2.4. Experimental design and data analysis Number of embryos were recorded after 12 weeks of culture. Each treatment was repeated twice and each treatment con- sisted of 5 replicate culture tubes, each containing three proto- corms. Data were subjected to analysis of variance (ANOVA) and comparisons between the mean values of treatments were made by the Duncan multiple range test calculated at the con- fidence level of P 0.05. The statistical package SPSS (Version-17) was used for the analyses (see Tables l and 2)