ESTIMATION OF HYBRID SEED PRODUCTION AND EFFICIENT POLLEN FLOW USING INSECT POLLINATION OF MALE-STERILE SOYBEANS IN CAGED PLOTS

The aptitude of leafcutter bees to pollinate male sterile soybean plan ts (ms2 gene) in caged plots was evaluated in four experiments from bo th quantitative and qualitative points of view. The m.s. plant seed se t was satisfactory: on average, it represented 60% of the male fertile isogenic seed set (with a range between 44 and 69%). The lower yield of m.s. plants was linked with a smaller number of fertile reproductiv e nodes. The efficient pollen flow was observed over the flowering per iod with both morphological and electrophoretic markers. Insect behavi our was not influenced by flower colour. Differences between flowering duration of pollen donors appear to be the major factor inducing unba lanced populations. The interest of this technique as a tool for dynam ic management of the genetic variation in populations or for hybrid se ed production is discussed.