Does growth rate determine leaf form in Pisum sativum?

1989 ◽  
Vol 67 (9) ◽  
pp. 2590-2595 ◽  
Author(s):  
Kevin S. Gould ◽  
Elizabeth G. Cutter ◽  
J. Peter W. Young
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Vertical Displacement ◽  
Significant Rise ◽  
Leaf Primordium ◽  
Relative Growth ◽  
Leaf Extension ◽  
Mutant Pea

We have examined the long-standing hypothesis that leaves are morphologically more complex following prolonged proximity to the shoot apical meristem. Growth rates of the petiole and rachis of conventional and mutant pea leaves were compared for successive nodes of insertion in seedling plants. Leaves were longer at higher nodes, though the relative growth rate did not vary. Mature afila leaves were longer than those of conventional and tendril-less genotypes. The afila leaf alone exhibited a transient, highly significant rise in relative growth rate during the plastochron interval P4.5–P5.5. This rise occurred after the stage at which leaves of the different genotypes were anatomically distinguishable (stage P2–P3). Rates of vertical displacement of the leaf primordium from the shoot apical meristem did not differ significantly among genotypes. Our data suggest that the rate of leaf extension is one of the consequences, rather than a cause, of leaf morphology.

The effect of photoperiod on the growth and development of Echinochloa spp. Millets

1985 ◽  
Vol 25 (2) ◽  
pp. 428 ◽  
Author(s):  
DK Muldoon
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth And Development ◽  
Apical Meristem ◽  
Leaf Number ◽  
Relative Growth ◽  
Short Day ◽  
Crop Development ◽  
Abnormal Head ◽  
Main Tiller

Two cultivars of Echinochloa utilis, Ohwi et Yabuno, and one E.frumentacea (Roxb.) Link cultivar were grown in a glasshouse under three photoperiod regimes: naturally varying photoperiods (1 2-1 3 h), and fixed photoperiods of 14 and 16 h. Both species behaved as quantitative short-day plants although, in E. utilis, extending the photoperiod from 14 to 16 h delayed head emergence disproportionately. The delay in head emergence did not affect the relative growth rate, and longer photoperiods led to higher shoot weights; main tiller leaf number increased only slightly. The commencement of apical meristem elevation was delayed under longer photoperiods, a feature believed to be beneficial to regrowth. A time-of-sowing study in the field illustrated the effect of this short-day response upon crop development. Sixteen introduced E. utilis cultivars and 10 E. frumentacea cultivars also behaved as quantitative short-day plants. Within each species there were differences between cultivars in sensitivity to photoperiod. Some cultivars of E. utilis were very late and had abnormal head emergence at 16 h. Latitudinal effects on the performance of these cultivars are discussed.

Phyllotaxis of the palm Euterpe oleracea Mart. at the level of the shoot apical meristem

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 528-536 ◽  
Author(s):  
Denis Barabé ◽  
Laura Bourque ◽  
Xiaofeng Yin ◽  
Christian Lacroix
Keyword(s):  
Shoot Apical Meristem ◽  
Fundamental Theorem ◽  
Apical Meristem ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Divergence Angle ◽  
Euterpe Oleracea ◽  
The Mean ◽  
The Relationship ◽  
Euterpe Oleracea Mart

Previous studies on palm phyllotaxis deal mainly with the mature trunk. The goals of this study are (i) to determine the relationship between the number of parastichies, the divergence angle, and the plastochrone ratio at the level of the shoot apical meristem; (ii) to examine whether there are fluctuations in the divergence angle; (iii) to interpret the significance of phyllotactic parameters with respect to the mode of growth of the apex. The tubular base of the leaf primordium is more or less asymmetrical, and completely surrounds the shoot apical meristem. The phyllotactic system corresponds to a (2, 3) conspicuous parastichy pair. The mean divergence angle per apex varies between 126.9° ± 9.3° (mean ± SD) and 135. 8° ± 8.0°. Divergence angles for all apices fluctuate within a range of 115.89° to 157.33°. The mean plastochrone ratios between apices varies from 1.35 ± 0.18 to 1.58 ± 0.12. The plastochrone ratio at each plastochrone for all apices ranges from 1.09 to 2.00. There is no correlation between the angle of divergence and the plastochrone ratio. There is a fluctuation in the value of the divergence angle that falls within the range predicted by the fundamental theorem of phyllotaxis. The high value of the ratio of the diameter of leaf primordia over the diameter of the apex, and the long plastochrone might explain the lack of correlation between certain phyllotactic parameters.

scholarly journals Seed mass effects on germination and growth of diverse European Scots pine populations

1994 ◽  
Vol 24 (2) ◽  
pp. 306-320 ◽  
Author(s):  
P.B. Reich ◽  
J. Oleksyn ◽  
M.G. Tjoelker
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Scots Pine ◽  
Field Experiments ◽  
Seed Mass ◽  
Growing Season ◽  
Turkish Population ◽  
Dry Mass ◽  
Relative Growth ◽  
Mass Effects

Seedlings of 24 European Scots pine (Pinussylvestris L.) populations were grown in controlled environment chambers under simulated photoperiodic conditions of 50 and 60°N latitude to evaluate the effect of seed mass on germination and seedling growth characteristics. Seeds of each population were classified into 1-mg mass classes, and the four classes per population with the highest frequencies were used. Photoperiod had minimal influence on seed mass effects. Overall, seed mass was positively related to the number of cotyledons and hypocotyl height. Populations differed significantly in seed mass effect on biomass. In northern populations (55–61°N), dry mass at the end of the first growing season was little affected by seed mass. However, dry mass in 9 of 15 central populations (54–48°N) and all southern (<45°N) populations correlated positively with seed mass. Relative growth rate was not related to seed mass within or across populations, and thus early growth is largely determined by seed mass. Relative growth rate also did not differ among populations, except for a geographically isolated Turkish population with the highest seed mass and lowest relative growth rate. After one growing season, height was positively correlated (r2 > 0.6) with seed mass in 15 populations. To check the duration of seed mass effects, height growth of 1- to 7-year-old field experiments established with the same seed lots were compared. Seed mass effects on height were strongest for 1-year-old seedlings and declined or disappeared by the age of 5–7 years among central and southern populations, but remained stable over that time in northern populations.

Sign in / Sign up

Export Citation Format

Share Document