Hernández LF^1,2, PM Bellés³, MA Bidegain^4,5, PD Postemsky⁴

Phyton-International Journal of Experimental Botany, Vol.87, pp. 198-208, 2018, DOI:10.32604/phyton.2018.87.198

Abstract Absence or underdevelopment of sunflower fruits come usually from failure in fertilization, stresses as well as physiological and morphological defects in the ovary. Thigmomorphogenesis has never been included as a possible cause. We have previously shown that a 2-3 day fertilization shift can occur between neighboring florets in the sunflower capitulum. It is proposed here that those ovaries with advanced fertilization can generate a significant radial and axial compressive stress on ovaries with delayed fertilization. This mechanical stimulus could be strong enough to trigger a thigmo response that affects further ovary development. In vivo tests… More >

Mirleau-Thebaud V^1,2, J Dayde¹, JD Scheiner^1,3,4

Phyton-International Journal of Experimental Botany, Vol.86, pp. 53-67, 2017, DOI:10.32604/phyton.2017.86.053

Abstract Soil compaction represents an important issue in the actual context of agricultural system sustainability. Research on the various developments of root systems under tillage has been explored for many crops, whether for the biomass area or the underground, but very little concerns Sunflower (Helianthus annuus L.). The objectives of the study were to understand the impact of soil tillage and of the induced mechanically compacted soil on: i) sunflower’s root system architecture, ii) biomass area iii) production. Two complementary experiments were realized in the south of France (France’s main sunflower production area). In both experiments, increased More >

Hernández LF^1,2, MV Rosetti¹

Phyton-International Journal of Experimental Botany, Vol.85, pp. 291-296, 2016, DOI:10.32604/phyton.2016.85.291

Abstract The involucral bracts (IB or phyllaries) of the sunflower (Helianthus annuus L.) capitulum constitute an example of photosynthesizing organs that contribute to the photosynthesis budget during the generation of crop yield. The anatomy of IB was analyzed in two domesticated primitive sunflower genotypes, Havasupai and Hopi, in the sunflower line HA89B, in the wild Helianthus annuus ssp. annuus, in the sunflower male-fertile line R013 and in the commercial hybrid DKOP3845. Stomata and trichomes were counted on the adaxial and abaxial epidermis. In all cases, the IB showed a one-layered adaxial and abaxial epidermis, secretory ducts and parenchymatic cells… More >

Piña-González JL¹, EJ Morales-Rosales², A Domíngez-López², JF Ramírez-Dávila², G Estrada-Campuzano², O Franco-Mora²

Phyton-International Journal of Experimental Botany, Vol.83, pp. 101-108, 2014, DOI:10.32604/phyton.2014.83.101

Abstract The aim of this study was to assess the land equivalent ratio, biomass, grain yield and ethereal extract of Helianthus annuus in monoculture and associated with Pisum sativum in function of stabilized urea (0, 40, 80 kg N/ha) in El Cerrillo, México. It was also estimated pod yield obtained by P. sativum as a pure stand and associated with H. annuus. The six treatments (in each experiment) were evaluated in a 2 × 3 factorial experiment in a randomized complete block design with four replications. When F values were significant, the honestly significant difference test at the 5%… More >

Astiz V¹, LF Hernández^2,3

Phyton-International Journal of Experimental Botany, Vol.83, pp. 27-36, 2014, DOI:10.32604/phyton.2014.83.027

Abstract The intra-plant pollen production in cultivated sunflower (Helianthus annuus L.) was quali- and quantitatively studied. Two modern self-pollinated, high oleic sunflower hybrids were grown during two consecutive seasons: 2009 in three planting dates, and 2010 in two planting dates. Two cross-pollinated varieties of sunflower, Hopi and Havasupai, were also studied to determine if an anomalous intracapitulum pollen gradient observed in preliminary studies could be a remnant character inherited from primitive genotypes. Pollen grains per flower (PGF), anther volume (AV), pollen grain volume (PGV) and pollen viability (PV) were measured in three capitulum sectors, external (ES), middle… More >

Astiz V¹, LF Hernández^2,3

Phyton-International Journal of Experimental Botany, Vol.82, pp. 297-302, 2013, DOI:10.32604/phyton.2013.82.297

Abstract During microsporogenesis, sunflower florets might be exposed to episodes of day- and night-time temperatures exceeding 30 and 20 °C, respectively, that can affect pollen availability and consequently plant’s yield. The relationship between air temperature and relative humidity during the meiotic phase of microsporogenesis, and the quantity and quality of pollen produced by the flowers, were studied in two sunflower hybrids during two years. The hybrids were grown on irrigated plots in Bahía Blanca (38° 45’ S; 62° 11’ W) in three planting dates (PD) at a density of 5.6 plants/m2. Flowers were consecutively taken as… More >

Mirleau-Thebaud V^1,2, JD Scheiner¹, J Dayde¹

Phyton-International Journal of Experimental Botany, Vol.80, pp. 203-210, 2011, DOI:10.32604/phyton.2011.80.203

Abstract Plant yield and oil content determine sunflower production. Those plant production determinants depend in turn on the plant–environment interaction. In the South West of France, there have been recent advances in soil tillage. To date, 35% of the soil surface dedicated to sunflower is cropped under a reduced tillage system. Major constraints to sunflower cropping are water stress and cryptogamic diseases. The second most important sunflower disease in the South West of France is premature ripening caused by Phoma macdonaldii. Aims of this work were to: 1) understand how these factors influence sunflower yield, and 2) More >

M.M. GOTELLI*, B.G. GALATI, D. MEDAN

BIOCELL, Vol.34, No.3, pp. 133-138, 2010, DOI:10.32604/biocell.2010.34.133

Abstract This is the first report of the ultrastructure of the stigma and style during and after anthesis in Helianthus annuus L. using light and transmission electron microscopy. The stigma is bifid with unicellular papillae. There is no secretion of lipids, carbohydrates or proteins at anthesis. The style is semisolid in the upper portion, closer to the stigma, and becomes solid below. Ultrastructural changes on cells of the stigma and the style are described. The transmitting tissue of the ovule is first evident 40 minutes after pollination and persists during the first stages of embryogenesis. Only one More >

Franchini¹ MC, LF Hernández², LI Lindström³

Phyton-International Journal of Experimental Botany, Vol.79, pp. 153-161, 2010, DOI:10.32604/phyton.2010.79.153

Abstract Wax in the sunflower (Helianthus annuus L.) pericarp is an important morphological feature that interferes with oil quality and varies with crop management and environmental conditions. We studied the effect of a moderate water deficit (MWD) generated from early to late anthesis on quantitative development of the cuticle, and qualitative and quantitative development of the cuticular waxes (CW) of the pericarp in two hybrids grown under field conditions. The experiment was repeated during two consecutive seasons (Exp-I and Exp-II). At harvest maturity (HM), plants grown under a MWD showed higher CW content (31 to 47%) and… More >

Hernández LF

Phyton-International Journal of Experimental Botany, Vol.79, pp. 109-115, 2010, DOI:10.32604/phyton.2010.79.109

Abstract The relationships between (1) leaf biomass and morphology (lamina area and petiole and lamina inclination), (2) petiole’s mechanical and structural properties, and (3) the vertical light gradient inside the crop’s canopy were studied in field grown sunflower (Helianthus annuus L.) plants, maintained at optimum soil water and mineral levels. At flowering, incident photosynthetic active radiation (PAR) was measured at the top of the canopy and on individual leaves using a quantum sensor. The fraction of direct incident radiation which passed through the canopy reaching each individual leaf was then calculated. Individual petiole and lamina inclination angles (ia_Petiole… More >