Avocado Sunblotch Viroid (ASBV) is an important disease affecting avocado trees. A disease is an abnormal condition of the body or mind that causes discomfort, dysfunction, or distress to the person afflicted or those in contact with the person. ... Binomial name Persea americana Mill. ... The coniferous Coast Redwood, the tallest tree species on earth. ...

Infections result in lower yields and poorer quality fruit. ASBV is the smallest known viroid that infects plants and is transmitted by pollen and infected seeds or budwood. Infected (Podcast) is also the name of an internet radio podcast hosted by Martin Sargent. ... Families Pospiviroidae Avsunviroidae Viroids are infectious agents that consist of single-stranded RNA. They are much smaller and simpler than viruses and lack the protein cover that is typical for viruses. ... SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomea purpurea), hollyhock (Sildalcea malviflora), lily (Lilium auratum), primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ... A ripe red jalapeno cut open to show the seeds For other uses, see Seed (disambiguation). ...

Trees infected with the viroid often show no symptoms other than a reduction in yield, (by 30% or more). However, they are still carriers and can pass the disease onto other plants. Symptoms in more serious infections include depressed longitudinal streaks of yellow in the fruit. The fruit may also become red or white in colour. Symptoms in the leaf are uncommon but include bleached veins and petioles. Rectangular cracking patterns also occur in the bark of older branches. A petiole (also called a pedicel) is the first abdominal segment of members of the Apocrita. ...

The amount (titre) of viroid particles present in avocado trees varies a great deal. Viroids levels can vary by 1000 times between branches on the same tree and by 10000 times between trees. Infected but symptomless trees have a higher concentration of viroid particles than those showing symptoms. Symptomless trees also represent a greater danger in terms of spread of the viroid. A titer (or titre) is the unit in which the analytical detection of many substances is expressed. ...

PCR is used to detect infection. Polymerase chain reaction (PCR) is a molecular biology technique for enzymatically replicating DNA without using a living organism, such as E. coli or yeast. ...

References

• ARC- Institute for Tropical & Subtropical Crops