Shoot phenology and water relations of Piceaglauca

1989 ◽  
Vol 19 (10) ◽  
pp. 1287-1290 ◽  
Author(s):  
Steven C. Grossnickle

Piceaglauca var. albertiana (S. Brown) Sarg. shoot phenology and water relation parameters were monitored monthly for 1 year. Seedlings were kept outdoors, well watered, and exposed to seasonal changes in temperature and day length. Changes in shoot water relation parameters corresponded with changes in phenology. During spring, shoot elongation, osmotic potential at saturation, and turgor loss point were least negative, −1.30 and −1.56 MPa, respectively, whereas bulk modulus of elasticity at full turgor was at its highest, 22 MPa. Both osmotic potential at saturation and turgor loss point were most negative, −2.01 and −2.73 MPa, respectively, during late winter just before bud break. Shoot dry weight fraction was at its lowest, 0.33 g dry wt./g shoot weight and maximum symplastic water per unit weight of shoot tissue was at its highest, 3.99 g H2O/g dry wt., during spring shoot elongation. Number of osmoles of solute per kilogram shoot dry weight was highest during spring and late summer shoot elongation phases, 1.03 and 0.91 osmol/kg dry wt., respectively. These data suggest that P. glauca seedlings do not adjust well to dry site conditions.

Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 489-493 ◽  
Author(s):  
Frank L. Young ◽  
David R. Gealy ◽  
Larry A. Morrow

In the greenhouse, glyphosate [N-(phosphonomethyl)glycine] at 0.6 kg ae/ha applied directly to seeds alone or seeds on the soil surface reduced germination and shoot dry weight of common rye (Secale cerealeL. ♯3SECCE). Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) applied similarly at 0.6 kg ai/ha reduced germination and shoot dry weight of downy brome (Bromus tectorumL. ♯ BROTE) and wheat (Triticum aestivumL. ‘Daws' ♯ TRZAX). Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H)-one] at 0.6 kg ai/ha applied to seeds, soil, or seeds and soil had very little effect on germination, but significantly reduced shoot dry weight of common rye, downy brome, wheat, and jointed goatgrass (Aegilops cylindricaHost. ♯ AEGCY). Pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide] at 0.6 kg ai/ha, and propham (isopropyl carbanilate) at 3.4 kg ai/ha plus extender (p-chlorophenyl-N-methylcarbamate) at 0.4 kg ai/ha substantially reduced shoot height and dry weight of all species, regardless of application method, with pronamide completely inhibiting shoot elongation and dry-weight production in three of the four species.


1987 ◽  
Vol 17 (7) ◽  
pp. 635-643 ◽  
Author(s):  
Laura E. DeWald ◽  
Peter P. Feret

Loblolly pine (Pinustaeda L.) 1 + 0 seedlings were periodically hand lifted from a Virginia nursery to determine how root growth potential (RGP) varied between September and April. Several seedling characteristics, RGP, and shoot phenology were recorded for each lift date in 1983–1984 and 1984–1985. An attempt was made to relate RGP variation to changes in the nursery environment and to shoot phenology. Root growth potential variation was consistent between years and was more closely related to shoot phenological changes than to short-term environmental changes. During the development of dormancy, RGP was low, RGP increased when shoot activity resumed during the RGP tests (late winter, early spring), and declined as active shoot elongation began in the nursery. When RGP was low, elongation of existing lateral roots primarily contributed to the new root systems, but as seedling metabolism increased in the late winter, new root initiation also contributed to new root systems. Absolute differences in RGP between years may be related to the fibrosity of seedling root systems.


1966 ◽  
Vol 19 (4) ◽  
pp. 517 ◽  
Author(s):  
D Aspinall

Apical growth, floral development, stem elongation, tillering, and dry weight at ear emergence were compared for 10 varieties of barley (Hordeum vulgare L.) growing in a range of photoperiods. All the varieties could be described as quanti. tative long. day plants but there was a wide range of response to the photoperiod. In all the varieties and over all photoperiods, apical primordium production was linked with floral organogenesis, suggesting a common mechanism of photoperiodic influence on the two proce~es. The control of internode elongation, however, varied between different varieties, commencing at a much earlier stage of floral organogenesis in some varieties than in others. Tillering appeared to be controlled more by the amount of energy available for photosynthesis than by any photoperiodic process, and this was also an important factor in shoot dry weight at ear emergence.


