Resource allocation and floral sex ratios in Zizania aquatica

1984 ◽  
Vol 62 (4) ◽  
pp. 799-805 ◽  
Author(s):  
Mary F. Willson ◽  
Kurt P. Ruppel
Keyword(s):  
Biomass Allocation ◽  
Wild Rice ◽  
Reproductive Effort ◽  
Plant Biomass ◽  
Sex Ratios ◽  
Total Biomass ◽  
Female Function ◽  
Zizania Aquatica ◽  
Maternal Function ◽  
Female Flowers

Reproductive effort (RE) in Zizania aquatica (wild rice) averaged about 11% of total biomass except in extremely large plants, in which RE was about 17%. Plant biomass of wild rice was correlated positively with the numbers of male and female flowers produced. The average number of flowers per inflorescence varied markedly among stands and at different times in several lakes in northwestern Minnesota. Floral sex ratios of individuals (and of stands) consistently favored males, but the estimated allocation of biomass to female function (including seeds) consistently exceeded male allocation. Average flora sex ratios of individuals differed among stands and zones within stands, and very often declined steadily on successively produced inflorescences. The observed variation in biomass allocation to each gender and the consistent marked excess of biomass allocation to maternal function do not fit simple expectations of nearly equal expenditures in chiefly outcrossing cosexual plants nor of relatively high male allocation in wind-pollinated plants.

Seasonal pattern of biomass allocation in flowering and nonflowering specimens of three Pinguicula species

1986 ◽  
Vol 64 (12) ◽  
pp. 2872-2877 ◽  
Author(s):  
P. S. Karlsson
Keyword(s):  
Biomass Allocation ◽  
Reproductive Effort ◽  
Plant Biomass ◽  
Seasonal Pattern ◽  
Reproductive Organs ◽  
The Other ◽  
Seasonal Patterns ◽  
Flower Stalk ◽  
Investment In Reproduction ◽  
Winter Buds

The seasonal patterns of biomass allocation in flowering and nonflowering specimens of Pinguicula alpina L., P. villosa L., and P. vulgaris L. were compared in a subarctic environment. Pinguicula alpina had a large perennial root system, comprising 50% of the nonreproductive biomass. The other two species had smaller, annual roots, representing 5–10% of their biomass. Nonflowering specimens usually had winter buds about twice as large as flowering specimens, P. vulgaris varied, however, with site in this respect. Flowering P. alpina allocated approximately equal proportions of biomass to reproduction (flower stalk, capsule, and seeds) and over-wintering organs (bud and roots), while P. villosa's investment in reproduction was about five times that invested in the winter bud. For P. vulgaris, no correlation was found between the size of reproductive organs and the size of the bud. The number of seeds produced per capsule varied from 30 in P. villosa to 110–140 in the other two species. Seed weight was lower in P. alpina (15 μg/seed) than in P. vulgaris (24μg) and P. villosa (28μg). Plant biomass and reproductive effort varied between sites for P. vulgaris; however, this variation was apparently not related to differences in nutrient availability between sites.

Biomass-allocation patterns in populations of Trillium erectum and T. grandiflorum in southern Ontario

1987 ◽  
Vol 65 (8) ◽  
pp. 1671-1675 ◽  
Author(s):  
Jerry G. Chmielewski ◽  
Gordon S. Ringius
Keyword(s):  
Biomass Allocation ◽  
Reproductive Effort ◽  
Total Biomass ◽  
Southern Ontario ◽  
Allocation Patterns

Biomass-allocation patterns to aerial tissues were examined among six populations for each of Trillium erectum L. and T. grandiflorum (Michx.) Salisb. in southern Ontario. Total biomass did not differ among populations of T. erectum, but androecial proportions and reproductive effort generally decreased from southwest to northeast. Total biomass of T. grandiflorum varied significantly among populations and its pattern of reproductive effort was the reverse of that of T. erectum. Androecium–gynoecium ratios decreased across southern Ontario from southwest to northeast for both species. These results suggest that there may be a shift from allogamy to autogamy in a northeasterly direction across southern Ontario.

