Mariela Cid

Field performance of artificial seed-derived sugarcane plants

This study shows the behaviour of sugarcane plants cv. CP-5243 derived from artificial seed compared with traditional and isolated bud methods. Artificial seed-acclimatised plants were planted in field conditions simultaneously with two-control treatments previously germinated: macropropagated plants derived from stems of three buds and axillary buds isolated from field-grown plants. Plants from artificial seed were taller and had a smaller diameter at 8 months, but these differences disappeared at 12 months. With respect to sugar analysis and yield, no differences in all parameters evaluated were found between artificial seed-derived plants and plants derived from the two other methods.

GROWTH AND PHOTOSYNTHETIC ACTIVITY DURING ACCLIMATIZATION OF SUGARCANE PLANTLETS CULTIVATED IN TEMPORARY IMMERSION BIOREACTORS

Abstract Acclimatization of sugarcane plantlets (Saccharum spp. hybrid) var. C91-301, micropropagated in temporary immersion bioreactors, was studied. When in vitro plantlets were transferred to acclimatization conditions, photosynthesis increased only slightly during the first 7 d. After this period, the increase was constant with only a small decline after transfer to uncontrolled external conditions. Production of fresh and dry weights, number of leaves and roots, leaf area, stomatal density and chlorophyll contents were evaluated during the acclimatization period. From day 14 on, sugarcane plantlets exhibited low but positive photosynthesis due to the new formation of leaves and roots. The increase in light intensity and the gradual reduction of relative humidity during acclimatization did not constitute inhibitory factors, as can be interpreted from the increased photosynthetic activity until 21 d. Stomatal density and leaf area after 21 d were also increased, while the chlorophyll content declined.