Pg. 8-10 Evaluating the Success of Cross-Pollinating Techniques in Litchis (Litchi chinensis Sonn)

Single inflorescences of litchi trees produce several hundred flowers each. The sexes are separated on different flowers and male, female and male flowers are produced successively on a given inflorescence. Self-pollination occurs commonly since pollen shed overlaps with receptivity of the female flowers. Two methods, daily physical removal of the male flowers prior to hand pollination, and the use of a pollen dispenser attached to a beehive inside an encaged tree were used to produce directed crosses as part of a litchi breeding programme. The success of the two methods was investigated with isozyme analysis of the parents and progeny. Both methods resulted in the production of a satisfactory percentage of hybrid progeny. Physical removal of the male flowers followed by hand pollination is, however, the preferred method since it resulted in a minimum of 75% hybrid progeny.