Evogene Seminar Thursday June 5
Understanding organ abscission as a way to regulate citrus fruit Production.
Dr. Francisco R. Tadeo
Centre de Genòmica – Institut Valencià d’Investigacions Agràries (Spain).
Summary. Citrus is one of the most important fruit crops in the world due to the large number of endogenous compounds (vitamins, minerals and phytochemicals) necessary for the human diet that are accumulated in this fruit.
Spain is the sixth citrus producer in the world (5.5 million tons in 2012) and also the world's largest exporter of citrus fresh fruit (3.7 million tons in 2012 with an exports value of 3,500 million dollars). Within Spain, the Valencia Region represents 60% of the total citrus production. The above information indicates the high economic and social value that the commercial cultivation of citrus represents for the Valencia Region. Citrus blooms profusely and the final production of fruit depends on the amount of flowers and young fruits that are detached from the tree during the fruit-set period. On the other hand, the market value of harvested fruit depends on the external and internal fruit quality and the length of the harvesting season that is determined by the decline in the fruit retention force during the fruit ripening period. The harvest of citrus fruit in the Valencia Region is carried out entirely by hand because citrus production is dedicated almost completely to the fresh citrus market. However, the cost of harvesting labor of fruits destined to processed products (juices and concentrates) could be reduced by using mechanical fruit harvesting systems. The efficiency of these systems could be increased using fruit loosening chemicals. In addition, these chemicals could also be used to facilitate the shedding of unmarketable fruit remaining on the trees as a way to improve cultivation practices and reduce citrus cultivation costs. The physiological process that activates the detachment of organs from the plant body is called abscission. In this talk I would like to show you our results on gene expression in a group of functionally specialized cells responsible of organ abscission known as abscission zone during ethylene-promoted citrus fruit abscission and during differentiation and activation of the abscission zone located in the style of the citrus flower.