Turnera hermannioides
Encyclopedia
Turnera hermannioides is a distylous, diploid perennial restricted to open, sandy sites in northeastern Brazil
. Four populations sampled in Sergipe
contained equal proportions of long- and short-styled plants. The style
and stamen
dimorphism in floral morphs is associated with differences in pollen
size and pollen production. In contrast, flower size, ovule number, and seed fertility of the morphs are not significantly different. A controlled pollination program demonstrated that individuals of T. hermannioides possess a self- and intra-morph incompatibility system. The only pollinations resulting in significant seed production were between the floral morphs. Populations of T. hermannioides grow intermingled with T. ulmifolia
, a widespread polymorphic complex containing forms that resemble T. hermannioides. A crossing program between T. hermannioides and diploid and tetraploid varieties of T. ulmifolia revealed barriers to hybridization particularly in crosses at the diploid level. It is concluded that T. hermannioides is a restricted diploid species that is reproductively isolated from T. ulmifolia.
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. Four populations sampled in Sergipe
Sergipe
Sergipe , is the smallest state of the Brazilian Federation, located on the northeastern Atlantic coast of the country. It borders on two other states, Bahia to the south and west and Alagoas to the north, and to the east is the Atlantic Ocean...
contained equal proportions of long- and short-styled plants. The style
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
and stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
dimorphism in floral morphs is associated with differences in pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
size and pollen production. In contrast, flower size, ovule number, and seed fertility of the morphs are not significantly different. A controlled pollination program demonstrated that individuals of T. hermannioides possess a self- and intra-morph incompatibility system. The only pollinations resulting in significant seed production were between the floral morphs. Populations of T. hermannioides grow intermingled with T. ulmifolia
Turnera ulmifolia
Turnera ulmifolia, the Yellow Alder, is a species of plant of family Passifloraceae, native to Mexico and the West Indies. A recent study found that yellow alder potentiated the antibiotic activity against methicillin—resistant Staphylococcus aureus ....
, a widespread polymorphic complex containing forms that resemble T. hermannioides. A crossing program between T. hermannioides and diploid and tetraploid varieties of T. ulmifolia revealed barriers to hybridization particularly in crosses at the diploid level. It is concluded that T. hermannioides is a restricted diploid species that is reproductively isolated from T. ulmifolia.