. Nevertheless, the information available in the literature shows that the effects of these mechanisms on the mineral composition of plant tissues are not consistent ( Cuartero and Fernández-Muñoz, 1999 ). Additionally, there is a lack of information about the
Francesco Giuffrida, Marianna Martorana, and Cherubino Leonardi
Kyong Ju Choi, Gap Chae Chung, and Sung Ju Ahn
Cucumber (Cucumis sativus L.) seedlings were grafted onto cucumber-(CG) or figleaf gourd (FG, Cucurbita ficifolia Bouche) seedlings in order to determine the effect of solution temperature 12, 22, and 32C) on the mineral composition of xylem sap and plasma membrane K+–Mg++–ATPase activities of the roots. Low solution temperature (12C) lowered the concentration
Youssef Rouphael and Giuseppe Colla
the concentrations of glucose (average 7.1 mg·g −1 fresh wt), fructose (average 6.6 mg·g −1 fresh wt), and sucrose (average 1.2 mg·g −1 fresh wt) (data not shown). Concerning the fruit mineral composition, the N and K concentrations were
Neo Edwin Nyakane, Moosa Mahmood Sedibe, and Elisha Markus
. Cations of nutrient solutions used to study effects of Ca:Mg ratio, magnetic field, and mycorrhizal fungi on yield and mineral composition of rose geranium. Layout. Treatments were arranged in a completely randomized block design with three replications
Harbans L. Bhardwaj and Anwar A. Hamama
Tepary bean (Phaseolus acutifolius A. Gray), a native of southwestern U.S., is a promising plant for crop diversification and for production in short rotations with wheat. However, protein and mineral concentrations in tepary bean seed produced outside the southwestern U.S. are largely unknown. We evaluated concentrations of protein and various minerals in seed produced by eight tepary bean genotypes planted at three different dates each during 1997 and 1998 at Ettrick, Virginia. Significant year × planting date and year × genotype interactions existed for protein and other traits. Protein and zinc concentrations increased and calcium concentrations decreased with later plantings during both years. Mid-June planting had 14% higher protein concentration (24.5%) than late-May planting (21.4%) and mid-July planting had 6% higher protein concentration (25.9%) than mid-June planting. Color of seedcoat was not associated with concentrations of protein or minerals. The average concentrations of boron, calcium, copper, iron, potassium, magnesium, manganese, phosphorus, sulfur, and zinc (mg/100g) were: 1, 184, 1, 11, 1531, 192, 3, 451, 311, 4, respectively. Tepary bean seeds contained 24% protein as compared to reported average values of 22.3% in navy, 22.5% in red kidney, and 20.9% in pinto bean. The average iron concentration (mg/100g) in tepary bean seed (10.7) was higher than that in navy (6.4), red kidney (6.7), and pinto (5.9) bean. Based on protein and mineral concentrations tepary bean seed compared well with seeds of navy, red kidney, or pinto bean.
Glenn C. Wright, Kim D. Patten, and Malcolm C. Drew
`Tifblue' and `Brightwell' rabbiteye blueberry (Vaccinium ashei Reade) and `Sharpblue' southern highbush blueberry (primarily V. corymbosum) were treated with 0, 25, and 100 mm Na+ as Na2SO4 or NaCl, and 0, 1, 3, and 10 mm supplemental Ca2+ in sand culture in the greenhouse. For rabbiteye plants salinized with Na2SO4, leaf Na+ concentrations increased 54-fold and the percentage of total plant Na+ found in the leaves increased from 9% to 63% with increasing external Na+. Calcium supplementation reduced the Na+ concentrations in leaves by up to 20%. Leaf Ca2+ concentrations increased with Ca2+ supplementation, but accounted for a decreasing percentage of the total Ca2+ found in the plant, since root Ca2+ concentrations were much higher. Root Na+ concentrations increased with increasing Na+ treatments to a smaller extent than in the leaves and were also reduced by Ca2+ supplements. Potassium concentrations in leaves and roots decreased with increasing Na+ treatment levels, particularly in roots, where K+ concentration was about half at 100 mm Na+ (as Na2SO4.) Leaf Na+ concentrations were up to two times greater when Na was supplied as NaCl compared to Na2SO4. For plants salinized with NaCl, leaf Na+ levels increased to 1.1% and did not decrease when supplemental Ca2+ was applied. Leaf Cl- concentrations also increased greatly with NaCl, reaching >1.0% (dry weight basis.). Root Cl- concentrations also increased with increasing salinity and were not affected by Ca2+ supplements. Ca2+ supplementation led only to a greater Ca2+ concentration in leaves and roots, but this did not alter Na+ concentrations. Nutrient concentrations in `Sharpblue' leaves, stems, and roots were greater than those of the rabbiteye cultivars, but were influenced by salinity and Ca2+ in essentially the same way. Excess Na+, Cl-, or both, together with lowered K+, were likely the cause of extensive leaf necrosis and may be indicative of a lack of a mechanism to control Na+ influx into blueberry leaves.
