The temperature sensitivity is reported for the latent period preceding ethylene-induced elongation in the adaxial half of the leaf petiole of Helianthus annuus. When intact plants were exposed to 10 mul of ethylene/l of air over the temperature range 18 to 35 C, the minimum latent time was 62 minutes at 28 C and the maximum was 132 minutes at 18 C. The temperature coefficient, Q(10), changed f...

Many key aspects of early angiosperms are poorly known, including their ecophysiology and associated habitats. Evidence for fast-growing, weedy angiosperms comes from the Early Cretaceous Potomac Group, where angiosperm fossils, some of them putative herbs, are found in riparian depositional settings. However, inferences of growth rate from sedimentology and growth habit are somewhat indirect; ...

Present studies show that nitrate accumulation is the major factor influencing the water uptake by vegetables, but there is lack of knowledge on how the relationship between nitrate and water concentrations in different vegetable tissues. We determined nitrate accumulation and water content in vegetables of rape, Chinese cabbage, and spinach under different nitrogen levels (experiment I), 29 sp...

salinity stress is one of the most important abiotic stresses which threaten plants. in order to study the effect of salinity stress on yield and yield components of sunflower and also genetic analysis of these traits in relation with salt tolerance, a factorial experiment based on a completely randomized design with three replications was conducted. pots were arranged outside the greenhouse in...

Recent studies using LED lighting at low to modest intensity have indicated that compared with red light, blue light can promote plant elongation in many crops as a shade avoidance response despite varying sensitivity environments, species, and growth stages. Currently, there is limited understanding of how temperature affects the light-mediated response. To clarify this point, two microgreen s...

' Received Sept. 27, 1962. ing 125 mm being miiade up with either argon or ethylene. The followiing gas mixtures were used: air, 10 % 02 + 90% A, 7.5% O., + 92.5 % A, 5% 02 + 95% A. In other experimlenits the partial pressure of ethylene in the jars was varied from 0 to 253 nim Hg, while the O. level was maintained at 5 % and total pressure adjusted to 760 mim with argon. For comparative purpos...

A new taxon of probable gymnosperm affinities is described from the base of the Carboniferous (Mississippian, Middle Tournaisian) of Montagne Noire, southern France. It is based on a permineralised stem showing vascular and cortical tissues, and one attached petiole base. Faironia difasciculata gen. et sp. nov. shows the combination of a broad eustele and dense wood with a multifascicular leaf ...

To develop antibody probes for the neutral side chains of pectins, antisera were generated to a pectic galactan isolated from tomato (Lycopersicon esculentum) pericarp cell walls and to a (1 +4)-pgalactotetraose-bovine serum albumin neoglycoprotein. l h e use of these two antisera in immunochemical assays and immunolocalization studies indicated that they had very similar specificities. A monoc...