scholarly journals Variation Between Cut Chrysanthemum Cultivars in Response to Suboptimal Temperature

2007 ◽  
Vol 132 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Anke van der Ploeg ◽  
Ranathunga J.K.N. Kularathne ◽  
Susana M.P. Carvalho ◽  
Ep Heuvelink
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Temperature Response ◽  
Dry Weight ◽  
Stem Length ◽  
Long Day ◽  
Cultivation Period ◽  
Optimum Response ◽  
Total Dry Weight ◽  
Response To Temperature

To breed for more energy-efficient cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivars it is important to know the variation of the temperature response existing in modern cultivars. In a greenhouse experiment with 25 chrysanthemum cultivars, a significant variation was observed in temperature response (16 °C or 20 °C) for reaction time, total dry weight produced, stem length, and flower size and number. To study this genetic variation in temperature response over a larger range of temperatures (15 °C to 24 °C), four contrasting cultivars (Annecy, Delianne, Reagan, and Supernova) were selected in a second experiment. Furthermore, a third experiment was performed in which the cultivation period was split into three phases and the influence of temperature in each of these phases was studied for the four selected cultivars. Dry weight production in all cultivars was very sensitive to temperature during the long day period. Relative growth rate showed an optimum response to temperature, with the optimum around 24 °C. Net assimilation rate also showed an optimum response to temperature, whereas leaf area ratio increased linearly with temperature. Compared with these temperature effects during the long day, the effect of temperature on absolute growth rate during the short day was, depending on the cultivar, relatively small or even absent. The reaction time, on the other hand, was very temperature sensitive, showing an optimum that was cultivar dependent. The temperature response of the total dry weight production during the whole cultivation period was, therefore, very cultivar dependent. Furthermore, depending on the cultivar, stem length increased with temperature, especially during long day, as a result of both increasing internode number and average internode length. The response of both flower size and number to temperature was also highly cultivar specific. The possibilities of using this genetic variation for breeding are discussed.

scholarly journals The effect on the growth of Lemna minor of alternating periods of light and darkness of equal length

1938 ◽  
Vol 125 (838) ◽  
pp. 115-123 ◽  
Keyword(s):  
Growth Rate ◽  
Lemna Minor ◽  
Stomatal Closure ◽  
Continuous Light ◽  
Dry Weight ◽  
Culture Solution ◽  
Single Individual ◽  
Lighting Conditions ◽  
Net Assimilation ◽  
Total Dry Weight

Garner and Allard (1931) showed that plants grown in alternating light and dark periods of equal duration respond differently according to the length of the period. They found that the growth of Cosmos sulphureus, for example, was progressively poorer as the alternating periods decreased from 12 hr. to 1 min., after which it improved rapidly so that at 5 sec. intermittency the plants were of fairly normal appearance, i.e. like those in 12 hr. alternations. No measurements of these effects however were made. Portsmouth (1937) carried out similar experiments with cucumber plants, and has shown that the increase in total dry weight is greatest in continuous light, only slightly less in 12 hr. alternations and considerably less in 1 min. alternations. He suggests that the effects observed were related to carbohydrate deficiency occasioned by a falling net assimilation rate and partial closure of the stomata at 1 min. alternations. Gregory and Pearse (1937) have shown that short alternating light and dark periods are accompanied by a closing of the stomata in Pelargonium , and here again the effect was at a maximum with intermittencies of about 1 min. duration. In view of the above results it was decided to repeat and extend the growth-rate determinations with Lemna minor , which is simple in structure and is eminently suitable for experimental work under laboratory conditions. It had also the advantage, as its stomatal opening does not change, that should results similar to those of Garner and Allard, and Portsmouth, be obtained it would be possible to assess the value of stomatal closure at rapid intermittencies on growth rate. 2. Experimental procedure Two different stocks of Lemna were employed, one, coming originally from the Chelsea Physic Garden, had been used previously in this de-partment, while the other was a fresh stock obtained from Sutton. Each stock was established in the first instance from a single individual. In all cases colonies were grown under 12 hr. alternating light and darkness for 14 days before being placed under the lighting conditions in which their growth rate was to be measured. Apart from the light factor all environmental conditions were the same during the preliminary 14 days as when measurements were being made. The plants were grown in a culture solution made up as follows: CaH 4 (PO 4 ) 2 . H 2 O 0·100 g., KNO 3 0·800 g., MgSO 4 . 7H 2 O 0·25 g., FeCl 3 0·002g., distilled water 1000 ml. In some cases the water used was condensed on glass, in others on copper. The culture solution was changed only when the plants were being measured; it was not aerated but always shaken up with air immediately before being used. The solution was made up in amounts of 2 litres, but as the number of colonies to be supplied varied from time to time the several lots lasted for different periods.

