scholarly journals Hybrid tea-roses under controlled light conditions. 3. Flower and blind shoot production in the glasshouse of seedlings selected for flowering or flower bud abortion at low irradiances in a growth room.

1978 ◽  
Vol 26 (4) ◽  
pp. 399-404
Author(s):  
D.P. de Vries ◽  
L.A.M. Dubois ◽  
L. Smeets
Keyword(s):  
Lower Percentage ◽  
Light Conditions ◽  
Flower Bud ◽  
Low Light ◽  
Light Intensities ◽  
Shoot Production ◽  
Growth Room ◽  
Selection For ◽  
Flower Bud Abortion ◽  
Made In

Seedlings of hybrid tea roses, previously selected in a growth room for flowering or flower bud abortion at low light intensities were grown in a greenhouse for periods of at least 14 months. Previously flowering seedlings whether grown on their own roots or on a rootstock yielded more flowers, particularly in winter, than previously aborting ones. This was due to a lower percentage of blind shoots and a tendency to produce more shoots. It was shown that selection for better winter performance under glass could be made in young seedlings. [For part 2 see HcA 48, 7528.] (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Hybrid tea-roses under controlled light conditions. I. The effect of the level of irradiance on the growth and development of seedlings.

1978 ◽  
Vol 26 (1) ◽  
pp. 119-127
Author(s):  
D.P. de Vries ◽  
L. Smeets
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Growth And Development ◽  
Day Length ◽  
Light Conditions ◽  
Flower Bud ◽  
Juvenile Period ◽  
Low Light ◽  
Bud Formation ◽  
Flower Bud Abortion

As a basis for breeding cvs adapted to flowering in winter light conditions, the growth of hybrid tea rose seedlings under controlled conditions was studied. Irradiance varied from 4-24 W/m2, day length was 8 h, temperature 21 deg C. Like cvs, the seedlings sometimes aborted the flower bud at low light intensity. With increasing irradiances, the following phenomena were observed: the juvenile period of the seedlings shortened; plants were longer at bud formation, at first flowering and at flower bud abortion; leaf area and the number of petals increased. Leaf number was constant at all irradiances. Flowering seedlings were smaller at bud formation, but taller at actual flowering than blind ones. Blind seedlings had fewer leaves with a smaller area. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Hybrid tea-roses under controlled light conditions. 2. Flowering of seedlings as dependent on the level of irradiance.

1978 ◽  
Vol 26 (1) ◽  
pp. 128-132
Author(s):  
D.P. de Vries ◽  
L. Smeets
Keyword(s):  
Selection Procedure ◽  
Light Conditions ◽  
Low Light ◽  
Light Requirement ◽  
Experimental Conditions ◽  
Light Intensities

Under the experimental conditions described in the preceding abstract, mortality increased with decreasing light intensities. The percentage of flowering seedlings increased and that of aborting ones decreased with irradiance. For the populations studied, no genotype-environment interactions for the percentages of flowering seedlings occurred. A selection procedure for roses with a low light requirement for flowering is considered. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Interactions entre mitochondries et chloroplastes dans la cellule. II. Action du DBMIB, de l'antimycine A et du FCCP sur la spore de Funaria hygrometrica

1977 ◽  
Vol 55 (12) ◽  
pp. 1650-1659 ◽  
Author(s):  
D. Chevallier ◽  
R. Douce ◽  
F. Nurit
Keyword(s):  
Cytochrome Oxidase ◽  
Dark Respiration ◽  
High Light ◽  
Light Conditions ◽  
Oxygen Production ◽  
Low Light ◽  
Funaria Hygrometrica ◽  
Light Intensities

The effect of DBMIB, antimycine A, and FCCP on respiration and photosynthesis of intact chlorophyllic moss (Funaria hygrometrica) spore was investigated.Antimycine A (1 μM) strongly inhibited dark respiration, was without effect on photosynthesis at high light intensities (above the saturation plateau values), and stimulated photosynthesis at low light intensities (below the saturation plateau values).DBMIB (3 μM) inhibited photosynthesis and was without effect, even under light conditions, on the dark respiration. Low amount of FCCP (3 μM) partially inhibited oxygen production at high light intensities. In this case, the inhibition observed was partially relieved by 1 μM antimycine A or 30 μM of KCN; higher concentration of FCCP totally inhibited the oxygen production.It seems likely, therefore, that in the chlorophyllic moss spore the cytochrome oxidase pathway is not functioning under high light intensities and that this inhibition of respiration is attributable to the low cytoplasmic ADP:ATP ratio.

scholarly journals Low Light Availability Reduces the Subsurface Sediment Carbon Content in Halophila beccarii From the South China Sea

