feathery stigma. Fertilization occurs as a natural process. Fruit is a caryopsis with a single tightly fitting seed in which the fruit wall and seed-coat are inseparably joined.
A significant number of grains, or fruits, remain firmly packed on the spongy axis (Figure 3). The seeds contain albumin. The absorbing organ is the solitary cotyledon, scutellum. Hypogeal germination occurs.
The plant is the most visible generation, with diploid (2N) chromosomes in the nucleus of the cells, and “the gametophytes with haploid (N) chromosomes are represented by embryo-sac and pollen tube’.
They are tiny, shrunken, and reliant on the sporophyte. Gametophytic generation starts with reduced division in microspore-mother cells and megaspore-mother cells, followed by the creation of microspores and megaspores. It is repaired with fertilisation ‘2n’ number and sporophyte begins.