Development of yield in two grain-sorghum hybrids. I. Dry weight and carbon-14 studies

1982 ◽  
Vol 33 (6) ◽  
pp. 1009 ◽  
Author(s):  
RJ Chamberlin ◽  
GL Wilson
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Growth And Development ◽  
Dry Weight ◽  
Grain Sorghum ◽  
Carbon 14 ◽  
Biological Yield ◽  
Total Dry Weight ◽  
Weight Data

Growth and development of two grain-sorghum hybrids (De Kalb E57 and Texas 610) were examined under glasshouse conditions by sequential harvesting and the use of I4C. The grain yield per plant of Texas 610 was higher than that of E57, with higher total biological yield and similar harvest indices. The contribution to grain weight at maturity, of carbon assimilated prior to anthesis, was about 10% for each hybrid. The leaves were the main source of this material. After anthesis, dry weight data indicated that temporary storage of assimilates before retranslocation to the grain was of greater importance in Texas 610 than E57. This storage was largely in the leaves (including sheaths), upper internodes, and roots. A high grain-growth rate was maintained for longer by Texas 610 than by E57. Total dry weight production after anthesis in both hybrids was, at all stages examined, more than sufficient to maintain grain growth.

Genetic variation for leaf carbon isotope discrimination and its association with transpiration efficiency in canola (Brassica napus)

2020 ◽  
Vol 47 (4) ◽  
pp. 355
Author(s):  
Shek M. Hossain ◽  
Josette Masle ◽  
Andrew Easton ◽  
Malcolm N. Hunter ◽  
Ian D. Godwin ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Carbon Isotope ◽  
Carbon Isotope Discrimination ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Transpiration Efficiency ◽  
Isotope Discrimination ◽  
Leaf Chlorophyll ◽  
Total Dry Weight ◽  
Positive Correlations

Drought is a major constraint to canola production around the world. There is potential for improving crop performance in dry environments by selecting for transpiration efficiency (TE). In this work we investigated TE by studying its genetic association with carbon isotope discrimination (Δ) and other traits, e.g. specific leaf weight (SLW) and leaf chlorophyll content (SPAD). Among the 106 canola genotypes – including open-pollinated, hybrid, inbred types and cytoplasmic variants – tested in the field and glasshouse there was significant genotypic variation for TE, Δ, plant total dry weight, SLW and SPAD. Strong negative correlations were observed between TE and Δ (–0.52 to –0.76). Negative correlations between Δ and SLW or SPAD (–0.43 to –0.78) and smaller but significant positive correlations between TE and SLW or SPAD (0.23 to 0.30) suggested that photosynthetic capacity was, in part, underpinning the variation in TE. A cytoplasmic contribution to genetic variation in TE or Δ in canola was also observed with Triazine tolerant types having low TE and high Δ. This study showed that Δ has great potential for selecting canola germplasm with improved TE.

