Angiosperms are the most diverse group of land plants which provides fruits, food, seed for cultivation and material for hybridization purpose etc. Approximately 90% of all angiosperm species have hermaphrodite (bisexual) flowers and the remaining, onetenth are either monoecious (male and female flowers are separate but grow in same plant) or dioecious (male and female flower grow on different ...

Andromonoecy is hypothesized to evolve as a mechanism enabling plants to independently allocate resources to female and male function. If staminate flower production is a mechanism to regulate allocation to female function (i.e., fruit production), then large-fruited species should be more strongly andromonoecious than smaller-fruited taxa because more resources are required to mature large fru...

BACKGROUND Research on the potentially adverse effects of occupational pesticide exposure on risk of spontaneous abortion (SAB) is limited, particularly among female agricultural workers residing in developing countries. METHODS Reproductive histories were obtained from 217 Ecuadorian mothers participating in a study focusing on occupational pesticide exposure and children's neurobehavioral d...

How different organs are formed from small sets of undifferentiated precursor cells is a key question in developmental biology. To understand the molecular mechanisms underlying organ specification in plants, we studied the function of the homeotic selector genes APETALA3 (AP3) and PISTILLATA (PI), which control the formation of petals and stamens during Arabidopsis flower development. To this ...

Pumpkin (Cucurbita pepo) production relies on insect-mediated pollination, which is provided by managed and wild pollinators. The goals of this study were to measure the visitation frequency, longevity and temporal activity patterns of pumpkin pollinators and to determine if local habitat management and landscape composition affected this pollination service. We used video surveillance to monit...

BACKGROUND AND AIMS Sexual dimorphism, at both the flower and plant level, is widespread in the palm family (Arecaceae), in contrast to the situation in angiosperms as a whole. The tribe Chamaedoreeae is of special interest for studies of the evolution of sexual expression since dioecy appears to have evolved independently twice in this group from a monoecious ancestor. In order to understand t...

The popular ornamental flowering plant Dianthus hybrida cv. Telstar Scarlet has been found to exhibit two populations, each with distinct flower morphology: female-like and hermaphroditic. In this work, development of D. was characterized through scanning electron microscopy, light- or stereo- from meristem formation the fully matured, open flower. difference between hermaphrodite plants initia...

Papaya (Carica papaya L.) plants are polygamous, with female, male, and hermaphroditic flowers. To understand the roles of MADS-box genes in flower development and sex determination, we cloned cDNAs of E-class genes CpMADS1 and CpMADS3 and a TM6 lineage of the B-class gene CpMADS2 from young flower buds of papaya. Reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR analys...

The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flowered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms responsible for their maintenan...

In self-compatible, hermaphroditic plants, display size-the number of flowers open on a plant at one time-is believed to be influenced by trade-offs between increasing geitonogamous selfing and decreasing per-flower pollen export as display size increases. Experimental results presented here indicate that selection through male function favors smaller display sizes in Ipomoea purpurea. In small...