chlorosis, but the addition of urea to the solu tion appeared to enhance the effect of the biuret. Experiment 4. When different amounts of commercial urea and crystalline urea were ap plied to the soil, 10 weeks were necessary for the chlorosis to appear on the trees which had received 60 and 80 grams of the commercial urea. No chlorosis resulted from the crystal line urea. Experiment 5. As a r...

MANY POSTZYGOTIC REPRODUCTIVE BARRIER FORMS HAVE BEEN REPORTED IN PLANTS: hybrid weakness, hybrid necrosis, and hybrid chlorosis. In this study, linkage analysis of the genes causing hybrid chlorosis in F(2) generation in rice, HCA1 and HCA2, was performed. HCA1 and HCA2 are located respectively on the distal regions of the short arms of chromosomes 12 and 11. These regions are known to be high...

Chlorosis level is a useful parameter to assess imidazolinone resistance in sunflower (Helianthus annuus L.). The aim of this study was to quantify chlorosis through two different methods in sunflower plantlets treated with imazapyr. The genotypes used in this study were two inbred lines reported to be different in their resistance to imidazolinones. Chlorosis was evaluated by spectrophotometri...

BACKGROUND AND AIMS Rhizobitoxine, produced by the legume symbiont Bradyrhizobium elkanii, inhibits cystathionine-beta-lyase (EC 4.4.1.8) in methionine biosynthesis and 1-aminocyclopropane-1-carboxylate synthase (ACC) in ethylene biosynthesis. Rhizobitoxine production by B. elkanii enhances nodulation of host legumes via the inhibition of ethylene synthesis, but causes foliar chlorosis in susce...

Iron deficiency chlorosis in plants is often associated with soil conditions that appear to restrict exchange of gases with the atmosphere, such as fine texture, lack of aggregation, excessive moisture, or discontinuity in the profile in the form of plowsole, hardpan, claypan, or stratified deposits. These conditions can cause CO2 to accumulate in the soil and, particularly in calcareous soils,...

Water deficit and iron nutritional deficiency (iron chlorosis) are frequent environmental stresses affecting grapevine production in the Mediterranean region. The objectives of this work were (i) to study combined effects both on aromatic profile Tempranillo grapes, occurring simultaneously vineyard, (ii) evaluate viability foliar chlorophyll content at veraison (Chl) early assess quality poten...