Tansy plants (Tanacetum vulgare L.) exhibit high chemical variation, particularly in mono- and sesquiterpenes that are stored in specialised glands on the plant surface. In the present work we investigated the effects of terpene chemotypes on Metopeurum fuscoviride, an aphid species specialised on tansy, and their tending ants, at the field scale. Previous studies have chemotyped tansy by asses...

introduction evaluating yield in intercropping systems is based on selecting compatible plants with appropriate characteristics to establish minimum competition and maximum cooperation, and the application of suitable agricultural practices (crop density and intercropping ratio). the use of plant species with different morphological characteristics in terms of nutrient uptake and utilization of...

BACKGROUND AND AIMS Bolting, the first visible sign of reproductive transition in beets (Beta vulgaris), is controlled by the dominant bolting gene B (B allele), which allows for flowering under long days (LDs, >14 h light) without prior vernalization. The B-locus carries recessive alleles (bb) in sugar beet (Beta vulgaris L. spp. vulgaris), so that vernalization and LDs are required for boltin...

Leaf trichomes may protect plants against herbivorous insects, and may increase tolerance to drought and UV-radiation. The perennial herb Arabidopsis lyrata (Brassicaceae) is polymorphic for trichome production and occurs in a glabrous and trichome-producing form. In addition, there is quantitative variation in trichome density among trichome-producing plants. To examine the genetic basis of gl...

Ethylene inhibits the establishment of symbiosis between rhizobia and legumes. To examine how and when endogenous ethylene inhibits rhizobial infection and nodulation, we produced transgenic Lotus japonicus carrying the mutated melon ethylene receptor gene Cm-ERS1/H70A that confers ethylene insensitivity and fixes the transgene in the T(3) generation. The resultant transgenic plants showed redu...

Aim This study investigated the antifungal properties of aqueous extracts obtained from indigenous plants that grow spontaneously in the Northern Sahara of Algeria. The activities of these plants in controlling two fungal species that belong to Fusarium genus were evaluated in an in vitro assay. Materials and Methods Fresh aerial parts of four plant species (Artemisia herba alba, Cotula ciner...

Consider the problem of selection involved in choosing seeds from plants showing a certain dominant character, while no effort is made to influence the source of pollen. In the following discussion the fate of a single Mendelian character will be studied under such mating. The conclusion can be stated thus: The limiting population resulting from the type of mating in question i s all of one cl...

Dominant species play key roles in shaping community structure, but their behavior is far from uniform. We speculated that recognition of different behaviors (determined objectively) would be an indicator of the condition of plant communities. We developed a species dominance index (SDI) to identify dominant species and compare their behavior across multiple spatial scales. The SDI is based on ...