HortScience ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Xue-Min Hou ◽  
Zi-Hua Wang ◽  
Xi-Min Deng ◽  
Guo-Hui Li

This experiment was carried out to obtain a pressure–volume (P-V) curve and Höfler diagram of the cortex tissue of fresh ‘Fuji’ apple fruit (Malus ×domestica Borkh.) with a novel centrifuge method. Based on the P-V curve and Höfler diagram, several water relation parameters of cortex tissue were determined and the interrelationship of these parameters was established. Turgor loss point (TLP) occurred at –1.74 MPa and 73.7% of relative water content (R*). At full hydration, osmotic potential (ψS) was –1.30 MPa and symplastic water accounted for 86.8% of R*. Bulk elastic modulus decreased linearly by 28% as pressure potential declined from 1.30 MPa at full hydration to zero at the TLP. This centrifuge technique can provide a simple and efficient way to determine water relation parameters of fleshy fruits.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 854C-854
Author(s):  
Ursula K. Schuch ◽  
Barbara Biernacka

Four azalea cultivars [Rhododendron × `White Lace' (WT), `Southern Charm' (SC), `Formosa' (F), and `George Tabor' (GT)] with different growth and flowering habits were treated with a foliar spray of uniconazole (U) at 0, 10, or 15 mg·liter–1 with or without a surfactant. GA was applied at 0 or 15 mg·liter–1 as a foliar spray to half of the plants on 23 Sept. 1993, 53 days after the uniconazole application. U reduced number, length, and dry weight of bypass shoots, and increased number of flower buds for all cultivars by Dec. 1993. Application of GA after U further increased the number of flower buds on SC and GT, which otherwise had few flowers. At the final evaluation in Mar. 1994, time to anthesis for cultivars F and GT was not affected by any treatment. Anthesis of SC and WL treated with 15 mg U and GA/liter started 6 days earlier than those treated with 15 mg U/liter. Number of flowers at anthesis and number of flower buds was increased two to four times on U-treated vs. nontreated plants. U decreased plant height, size, leaf area, and shoot dry weight of all cultivars. Shoot elongation of F and GT was further reduced with the 15 vs. 10 mg U/liter treatment. Application of GA increased the retarding effects of U on plant height for WL, SC, and GT, and on leaf area and shoot dry weight for WL.


1999 ◽  
Vol 47 (4) ◽  
pp. 587 ◽  
Author(s):  
D. Eamus ◽  
L. D. Prior

The monsoonal areas of northern Australia experience extreme seasonal variations in rainfall, with an annual dry season of 7 months or more. Seasonal changes in leaf water relations were investigated for saplings of two tree species common in northern Australian savannas: Eucalyptus tetrodonta F.Muell, an evergreen, and Terminalia ferdinandiana Excell, which is deciduous. Saplings may experience more severe water stress than mature trees because their root systems are less extensive. This study found a positive correlation between pre-dawn leaf water potential and tree height during the dry season, but not during the wet season, for both E. tetrodonta and T. ferdinandiana trees. Pressure–volume curves were constructed for leaves of E. tetrodonta saplings at 2-monthly intervals throughout the year. Osmotic potential at full turgor decreased from a maximum of −1.33 MPa in February (wet season) to −2.25 MPa in October (late dry season), then increased to an intermediate value of −1.71 MPa in December (early wet season). Leaves of T. ferdinandiana saplings were compared in February (wet season) and April (end of wet season; before leaf senescence). Osmotic potential at full turgor decreased from −1.18 MPa in February to −1.39 MPa in April. The capacity for turgor maintenance was larger for E. tetrodonta than for T. ferdinandiana, with osmotic potential at full turgor and the turgor loss point, relative water content at the turgor loss point and the ratio of turgid weight to dry weight all lower in E. tetrodonta.


2021 ◽  
Author(s):  
Nguyen Thanh Tam ◽  
Maria Stefanie Dwiyanti ◽  
Shuntaro Sakaguchi ◽  
Yohei Koide ◽  
Le Viet Dung ◽  
...  

