A study was carried out to assess the combining ability of ten CMS lines with four testers using line x tester method. Biometrical observations were taken for days 50% flowering, plant height, head diameter, maturity, volume weight, hundred seed yield /plant, oil content and yield/plant.  Specific combing variance greater than general all characters which indicated that non-additive gene a...

Mitochondrial DNA from 1 fertile and 6 cytoplasmic male sterile (CMS) sunflower genotypes was studied. The CMS genotypes had been obtained either by specific crosses between different Helianthus species or by mutagenesis. CMS-associated restriction fragment length polymorphisms (RFLPs) were found in the vicinity of the atpA locus, generated by various restriction enzymes. The organization of th...

Elevated CO2 concentrations were found to cause early senescence during leaf development in sunflower (Helianthus annuus L.) plants, probably by reducing nitrogen availability since key enzymes of nitrogen metabolism, including nitrate reductase (NR); glutamine synthetase (GS) and glutamate dehydrogenase (GDH), were affected. Elevated CO2 concentrations significantly decreased the activity of n...

The response of RIMI [imazethapyr-tolerant (T)] sunflower (Helianthus annuus L.) hybrid and the local imazethapyr-sensitive hybrid "Zoltan" (S) was investigated under controlled conditions. Hybrids grown in pots were treated post-emergence with imazethapyr at the two pairs of leaves stage. Visual injury evaluation and vegetative parameters were recorded. ALS (acetolactate synthase) enzyme activ...

the effect of arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria, with the ability to produce acc deaminase enzyme, on water relationships and agronomic indices of sunflower (helianthus annuus l.) cultivars was investigated. the soil used was of an ec equal to 7.6 ds m-1. a greenhouse factorial experiment on the basis of a completely randomized block design with three levels ...

Rates of photosynthesis, dark respiration, and leaf enlargement were studied in soil-grown corn (Zea mays), soybean (Glycine max), and sunflower (Helianthus annuus) plants at various leaf water potentials. As leaf water potentials decreased, leaf enlargement was inhibited earlier and more severely than photosynthesis or respiration. Except for low rates of enlargement, inhibition of leaf enlarg...

Abscisic acid (ABA) levels in 3-mm apical root segments of slowly droughted sunflower plants (Helianthus annuus L. cv Russian Giant) were analyzed as the methyl ester by selected ion monitoring gas chromatography-mass spectrometry using characteristic ions. An internal standard, hexadeuterated ABA (d6ABA) was used for quantitative analysis. Sunflower seedlings, grown in aeroponic chambers, were...