MSc

The studies on refinement of in vitro propagation technique in pineapple var. Mauritius and mass multiplication of elite clones were conducted at Kerala Horticulture Development Programme, Kerala Agricultural University, Vellanikkara during 1993 – ’95.
Based on the survey conducted at the major pineapple growing areas, namely, Vazhakulam – Muvattupuzha regions of Ernakulam district, five elite clones of Mauritius variety with higher yield and other desirable fruit characters were selected propagules from the selected clones were planted at Vellanikkara for taking explants for their mass multiplication through refined in vitro propagation techniques.
For shoot tip explants, treatment with emisan 0.1 per cent for 35 minutes followed with mercuric chloride 0.1 per cent for 10 minutes and for lateral bud explants treatment with emisan 0.1 per cent for 10 minutes followed by 0.1 per cent mercuric chloride for three minutes was found to be the ideal surface sterilization treatment.
Culture establishment and growth initiation of shoot tip explants from different sources (suckers, crowns and slips) and lateral bud explants were better in MS medium supplemented with BAP 3 and 4 mg 1-1. Explants from shoot tips were found to be better than those from lateral buds for achieving faster culture establishment and growth initiation.
Enhanced release of axillary buds was the maximum in Ms medium containing BAP 4.0 mg 1-1. Among the different subculture stages, multiple axillary bud production was higher in second suculture stage. Addition of casein hydrolysate 100.0 mg 1-1 in to the medium with BAP 4.0 mg 1-1 favoured the production of axillary buds.
Adventitious bud initiation from sucker shoot tips was fastest in MS medium supplemented with BAP 5.0 mg 1-1 + NAA 1.0 or 0.5 mg 1-1. For adventitious bud production from lateral buds, treatment with BAP 7.5 mg 1-1 + NAA 1.0 mg 1-1 was the best.
Proliferation rate of adventitious buds was maximum in MS medium supplemented with BAP 4.0 mg 1-1 + NAA 0.5 or 1.0 mg 1-1. Rate of multiplication of adventitious buds was higher in liquid medium under shake culture condition, than in solid medium.
Faster shoot regeneration and increased vigour of the shoots were resulted in growth regulator free MS medium. However, highest number of shoots were produced in MS medium supplemented with BAP 1.0 mg 1-1. Liquid medium under shake culture condition was found superior of solid media with respect to initiation of shoots and mean number of shoots, however, the latter resulted in longer shoots.
In vitro rooting was fastest in MS medium, without any growth regulator, which produced longer and normal roots with secondaries and root hairs. Though addition of NAA (3 mg 1-1) resulted in increased number of roots, they were very short and hair like. Stationary liquid medium was found superior to solid