Abstract The Mekong Delta River in Vietnam is facing salinity intrusion caused by climate change and sea-level rise that is severely affecting rice cultivation. Here, we evaluated salinity responses of 97 rice accessions (79 landraces and 18 improved accessions) from the Mekong Delta population by adding 100 mM NaCl to the nutrient solution for up to 20 days. We observed a wide distribution in salinity tolerance/sensitivity, with two major peaks across the 97 accessions when using the standard evaluation system (SES) developed by the International Rice Research Institute. SES scores revealed strong negative correlations (ranging from –0.68 to –0.83) with other phenotypic indices, such as shoot elongation length, root elongation length, shoot dry weight, and root dry weight. Mineral concentrations of Na+ in roots, stems, and leaves and Ca2+ in roots and stems were positively correlated with SES scores, suggesting that tolerant accessions lower their cation exchange capacity (CEC) in the root cell wall. The salinity tolerance of Mekong Delta accessions was independent from the previously described salinity tolerance–related locus Saltol, which encodes an HKT1-type transporter in the salinity-tolerant cultivars Nona Bokra and Pokkali. Indeed, genome-wide association studies (GWASs) using SES scores and shoot dry weight ratios of the 79 accessions as traits identified a single common peak located on chromosome 1. This SNP did not form a linkage group with other nearby SNPs and mapped to the 3′ untranslated region of gene LOC_Os01g32830, over 6.5 Mb away from the Saltol locus. LOC_Os01g32830 encodes chloroplast glycolate/glycerate translocator 1 (OsPLGG1), which is responsible for photorespiration and growth. SES and shoot dry weight ratios differed significantly between the two possible haplotypes at the causal SNP. Through these analyses, we characterize Doc Phung, one of the most salt-tolerant varieties in the Mekong Delta population and a promising new genetic resource.


1964 ◽  
Vol 17 (4) ◽  
pp. 807 ◽  
Author(s):  
D Aspinall ◽  
LG Paleg

The effects of variations in light intensity, photoperiod, and light quality on shoot dry weight, tillering, and leaf growth of barley (cv. Prior) have been examined in controlled environments. The rates of tillering and of dry matter production were primarily dependent upon the total radiant energy incident upon the plants. Tiller-iug was unaffected by changes in the photoperiod (independent of light energy) or in the spectral composition of the light which profoundly affected apical develop-ment. At low light intensities, tiller buds on the main axis only elongated, whereas at higher intensities secondary and higher�order tillers were produced. The largest number of tillers was associated with the coieoptile node, and tiller production declined regularly with each successive node up the main axis.


1986 ◽  
Vol 16 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Kyoji Doi ◽  
Yasushi Morikawa ◽  
Thomas M. Hinckley

The role of osmotic adjustment in turgor maintenance during periods of either cold soil or plant temperatures or of high evaporative demand was described for 2-year-old Cryptomeriajaponica D. Don seedlings. Water relations parameters were measured by the pressure–volume technique for a 1-year period. The osmotic potential at full turgidity and at the point of zero turgor ranged from −1.32 to −2.70 MPa and from −1.70 to −3.52 MPa, respectively. Highest values of osmotic potential were associated with the period of foliage expansion, while lowest values were noted in mid-February during the period of lowest air temperatures. The role of solute changes or changes in symplastic water relative to tissue dry weight in osmotic adjustment is described.


1996 ◽  
Vol 74 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Steven C. Grossnickle ◽  
John H. Russell

Yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) shoot water relations parameters were measured in response to (i) seasonal changes in photoperiod and temperature and (ii) controlled changes in root temperature and soil moisture. Pressure–volume curves determined measurements of shoot water relation parameters. Osmotic potential at saturation (Ψsat) and turgor loss point (Ψtlp) were lowest during February at −1.73 and −2.35 MPa, respectively. Both Ψsat and Ψtlp increased in the spring to a high in July of −1.05 and −1.28 MPa, respectively, when shoot growth was occurring. Total turgor (ΨPTotal) was 18.2 MPa in December and declined to its lowest level of 5.98 MPa in July. Increased ΨPTotal from late summer through winter could be attributed to osmotic and (or) elastic components, while decreased ΨPTotal in the spring was due to a decrease in both osmotic and elastic components. Both Ψsat and Ψtlp decreased as root temperatures were reduced from 22 to 1 °C. There was an increase in ΨPTotal as root temperatures declined from 15 to 8 °C because of both osmotic and elastic adjustment, with osmotic adjustment the primary factor. Turgor decreased at root temperatures below 8 °C, even though osmotic adjustment was occurring, and this was due to a reduction in the elastic component. Both Ψsat and Ψtlp decreased in response to drought, though Ψtlp decreased at a greater rate. Increased turgor during the initial stages of long-term drought results from an increase in both osmotic and elastic components, while increased turgor was solely due to the osmotic component as drought became more severe. Under rapid drought, turgor adjustment was minimal because the increased osmotic component was offset by a decrease in the elastic component. Results from these experiments indicate that turgor maintenance of yellow-cedar occurs through the use of both osmotic and elastic components in varying degrees at different times of the year and under differing environmental conditions. Keywords: Chamaecyparis nootkatensis, osmotic potential at saturation and turgor loss point, total turgor with osmotic and elastic components, seasonal patterns, root temperature, drought.


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