Rice (Oryza sativa L) belongs to
the family Poaceae. The basic chromosome number of rice is n=12. The species
can be either diploid or tetraploid. In this respect, Oryza sativa L. and Oryza
glaberrima L both are diploid species (2n= 24). The Asian cultivated rice
(Oryza sativa L) is the first fully sequenced crop genome and is a model crop
species.
Rice is considered as a major
food crop across major countries worldwide. As a food crop, it forms the staple
food of more than three billion people accounting for about 50-80% of their
daily calorie intake. It yields about one third of the total carbohydrate
source. It provides the considerable amount of recommended Zinc and Niacin.
Rice protein is biologically richest as its digestibility is very high (88%).
It is the 2nd most important crop
in the world after wheat, covering almost 90% of area across Asia alone. The
use of the crop varies widely ranging from its use as food in cereals, snacks,
brewed beverages, flour, rice bran oil to its use in religious events across
India. The medicinal value of the crop adds on more to the list.