G.H. Neilsen, P. Parchomchuk, W.D. Wolk, and O.L. Lau
Newly planted `Jonagold' and `McIntosh' apple (Malus domestica Borkh.) on M.26 fertigated with Ca(N03)2 showed increased early tree vigor and leaf Ca concentration but decreased leaf Mg and Mn compared to trees fertigated with urea or NH4N03. Fertigation with P increased early tree vigor, leaf and fruit P concentration, and decreased leaf Mn in the first year relative to a single planting hole application of granular P. Increased fruit Ca concentration in `Jonagold' in one year was associated with the use of Ca(N03)2 and fertigation of P. Fruit quality was generally unaffected by the experimental treatments.
Thomas E. Marler and Yasmina Zozor
Leaf gas exchange, chlorophyll fluorescence, water relations, and mineral nutrient relations responses of Annona squamosa seedlings to mild salinity were studied in sand culture in five experiments during 1990, 1991, and 1993. Trees were irrigated with a complete nutrient solution (control) or with this solution amended to 3 or 6 dS·m-1 with sea salt. Inhibition of net CO2 assimilation, stomatal conductance of CO2, and transpiration was apparent within 2 weeks of initiating salinity treatments, and gas exchange continued to decline until day 30 to 35. The diurnal pattern of leaf gas exchange was not altered by increased salinity. Salinity reduced CO2, light energy, and water-use efficiencies. Salinity sometimes reduced the ratio of variable to maximum fluorescence below that of the control, and this response was highly dependent on the ambient light conditions that preceded the measurements. Dark respiration was unaffected by salinity stress. Root zone salinity of 3 dS·m-1 administered for 52 days did not influence foliar sodium concentration or the ratio of sodium to potassium, but increased chloride concentration and decreased nitrogen concentration. The sodium response indicated that some form of exclusion or compartmentation occurred. Salinity reduced osmotic potential of root tissue but did not influence foliar osmotic or predawn xylem potential. These results indicate that A. squamosa is sensitive to salinity stress, and that the responses to salinity are consistent with other salt-sensitive woody perennial species.
Reza Salehi, Abdolkarim Kashi, Jung-Myung Lee, Mesbah Babalar, Mojtaba Delshad, Sang-Gyu Lee, and Yun-Chan Huh
) high concentrations of P, Ca, and Mg in watermelon/squash; 2) high K concentration in watermelon/bottle gourd; and 3) no difference in NO 3 -N concentration among rootstocks. This trend of mineral composition was slightly different from our results
Wesley R. Autio
The effects of rootstock on `Delicious' (Malus domestics Borkh.) apple ripening, quality, size, mineral composition, and storability were studied over 4 years. Removal of the effects of crop load by analysis of covariance suggested that M.27 EMLA advanced fruit ripening and that M.7 EMLA delayed fruit ripening. Ott.3, M.9, MAC 9, OAR 1, M.9 EMLA, and M.26 EMLA either were inconsistent in their effects on ripening or consistently-resulted in an intermediate time of ripening. Fruit size consistently was largest from trees on M.9 EMLA and smallest from trees on OAR 1. Fruit from trees on MAC 9 generally had relatively high Ca contents, and fruit from trees on OAR 1 had relatively low Ca concentrations. The effects of rootstock on storability appeared to be related to their effects on maturity arid Ca levels.