ANALYSIS OF GROWTH OF IRRIGATED RAPE

1977 ◽  
Vol 57 (1) ◽  
pp. 193-197 ◽  
Author(s):  
D. J. MAJOR
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Dry Matter ◽  
Brassica Campestris ◽  
Dry Weight ◽  
Crop Growth ◽  
Crop Growth Rate ◽  
Low Levels ◽  
Total Dry Weight ◽  
Leaf Dry Weight

Irrigated Polish rape (Brassica campestris L. cv. Span) and Argentine rape (B. napus L. cv. Zephyr) were harvested at 1-wk intervals at Lethbridge, Alberta and separated into leaves, stems, pods, and seed. Leaves reached maximum dry weight on 8 July for Span and 15 July for Zephyr and then senesced completely or to low levels. Maximum plant dry matter, which ranged from 312 to 1,174 g/m2, occurred in the last half of August. Although total dry weight increased substantially during the period that leaf dry weight was decreasing, crop growth rate also decreased, indicating that leaves were an important source of photosynthates for plant growth.

scholarly journals Growth analysis in chard plants (Beta vulgaris L. Cicla, cv. 'Pencas Blancas') exposed to different light quality

2014 ◽  
Vol 32 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fánor Casierra-Posada ◽  
Esteban Zapata-Casierra ◽  
Daniel A. Chaparro-Chaparro
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Light Quality ◽  
Dry Weight ◽  
Dry Mass ◽  
Dry Matter Partitioning ◽  
Absolute Growth ◽  
Net Assimilation ◽  
Total Dry Weight

To determine the effects of light quality on the growth indices of plants, Pencas Blancas cultivar chard plantlets were grown for 2 months under five different light treatments, obtained by filtering sunlight through colored polyethylene films. The treatments included: red, blue, green, yellow and transparent cover colors. A transparent cover (white light) was used as the control. The colored covers affected the plant growth. The plants grown under the yellow cover presented a better behavior with regards to growth, taken as: total dry weight per plant, leaf area, specific leaf area, absolute growth rate, relative growth rate, harvestable dry matter and root to shoot ratio. The dry matter partitioning in the leaves and roots was affected by the light quality, but not in the petioles, with a higher accumulation of dry mass in the leaves of plants grown under the yellow cover. As a consequence of the enhanced leaf area in the plants under the yellow cover, they also had the highest water uptake. On the other hand, the highest net assimilation rate value was found in plants grown under the transparent cover. These results open up the possibility of using yellow colored cover in leafy green vegetables, especially in chard plants grown under controlled conditions.

scholarly journals ALTITUDINAL GENETIC VARIATION AMONG Pinus pseudostrobus POPULATIONS FROM MICHOACÁN, MÉXICO. TWO LOCATION SHADEHOUSE TEST RESULTS

2012 ◽  
Vol 35 (2) ◽  
pp. 111 ◽  
Author(s):  
Cuauhtémoc Sáenz-Romero ◽  
Gerald E. Rehfeldt ◽  
José Carmen Soto-Correa ◽  
Selene Aguilar-Aguilar ◽  
Verónica Zamarripa-Morales ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Final Height ◽  
Growth Period ◽  
Dry Weight ◽  
Test Results ◽  
Growth Duration ◽  
Climatic Zones ◽  
West Mexico ◽  
Total Dry Weight ◽  
Pinus Pseudostrobus

