To determine the effects of the hours after pollination and the treatment durations on triploid production and reveal the effective stages of embryo sac chromosome doubling by high temperature exposure. At least three catkins were sampled, and 80 ovules were used for the determination of the embryo sac developmental process. Catkins (2-74 h after pollination) were treated to induce embryo sac c...

opening frontiers has led in the last two decades to a massive migration of romanians to spain and italy, two countries known to have large areas planted with olives. romania owns large areas planted with ash forests. because of cross-reactivity between these two trees belonging to the oleaceae family and the big allergenic potential of olive pollens, after a number of years of residence in the...

The role of ethylene and auxin in stigma-to-ovule signalling was investigated in maize (Zea mays L.). Maturation of the egg cells in an ear was stimulated before actual fertilization by the application of fresh pollen grains or quartz sand to fully receptive stigmas. Ethylene emission by maize ears increased in response to those treatments. Silks and ovaries were involved in ethylene synthesis ...

BACKGROUND Olive (Olea europaea; O.e.) pollen is a major cause of seasonal respiratory allergy. The O.e. pollination season lasts two months from the beginning of May till the end of June. It was expected that patients with allergic disease from O.e. sensitization were symptomatic only during this period. However, during the last few years, we have observed that the clinical symptoms appear not...

BACKGROUND Co-flowering plant species frequently share pollinators. Pollinator sharing is often detrimental to one or more of these species, leading to competition for pollination. Perhaps because it offers an intriguing juxtaposition of ecological opposites - mutualism and competition - within one relatively tractable system, competition for pollination has captured the interest of ecologists ...

Pollination is the first crucial step of sexual reproduction in flowering plants, and it requires communication and coordination between the pollen and the stigma. Maize (Zea mays) is a model monocot with extraordinarily long silks, and a fully sequenced genome, but little is known about the mechanism of its pollen-stigma interactions. In this study, the dynamic gene expression of silks at four...

Silene alba, a perennial, dioecious plant, produces flowers that open in the evening and can remain open and receptive to pollination for up to 5 d, though in hot and dry conditions the flowers will wilt during the day only to reopen night after night. In the field, it is visited by two different kinds of pollinators with differential success: moths visit the flowers at night, and their movemen...

The effects of two viviparous genes, vp(1) and vp(5), on development of the maize (Zea mays L.) embryo and endosperm were investigated. Differences between viviparous and normal embryos first appeared at 25 to 30 days after pollination. Increases in fresh weights indicated that viviparous began to grow more rapidly than normal embryos at that time. Amino acids and ethanol-soluble carbohydrates ...

to evaluate the effects of presence of insect pollinators on quantity and quality of seeds of two common cultivars of onion (allium cepa l.), namely red azar shahr and yellow sweet spanish, an experiment in a factorial randomized complete block design was carried out at two sites. bulbs of equal size were planted with plant to plant 35 cm and row to row 50 cm spacing. at each site, experimental...

in vitro pollen germination and also pollen tube growth dynamics in different pollination treatments under controlled temperature, humidity and photoperiodicity were studied regarding four cultivars (‘shastomi - e - do’, ‘ebrahim - e - kalajah’, ‘sefid - e - rezaeeieh’ and ‘razi’) under self and under cross-pollination along with three superior genotypes (‘269’, ‘416’ and ‘464’) of apricot. fol...