Effects of Diverse Pretreatments on Seed Germination in Cleome gynandra L. (Capparidaceae) - A Threatened Species, Collected from Different Agro-Ecological Zones in Benin

Abstract

A b s t r a c t A r t i c l e I n f oWe analyzed in preliminary survey the behaviour of Cleome gynandra vis-à-vis germination characteristics as initial goal in any subsequent program towards its conservation and rehabilitation. To optimize seed germination, the influence of four different chemical treatments (drinkable water, distilled water, potassium nitrate [KNO 3 ] solutions 2 and 5 gL -1 ) on the seed germination parameters in three provenances collected in the main agro-climatic zones in Benin was examined. Final germination rate, germination speed and kinetics were analyzed and the data submitted to ANOVA. Kruskal-Wallis non parametric test were used to identify and classify treatments and accessions. Results revealed significant differences between them for all parameters. Germination capacity reached 72.00, 23.66 and 8.00% within Pop 16, Nord 14 and Sud 13, respectively when seeds were treated in KNO 3 5 gL -1 . Treatment KNO 3 2 gL -1 revealed the weakest germination capacities and no significant difference were noted anymore between Pop 16 and Sud 13 (TG=12.00%). Distilled water permitted to get meaningful differences between populations, and delivered best results compared to tap water and KNO 3 2 gL -1 . Little difference was noted for the germination speed (VG=0.17-0.18 seed/day) whatever the treatment. Germination capacity varied very significantly between treatments and accessions. Germination speed varied rather between accessions and less between treatments. Interactions Accession×Treatment were very significant for all estimated parameters indicating a relatively important contribution of the treatments to the phenotypic expression.