Abstract

Success of interspecific hybridization in Eucalyptus depends on the availability of contamination free, clean and viable pollen from elite paternal trees. Unlike the natural process of open pollination, control pollination (CP) in Eucalyptus orchards, is a slow, tedious and labour-intensive procedure that involves high costs, but results in low seed yields. In order to overcome these short-comings, Eucalyptusbreeders use various methods of pollen isolation (PI) procedures and pollination techniques. Here, we report an efficient method of PI, named as wet-lyophylisation method (WL) and compared the same with the conventionally followed dry sieving (DS) method. Clean pollen isolated by WL method resulted in a reduced debris content, in which the percent pollen viability and quantity of pollen obtained/gram of stamen were not significantly different between WL and DS methods at P < 0.05. During wide-interspecific hybridization, the use of clean pollen isolated by WL method resulted in an enhanced pollen density per receptive stigma. When compared to the conventional dry sieving method, the new (WL) method of PI was efficient in reducing the debris content and enhanced the number of pollen deposited on the receptive stigmas. In addition, the amount of pollen obtained per gram of stamen and percent pollen viability are not significantly different between the two methods of pollen collection under study.

Key words: Eucalyptus, hybridization, control pollination, wet-lyophylisation method, pollen viability.