Abstract

The ultimate test for utility of a pollen sample is the seed yield following control pollination (CP). In the present study, two different methods of eucalyptus pollen isolation (PI) viz., wet-lyophylisation (WL) and conventionally dry-sieving (DS) were followed. The pollen thus isolated was used to carry interspecific hybridization in order to evaluate and compared the efficiency the above two methods of PI in eucalyptus. Apart from testing the efficiency of the above two methods of PI, CP was carried to generate new combinations of alleles towards developing hybrid eucalyptus for commercial use. Wide-interspecific hybridization was performed between important eucalyptus species following a partial diallel mating design. Pollen from three paternal species namely E. globulus (5 trees), E. pellita (1 tree) and E. urophylla (1 tree) were used to CP three elite commercial clones of E. camaldulensis. Except in few occasions, the percent capsule set and number of seeds obtained per 10 capsule (≥30 seeds) with the PI through WL method was comparatively high and significantly different from conventional DS method (≤30 seeds)  at P<0.01. The results of this experiment prove that the method of PI affects the outcome of wide-interspecific hybridisation in eucalyptus.

Key words: Wet-lyophylisation, pollen isolation, control pollination, interspecific hybridization, eucalyptus.