A Comprehensive Review of Sugarcane

Sugarcane is an important industrial crop of semitropical and tropical areas. Due to the importance of this crop it is cultivated on nearly 20 million hectares by more than 90 countries. This crop belongs to family Poaceae , a grass family which is economically vital tracheophyte family that has properties much like that of wheat, maize, rice and sorghum. The Poaceae family is globally vital for providing dietary macromolecules, carbohydrates, and different nutrients. The most important item of sugarcane for the consumption is sucrose that gets accumulated in the stalk internodes. Sucrose is taken out and refined by different mills which is used as a sweetener in human food industries and in the fermentation industry. Large production of alcohol is attained by Brazilian sugarcane industries.


Introduction
The capability of sugarcane to accumulate high level of sucrose and vegetative propagation ability make it most important crop among others (Welbaum and Meinzer, 1990; Dillon et al., 2007).
World generation of this crop in 2011 brought about around two billion tons of crude material, which related to a gross pay of more than US$ 52 billion (Tilman et al., 2011). Despite the importance of this crop there are still lots of challenges related to genetic mechanism due to most difficult genome, with diploid numbers ranging from 100 to 130 chromosomes, showing a high ploidy level, and also consistent aneuploidy events (Jannoo et al., 2007). Owing to this complexness, the use of molecular tools represents a gorgeous approach to the development of sugarcane breeding programs.
The high concentration capacity of sucrose in sugarcane makes it most valuable crop among the tropical and subtropical sides. It is necessary to identify the genes that are responsible for control and sucrose accumulation in sugarcane would provide attractive tools for increasing the concentration of sugar by either using genetic modification and selection strategies (Iskandar et al., 2004). Recently, by the analysis of expressed sequence tags (ESTs) several expressed genes have been detected in different tissues of sugarcane ( Vettore et al., 2001). Through the macro or microarrays technique a number of gene expressions can be analyzed ( Meotti et al., 2003) and by use of these strategies the expressed genes in the mature and immature stems and tissues of the sugarcane have been identified (Iskandar et al., 2004).

Sugarcane cultivation
Sugarcane producing countries of the world lie between 36 0 N and 31 0 S of the equator reaches out from tropical to semitropical zone. Worldwide in 107 nations, sugarcane possesses territory of 20.42 million ha with an aggregate production of 1333 million tons (Natrajin, 2005). Sugarcane territory and profitability vary broadly from country to country. Brazil has most astounding zone (5.34 million hectare) while Australia has most elevated profitability (85.1 t ha-1). The biggest makers are Brazil, India, China and Pakistan accounting over half of world creation (Qureshi and Afghan, 2005).
World largest producer of sugarcane is Brazil with around 4.5 million hectares planted in northeastern and southeastern region of the country (Galvao et al., 2005). In Brazil, sugarcane is involved to get sugar, anhydrous alcohol (gasoline additive) and hydrous alcohol (natural, clean and renewable pure fuel for vehicles) for the inner external markets (de Oliveira, 2002). To 3 enhance the productivity of the Brazilian business, new verities of sugarcane with higher yields are persistently created and tried. A perfect sugarcane verity should adopt environmental variation like climate, soil type and cutting season (Badaloo et al., 1999;Bissessur et al., 2000). It also should have immune to pest, disease and draught conditions having high concentration of sucrose in their tissues (Croft et al., 2000). According to 2018 data the top ten sugarcane producing countries are following.

Sugarcane modification
Traditional strategy like breeding is not so effective for the resistance improvement due to the lack of information related to stress tolerance trait. Therefore, world demand cannot be full fill because The term housekeeping gene was earlier often used to define a gene that was anticipated to be essential and stably expressed in the cell and, thus, generally accepted for normalization without the need for experimental evidence for its stability. This is in contrast to the term reference gene, which should be reserved for genes that are experimentally found to be stably expressed in given A reference gene always expressed regularly with minimal change in their expressions and has no experimental effect on them (Dean et al., 2002). In some studies the activities of these genes showed that, it can go through stability changes in different abiotic stress conditions (Nicot et al., 2005).Study showed, GAPDH,eukaryotic elongation factor alpha1 and eukaryotic elongation factor alpha4 showed the most stable activity in multiple genotypes coressponding to the different