Value estimates of ecosystem goods and services are useful to justify the allocation of resources towards conservation, but inconclusive estimates risk unsustainable resource allocations. Here we present replacement costs as a more accurate value estimate of insect pollination as an ecosystem service, although this method could also be applied to other services. The importance of insect pollina...

Most gymnosperms are wind-pollinated, but some are insect-pollinated, and in Ephedra (Gnetales), both wind pollination and insect pollination occur. Little is, however, known about mechanisms and evolution of pollination syndromes in gymnosperms. Based on four seasons of field studies, we show an unexpected correlation between pollination and the phases of the moon in one of our studied species...

tall fescue (lolium arundinaceum (schreb) sj darbysh.) is one of the fescue species that widely used as forage grass. tall fescue is self-incompatible and wind cross pollination. this study was conducted to study agronomic and morphological characteristics of 25 polycross families of tall fescue during 2011 and 2012 at research station farm in isfahan. number of days to pollination, height of p...

BACKGROUND AND AIMS Pollen limitation is a significant determinant of seed production, and can result from both insufficient pollen quantity (pollen shortage) and quality (mainly relating to self-pollination). For animal-pollinated tree species with large floral displays, pollen limitation may be determined by a balance between increased pollen quantity due to increased attractiveness for polli...

Pollinator-mediated evolutionary divergence has seldom been explored in generalist clades because it is assumed that pollinators in those clades exert weak and conflicting selection. We investigate whether pollinators shape floral diversification in a pollination generalist plant genus, Erysimum. Species from this genus have flowers that appeal to broad assemblages of pollinators. Nevertheless,...

a r t i c l e i n f o Keywords: Apis mellifera biodiversity-ecosystem function ecosystem services native bee pollinator valuation ecosystem service valuation wild bee Crop pollination by animal pollinators is an important ecosystem service for which there is no generally accepted valuation method. Here, we show that two existing valuation methods, previously thought to be unrelated , are each a...

A gene from maize that encodes a hybrid proline-rich protein (HyPRP) formed by two well-defined domains, proline-rich and hydrophobic, respectively, has been characterized at the level of its structure and expression. The proline-rich domain is composed of elements PPYV and PPTPRPS, similar to those found in PRP proteins from soybean. The hydrophobic domain is rich in cysteine and is similar to...

The effect of gamma radiation on pollen germination capacity and pollen tube growth was evaluated in vitro and in situ conditions. In vitro experiments, revealed that irradiation signi®cantly affects pollen viability, mainly for levels higher than 200 Grays (Gy). Also, for levels higher than 200 Gy, in situ observations showed that no pollen tube reached the ovule. Fruit set results con®rmed th...