2021 ◽  
Vol 12 ◽  
Author(s):  
Chanaka Premarathne ◽  
Zhijian Jiang ◽  
Jialu He ◽  
Yang Fang ◽  
Qiming Chen ◽  
...  
Keyword(s):  
Carbon Content ◽  
Light Availability ◽  
Seagrass Beds ◽  
Biomass Carbon ◽  
Light Conditions ◽  
Above Ground Biomass ◽  
Low Light ◽  
Subsurface Sediment ◽  
Light Intensities ◽  
Sediment Carbon

Eutrophication, dredging, agricultural and urban runoffs, and epiphyte overgrowth could reduce light availability for seagrass. This may affect “blue carbon” stocks in seagrass beds. However, little research is available on the effect of light intensities on carbon sequestration capacity in seagrass beds, especially small-bodied seagrasses. The dominant seagrass Halophila beccarii, a vulnerable species on the IUCN Red List, was cultured in different light intensities to examine the response of vegetation and sediment carbon in seagrass beds. The results showed that low light significantly reduced leaf length and above-ground biomass, while carbon content in both above-ground and below-ground tissues were not affected. Low light reduced both the above-ground biomass carbon and the total biomass carbon. Interestingly, while under saturating light conditions, the subsurface and surface carbon content was similar, under low light conditions, subsurface sediment carbon was significantly lower than the surface content. The reduction of subsurface sediment carbon might be caused by less release flux of dissolved organic carbon from roots in low light. Taken together, these results indicate that reduced light intensities, to which these meadows are exposed to, will reduce carbon sequestration capacity in seagrass beds. Measures should be taken to eliminate the input of nutrients on seagrass meadows and dredging activities to maintain the “blue carbon” storage service by enhancing light penetration into seagrass.

scholarly journals Selection of full-sib families of Panicum maximum Jacq under low light conditions

Revista CERES ◽  
2015 ◽  
Vol 62 (2) ◽  
pp. 199-207
Author(s):  
Douglas Mochi Victor ◽  
Liana Jank ◽  
Beatriz Lempp ◽  
Rosangela Maria Simeão ◽  
Marcos Deon Vilela de Resende ◽  
...  
Keyword(s):  
Shade Tolerance ◽  
Genetic Difference ◽  
Dry Mass ◽  
Panicum Maximum ◽  
Light Conditions ◽  
Low Light ◽  
Breeding Programs ◽  
Light Reduction ◽  
Light Intensities ◽  
Mass Accumulation

The silvopastoral system is a viable technological alternative to extensive cattle grazing, however, for it to be successful, forage grass genotypes adapted to reduced light need to be identified. The objective of this study was to select progenies of Panicum maximum tolerant to low light conditions for use in breeding programs and to study the genetic control and performance of some traits associated with shade tolerance. Six full-sib progenies were evaluated in full sun, 50% and 70% of light reduction in pots and subjected to cuttings. Progeny genotypic values (GV) increased with light reduction in relation to plant height (H) and specific leaf area (SLA). The traits total dry mass accumulation (DM) and leaf dry mass accumulation (LDM) had GV higher in 50% shade and intermediate in 70% shade. The GV of tiller number (TIL) and root dry mass accumulation (RDM) decreased with light reduction. The highest positive correlations were obtained for the traits H and RDM with SLA and DM; the highest negative correlations were between TIL and SLA and RDM, and H and LDM. The progenies showed higher tolerance to 50% light reduction and, among them, two stood out and will be used in breeding programs. It was also found that it is not necessary to evaluate some traits under all light conditions. All traits had high broad sense heritability and high genotypic correlation between progenies in all light intensities. There is genetic difference among the progenies regarding the response to different light intensities, which will allow selection for shade tolerance

PROBLEMS OF SELECTION FOR ADAPTATION TO LOW-LIGHT CONDITIONS IN CUT-FLOWERS

1976 ◽  
pp. 131-138
Author(s):  
L.D. Sparnaaij ◽  
D.P. de Vries ◽  
J. de Jong
Keyword(s):  
Light Conditions ◽  
Cut Flowers ◽  
Low Light ◽  
Selection For

Cold tolerance and winter hardiness in Lolium perenne: II. Influence of light and temperature during growth and hardening

1973 ◽  
Vol 80 (2) ◽  
pp. 341-348 ◽  
Author(s):  
T. Lawrence ◽  
J. P. Cooper ◽  
E. L. Breese
Keyword(s):  
Light Intensity ◽  
Cold Tolerance ◽  
Lolium Perenne ◽  
Water Soluble ◽  
Light Conditions ◽  
Low Light ◽  
Growing Period ◽  
Light Intensities ◽  
Lower Light ◽  
Light Input

