The sensitivity of the Nicotiana plumbaginifolia wild-type and phytochrome B (hlg) mutant to photoperiod was investigated. Leaf number at bolting and rosette-leaf movement were measured under conditions of different light quality and photoperiod. Bolting in wild-type plants was slightly delayed under short days (SD), compared to plants grown under long days (LD). The hlg mutant bolted later tha...

Environmental influences on lactation efficiency are frequently associated with reductions in milk output. Heat stress, for example, leads to depressed feed intake and, subsequently, losses in production. Conversely, cold stress may limit nutrients available for milk synthesis. Fortunately, one environmental factor, photoperiod, can exert a positive effect on dairy performance when managed prop...

Crop production is inherently sensitive to variability in climate. Temperature is a major determinant of the rate of plant development and, under climate change, warmer temperatures that shorten development stages of determinate crops will most probably reduce the yield of a given variety. Earlier crop flowering and maturity have been observed and documented in recent decades, and these are oft...

The Ma3 gene is one of six genes that regulate the photoperiodic sensitivity of flowering in sorghum (Sorghum bicolor [L.] Moench). The ma3R mutation of this gene causes a phenotype that is similar to plants that are known to lack phytochrome B, and ma3 sorghum lacks a 123-KD phytochrome that predominates in light-grown plants and that is present in non-ma3 plants. A population segregating for ...

The Ma, gene is one of six genes that regulate the photoperiodic sensitivity of flowering in sorghum (Sorghum bicolor [L.] Moench). The masR mutation of this gene causes a phenotype that is similar to plants that are known to lack phytochrome B, and masR sorghum lacks a 123-kD phytochrome that predominates in light-grown plants and that is present in non-magR plants. A population segregating fo...

to photoperiod. It is widely accepted that the early phase of soybean development is not influenced by photopeTo accurately model the flowering process in soybean, it is essential riod and can therefore be described as a juvenile phase to identify photoperiod-sensitive and photoperiod-insensitive phases (Shanmugasundaram and Tsou, 1978; Hodges and of development. Despite extensive studies, ther...

In wild mammals, offspring development must anticipate forthcoming metabolic demands and opportunities. Within species, different developmental strategies may be used, dependent on when in the year conception takes place. This phenotypic flexibility is initiated before birth and is linked to the pattern of day length (photoperiod) exposure experienced by the mother during pregnancy. This progra...

We present findings suggesting that photoperiod is important in determining the sensitivity of the late-pregnant rabbit uterus to oxytocin (OT). Longitudinal myometrial strips were taken from term-pregnant and estrous rabbits and mounted in an organ bath for isometric myographic recording at different times during a 16:8-h light-dark cycle (lights on 0600-2200; n = 5/group), and the strength of...