Pinus pseudostrobus Lindl. is the forest species most important economically in the state of Michoacán, at central-west México. We investigated genetic variation among P. pseudostrobus populations along an altitudinal gradient in the native indian community of Nuevo San Juan Parangaricutiro, Michoacán, México. Cones were collected from eight populations at 100 m of altitudinal intervals between 2200 m and 2900 m. Seedlings were grown for approximately two years in two shadehouse environments at Morelia, Michoacán, México and at Moscow, Idaho, USA. Total height was periodically measured during the second growing season to estimate a series of growth indexes for both locations, and dry weights were obtained only for the Morelia test. For the Moscow test there were significant differences (P < 0.05) among populations for cessation of growth, duration of the growth period, and final height. For the Morelia tests there were differences among populations for foliage, shoot and total dry weight (P < 0.025), and significant differences for stem dry weight at P = 0.055 level. There was a strong altitudinal cline for dry weight variables, with seedlings originated from populations from the lowest altitudes having more biomass (r2 = 0.80, P = 0.003). Populations separated altitudinally by about 295 m are likely to be genetically different. We suggest delineation of three altitudinal seed zones (Zone I: 2100 m to 2400 m; Zone II: 2400 m to 2700 m; Zone III: 2700 m to 3000 m), that can be translated into climatic zones delimited according to mean annual temperatures or by degree days > 5 °C. To accommodate climate change we suggest implementing assisted migration programs by transferring populations 300 m upwards to maintain adaptiveness of populations for future climates.

Performance After Planting of Four Types of Container-grown Lodgepole Pine Seedlings

1973 ◽  
Vol 3 (2) ◽  
pp. 185-195 ◽  
Author(s):  
F. Endean ◽  
D. Hocking
Keyword(s):  
Lodgepole Pine ◽  
Dry Weight ◽  
Total Weight ◽  
Stem Length ◽  
Controlled Environment ◽  
Root Weight ◽  
Pine Seedlings ◽  
Total Dry Weight ◽  
Shoot Weight ◽  
Environment Experiment

Four types of container-grown lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) seedlings differing in age and rearing regime were transplanted into a controlled laboratory environment and into the field. After 12 weeks, seedlings were excavated and stem length and dry weight of shoot and roots were measured, these and derived parameters were compared with values obtained at the time of planting. Survival was uniformly high, the largest seedlings prior to planting performed best under all conditions. In the controlled environment experiment, initial shoot weight, total weight, and ratio of shoot weight/shoot length were significantly correlated with final root weight, an important factor in initial establishment; in addition shoot and total weight increment were significantly and positively correlated with initial shoot/root ratio. In the field no overall significant correlations were obtained. Shoot/root ratio decreased slightly in the controlled environment and significantly in the field after outplanting. Results suggest that the largest plant which can be grown and planted economically shows largest increment and achieves largest final total dry weight and root dry weight in the first growing season after outplanting. The need for a physiological rather than morphological grading of seedlings is stressed.

scholarly journals GENETIC VARIATION FOR TEMPERATURE RESPONSE IN ALFALFA (MEDICAGO SATIVA L.)

1980 ◽  
Vol 60 (2) ◽  
pp. 547-554 ◽  
Author(s):  
R. J. McLAUGHLIN ◽  
B. R. CHRISTIE
Keyword(s):  
Genetic Variation ◽  
High Temperature ◽  
Medicago Sativa ◽  
Temperature Response ◽  
Field Performance ◽  
Field Trials ◽  
Growth Room ◽  
Medicago Sativa L ◽  
High Yields ◽  
Response To Temperature

Physiological studies had indicated that low mid-summer yields of alfalfa (Medicago sativa L.) can be attributed to high temperature. A program was initiated to study genetic variation for response to high temperatures. Two thousand genotypes were grown from seed in the growth room at 20/15 °C, harvested twice, then grown at 30/25 °C for two more harvests. A great deal of variation among genotypes was found to exist for response to temperature. Genotypes that were found to yield well at higher temperatures tended to be early-maturing with few stems per plant. Genotypes that yielded well at low temperatures tended to be later in maturity and to have a large number of stems. Based upon dry matter yields, 300 genotypes were selected to represent differences in responses, namely: 100 had high yields at high temperature only; 100, high at low temperature only; and 100, high at both temperatures. These selections were transplanted to the field for subsequent field trials to substantiate growth room findings. Little or no relationship was found between growth room performance and field performance. This lack of association was due in part to winter injury experienced the first year. In addition, temperatures experienced in the field were much lower than those used indoors.

