Irish faba beans (Fabales: Fabaceae) depend on wild bumblebee pollination for marketable yields

1. Quantifying the contributions of insect pollinators to crops provides insight into how pollination services should be managed and protected into the future.
2. Faba bean, Vicia faba var minor (Linneaus), is a widely grown crop globally that can benefit from pollinator visitation, but only from species that are morphologically compatible with the plant's long-corollae flowers. Here, we rank insect pollinators in terms of their potential importance to faba bean pollination and quantify the economic value of pollination for Irish faba beans.
3. Our findings demonstrate that bee pollination contributes significantly to the pod set of faba beans, and, consequently, the crop's production value. We find that pollination services account for almost half of Ireland's total faba bean market value, with the pollinator contribution estimated at almost €4,000,000 per year.
4. We estimate that, relative to other pollinators, wild bumblebees contribute to approximately 70% of the economic value of pollination services in faba bean fields, driven mainly by the contributions of a long-tongued bumblebee species, Bombus hortorum (Linneaus; Hymenoptera: Apidae).
5. Based on these results, we suggest that B. hortorum populations be encouraged on farmland through appropriate management to ensure the continued delivery of pollination services to Irish faba beans.

     

Pollen morphology of families Quillajaceae and Surianaceae (Fabales)

The Fabales clade comprises four families: Leguminosae, Polygalaceae, Quillajaceae and Surianaceae. This study presents new information on the pollen morphology of Quillaja, the only genus of Quillajaceae, and Recchia, Guilfoylia, Cadellia, Suriana and Stylobasium, the five genera that comprise Surianaceae. The pollen of 9 of the 11 species currently recognised within the two families was examined using light microscopy (LM), scanning electron microscopy (SEM) and, selectively, with transmission electron microscopy (TEM). Pollen of all taxa is isopolar with tri-zonocolporate apertures, lalongate endoapertures with fastigia adjacent to the endoaperture, and long ectoapertures that are nearly equal to the polar length. Apocolpia are correspondingly small. Quillaja pollen is subprolate to prolate, and striate with a granular aperture surface membrane. Ectexine protrudes over the endoapertures. In thin section the foot layer is thicker in mesocolpial areas and thin to discontinuous around the apertures, where the endexine is thicker. Cadellia pollen is prolate spheroidal, and striate with a granular aperture surface membrane. Exine protrudes over the endoapertures. In thin section the endexine is thicker and lamellate around the endoaperture area, and the foot layer is thicker in mesocolpial regions. Guilfoylia pollen is oblate and gemmate-verrucate, with a granular aperture surface membrane. Columellae are short. Recchia pollen is suboblate to oblate spheroidal, and microreticulate-perforate with a granular aperture surface membrane. Exine protrudes over the endoapertures. The foot layer is thin to discontinuous around aperture margins and thick in mesocolpial regions. Stylobasium pollen is suboblate, and finely rugulate-perforate with a granular aperture surface membrane. Columellae are short, the foot layer is thin or absent. Suriana pollen is suboblate, and finely rugulate-perforate with a granular aperture surface membrane. Pollen of Cadellia and Recchia, and Stylobasium and Suriana are morphologically similar. Verrucate surface ornamentation is only present in Guilfoylia. Quillaja, Cadellia and Recchia share the character of protruding exine over the endoaperture area. Striate ornamentation occurs in Quillaja and Cadellia. The pollen morphology of Quillajaceae has more in common with that of Leguminosae and Surianaceae, and with Cadellia in particular, than with Polygalaceae.     

A new isoflavone from soya beans

A new isoflavone was isolated from soya beans and shown to be 7,4′-dihydroxy, 6-methoxyisoflavone, for which the name glycitein is proposed.     

Ecology of Hup+ Rhizobium strains of cow pea miscellany: native frequency and competence

Rhizobium strains nodulating summer legumes cow pea [Vigna unguiculata (L.)], green gram [V. radiata (L.) (Wilczek)], black gram [V. mungo (L.) (Hepper)] and cluster bean [Cyamopsis tetragonoloba (L.) (Taub)] and a winter legume chick pea [Cicer arietinum (L.)] were surveyed in the Northern Plains of India and screened for hydrogenase activity to determine distribution of Hup character in the native ecosystem. It was observed that 56% of the Rhizobium strains of summer legumes were Hup⁺ whereas that of the winter legume, chick pea, were all Hup^-. Ex planta acetylene reduction activity was observed in most of the Hup⁺ but not in the Hup^- strains of any of the host species. In summer legume, mixed inoculation of Hup⁺ and Hup^- strains, under sterilized as well as unsterilized soil conditions, showed that the host species were predominantly nodulated with Hup⁺ strain.     

Effects of the herbicide trifluralin in the initial development of Piptadenia gonoacantha (Fabales: Fabaceae)

Abstract

Trifluralin, a pre-emergent herbicide, is widely used in Brazil in the weed grass management in restoration areas. The objective was to evaluate the tolerance of Piptadenia gonoacantha to trifluralin. The treatments had three trifluralin doses (445, 890, and 1335?g a.i. ha^?1), applied in pre-sowing, as well as the control, without herbicide. Visual intoxication, seed germination, survival rate, emergence speed index (EMI), mean germination period, seedling height, and diameter, micromorphometric parameters of plant roots collected at 60 d after sowing, root length (RL) and volume, leaf area (LA), leaf numbers, root and shoot dry matter, and fluorescence of chlorophyll a at 30, 45, and 60 d after sowing were analyzed. Visual intoxication values above 50% were observed only with 1335?g a.i. ha^?1. The herbicide did not affect seed germination, EMI, average germination period, seedling height, and diameter, root micromorphometric parameters, length, dry matter or root volume, and chlorophyll a fluorescence. The dose 1335?g a.i. ha^?1 caused a reduction of 41.5% in survival, 50.3% in the LA, 36.7% in the number of leaves (LN), and 59.8% in the aerial dry mass of seedlings. The trifluralin presents potential for restoration programs of degraded areas with this forest species.