Floral sex ratios in scrub oak (Quercus ilicifolia) vary with microtopography and stem height

1990 ◽  
Vol 68 (6) ◽  
pp. 1364-1368 ◽  
Author(s):  
Marcelo A. Aizen ◽  
Alejandra Kenigsten
Keyword(s):  
Sex Ratios ◽  
Scrub Oak ◽  
Size Dependent ◽  
Female Function ◽  
Dependent Relationship ◽  
Quercus Ilicifolia ◽  
Allocation Patterns ◽  
Male Flowers ◽  
Short Stems ◽  
Female Flowers

We measured floral sex ratios (number of male inflorescences:number of female flowers) and height of stems (= ramets) of monoecious scrub oak (Quercus ilicifolia) growing along a topographic gradient on the slope of a 20 m deep depression. Stems lower in the gradient experienced increasingly severe conditions in terms of a shorter growing season and a higher incidence of killing frosts. At the top of the gradient, floral sex ratios of tall stems were male biased; however, sex allocation patterns at the bottom showed no such size-dependent relationship. With decreasing elevation (greater stress), the production of male flowers declined more rapidly than that of female flowers. Tall stems reduced overall resource allocation to flower production proportionately more with decreasing elevation than did short stems, but this reduction was again more marked in the male flowering function than in the female. These differential patterns of sex investment explain, at least in part, the variation in size-related gender relationships along this gradient. The more stressful environmental conditions prevailing at the bottom of the depression and the relative costs of the male and prezygotic female function may combine to produce these flowering patterns.

Effects of CO2 enrichment and nutrition on growth, photosynthesis, and nutrient concentration of Alaskan tundra plant species

1986 ◽  
Vol 64 (12) ◽  
pp. 2993-2998 ◽  
Author(s):  
Steven F. Oberbauer ◽  
Nasser Sionit ◽  
Steven J. Hastings ◽  
Walter C. Oechel
Keyword(s):  
Plant Biomass ◽  
Co2 Enrichment ◽  
Nutrient Content ◽  
Interactive Effects ◽  
Photon Flux ◽  
Nutrient Concentrations ◽  
Total Biomass ◽  
Ledum Palustre ◽  
Carbon Dioxide Concentrations ◽  
Alaskan Tundra

Three Alaskan tundra species, Carex bigelowii Torr., Betula nana L., and Ledum palustre L., were grown in controlled-environment chambers at two nutrition levels with two concentrations of atmospheric CO2 to assess the interactive effects of these factors on growth, photosynthesis, and tissue nutrient content. Carbon dioxide concentrations were maintained at 350 and 675 μL L−1 under photosynthetic photon flux densities of 450 μmol m−2 s−1 and temperatures of 20:15 °C (light:dark). Nutrient treatments were obtained by watering daily with 1/60- or 1/8- strength Hoagland's solution. Leaf, root, and total biomass were strongly enhanced by nutrient enrichment regardless of the CO2 concentration. In contrast, enriched atmospheric CO2 did not significantly affect plant biomass and there was no interaction between nutrition and CO2 concentration during growth. Leaf photosynthesis was increased by better nutrition in two species but was unchanged by CO2 enrichment during growth in all three species. The effects of nutrient addition and CO2 enrichment on tissue nutrient concentrations were complex and differed among the three species. The data suggest that CO2 enrichment with or without nutrient limitation has little effect on the biomass production of these three tundra species.

Biomass allocation in tomato (Lycopersicon esculentum) plants grown under partial rootzone drying: enhancement of root growth

2004 ◽  
Vol 31 (10) ◽  
pp. 971 ◽  
Author(s):  
Darren M. Mingo ◽  
Julian C. Theobald ◽  
Mark A. Bacon ◽  
William J. Davies ◽  
Ian C. Dodd
Keyword(s):  
Lycopersicon Esculentum ◽  
Root System ◽  
Biomass Allocation ◽  
Root Biomass ◽  
Leaf Water ◽  
Total Biomass ◽  
Split Root ◽  
Split Root System ◽  
Partial Rootzone Drying ◽  
And Control

