However, the early stages of seed development particularly
pollination and fertilization are so highly sensitive to drought that it may cause a complete crop failure.
Although
pollination at bud-stages and double
pollination allow self-fecundation in passion fruit, these methods demand considerable labor and time by choosing the appropriate flower development stage and with flower protection to avoid cross-pollination.
Much research has investigated the validity of
pollination syndromes and how useful these floral characters actually are for predicting particular aspects of a plant's
pollination ecology (see reviews in Fenster et al, 2004; Johnson and Steiner, 2000; Waser et al, 1996).
With regard to the
pollination requirements of sesame, there is no consensus on the predominant type of
pollination.
After
pollination, the expression level of Pb[S.sub.26]-RNase allele gradually decreased in the style of both different
pollinations (Figure 7).
One plant of each ploidy level was selected as control to evaluate ovule development without
pollination. The female inflorescences of the improved diploids (AA) and of the triploids (AAA and AAB) were protected with polyethylene bags one day before anthesis (opening of the flowers) to avoid contamination by insectcarried pollen.
The bees while collecting pollen from the anthers normally contacted the stigma on their underside and hence were considered to be transferring pollen and effecting
pollination. Trigona bees tended to stay mostly on the same tree for forage collection effecting mostly self-pollinations.
All of these factors combined (timing of
pollination, mating system, growth form, and environment) will influence reproductive success.
All experimental
pollinations were performed in two populations in 1995.
viridis is not clonal and, therefore, hand
pollinations between plants within this population represent outcrosses.
In the natural population, the difference observed between fruit set resulting from spontaneous self-pollination and the one resulting from open
pollination (Table 1) reinforced the importance of geitonogamy in that species.
China is rich in plant species and diverse in topography (Lopez-Puyol et al., 2006; Wei et al., 2010), providing a suitable study region to evaluate potential drivers of evolutionary change in floral syndromes and
pollination syndromes between mainland and islands.
Hybrids with faster silk growth rates may have more silks available for
pollination at the beginning of flowering.
Particular interest therefore attaches to cases of racial and specific differentiation in methods of
pollination" (Grant and Grant 1965, p.
