• Sex ratio polymorphism has been extensively studied in Silene latifolia, but it is neither known whether inbreeding (which is likely to occur under field conditions) affects it nor which of the proposed mechanisms (Y degeneration, X-linked drive) is more important. Both mechanisms predict reduced pollen performance. • In this study, females were crossed with pollen from related and unrelated ...

Speciation involves the formation of reproductive isolating mechanisms such as a difference in pollinators, incompatibility between pollen tubes and stylar tissue, hybrid seed abortion, or poor growth of hybrid seedlings. We studied reproductive isolating mechanisms in naturally sympatric populations of Penstemon spectabilis Thurber and Penstemon centranthifolius (Benth.) Benth. where F1 hybrid...

COMATOSE (CTS) encodes a peroxisomal ATP-binding cassette transporter required not only for beta-oxidation of storage lipids during germination and establishment, but also for biosynthesis of jasmonic acid and conversion of indole butyric acid to indole acetic acid. cts mutants exhibited reduced fertilization, which was rescued by genetic complementation, but not by exogenous application of jas...

In crop growth and development, boron (B) is an essential trace element. Boron deficiency is common in highly leached, acidic sandy soils of cotton (Gossypium hirsutum L.) growing regions in the world. Boron is particularly important in pollen germination and pollen tube growth resulting in successful fruit setting. Therefore, B deficiency during flowering and fruiting may significantly reduce ...

In flowering plants, the vegetative nucleus and the two sperm cells are proposed to form a functional assemblage, the male germ unit (MGU). Here, we describe the developmental pathway of MGU assembly in Arabidopsis and report two classes of mutations that affect the integrity and/or the positioning of the MGU in the mature pollen grain. In germ unit malformed (gum) mutants, the vegetative nucle...

Heat-tolerant and -sensitive Lycopersicon esculentum Mill. and L. pimpinellifolium (Jusl.) Mill. genotypes were grown in the greenhouse under optimum(27/23C, day/night) and high-temperature (35/23C) stress regimes. Heat tolerance levels in the genotypes were established by determining percent fruit set at high and optimum temperatures. Under optimum temperature, fruit set ranged from 41% to 84%...

Cell–cell interactions in plants are expected to occur between adjoining cells that share a common developmental history. One exception is the interaction of the pollen or pollen tube with cells of the pistil. As a result, pollen–pistil interactions have emerged as models for the study of cell-to-cell signaling, particularly in the context of genetic self-incompatibility (SI). SI is an intraspe...

Self-compatibility of local olive (Olea europaea L.) accessions and of the cultivars "Frantoio" and "Leccino" was investigated in Garda Lake area, northern Italy. Intercompatibility was determined for "Casaliva," "Frantoio," and "Leccino," as well as the effects of foliar Boron applications (0, 262, 525, or 1050 mg.L(-1)) applied about one week before anthesis on fruit set, shotberry set, and o...

In temperate climates, most plants flower during the warmer season of the year to avoid negative effects of low temperatures on reproduction. Nevertheless, few species bloom in midwinter and early spring despite severe and frequent frosts at that time. This raises the question of adaption of sensible progamic processes such as pollen germination and pollen tube growth to low temperatures. The p...