The postharvest quality of Pelargonium Xdomesticum L. H. Bailey

Regal pelargoniums (Pelargonium Xdomesticum) were evaluated for: post-harvest quality in a simulated consumer environment (SCE); responsiveness to silver thiosulfate (STS) and exogenous ethylene; production of endogenous ethylene; and the presence of genetic components that condition post-harvest quality. Abscission of turgid petals was the limiting factor in post-harvest longevity. 'Parisienne' had petal abscission on almost half of its open inflorescences after 2 weeks in the SCE (3 weeks post-anthesis). In contrast, 'Lavender Grand Slam' had abscised few petals. STS (1 mM foliar application at anthesis) increased petal retention of 'Parisienne' from 56% (control) to 77% (treated).;Detached inflorescences were very sensitive to low dosages of exogenous ethylene (0.5 ppm for one hour). Ethylene increased petal abscission as much as 45% when compared to controls; this effect of ethylene was reversed by STS. Petal abscission also increased after intact inflorescences were exposed to exogenous ethylene (0.6 ppm for one hour); the longevity of 'Virginia' florets that were 3 days post-anthesis at time of ethylene treatment was reduced about 46% by ethylene. This sensitivity to exogenous ethylene was reduced by STS, and floret longevities were extended beyond those of the controls.;There was a climacteric-like rise in endogenous ethylene production from excised gynoecia (including the receptacle) as floret age increased from 1 to 12 days post-anthesis. Ethylene production increased a few days earlier and peaked at a higher level in 'Parisienne' (1.5 nl;Post-harvest quality can be used as a selection criterion in a breeding program since regal pelargoniums segregated for susceptibility to petal abscission.