In disease diagnosis, Cenicaña bets on precision

Currently, Cenicaña has advanced methodologies and diagnostic techniques that allow to accurately detect diseases or pests that could affect sugar cane crops and avoid any risk of multiplication of infected seed. 

Currently, Cenicaña has advanced methodologies and diagnostic techniques that allow to accurately detect diseases or pests that could affect sugar cane crops and avoid any risk of multiplication of infected seed. 

One of the Center's greatest advances in recent years with regard to disease diagnosis is the adoption, in 2010, of the molecular techniques of conventional PCR and real-time PCR, which make it possible to determine, as in the case of the leaf virus yellow, the existence of a few cells or particles of the pathogen in the tissue and when this occurs the sample is considered infected and is therefore rated positive.

From that moment on, the concern over techniques that offered not very precise results was over, since a sample was only supposed to be infected when the infection levels were higher than the detection levels of the techniques used. In 1984, for example, methods were used that detected 50 million cells / ml of juice, in such a way that if the analyzed sample was infected, but had less than that number of cells of the pathogen, the sample was considered negative for the presence of the illness.

For this reason, the development and use of techniques that had greater sensitivity was passed. One of them had the sensitivity to diagnose the presence of the pathogen when it was in amounts greater than 30,000 cells / ml in juice.

However, using the diagnostic techniques of conventional PCR and / or real-time PCR, the results delivered to the growers are positive or negative. It is negative when the 20 leaves of the analyzed sample come entirely from healthy plants, and it is positive when at least one of the 20 leaves comes from an infected plant, which means that you have at least 5% infection.

Thanks to these diagnostic methodologies, yellow leaf virus has been detected in seedlings and commercial lots from CC 01-1940 and SP 71-6949, and when the samples analyzed have been infected they have been rejected as a source of seed and discarded for multiplication.

However, with the results of these diagnoses it cannot be concluded that a variety is resistant or susceptible to a disease. For this, tests are carried out with the mentioned varieties, from which their resistance levels and susceptibility to yellow leaf virus will be defined.

Source: Cenicaña Variety Program