Comparative growth of micropropagated plantlets and seedlings of citrus varieties. In: Agrotrópica v. 15 p. 9-16, 2003.

Abstract

Twelve important citrus cultivars mostly indigenous to North East region of India were studied along with C.volkameriana as control . Growth of tissue culture derived plantlets was compared with seedlings at the age of 60 days and at one year. In general at initial stage of growth seedling were more vigorous than micropropagated plantlets but later micropropagated plantlets became robust. The results indicated that shoot and root growth were higher in seedlings than micropropagated at initial stage. However, number of leaves was found higher in micropropagated plantlets. The differences of growth could be attributed to the fact that micropropagated plantlets lacked more food than seedlings (food stored in cotyledon) and underwent shock during acclimatization. However at the age of one year micropropagated plantlets performed better than seedling. Micropropagated plants had significantly higher plant height, root length, number of leaves, number of secondary roots and plant weight than seedling. Interaction between cultivar and method of propagation were also found to be significant indicating that micropropagation is one of the best alternative for propagation of citrus. Furthermore, the improved phytosanitary status of in vitro plants makes them the planting material of choice with reduced risk of pest and disease introduction in new planting area. Principal component analysis indicated that Sohmyndong, Jaintia lemon, Pummelo and Assam lemon showed very high positive loading in PC1 indicative of their responsiveness towards the propagation by tissue culture and seedling, while Khasi mandarin, Satkara and Indian wild orange registered lowest positive loading indicating weak response under any propagation method.