Using genomic slot blot hybridization to assess intergeneric Saccharum x Erianthus hybrids (Andropogoneae-Sacoharinae)

The use of genomic slot blot hybridization enabled the differentiation of hybrids from selfs in Saccharum x Erianthus intergeneric crosses in which Saccharum was used as the female parent. Based on the genomic in situ hybridization technique, slot blots of DNA from the parents and the progeny were blocked with the Saccharum parent DNA and hybridized with the labelled male Erianthus genomic DNA. This technique allowed a rapid screening for hybrids and was sensitive enough to detect a 1/20 dilution of Erianthus in Saccharum DNA, which should enable the detection of most partial hybrids. The genomic slot blot hybridization technique was shown to be potentially useful for assessing crosses involving Saccharum species with either Old World Erianthus section Ripidium or North American Erianthus (= Saccharum) species. The effectiveness of the technique was assessed on 144 progeny of a Saccharum officinarum x Erianthus arundinaceus cross, revealing that 43% of the progeny were selfs. The importance of this test as a tool to support intergeneric breeding programs is discussed.