GENOME OF SUGARCANE:

                                                                  

Genome of sugarcane

• Sugarcane pic

Sugarcane is an important crop that contributes significantly to the global sugar industry. The complex genome of Sugarcane (Saccharum spp.) consists of genes derived from S. spontaneum L. and S. officinarum L., with lesser assistance from S. sinense Roxb. Amend. Jeswiet and S. barberi Jeswiet. The aneuploid and highly polyploidy nature of interspecific hybrids is related to the problems of controlled hybridization. In this article, we will discuss the various aspects related to the genome of sugarcane.

Basic Chromosome

The basic numbers of chromosome Saccharum genus, giving x=10 for SO and x=8 for SS have been explained by current cytogenetic studies. The genomic composition of sugarcane is explained 1, multiple chromosome types (So, R, and Ss); 2, chromosomal assignment in the homology group (HG); 3, the low source substance and various basal rates.

Diseases

Sugarcane production can be affected by several crop diseases, with common conditions including brown leaf rust, smut, red rot, stem canker, sugarcane mosaic virus, leaf spot, pookah ,dull etc. These diseases are caused by different pathogens such as bacteria, viruses, fungi, and nematodes. Other factors also involve lowering sugarcane yields as nutritional shortage, regional effects, physiological defects, and environmental factors. Sugarcane has two main rust diseases, brown rust disease, and orange rust disease. The use of resistant cultivars plays an important role in the control of rust diseases.

Symptoms

In sugarcane, the initial symptoms of rust disease appear on both surfaces of the leaves, which are small in size and in elongated form, yellowish, and brown to orange-brown or red-brown spots. The elongated spots size about 2 to 10 mm in length, but rarely reach 30 mm, because the death of immature leaves is caused by leaf necrosis in severe infections.

Control Disease

In sugarcane crops, using various cultural practices and fungicide sprays really helps to control and decrease rust disease and its effects and frequencies. The removal of susceptible cultivars is necessary for the development of rust resistance cultivars, however, breeding has played the most important method for controlling and reducing economic losses in plant diseases. In the past times, the development of molecular marker tools has brought a revolution in the analysis of the molecular biology of sugarcane. The identification of desired characters in plant breeding programs, and molecular tools have also been practiced effectively.

Bru1 Resistance Gene

Presently two most important resistance genes identified in sugarcane are, Bru1 can control leaves sporulation of fungus infection. For the First time, the Bru1 resistance gene was discovered in the R570 cultivar. The Bru1 showed the best resistance range against rust isolates accumulated from different geographic locations including Colombia, French, Guadeloupe, Brazil, West Indies and the Mascareign, Florida, and Reunion Island (three isolates). Through gene mapping, it was confirmed that Bru1 is the major gene and identified markers 1.9 and 2.2 cm of the gene.

In a sample of 380 modern cultivars, the Bru1 gene was 86% identified commonly in brown rust-resistant clones and breeding resources facing worldwide diversity. Use of these methods to apply Bru1 in marker-assisted selection and breeding in order to improve brown rust resistance in sugarcane.

In conclusion, the genome of sugarcane is complex, and its susceptibility to various diseases can cause significant economic losses. The identification of resistant cultivars and the development of molecular tools have played a significant role in controlling and reducing economic losses in plant diseases such as rust disease. The Bru1 resistance gene has proven to be an effective tool in marker-assisted selection and breeding to improve brown rust resistance in sugarcane.