Traits that we have studied so far fall into a few easily distinguishable classes that we use to foretell the genotypes of the individuals (McClean, 1997).
Mendel toiled with traits that were all discrete, example of such traits were yellow or green, round or wrinkled, etc. A phenotype can be predicted from the known genotype and various alleles give distinctly discernible phenotypes (McClean, 1997). These types of phenotypes are known as discontinuous traits. However, many traits don’t fall into discrete categories since a continuous distribution of phenotypes is found. The distribution is similar to the bell-shaped curve for a normal distribution. These types of phenotypes are known as continuous traits and are studied differently compared to discontinuous traits. Examples of these traits are learning ability in humans, weight gain in animals or ear length in corn. These traits are regulated by multiple genes, each separating according to Mendel's laws and can also be influenced by the environment to varying levels (McClean, 1997).
Since continuous traits are frequently calculated and given a quantitative value, they are commonly referred to as quantitative traits. Thus, quantitative genetics is known as the area of study of inheritance of consistently calculated traits and their mechanisms (McClean, 1997).
Today, famine is rare because the management of quantitative traits has brought about a major increase in crop yield in the past 80 years. The yield is the most essential and intricate trait for the genetic improvement of crops as it displays the interaction of the environment with all the advance procedures that occurs throughout the life process (2). This was the most profitable feature of genetics until not long ago.
It was disputed that quantitative traits worked through a genetic methodology quite unrelated to Mendelian genetics early in the former record of genetics. However, this idea has been rebutted, and the theory of quantitative genetics has been proven to be based on Mendelian principles (McClean, 1997).
Amid the genetic perspectives used to enhance yield potential, “ideal-type breeding” was utilized to alter the plant architecture (morphology); for example, the improved rice cultivar IR24 has additional tillers, decreased plant height and erects leaves. In order to improve rice plant architecture, rice breeders have harnessed natural variation in cultivars. For example, incorporating the recessive gene sd1 from the Chinese variety Dee-geowoo-gen, decreased plant height, and combining the photoperiod-insensitive gene se1 elevated rice adaptability to an extensive range of latitudes (3).
The demand for rice varieties with higher yield capacity and prominent yield stability has steadily rise due to growing human population and changing worldwide climate despite the genetic variants playing an essential role in the noticeable growth in crop production. To further intensify the yield potential of rice over that of prevailing...