Correlations between in vivo resistance to Fusarium and in vitro response to fungal elicitors and toxic substances in carnation

Abstract

With the aim of ascertaining the existance of a correlation between in vivo resistance to Fusarium oxysporum f. sp. dianthi and in vitro response to fungal elicitors and toxic substances, phenylalanine ammonialyase and phytoalexin accumulation, on one hand, and resistance to culture filtrate, on the other, were assayed in "in vitro" cultures of three susceptible and four resistant Dianthus caryophyllus cultivars. Cultivars showing varying degrees of resistance in vivo either tolerated higher culture filtrate concentrations ('Niki') or showed high PAL activity and phytoalexin production when treated with Fusarium elicitor ('Duca'), or responded positively to both treatments ('Mei-Ling', 'Pulcino'). No such responses were shown in tissue cultures of susceptible cultivars. The differential response to the fungal elicitor seemed to be highly specific as genetic differences between cultivars were not observed in tissue cultures treated with other biotic (Phytophthora infestans) and abiotic (HgCl2) elicitors.

Selection of turmeric callus tolerant to culture filtrate of Pythium Graminicolum and regeneration of plants

“…Hence, in the present study continuous in vitro selection technique was adopted for early screening and selecting of tolerant cell lines under culture conditions. This agrees with the findings of Buiatti et al, (1985). This confirms the usefulness of callus as a source for either selecting or recovering root rot disease tolerant clones in turmeric.…”

Selection parameters for resistance to Fusarium oxysporum f. sp. cubense race 1 and race 4 on diploid banana (Musa acuminata Colla)

“…dianthi interaction using two different systems, i .e . culture filtrate and fungal cell wall elicitor, showed that the latter is a more efficient experimental system for the identification and characterization of susceptible and tolerant responses in the host plant (Buiatti et al ., 1985(Buiatti et al ., , 1987 .…”

The use of excised roots from in vitro culture for the determination of superoxide production in plants

“…About 200 mg of roots from axenic culture were used for measuring superoxide release by evaluating the reduction of exogenously supplied Cyt c. The concentration of Cyt c used was 2 mM. Each data point is the average of three independent measurements glucose equivalents) extracted as previously described (Buiatti et al 1985). Superoxide measurements thus obtained were found not to be reliable due to the intrinsic characteristics of the elicitor solution (colour, turbidity and high pH) that severely hampered both the colorimetric reaction and the enzymatic activity of SOD.…”