Effect of protease inhibitors on physiological and biochemical changes influencing keeping quality in gladiolus

Abstract

An experiment was conducted to evaluate 30 gladiolus varieties for their keeping quality in the field (field life) and also under laboratory conditions during 2011–12. It was found that the varieties Big Time Supreme and Jackson Ville Gold recorded the maximum keeping quality in terms of field-life and vase-life (15.67, 13.67 and 13.67, 12.67 days, respectively). Minimum keeping quality was observed in the varieties Purple Flora (7.33 and 5.67 days) and White Friendship (8.00 and 6.33 days). The variety Big Time Supreme recorded highest floret diameter (10.30 cm) whereas minimum was recorded in Purple Flora (5.75 cm). The maximum vase water uptake was recorded in Jackson Ville Gold (63.00 ml) and Big Time Supreme (59.67 ml), whereas minimum was observed in Purple Flora (30.33 ml) followed by White Friendship (34.00 ml). Water uptake showed positive correlation with the vase-life. In another experiment, five protease inhibitors, viz., 5-sulfosalicylic acid, Nethylemaleimide, aprotinin, leupeptin and E-64 were evaluated their effect on increasing the keeping quality of gladiolus cut spikes. It was found that 5-sulfosalicylic acid resulted in improvement of vase-life irrespective of the variety (12.33 day) over control (9.58 day) followed by N-ethylmaleimide and aprotinin (10.33 day each). The protease activity was found to decrease with the treatment of protease inhibitors and maximum reduction was recorded with the use of 5-sulfosalicylic acid. Similarly, the total soluble protein content was observed maximum in the same treatment.