Dataset for: Standard evaluation trial for late blight resistance documentation of CIP advanced breeding clones uri icon

abstract

  • One of the most notorious and economically devastating disease of potatoes is late blight caused by Phytophthora infestans (Pi). Pi is a hemibiotroph that can affect most parts of the potato plant, leaves stems flowers fruits stolons and tubers. Late blight is a polycyclic disease, having several cycles of infection and inoculum production during one growing season. Infection may increase proportionally to both the initial amount of inoculum and the amount of new inoculum produced during the growing season. The disease appears as water-soaked irregular pale green lesions mostly near tips and margins of leaves that rapidly grow into large brown to purplish black necrotic spots. When stems are attacked light and dark brown lesions appear that elongate and stems become brittle at lesion areas and break. Infected tuber show irregular reddish-brown to purplish slightly depressed areas that extend deep into internal tissue of the tubers. Standard evaluation trial (SET) for assessment late blight resistance in advanced clones are conducted in experimental trials under field conditions in endemic locations of the subtropical highlands. The percentage of leaf area affected by late blight infection is recorded by plot throughout the season to subsequently compute the area under the disease progress curve (AUDPC). Since AUDPC is subject to variation from factors that are experiment specific it is not appropriate for use as a measure to determine the level of resistance of a genotype across trials. However, AUDPC values are used to compute the predicted susceptibility scale value of any candidate genotype within a scale where increasing numbers represent increasing susceptibility. The predicted susceptibility scale value of any candidate genotype is calculated as the scale value of the standard cultivar (1 =for the most resistance standard cultivar -9 = for the most susceptible one) multiplied by the observed disease measure (AUDPC) of the candidate genotype divided by the disease measure (AUDPC) of the standard genotype. This predicted susceptibility scale (sAUDPC) is a disease measure used by SET for classifying potato genotypes for susceptibility to P. infestans with the advantage that its calculation is not affected by the inoculum, location, season, and host susceptibility variation. Thus sAUDPC allows to compare the level of resistance of a genotype under different environments and determine its overall performance

publication date

  • 2017