Plant resistance to canegrubs : SRDC final report BSS132

Abstract

The project sought to determine the range and types of resistances to feeding by canegrubs in sugarcane clones and their wild relatives. Resistance was tested in both pot trials and field trials and the importance of several biochemical factors in this resistance was investigated.Field and pot trials showed that a range of tolerance and antibiosis resistance mechanisms to canegrub feeding exists within the current sugarcane genome and close relatives. Tolerance effects were apparent in the growth of tops, roots and stubble. Antibiosis effects were apparent on grub survival and grub growth. Some of these tolerance effects are partially correlated with the general vigour of clones, but there are a number of clones that depart from the general relationships for tolerance and antibiosis. These clones would be especially important in any future program to increase the levels of resistance within the breeding gene pool.There was reasonable repeatability of pot-based tolerance levels between pot trials and with results derived from field trials. However, the type of canegrub and its underlying biology influenced the usefulness of field trials.Biochemical investigations showed no clear relationships between any factor and antibiosis phenotypes. However, there were indications that the type of cell-wall sugars may influence resistance to canegrubs. In addition, the data clearly indicated that the quantity and type of phenolic compounds in the roots change following feeding by canegrubs.