Effect of Different Seed Priming Treatments on Germination and Seedling Establishment of Two Threatened Endangered Medicinal Plants of Darjeeling Himalaya

Abstract

Present investigation was conducted under the aegis of Uttar Banga Krishi Viswavidyalaya, in Algarah (1900 m asl) under Darjeeling Himalaya. The aim was to study the effects of priming with different concentration of growth hormone, etc. on seed emergence characteristics and seedlings vigour of two endangered plant species of Swertia chirayita and Valeriana jatamansi. An experiment as randomized block design in 14 pretreatment seeds of S.chirayita and 15 pretreatment seeds of V. jatamansi with 3 replications was carried out in the field condition during November 2011 to November 2014. The pretreatments include osmo-priming with GA₃ 50, 100, 200, 400 and 800 ppm; IAA 50, 100, 200, 400, 800 ppm and KNO₃ 1, 2, 3 and 4% and hydro-priming (control with distilled water) for S.chirayita. In another experiment V. jatamansi seed osmo-priming with IBA 50, 100, 150, 200, 250 ppm; GA₃ 50,100, 150, 200, 250 ppm, kinetin 50, 100, 150, 200, 250 ppm and hydro-priming (control with distilled water). The maximum seed germination was observed with GA₃ 400 ppm and was at par with the GA₃ 200 ppm. Onset of germination was earliest, i.e. 19.00 days after sowing as registered by GA₃ 800 ppm for 12 h, which was statistically at par with IAA 200 ppm (20.33 days) and IAA 50 ppm (22 days). Mean germination time (MGT) 44.11 days in untreated (control) seeds which were significantly reduced to 27.34 days in seeds pretreated with IAA 400 ppm, which was 38.01% lower than the control and was at par with 29.63 and 30.67 days in seed pretreated with GA₃ 400 ppm and KNO₃ (2%). Seeds treatment with GA₃ 400 ppm for 24 h showed maximum SV-I (71.11), which was 207.71% higher than the control. The highest SV-II of 54.18 was registered by KNO₃ (2%), which was 68.16% higher than the control and was statistically at par with GA₃ 200 ppm. Germination energy of 1.16 was found in seeds pretreated with GA₃ 400 ppm, which was statistically at par with GA₃ 200 ppm, GA₃ 800 ppm, KNO₃ (1%) and KNO₃ (2%). Highest germination percentage seed of V. jatamansi was observed with the kinetin 200 ppm treated seeds and significantly better to all other treatments measures. Days require for onset of germination was earlier recorded with the IBA 200 and kinetin 250 ppm and was at par with the kinetin 200 and IBA 150 ppm. MGT was 33.03 days in untreated (control) seeds which were significantly reduced to 22.95 days with GA₃ 250 ppm, which was 31.88% lower than the control and was at par with kinetin 200, kinetin 250 and IBA 200 ppm primed seeds. Kinetin 100 ppm showed maximum SV-I (303.33), which was 484.15% higher than the control and was significantly better to all other 14 seed priming treatments. The highest SV-II of 190.06 was registered with kinetin 200 ppm, which was 362.32% higher than the control and was statistically better to other treatments. Maximum emergence index and germination energy were exhibited by kinetin 200 ppm.