Sterol Composition in Relation to Chill-Sensitivity inPhaseolusspp.

Guye, M. G. 1988. Sterol composition in relation to chill-sensitivity in Phaseolus spp.—J. exp. Bot. 39: 1091–1096. The relative composition of the free sterols campesterol, sitosterol and stigmasterol was determined in the primary leaf laminae of six bean (Phaseolus spp.) cultivars, known to differ in chill-sensitivity, prior to, during and following chilling of whole plants at 5°C for 24 h. Campesterol levels showed no significant changes during the chill-warm cycle and no relation was found between campesterol levels and chill-sensitivity. Transfer of plants from chilling to warm conditions resulted in an increase in the mol ratio of sitosterol to stigmasterol (S/S) in one of the most chill-tolerant genotypes (P. coccineus cv. Prizewinner) and a decrease in this sterol ratio in the most chill-sensitive genotype {P. aureus cv. Berken). Genotypes representing a range of intermediate chill-sensitivities (P. vulgaris cvs 251, 222 and Tendergreen) showed no changes in S/S during a chill-warm cycle. Prior to and during chilling S/S was positively related to chill-tolerance