The 8-6-6 –Months Protocol: A Quick Method for Field Screening of Sugarcane to Smut

Abstract

This field study was conducted at the Sugarcane Research
Centre at Guneid (latitude 150 N, longitude 330
E) for two consecutive
seasons (2007/08 and 2008/09). The objective was to evaluate and
validate the suitability of a new improved field evaluation method (IFEM)
in comparison to the conventional field evaluation method (CFEM) which
is widely used by pathologists worldwide in identifying resistant
sugarcane genotypes to the smut disease. Nine sugarcane genotypes were
tested, and sugarcane varieties CO 527, CO 997 and CO 6806 were used
as checks. These experimental materials were inoculated artificially by
two methods viz: i) Dip method (DM) and ii) Taiwanese pin-prick
method (TPPM). Smut resistance evaluations by the new improved 8-6-6
field evaluation method, which took 20 months, identified 10 genotypes
as highly resistant (HR) or resistant (R) using TPPM and 12 genotypes as
HR or R using DM. The conventional 12-12-12 method (CFEM), which
requires 36 months to complete, identified 9 genotypes as HR or R using
TPPM and 10 genotypes as HR or R using DM. Differences between
CFEM and IFEM were not significant in both DM and TPPM. Therefore,
IFEM can be used confidently for routine evaluations of sugarcane
germplasm as an alternative to CFEM, to efficiently save time and land.