Tomato (Lycopersicon esculentum Mill.) plants were grown in either a glasshouse (GH) or a controlled environment cabinet (CEC) to assess the effects of partial rootzone drying (PRD) on biomass allocation. Control and PRD plants received the same amounts of water. In control plants, water was equally distributed between two compartments of a split-root system. In PRD plants, only one compartment was watered while the other was allowed to dry. At the end of each drying cycle, wet and dry compartments were alternated. In the GH, total biomass did not differ between PRD and control plants after four cycles of PRD, but PRD increased root biomass by 55% as resources were partitioned away from shoot organs. In the CEC, leaf water potential did not differ between treatments at the end of either of two cycles of PRD, but stomatal conductance of PRD plants was 20% less at the end of the first cycle than at the beginning. After two cycles of PRD in the CEC, biomass did not differ between PRD and control plants, but PRD increased root biomass by 19% over the control plants. The promotion of root biomass in PRD plants was associated with the alternation of wet and dry compartments, with increased root biomass occurring in the re-watered compartment after previous exposure to soil drying. Promotion of root biomass in field-grown PRD plants may allow the root system to access resources (water and nutrients) that would otherwise be unavailable to control plants. This may contribute to the ability of PRD plants to maintain similar leaf water potentials to conventionally irrigated plants, even when smaller irrigation volumes are supplied.

The morphology of grain abscission in Zizania aquatica

1980 ◽  
Vol 58 (21) ◽  
pp. 2269-2273 ◽  
Author(s):  
H. B. Hanten ◽  
G. E. Ahlgren ◽  
J. B. Carlson
Keyword(s):  
Wild Rice ◽  
Cell Walls ◽  
Vascular Tissue ◽  
Embryo Sac ◽  
Middle Lamella ◽  
Abscission Zone ◽  
Rice Grains ◽  
Zizania Aquatica ◽  
Parenchyma Cells ◽  
Anatomical Evidence

The anatomical development of the abscission zone in grains of Zizania aquatica L. was correlated with development of the embryo. The abscission zone is well developed when the embryo sac is mature. Soon after pollination, the first anatomical evidence of abscission appears as plasmolysis of the separation layer parenchyma cells. This is followed by separation of the layers by dissolution of the middle lamella and fragmentation of cell walls. Persistence of intact vascular tissue and presence of a surrounding cone-shaped mass of lignified cells may be involved in abscission of wild rice grains.

scholarly journals Análisis de crecimiento de tres especies de Caesalpinia (Leguminosae) de la selva baja caducifolia de Chamela, Jalisco

2017 ◽  
pp. 5
Author(s):  
Emmanuel Rincón ◽  
Pilar Huante ◽  
Mariana Álvarez-Añorve
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Deciduous Forest ◽  
Growth Period ◽  
Growth Patterns ◽  
Tropical Deciduous Forest ◽  
Total Biomass ◽  
Allocation Pattern ◽  
Location Patterns ◽  
Net Assimilation

The objective of this study is to assess the biomass allocation pattern s and growth characteristics of three species of Caesalpinia (Leguminosae) from the highly diverse and seasonal Chamela tropical deciduous forest , where the plant growth period is restricted to the rainy season. The studied species, although they are phylogenetically related, presented different biomass al location patterns and RGR during growth, in order to carry out a differential exploitation of resources and to promote their coexistence. There were differences in relative growth rate (RGR), root to shoot ratio (R/ S), net assimilation rate (E), biomass allocation patterns and total biomass and leaf area attained among the studied species. Caesalpinia eriostachys and C. platyloba showed similar growth patterns between them but contrasting with those of C. sclerocarpa. This suggests a temporal uncuopling of their maximum resource demand. RGR was determined to a greater extent by parameters related with E than by parameters related with the specific leaf area (SLA).

scholarly journals Belowground plant biomass allocation in tundra ecosystems and its relationship with temperature

2016 ◽  
Vol 11 (5) ◽  
pp. 055003 ◽  
Author(s):  
Peng Wang ◽  
Monique M P D Heijmans ◽  
Liesje Mommer ◽  
Jasper van Ruijven ◽  
Trofim C Maximov ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Plant Biomass ◽  
Belowground Plant Biomass ◽  
Tundra Ecosystems
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