Heat tolerance of actively growing, bud-initiated, and dormant black spruce seedlings

1988 ◽  
Vol 18 (9) ◽  
pp. 1103-1105 ◽  
Author(s):  
R. S. Koppenaal ◽  
S. J. Colombo
Keyword(s):  
Heat Tolerance ◽  
Shoot Growth ◽  
Black Spruce ◽  
Test Chamber ◽  
Shoot Elongation ◽  
First Year ◽  
Main Shoot ◽  
Bud Development ◽  
Environmental Test ◽  
Heat Tolerant

To determine the effect of stage of bud development on heat tolerance, overwintered black spruce seedlings (Piceamariana (Mill.) B.S.P.) were (i) maintained in a dormant state, (ii) allowed to grow new shoots under favorable greenhouse conditions, or (iii) induced to initiate bud scales using short-photoperiod treatment following a period of new shoot elongation. Seedlings of the three shoot types were then exposed for 10 min to temperatures of 25, 42, 45, 50, or 55 °C in an environmental test chamber. Damage to the current-year shoot was lower in bud-initiated seedlings than in active seedlings, particularly at 42 °C, when 0 and 46%, respectively, of the length of the main shoot was damaged. The current-year shoot growth was much more sensitive to heat stress than the lignified first-year shoot, and therefore dormant seedlings, which had only first-year shoot growth, were most heat tolerant, showing damage only at 50 and 55 °C.

Accumulation and Utilization of Carbohydrate Reserves in Shoot Growth of Pinusresinosa

1973 ◽  
Vol 3 (3) ◽  
pp. 346-353 ◽  
Author(s):  
M. O. Olofinboba ◽  
T. T. Kozlowski
Keyword(s):  
Shoot Growth ◽  
Shoot Elongation ◽  
Bud Development ◽  
Carbohydrate Reserves ◽  
Late Season ◽  
Phloem Translocation ◽  
Food Reserves

Evidence is presented which emphasizes the importance of food reserves and conditions controlling late-season photosynthesis (e.g. during bud development) to subsequent-year shoot growth ofPinusresinosa. By the end of August, after shoot elongation ceased, current 14C-photosynthate was mobilized by roots, stems, and twigs. Much of the currently produced photosynthate accumulated as reserves in roots, stems, and twigs. When phloem blocks were applied in March behind the prior-year internode of defoliated shoots, thereby preventing phloem translocation of currently produced photosynthate from old needles to the buds, considerable shoot expansion still occurred, indicating utilization of reserve photosynthates of the prior-year internode.

scholarly journals Bud Dormancy Status, Frost Hardiness. Shoot Moisture Content, and Readiness of Black Spruce Container Seedlings for Frozen Storage

1990 ◽  
Vol 115 (2) ◽  
pp. 302-307 ◽  
Author(s):  
Stephen J. Colombo
Keyword(s):  
Moisture Content ◽  
Black Spruce ◽  
Frozen Storage ◽  
Shoot Elongation ◽  
Bud Dormancy ◽  
Frost Hardiness ◽  
First Year ◽  
Linear Relationships ◽  
Terminal Buds ◽  
Bud Initiation

Black spruce [Picea mariana (Mill) B. S. P.] first-year seedlings were exposed to 8-hr photoperiods and warm temperatures (26C maximum, 15C minimum) and tested weekly to determine bud dormancy status, frost hardiness, shoot moisture content, and the amount of damage caused. by a period of frozen storage (- 3C). Bud dormancy status, frost hardiness, and shoot moisture content were all strongly correlated to the time of bud initiation. Frost hardiness was low (- 5 to - 7.5C) during the period of needle primordia initiation until week 3 (3 weeks after 100% bud initiation), but bud dormancy decreased linearly over this period, from 37 days to budbreak for seedlings sampled at week - 1 (1 week before 100% of the seedlings had initiated terminal buds) and placed under conditions favoring shoot elongation, to 14 days to budbreak for seedlings sampled on week 3. From week 5 to week 8, there was a strong (r2 > 0.999) linear correlation between frost hardiness and bud dormancy status. Shoot moisture content declined linearly from 84% on week - 1 to 74% on week 8 (r2 = 0.97), and shoot moisture content was correlated with both frost hardiness (r2 = 0.87) and the percentage of seedlings that suffered needle damage in frozen storage (r2 = 0.85). Bud dormancy status, measured as number of days to 50% budbreak, was curvilinearly correlated with seedling damage following frozen storage, whereas linear relationships with damage in storage were found for dormancy release index (r2 = 0.92) and frost hardiness (r2 = 0.85).

