Gender Differences in Antioxidant Properties Phenotypic Plasticity and Freeze Tolerance in Seabuckthorn Hippophae Rhamnoides L along an Altitudinal Gradient in Trans Himalayan Ladakh India

Abstract

Seabuckthorn (Hippophae rhamnoides L., Elaeagnaceae) is an ecologically and economically important thorny dioecious shrub. All plant parts are reservoir of an array of important health-promoting substances. Female plant produces berries that are rich in vitamins, fatty acids and many other important compounds. Being a dioecious plant, gender differences in health promoting compounds in plants and plant adaptation to harsh environmental conditions are expected. However, not much is known on gender effect on antioxidant properties, phenotypic plasticity and freeze tolerance in Seabuckthorn (SBT), especially in trans-Himalayan region. Thus this thesis mainly aimed to study gender differences in SBT with five objectives. In first objective (Chapter 2), we made effort to develop an improved vegetative propagation method and to study the effect of plastic mulching, coloured shade netting, spacing, cutting thickness and gender differences on rooting and growth of SBT. Last year growth (one year old) stem cutting of diameter 2.9±0.8 mm thickness resulted in 97.6±2.2% rooting success in greenhouse condition. Use of rooting hormone did not have any significant result. Use of silver black plastic mulching film resulted in 10% higher rooting success. Reduction in light intensity using green shade net resulted in significant reduction in rooting and growth of nursery plants. Rooting and growth related parameters did not significant differed in three different spacing between cuttings suggesting that cuttings can be planted denser (3quot×3quot) under mulching to get higher number of nursery stock per unit area. Highest rooting percentage was observed in pencil thickness cuttings (7.5±1.6 mm diameter) then cuttings with 2.9±0.8 mm and 11.3±1.7 mm basal diameter. Gender did not showed significant difference in percent rootability. Present study could assist in generation of a vegetative propagation technique in which faster growth, larger number of cuttings can be propagated with high rooting success rate.