Enhanced resistance to common scab of potato was obtained by somatic cell selection. An added bonus identified concurrent enhanced resistance to powdery scab, however the mechanism of resistance was not known. This study sought to compare parental cv. Russet Burbank to three disease resistant somaclonal variants. Glasshouse and field experiments tested the performance of these clones in the presence of two soil-borne pathogens, Streptomyces scabiei and Spongospora subterranea f.sp.subterranea. Histological (Fluorescent microscopy) and molecular methods (qRT-PCR) were used to identify the thickness of phellem (periderm) layer, degree of phellem and lenticel suberisation and relative expression of three suberin synthetic genes (CYP833A, StKCS6 and POP_A) from pathogen treated tubers. The variants showed a greater degree of phellem suberisation, and up to 7-fold increased expression of the suberin gene StKCS6 compared to the parent. We hypothesize that this suberisation provides an enhanced physical structure and important barrier for pathogen invasion into tubers and is important for enhanced resistance to common and powdery scab.

Item Type:	Conference Extract
Research Division:	Biological Sciences
Research Group:	Plant Biology
Research Field:	Plant Pathology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Horticultural Crops
Objective Field:	Vegetables
UTAS Author:	Thangavel, T (Dr Tamil Thangavel)
UTAS Author:	Tegg, RS (Dr Robert Tegg)
UTAS Author:	Wilson, CR (Professor Calum Wilson)
ID Code:	78703
Year Published:	2012
Deposited By:	Tasmanian Institute of Agriculture
Deposited On:	2012-07-22
Last Modified:	2014-04-11
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