Seedling Shoot and Bud Development in Provenances of Sitka Spruce, Piceasitchensis (Bong.) Carr.

1975 ◽  
Vol 5 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Douglas F. W. Pollard ◽  
Abraham H. Teich ◽  
Kenneth T. Logan
Keyword(s):  
Growth Rate ◽  
Induction Period ◽  
Growth And Development ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Sitka Spruce ◽  
Bud Development ◽  
The Third ◽  
Terminal Bud ◽  
Needle Primordia

Growth and development of seedlings of ten provenances were compared in three investigations. The provenances ranged from Oregon to south-east Alaska and were collected for the I.U.F.R.O. International Sitka Spruce Provenance Experiment. The potential for seedling growth was studied by measuring (a) the rate of shoot growth and (b) the duration of shoot elongation. Growth rate was rather uniform, being only slightly faster among northern provenances. The duration of shoot growth, under artificial declining photoperiods was strongly influenced by latitude of origin. The critical photoperiods necessary for sustained growth in southern provenances were up to 4 hours shorter than those in northern provenances. In the third investigation development of the terminal bud was followed during the first 8 weeks. After a 4-week induction period buds attained macroscopic sizes with ca. 100 needle primordia. Northern provenances had up to 65% more primordia than southern ones. At 8 weeks, a strong but reversed relationship was evident, with southern provenances having up to 35% more than northern provenances. These observations indicate that latitude-correlated variations will be an important feature of the I.U.F.R.O. Experiment, with southern provenances performing especially well in southern trials. Potential advantages of southern provenances will be protracted periods of shoot growth in young seedlings and protracted periods of development of the primordial shoot in overwintering buds. However, where summer seasons are short, such advantages may not be realized.

scholarly journals Grape rootstock - scion interactions on shoot growth and cane maturing

1999 ◽  
Vol 5 (1-2) ◽  
Author(s):  
L. Kocsis
Keyword(s):  
Root Development ◽  
Shoot Growth ◽  
Growth Habit ◽  
Shoot Elongation ◽  
Fruit Production ◽  
Soil Conditions ◽  
First Year ◽  
Special Soil ◽  
Growth Characters

Interaction between the rootstock and scion varieties (clones) was examined. Berlandieri x Riparia T. K. 5BB, Berlandieri x Riparia T.5C being the most widely used varieties in Hungary, Fercal, Ruggeri 140 being recently used on special soil conditions ; Georgikon 28 a new established variety and Berlandieri x Riparia T. 8B GK 10 clone were the rootstocks used. The V. vinifera L. varieties were a clone of Italian Riesling and two new hybrids from the same cross population f ( Noble Italian Riesling X Ezerjó) X ( Noble Italian Riesling X Pinot Gris ) }. This study presents the results how the growth habit depends on different scion/stock combinations in the first three years. Shoot growth characters were observed during the initial years after plantation in the vineyard until we got the first yields. Our results did not agree with those of Pospisilova (1977) that the anticipated vigour of shoot growth will appear later in the vineyard only. However we agree with Zimmerman (1970), who showed that the differences are caused by the rootstocks in the growth habit of vines during the first two years already. The differences in shoot elongation decreased similarly to the rootstocks in the first year of fruit production. It shows us that the intense root development caused vigorous shoot growth, which we think to be a rootstock effect. When the vegetative and generative development are balanced already, the effect of scions in shoot elongation became stronger than the effect of rootstock. We also found great differences in the maturation of wood each year from planting of the vineyard to the year of fruit production. During the first years the differences of cane maturation were greater according to the scion varieties, the means were significantly different. In the first ripening year the differences dwindled or increased due to the rootstocks. This means that the effect of the rootstock on cane maturation became stronger in the first year of fruit production.  

