Stability and Variability of the Herb and Volatile Oil Traits in Geranium (Pelargonium graveolens)

Geranium; (Pelargonium graveolens) is one of the important medicinal and aromatic plants in Egypt, its essential oil is rose like odor and commercially used in high-grade soaps, cosmetics and perfumes. This investigation was carried out to study the stability analysis and variability for eight herb and oil traits (plant height, fresh weight/plant, fresh weight of herb/plant, fresh weight of root/plant, volatile oil percentage, volatile oil yield/plant, herb fresh weight/fedan and volatile oil yield/fedan) in geranium (Pelargonium graveolens) by growing 3 clones which were collected from different regions of Egypt, Al-Sharkia (G1), Ismailia (G2) and Beni Suef (G3) at three seasons  2017, 2018 and 2019, in the experimental farm of El-Kasaseen Research Station, Agriculture Research Center.The results indicated that the mean performances of the three clones at three seasons for the herb and oil traits were significant variation present between all the recorded traits. Furthermore, mean squares due to environment (years) and interactions between genotypes x environments for all traits were significant, this result indicating that clones behaved differently under different years. The relatively high values of the linear regression coefficients on environmental means in clone G2 with high mean performance for fresh weight/plant, fresh weight of herb/plant and volatile oil yield/plant (b= 1.22, 1.23, 1.29, respectively) reflected the suitability of this clone to favorable conditions. The most traits had non-significant deviation from regression S²d values for G1 and G2 clones. G2 clone had the highest value of herb fresh weight/fedan and volatile oil yield/fedan (29.41 tones and 76.63 L, respectively) and least non-significant deviation from regression (S²di). By gas liquid chromatograms for the essential oil, G1 clone recorded the highest  percentage from Linalool, Geraniol, Eugenol and Iso menthone (7.31%, 16.57%, 11.24% and 7.31%, respectively), while G2 clone gave highly citronellol, α-pinene and Β-caryophyllene percentage (24.19, 1.31 and 7.28 %, respectively).