The resistance of guar (Cyamopsis tetragonoloba (L.) Taub.) to attack by the root parasitic Alectra vogelii (Benth.)

Abstract

The nature of the resistance of guar to attack by the root parasitic A. vogelii was investigated, it was found that although seed of the parasite was induced to germinate in the presence of stimulants, radicle elongation was prevented owing to substances inhibitory to the germination Of Amaranfhus caudal us (L.). This effectively prevented penetration of the parasite into the tissue of the host. In this way guar couid act as a catch crop by eliminating A, vogelii seed from the soil in a process of suicidal germination. Indications of a resistance to penetration was also found. Chromatographic investigation of the stimulant as well as the inhibitor revealed almost co-eluting compounds on a Fractogel column.