ABSTRACT.
MORPHOANATOMIC STUDY OF A YELLOWING DISEASE OF GRAPES (Vitis vinifera L.)

Paulina Sepúlveda R.1, Mario Alvarez A.2, Claudia Botti G3, Jorge Valenzuela B.2 y Gonzalo Sepúlveda R.4
 

Symptoms development of a yellowing disease was studied in eight-year-old grapes cultivar Moscatel de Austria in a vineyard of El Tambo, Elqui, Chile. Macroscopic and histological symptoms were described. Moscatel de Austria obtained from the Experimental Station of INIA at Vicuña was used as healthy control.
The symptoms of the disease appeared on the leaves, fruit clusters and shoots, and were characterized by methalic yellow on some areas of leaf blades, die-back of tip shoots and fruit clusters. Also, a deep brown vascular discoloration was observed in trunks, arms, canes and petioles.
Histological analysis of leaves, canes and petioles of diseased grapes showed that the damage affected the xylematic tissue. A strong staining of fibers and presence of tyloses in the active xylem, specially in 2 year-old canes was observed. The phloem of diseased plants showed no alteration.

Keywords:
1Ingeniero Agrónomo.
2Ings. Agrs., Ph. D., Programa Frutales y Viñas, Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias, (INIA), Casilla 5427, Santiago, Chile.
3Ing. Agr., Profesor adjunto Morfoanatomía Frutal de Postgrado. Producción Agrícola, Fac. de Agronomía, Universidad de Chile, Casilla 1004, Santiago, Chile.
4Ing. Agr., Programa Frutales y Viñas, Subestación Experimental Vicuña, Instituto de Investigaciones Agropecuarias, (INIA), Casilla 73, Vicuña, Chile.