scholarly journals SOIL INJECTION OF BAS 111-06W REDUCES SHOOT GROWTH IN PEACH

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1168d-1168
Author(s):  
Gregory L. Reighard
Keyword(s):  
Growth Regulator ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
First Year ◽  
Flower Number ◽  
Flower Bud ◽  
Foliar Sprays ◽  
Short Shoots ◽  
Severe Leaf

The growth regulator BAS 111-06W was applied twice each spring for 3 years to 5-year-old 'Loring' trees. First year treatments were foliar sprays (1 or 2 g a.i.), trunk paints (2 or 4 g a.i.), and soil shank injections (2 or 4 g a.i.). Foliar treated trees developed severe leaf shotholing or bacteriosis. Shank treatments were the most effective in controlling shoot growth. Thus, second and third year treatments consisted only of the shank applications. Both the 2 and 4 g rates were equally effective in reducing shoot elongation 10-34% annually. Treated trees bloomed 1-2 days earlier and had shorter bloom periods than the controls. Flower bud density and flower number were greater on treated trees. Fruit yields were not affected. Treated trees required less summer and corrective winter pruning, but had more short shoots to thin out.

Bud development in Picea glauca. I. Annual growth cycle of vegetative buds and shoot elongation as they relate to date and temperature sums

1977 ◽  
Vol 55 (21) ◽  
pp. 2728-2745 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder ◽  
Hilary Langer
Keyword(s):  
Picea Glauca ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Growth Cycle ◽  
Bud Dormancy ◽  
Annual Growth ◽  
Bud Development ◽  
Leaf Initiation ◽  
Vegetative Buds ◽  
Vegetative Bud

Vegetative buds of Picea glauca (Moench) Voss were studied throughout the annual growth cycle in several trees in 1975 and 1976 and bud development was related to lateral vegetative shoot growth, date, and temperature sums.Vegetative buds became mitotically active in mid-April at lower elevations and about 6 weeks later at higher elevations. Shoot elongation was characterized by similar smooth sigmoid curves in both years. Shoot growth was slow for the 1st month, rapid during the 2nd month, and slow again for the 3rd month and ended by early August. Temperature sums related best to percentage of shoot elongation if the end of vegetative bud dormancy was used as the starting date and 5 °C was used as the threshold temperature. Arbitrarily chosen starting dates and threshold temperatures gave temperature sums which were related to shoot elongation only when shoot elongation was nearly completed. Generally, if the end of vegetative bud dormancy is known, the number of days from that time is nearly as accurate as the more complex use of temperature sums in predicting the percentage of shoot elongation or the stage of vegetative bud development.Bud-scale initiation occurred during shoot elongation. Axillary buds were initiated in mid-May and flushing occurred when shoots had elongated to about 30% of their final length in late May or early June. The end of shoot elongation coincided with the onset of leaf initiation on all trees in both years. The change from bud-scale initiation to leaf initiation was preceded by a marked increase in apical width and a slight increase in apical height and mitotic frequency. Leaf initiation was rapid for 6 weeks then slower for the last 4 weeks. Vegetative buds became dormant in mid-October.Vegetative bud development is closely related to shoot elongation. Breaking of vegetative bud dormancy was not affected by temperature but shoot elongation and flushing were affected by temperatures which occurred after dormancy was broken.

scholarly journals How to identify bud initiation and count needle primordia in first-year spruce seedlings

1993 ◽  
Vol 69 (4) ◽  
pp. 431-437 ◽  
Author(s):  
C. W. G. Templeton ◽  
K. D. Odlum ◽  
S. J. Colombo
Keyword(s):  
Black Spruce ◽  
First Year ◽  
Monitoring Methods ◽  
Tree Seedling ◽  
Bud Development ◽  
Nursery Production ◽  
Nursery Management ◽  
Bud Initiation ◽  
Needle Primordia ◽  
Bud Morphology

Bud initiation and subsequent bud development are key steps in the nursery production of first-year temperate spruce seedlings for reforestation. An understanding of the bud initiation and development processes and monitoring methods are of vital importance to both tree seedling nursery workers and foresters. A review of bud morphology and the bud development process is given for spruce seedlings. The equipment required and techniques used in the determination of bud initiation, and estimation of the number of needle primordia are presented. When properly applied, the examination of spruce buds forms a cornerstone for successful nursery management using extended greenhouse culture. Key words: bud initiation, bud morphology, bud dissection, black spruce, Picea mariana, needle primordia, nursery management