SummaryIn the first paper of this series it was shown that Lolium perenne material required hardening periods involving low, but above freezing, temperatures before frost tolerance was achieved. The present experiments show that the light conditions during the hardening and prehardening periods are also important. At both stages a reduction in total light energy reduced subsequent cold tolerance but the relative effects of light intensity and photoperiod differed between the prehardening and hardening treatments. Thus low light input during the hardening period at 2 CC reduced cold tolerance most when given at higher intensities over shorter days (8 h) while during the prehardening growing period at 20 °C the reduction was greatest when the lower light input was given at low intensity over longer days (16 h).Varieties of different climatic origins reacted differentially to the treatments. The Mediterranean variety Fano was particularly adversely affected by low light intensities during hardening and also benefited from higher temperatures during the prehardening growing period. With higher light intensities and higher growth temperatures this Mediterranean variety approached the more northern material in cold tolerance; but as a corollary it was clear that the N. European variety Veja was able to harden under lower light conditions, and lower growing temperatures. The varieties Melle and S. 321 from intermediate latitudes, were intermediate in response.Although water soluble carbohydrate content was increased during the hardening period, except at the lowest light intensity (2·9 W/m2), no simple relationship between the WSC content and the cold tolerance of the different varieties could be detected.The results provide a useful guide to the pre-treatments necessary to discriminate between varieties for cold tolerance in such a way that the results can be correlated with field performance.

Selection for resistance to the root-lesion nematode in alfalfa

1992 ◽  
Vol 72 (2) ◽  
pp. 593-598
Author(s):  
B. R. Christie ◽  
J. L. Townshend
Keyword(s):  
Medicago Sativa ◽  
Pratylenchus Penetrans ◽  
Root Lesion Nematode ◽  
Lesion Nematodes ◽  
Growth Room ◽  
Medicago Sativa L ◽  
Lesion Nematode ◽  
Selection For ◽  
Root Lesion Nematodes ◽  
Made In

A study was conducted to evaluate response of alfalfa (Medicago sativa L.) to selection for resistance to the root-lesion nematode (Pratylenchus penetrans (Cobb) Filipjev and Sch.-Stek.) under growth-room facilities. Six hundred plants of the cultivar Vernal were inoculated with root-lesion nematodes. Counts were made 13–14 wk later of the number of nematodes g−1 root. Selections were made for relatively low counts (resistant) and high counts (susceptible). Selections were self-pollinated, and the S1 progeny of nine plants (five resistant and four susceptible) were evaluated. The S1 progenies from both types of selections had similar counts. The S2 progenies of resistant S1 parents, however, had lower counts than those of susceptible parents. The F1 crosses generally reacted as expected on the basis of the S2 parents. Results of this study suggest that progress can be made in breeding for resistance to the root-lesion nematode in alfalfa.Key words: Nematode, Pratylenchus penetrans, alfalfa, selection

Divergent selection for flowering in annual bluegrass and its impact on plant development and turfgrass utility

2003 ◽  
Vol 83 (1) ◽  
pp. 157-162 ◽  
Author(s):  
D. J. Cattani
Keyword(s):  
Population Distribution ◽  
Divergent Selection ◽  
Main Stem ◽  
Poa Annua ◽  
Low Light ◽  
Annual Bluegrass ◽  
Light Levels ◽  
Turfgrass Quality ◽  
Selection For ◽  
Made In

Annual bluegrass (Poa annua L.) is a widely occurring turfgrass component. Recent efforts to develop cultivars of this species have led to increased interest in selection methods. The objectives of this study were to evaluate the utility of controlled growth studies for divergent selection for flowering and to evaluate the resultant selections for development and turfgrass quality. Two growth cabinet selection runs (1997 and 1998) were made at a constant 20°C and a 16-h photoperiod at low light levels. Selection was based upon the earliest and latest plants to produce a seedhead on the main stem. In the second selection run, mid-flowering selection was made to characterize the population distribution. Selections were grown out in the greenhouse in 1998 and 1999. Selections made in 1998 were seeded into a field study in August 1999 and maintained as golf green turf. Late selections flowered later than early or mid selections and produced more leaves on the main stem prior to inflorescence appearance. Seedhead ripening showed greater uniformity in late selections. Some late selections produced few seedheads under the greenhouse conditions. Selection for divergent flowering types was successful using the method employed. Turf performance was not related to flowering type, indicating that screening for turf performance will be required after initial selection for plant type. Key words: Poa annua L., selection, life history, tillering, seed production, turf performance

Sign in / Sign up

Export Citation Format

Share Document