Shoot development in Betula papyrifera. IV. Comparisons between growth characteristics and expression of vegetative long and short shoots

1984 ◽  
Vol 62 (3) ◽  
pp. 446-453 ◽  
Author(s):  
J. Cartey Caesar ◽  
Alastair D. Macdonald
Keyword(s):  
Growth Rates ◽  
Stem Elongation ◽  
Morphological Characteristics ◽  
Axillary Buds ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Long Shoots ◽  
Short Shoots

Postflush observations on shoots of Betula papyrifera Marsh. indicated that long and short shoots differ in a range of morphological characteristics. Long shoots developed from distal axillary buds and short shoots developed from proximal axillary buds on the previous year's long shoots. Consequently, the potential of a bud to develop into a long shoot decreased basipetally. Potential long-shoot buds had higher bud-relative growth rates, stem-relative growth rates, leaf-relative growth rates, and stem dry weights during the course of postflush growth. Changes in leaf thickness, expressed in terms of specific leaf area and specific leaf weight, indicated that long shoots temporarily had thinner leaves than did short shoots a few weeks after flushing. Net assimilate requirements in long shoots for late leaf and internodal expansion may explain these observations. Nearing maturity, long-shoot early leaves became thicker, possibly owing to greater shoot vigour and (or) higher photosynthetic efficiency. Consequently, mature long-shoot early leaves possessed larger and thicker laminae, longer petioles, more side nerve pairs, and tended to grow more in length than width than short-shoot leaves on shoots of comparable age. Leaves of older short shoots, 2–10 years old, attained a greater size and had longer petioles than those of 1-year-old short shoots. Stem elongation and the development and expression of leaves in long shoots seemed to have a correlative influence on the overall vigour of long shoots.

scholarly journals In Vitro Responses of Tissues from Rhododendron Plants With and Without Tissue Proliferation

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873D-873
Author(s):  
Yiqin Ruan ◽  
Mark H. Brand
Keyword(s):  
Growth Rates ◽  
Woody Plant ◽  
Shoot Tips ◽  
Shoot Cultures ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Tissue Proliferation ◽  
Long Shoots ◽  
Short Shoots

Rhododendron `Montego' shoot cultures initiated from plants with and without tissue proliferation (TP and NTP) served as explant sources for all studies (Note: in vitro TP shoot cultures produce primarily dwarf shoots, some long shoots, and stem tumors). Calli induced from TP leaves and tumors and NTP leaves were cultured on woody plant (WP) medium containing NAA and 2-iP. During the first 4 weeks of culture, calli from NTP leaves had higher relative growth rates than calli from TP leaves or tumors. However, calli from TP leaves and tumors grew faster than calli from NTP leaves for all subculture periods that followed. Shoot tips (5 mm) were excised from TP dwarf shoots, TP long shoots, and NTP shoots and were cultured on WP medium with or without 15 μM 2-iP. Shoot tips from TP dwarf and long shoots multiplied on medium without 2-iP, averaging 18.4 and 1.7 shoots per shoot tip in 12 weeks, respectively. Shoot tips from NTP shoots only multiplied when maintained on 2-iP-containing medium. When placed on 2-iP-containing medium, both types of TP shoot tips produced clusters of callus-like nodules that gave rise to highly tumorized, short shoots or leafy meristems.

Growth Analysis of Weed and Crop Species with Reference to Seed Weight

Weed Science ◽  
1993 ◽  
Vol 41 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Andrew C. Seibert ◽  
R. Brent Pearce
Keyword(s):  
Growth Rates ◽  
Seed Weight ◽  
Growth Analysis ◽  
Plant Root ◽  
Morphological Characteristics ◽  
Initial Size ◽  
Crop Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Length Increase

Growth and morphological characteristics of four weed and two crop species were analyzed to determine how small-seeded weeds can compete with large-seeded crops despite the initial size disadvantage. Small-seeded weeds had higher relative growth rates because of increased percentages of biomass devoted to leaves. This morphological scheme was achieved primarily through a reduction in the percentage of biomass devoted to roots. Yet, small-seeded weeds were able to develop larger mean plant root lengths as a result of having both roots of smaller diameter and higher rates of root length increase.