Growth and Branching Responses of Portulaca grandiflora to Foliar Applications of Chemical Growth Regulators

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447c-447
Author(s):  
T.J. Banko ◽  
M.A. Stefani
Keyword(s):  
Growth Regulators ◽  
Growth Habit ◽  
Stem Elongation ◽  
Block Design ◽  
Shoot Elongation ◽  
Main Shoot ◽  
Randomized Complete Block Design ◽  
Portulaca Grandiflora ◽  
Prostrate Growth ◽  
Secondary Shoot

During container production of portulaca, growth of long, prostrate, sparsely branched stems makes handling of plants difficult, and reduces their commercial appeal. Growers prefer to minimize shoot elongation while increasing branching to provide a full, compact plant. The objectives of this study were to evaluate growth regulators for promotion of branching and inhibition of stem elongation. Container-grown plants ≈21 cm in diameter were treated with sprays of ProShear (benzylaminopurine) at 62.4, 125, and 250 ppm; Promalin (benzyaminopurine + gibberellins 4+7) at 125, 250, and 500 ppm; Atrimmec (dikegulac) at 250, 500, and 750 ppm; and Florel (ethephon) at 250, 500, and 750 ppm. These treatments were compared with untreated controls in a randomized complete-block design. Main shoot lengths were measured at 16, 31, and 51 days after treatment (DAT). Numbers of new shoot breaks were counted 16 DAT. The growth habit, that is, tendency to grow upright or prostrate, was also evaluated 16 DAT. The most-effective material for retarding primary shoot elongation and for stimulating secondary shoot development was ProShear. At 16 DAT, 250 ppm ProShear reduced shoot elongation by 25% compared to control plants. This treatment also increased the number of secondary shoot breaks by 143%. Promalin increased the number of new shoot breaks, but it also increased the lengths of all shoots. High rates of Florel and Promalin caused shoots to grow predominantly upright rather then prostrate. ProShear, however, caused more prostrate growth as rate increased.

scholarly journals Heat-tolerant hot pepper exhibits constant photosynthesis via increased transpiration rate, high proline content and fast recovery in heat stress condition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sherzod Nigmatullayevich Rajametov ◽  
Eun Young Yang ◽  
Myeong Cheoul Cho ◽  
Soo Young Chae ◽  
Hyo Bong Jeong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Transpiration Rate ◽  
Stress Condition ◽  
Proline Content ◽  
Hot Pepper ◽  
Fast Recovery ◽  
Heat Stress Condition ◽  
Heat Tolerant

AbstractUnderstanding the mechanism for heat tolerance is important for the hot pepper breeding program to develop heat-tolerant cultivars in changing climate. This study was conducted to investigate physiological and biochemical parameters related to heat tolerance and to determine leaf heat damage levels critical for selecting heat-tolerant genotypes. Seedlings of two commercial cultivars, heat-tolerant ‘NW Bigarim’ (NB) and susceptible ‘Chyung Yang’ (CY), were grown in 42 °C for ten days. Photosynthesis, electrolyte conductivity, proline content were measured among seedlings during heat treatment. Photosynthetic rate was significantly reduced in ‘CY’ but not in ‘NB’ seedlings in 42 °C. Stomatal conductivity and transpiration rate was significantly higher in ‘NB’ than ‘CY’. Proline content was also significantly higher in ‘NB’. After heat treatment, leaf heat damages were determined as 0, 25, 50 and 75% and plants with different leaf heat damages were moved to a glasshouse (30–32/22–24 °C in day/night). The growth and developmental parameters were investigated until 70 days. ‘NB’ was significantly affected by leaf heat damages only in fruit yield while ‘CY’ was in fruit set, number and yield. ‘NB’ showed fast recovery after heat stress compared to ‘CY’. These results suggest that constant photosynthetic rate via increased transpiration rate as well as high proline content in heat stress condition confer faster recovery from heat damage of heat-tolerant cultivars in seedlings stages.

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