Heritability of resistance to ratoon stunting disease in sugarcane.
Studies were conducted to evaluate the effectiveness of tissue-blot enzyme immunoassay (TB-EIA) as a method for screening for the ratoon stunting disease (RSD, Clavibacter xyli subsp. xyli) in a sugarcane breeding programme and to investigate the genetics of resistance to RSD. The three experiments contained different genetic material and were relevant to different selection stages in the programme. In the genetics test 37% of the total variance was among clones within families, 4% was among families, and 59% was environmental. Since most of the genetic variance was among clones within crosses, it is tentatively concluded that a rational breeding strategy for RSD resistance will put greater emphasis on parental selection for agronomic quality rather than on selection for RSD resistance. It is apparent, however, that the strategy for breeding for resistance to RSD will remain transitory until more data from more crosses are available.