Impact of raw and pure saponins of six alfalfa ecotypes on Ditylenchus dipsaci egg hatching

The stem and bulb nematode, Ditylenchus dipsaci, is an important and damaging pathogen in a number of agricultural and ornamental plants, including alfalfa. The aim of this study was to investigate the effect of raw and pure saponins of six alfalfa ecotypes on the hatching of this nematode's eggs in order to find a biological method for its management.

The effect of raw and pure saponins of six alfalfa ecotypes on the hatching of stem nematode eggs was investigated in a completely randomized factorial design with two factors of alfalfa ecotypes (six ecotypes) and their saponins (raw and pure) in vitro.

Analysis of variance showed that the interaction effect between two factors, ecotype and saponin, is statistically significant. At concentrations of 50 and 90 microliters of crude saponin from different ecotypes, 30-42% and 33-59% of the nematode eggs did not hatch, respectively. The Nishaburi ecotypes caused the most and the Shiraz and Khrisari polycross caused the least number of egg hatching. Concentrations of 10 and 50 microliters of pure saponin resulted in between 56 and 69% and 61 and 79% of total nematode eggs failing to hatch, respectively. The local ecotypes Miandoab and Nishaburi had the highest and Shiraz Polycross the lowest number of egg hatches.

Pure saponins of alfalfa ecotypes have a greater effect on nematode egg hatching than raw saponins. Saponins of Shiraz Polycross alfalfa ecotype have a better effect than other ecotypes.