COMPARATIVE GROWTH ANALYSIS OF TISSUE CULTURED CLONES OF CORSICAN PINE WITH NATURAL SEEDLINGS

Abstract

The maturity or the physiological state of the mother plant in which the explants were collectedhas a greater effect on the growth of in vitro plants. Younger explants respond better in theculture medium. The physiological state of the mother plant has a direct effect on the growth invitro. Seasonal changes, also has a greater effect on the growth. Morphological andphysiological disorders in the growth of the tissue cultured plants also reported by manyresearchers. Therefore, this experiment was designed in order to determine: Any deviation of thegrowth comparing to the growth of the natural seedliugsThe effect of the nature Istatus of the mother plant of which the explants were collected on thegrowth of the plants produced in vitro.

Five clones of Corsican pine (Clone 1 - originated from embryo culture; Clone 2 - Originatedfrom meristems of 21-day -old seedlings; Clone 3 - Originated from axillary buds of 5-year-oldplants Clone 4 - Originated from mature shoot tips of lO-year-old plants: Clone 5 - Originatedfrom resting buds from 5-year-old plants) wen: produced by tissue culture. They wereacclimatized and were established in the field for a period of one year. A set of natural seedlingswas also cultivated in the same field in order to compare the growth of in vitro clones with thenatural seedlings.

Natural seedlings were from a same seed lot and the initial height of all the plants were aroundI5cm at the time of planting in the nursery. They were maintained over a period of one year andthe height of plants (em), mean shoot diameter at the soil level (cm) and number of branches pershoot was observed. Plants were fertilized regularly. There were 20 plants in each clone. Theresults were analysed using ANOVA and the pairwise comparisons were done with Turkey's testin Minitab Statistical package

There was no significant difference between clones 1-4 and natural seedlings on height; but theheight of the clone 5 - which the original explants from resting buds, was significantly lowerthan all other plants. There was a slight (non-sign'ficant) differences within height betweenclones 1 and 4-in which the original material from ru.ture (10 years-old) plants. The diameter atthe soil level also shows the similar pattern of growth. Branching patterns were almost the samein all four clones and also in plants from natural seedlings

It can be suggested that there is no significant difference in the growth pattern of the tissueculturedclones when comparing them with natural »lants. There is an effect ofthe physiologicalstate (dormancy) of the mother plant on the growth cf tissue cultured plants in the field but theage of the mother plant does not show any effect on the growth of the in vitro plants in the field.Therefore, the use of in vitro techniques for mass clonal propagation of Corsican pine forcommercial purposes is recommended.