METHODOLOGY FOR SCREENING FOR RESISTANCE TO <I>BELONOLAIMUS LONGICAUDATUS</I> IN TURFGRASS
Keywords:Belonolaimus longicaudatus, bermudagrass, Cynodon spp., germplasm screening, sting nematode, turf breeding
AbstractSchwartz, B. M., K. E. Kenworthy, W. T. Crow, J. A. Ferrell, G. L. Miller, K. H. Quesenberry. 2008. Methodology for screening Belonolaimus longicaudatus in a turfgrass breeding program. Nematropica 38:163-175. Efforts to screen large numbers of turfgrass genotypes would likely result in the discovery of genes associated with resistance or tolerance to plant-parasitic nematodes. The identification of germplasm with these characteristics will become increasingly important as stringent regulations regarding the use of soil fumigants and nematicides are put into place. Therefore, a glasshouse study was initiated to investigate plant-parasitic nematode evaluation methods on 'TifEagle' hybrid bermudagrass to identify a high throughput, accurate and repeatable greenhouse screen useful to turfgrass breeding programs during sequential trials in 2007. Three establishment methods, classified as: i) conetainers grown in for 45 days (45-d conetainers), ii) conetainers grown in for 90 days (90-d conetainers), and iii) clay pots grown in for 90 days (90-d clay pots) before inoculation with sting nematodes, respectively, were assessed. Two inoculation rates, 50 and 100 mixed life stages of Belonolaimus longicaudatus/100 cm3 of soil, were compared to an uninoculated control within each establishment method. Total dry root weights were 38% and 28% larger for uninoculated treatments when compared to an average of the two sting nematode inoculated treatments in the 45-d conetainers and 90-d conetainers, respectively. Root weights were not significantly reduced by sting nematode pressure in the 90-d clay pots. Total root lengths of uninoculated treatments were 57%, 55%, and 31% greater than an average of the two inoculated treatments in the 45-d conetainers, 90-d conetainers, and 90-d clay pots, respectively. Results were generally more variable for treatments grown in 90-d clay pots and some root length characteristics were not consistent between trials in the 90-d conetainers. Quantifying root damage using 45-d conetainers inoculated with 50 sting nematodes provided reproducible results characteristic of those reported in other greenhouse and field evaluations.