The influence of temperature and density on the growth of communities of subterranean clover (Trifolium subterraneum L. cv. Mount Barker)

1973 ◽  
Vol 24 (4) ◽  
pp. 479 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Plant Size ◽  
Area Index ◽  
Influence Of Temperature ◽  
Total Dry Weight ◽  
Increasing Temperature

The influence of temperature on the growth of high and low density communities of subterranean clover (Trifolium subterraneum L. cv. Mount Barker) was studied at four temperatures ranging from 12�C day/7�C night to 27�C day/22�C night. The response to temperature depended on leaf area index (LAI). When the LAI was low (0.2), growth rate increased with increasing temperature to a maximum at 22� day/ 17�C night. This agreed with the temperature response of single plants of the same species previously reported. However, when the LAI was 3 the growth rate was not influenced by temperature within the range tested. At a still higher value of LAI (5.5), the response in growth became negative with increasing temperature, communities at the highest temperature growing at only half the rate of those at the lowest. The frequency distribution of plant size in the dense communities was measured, at eight times during the experiment. The distribution was influenced by both temperature and the total dry weight of the community. At low temperature it was approximately symmetrical, but at high temperature it rapidly became asymmetric as total dry weight increased, the amount of skewness being greatest at the highest temperature and dry weight. Plant death was greatest at the high temperature. The communities were divided into five equally populated groups of ascending plant size. At high temperature the largest plants increased in size throughout the experiment, but each of the groups of smaller plants reached a maximum size, subsequently losing weight. At lower temperatures only the groups of smaller size lost weight, the number of groups losing weight depending on temperature. The distribution data were used to try to explain the interaction between temperature and LAI. It was proposed that community growth rate was best when canopy cover was complete and the distribution of plant weight was not strongly skewed.

scholarly journals Effects of the Light Irradiance on the Growth and Lipids Content of Amphidinium Carterae (Dinophyceae) for Biofuels Production

2022 ◽  
Author(s):  
Armando Mendoza-Flores ◽  
Clara Elizabeth Galindo-Sánchez ◽  
M. del Pilar Sánchez-Saavedra
Keyword(s):  
Growth Rate ◽  
Lipid Content ◽  
General Trend ◽  
Cell Concentration ◽  
Dry Weight ◽  
High Irradiance ◽  
Biofuel Production ◽  
Amphidinium Carterae ◽  
Irradiance Level ◽  
Total Dry Weight

Abstract The irradiance level used to the microalgae cultures can modify the growth and proximate composition, however, this response is specie specific. The dinoflagellate group had the potential to be used as a source to biofuel production. In this study was evaluated the effect of five irradiance levels (50, 100, 150, 200, and 250 µmol photon m-2 s­-1) on the growth rate, proximal composition, pigment content, and photosynthesis of Amphidinium carterae. The highest cell concentration was for the cultures at 150 µmol photon m-2 s-1 (130 × 103 cells mL-1), and the lowest values for 50 µmol photon m-2 s-1 (49 × 103 cells mL-1). The cultures maintained under the low irradiance (50 µmol photon m-2 s-1) had the highest values of total dry weight (TDW) (13418 pg cell-1), organic dry weight (ODW) (3836 pg cell-1), and inorganic dry weight (IDW) (9582 pg cell-1). The protein content as the general trend increases significantly concerning the irradiance level, with the higher values (87.47 pg cell-1) at high irradiance (250 µmol photon m-2 s-1). Carbohydrate content was different by the effect of irradiance, with the higher values (32.85 pg cell-1) at the low irradiance used (50 µmol photon m-2 s-1). Lipid content was modified by the effect of irradiance, with the highest values (534.74 pg cell-1) at the low irradiance used (50 µmol photon m-2 s-1). As a general trend, the high irradiances increased the photosynthesis curves. These findings demonstrate that the strain of A. carterae used in this work can grow in high irradiances (100 to 250 µmol photon m-2 s-1) and increase significantly the lipid content on low irradiance used (50 µmol photon m-2 s-1).

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