Shoot development in Betula papyrifera. I. Short-shoot organogenesis

1983 ◽  
Vol 61 (12) ◽  
pp. 3049-3065 ◽  
Author(s):  
Alastair D. Macdonald ◽  
D. H. Mothersill
Keyword(s):  
Axillary Buds ◽  
Axillary Bud ◽  
Bud Burst ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Mature Trees ◽  
Shoot Buds ◽  
Female Inflorescence ◽  
Terminal Bud ◽  
Short Shoots

Buds and developing branches of Betula papyrifera were collected weekly from mature trees during three successive growing seasons. Material was prepared to show stages of bud inception, development, and flushing and female inflorescence inception. Short shoots develop from (i) proximal axillary buds on long shoots (ii) short-shoot terminal buds, or (iii) axillary buds on flowering short shoots. An axillary bud apex forms a terminal bud after bud burst. An axillary bud possesses one outer rudimentary leaf, but all other short-shoot buds have three outer rudimentary leaves. All short-shoot buds possess, in addition, one–three embryonic foliage leaves and, distally, three primordial rudimentary leaves which form the outermost appendages of the succeeding terminal bud. Rudimentary leaf stipules form the cataphylls. Foliage leaf primordia are initiated in May – early June and rudimentary leaves arise in late June – July. If a bud apex is initiated in year n, female inflorescence induction occurs in late June of year n + 1 or any succeeding year. An axillary bud develops on a short shoot as a consequence of flowering; it is initiated concurrently with inflorescence development and its development is completed during flowering and seed maturation. Short- and long-shoot buds can be distinguished, upon dissection, in mid-July when buds are forming. Hence, determination of potential long and short shoots occurs the year before bud burst.

Shoot development in Betula papyrifera. II. Comparison of vegetative and reproductive short-shoot growth

1983 ◽  
Vol 61 (12) ◽  
pp. 3066-3071 ◽  
Author(s):  
J. Cartey Caesar ◽  
Alastair D. Macdonald
Keyword(s):  
Leaf Area ◽  
Shoot Growth ◽  
Inhibitory Influence ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Relative Growth ◽  
Shoot Buds ◽  
Mean Relative Growth Rate ◽  
Short Shoots ◽  
Terminal Buds

Short shoots of Betula papyrifera Marsh, may be vegetative or reproductive. The latter bear a female inflorescence. Early flushing and rapid growth of short-shoot buds depend on the age and position of the short shoot. Axillary short-shoot buds flush later than 2- to 4-year-old short-shoot terminal buds, which in turn flush later than 5- to 10-year-old shoots. Mean relative growth rate (RGR) of 5- to 10-year-old short-shoot buds is greater than that of younger short-shoot buds. It is suggested that older short-shoot buds are relatively autonomous and that the flushing long shoot exhibits an inhibitory influence on the proximal axillary buds and possibly on young short-shoot terminal buds. Reproductive short shoots differ from vegetative short shoots in that they have lower leaf area ratios and leaf RGR, higher specific leaf area, smaller leaf areas, and fewer side nerve pairs and they grow more in length than in width. These findings are related to reproductive cost. The developing inflorescences act as preferred "sinks" for resource allocation.

Selection for biomass production based on respiration parameters in eucalypts: effects of origin and growth climates on growth rates

1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca
Keyword(s):  
Temperature Dependence ◽  
Growth Rates ◽  
Heat Rate ◽  
Eucalyptus Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Metabolic Heat ◽  
Respiratory Parameters ◽  
Metabolic Heat Rate ◽  
Different Climates

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.

SEASONAL GROWTH CHARACTERISTICS OF LONG AND SHORT SHOOTS OF TAMARACK

1967 ◽  
Vol 45 (9) ◽  
pp. 1643-1651 ◽  
Author(s):  
J. Johanna Clausen ◽  
T. T. Kozlowski
Keyword(s):  
Seasonal Changes ◽  
Stem Elongation ◽  
Growth Characteristics ◽  
Weight Increase ◽  
Stem Length ◽  
Larix Laricina ◽  
Seasonal Growth ◽  
Long Shoots ◽  
Short Shoots ◽  
Food Reserves

Tamarack (Larix laricina (DuRoi) K. Koch) produces long shoots which bear two kinds of needles. Early needles are present in the bud and elongate rapidly after budbreak. Late needles, few of which are present in the bud, elongate later than early needles. Short shoots bear early needles only, and stem length seldom exceeds 1 mm. Seasonal changes in length and weight of needles and stems of both shoot types were measured. In long shoots, 75% of stem elongation, more than 70% of stem weight increment, and 65–70% of late needle elongation occurred after early needles were full-sized. Stem and late needle elongation ceased simultaneously, after which time needle weight decreased and stem weight increased. Early needles probably drew on food reserves while developing, and then themselves contributed to stem and late needle elongation. Final stem weight increase probably used photosynthate from both late and early needles of the current year.Shading of current and last year's needles showed that shoots in which photosynthesis was interrupted in this way produced shorter, lighter-weight stems than did control shoots.

Studies on the sowing dates of cotton in the Sudan Gezira: I. The influence of date of sowing on plant growth and development

1967 ◽  
Vol 69 (3) ◽  
pp. 305-315 ◽  
Author(s):  
J. E. Jackson
Keyword(s):  
Growth Rates ◽  
Slow Growth ◽  
Seasonal Pattern ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Research Division ◽  
Sowing Dates ◽  
Net Assimilation ◽  
State Growth ◽  
Sudan Gezira

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.

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