oleifera is a geitonogamous and xenogamous
diploid species (2n = 28; n = 14 chromosomes) whose gene pool and genetic base are expected to be wide with higher productivity [11, 12, 13, 14].
Fruit set under open pollination and manual xenogamous
cross-pollinations on 10 selected trees of Tirumala Hill population Tree Fruit set (%) Fruit set (%) number (open (hand cross- pollination) * pollination) ** TH1 4.3 24.2 TH2 9.8 12.0 TH3 3.4 19.2 TH4 2.4 19.0 TH5 2.9 31.6 TH6 4.1 26.4 TH7 4.0 15.2 TH8 1.8 16.8 TH9 8.7 33.7 TH10 4.1 10.8 * = average of 10 inflorescences/tree; ** = average of 125 pollinations/tree.
This species has been reported as an inbreeder favoring geitonogamous pollination (87% fruit set) compared with 53.33 percent fruit set under xenogamous
conditions (Chauhan et al.
These few species have breeding biologies that span the range of self fertility, from self compatible to self incompatible; a few are obligately xenogamous
. One annual species (A.
Tillandsia balbisiana is a xenogamous
species based on results of cross pollination but its fruit setting is relatively low, probably another case of pollinator limitant.
Mating systems: xenogamous
and autogamous species were associated only with plant life forms.
Considering the many simultaneous flowers produced by these species, the amount of nectar exuded, the hummingbird behavior, and the existence of SC, hummingbird visits likely favor geitonogamous rather than xenogamous
Thrips-mediated self-pollination of two facultatively xenogamous
For example, flowers of autogamous species have smaller corollas than flowers of xenogamous
species (Ornduff 1969; Cruden and Lyon 1985).
A group of plants (n = 20 plants at the Green County site, n = 40 plants at the Jefferson County site, n = 59 plants at the Waukesha County site) were crossed (xenogamous