Biological and Transcriptomic Characterization of Pre-Haustorial Resistance to Sunflower Broomrape ( W.) in Sunflowers ().

Infestations with sunflower broomrape ( Wallr.), an obligatory root parasite, constitute a major limitation to sunflower production in many regions around the world. Breeding for resistance is the most effective approach to reduce sunflower broomrape infestation, yet resistance mechanisms are often broken by new races of the pathogen.

Biological activity of natural phytoecdysteroids from Ajuga iva against the sweetpotato whitefly Bemisia tabaci and the persea mite Oligonychus perseae.

Background: Ecdysteroids are steroid hormones that control moulting and govern several changes during metamorphoses in arthropods. The discovery of the same molecules (phytoecdysteroids) in several plant species displayed a wide array of rather beneficial agricultural impact. Many representatives of the genus Ajuga plants contain phytoecdysteroids with a 5β-7-ene-6-one system exhibiting physiological activities in insects.

Dehydrocostus lactone is exuded from sunflower roots and stimulates germination of the root parasite Orobanche cumana.

The germination of the obligate root parasites of the Orobanchaceae depends on the perception of chemical stimuli from host roots. Several compounds, collectively termed strigolactones, stimulate the germination of the various Orobanche species, but do not significantly elicit germination of Orobanche cumana, a specific parasite of sunflower. Phosphate starvation markedly decreased the stimulatory activity of sunflower root exudates toward O.

Broomrape can acquire viruses from its hosts.

Broomrapes (Phelipanche, formerly Orobanche) are parasitic plants that physically connect with the vascular systems of their hosts through haustorial structures. In this study, we found that Cucumber mosaic virus (CMV), Tomato mosaic virus (ToMV), Potato virus Y (PVY), and Tomato yellow leaf curl virus (TYLCV) translocate from infected host plants to Phelipanche aegyptiaca. In order to examine whether these viruses, and specifically CMV, replicate in the parasite, we tested several replication parameters.

Is seed conditioning essential for Orobanche germination?

Background: Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity.

High-nitrogen compost as a medium for organic container-grown crops.

Compost was tested as a medium for organic container-grown crops. Nitrogen (N) loss during composting of separated cow manure (SCM) was minimized using high C/N (wheat straw, WS; grape marc, GM) or a slightly acidic (orange peels, OP) additives. N conservation values in the resultant composts were 82%, 95% and 98% for GM-SCM, OP-SCM and WS-SCM, respectively.