Spatial variation in seed size and seed set on spikes of some Canadian spring wheat cultivars

1991 ◽  
Vol 71 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Keith G. Briggs
Keyword(s):  
Seed Size ◽  
Seed Mass ◽  
Size Variation ◽  
Triticum Aestivum L ◽  
Quadratic Functions ◽  
Pure Stand ◽  
Wheat Cultivars ◽  
Frequency Distributions ◽  
Significant Variance ◽  
The Mean

The seed size (mass) distribution of grain on individual spikes of four Canadian wheat cultivars (Glenlea, HY320, Pitic 62 and Neepawa, Triticum aestivum L.) was determined on plant samples from two replicates of the 1984 High Yielding Wheat Cooperative trial grown at Ellerslie, Alberta. Specific grain mass was determined for individual floret locations on all spikes of each plant, and sterile floret locations were also determined. For all four cultivars the maximum amount of seed size variation from the samples was attributable to variation at the floret level, accounting for 92% of the seed size variance of Pitic 62, down to 74% for Neepawa. Neepawa differed from the other three cultivars in demonstrating a high (20%) and significant variance in seed size attributable to spikelet position. Pitic 62 was the only cultivar of the four that demonstrated significant variance (12%) due to plant differences within replicates. Consistent with previous literature, approximately 50% of total plant yield was accounted for by the mainstem spike, decreasing to 8 to 15% on the third spike. The mean number of seeds spike−1 on the mainstem was 26.8 (Neepawa), 35.9 (Glenlea), 46.8 (HY320) and 48.6 (Pitic 62), but this number decreased in response to tiller order, as did seed mass and floret fertility. Quadratic functions were calculated fitting seed mass to floret position (1 proximal to 4 distal), and were significant in all cases, with R2 values of 63% for Neepawa, 56% for Glenlea, 82% for Pitic 62 and 89% for HY320. The fitted quadratics suggest an optimization of seed size at floret site 2 for some cultivars, with a rapid decrease in seed size at floret sites 3 and 4, especially for the high-yielding cultivars Glenlea and Pitic 62. Fourth florets of the latter cultivars were shown in frequency distributions to produce seeds smaller than the mean seed size of the Neepawa seed size expected at Florets 1, 2 and 3. Large negative skewnesses for seed size for Glenlea, HY320 and Pitic 62 also underscored the tendency for the high-yielding cultivars to produce relatively large numbers of small seeds. Although determined in only one site-year, these differences in seed size distribution pattern amongst cultivars are of major significance to visual identification systems. Large-seeded, high-yielding wheats in pure stand can be expected to produce a significant number of small-seeded kernels that might be confused by visual inspection with CWRS seed type. Key words: Grain, grading, cultivar registration, seed identification, high-yielding wheats

scholarly journals Seed size and adventitious (nodal) roots as factors influencing the tolerance of wheat to waterlogging

2003 ◽  
Vol 54 (10) ◽  
pp. 969 ◽  
Author(s):  
D. K. Singh ◽  
V. Singh
Keyword(s):  
Plant Growth ◽  
Oxygen Concentration ◽  
Seed Size ◽  
Growth Rates ◽  
Plant Biomass ◽  
Seed Mass ◽  
Root Mass ◽  
Wheat Cultivars ◽  
Seedling Mortality ◽  
Nodal Roots

In a glasshouse study, two experiments were conducted to understand how inherent variability, such as the seed size or mass, and formation of adventitious nodal roots might influence the tolerance of various wheat and triticale cultivars at different growth stages to waterlogging. Waterlogging at germination resulted in 11% seedling mortality, but the waterlogged seedlings had a 19% increase in shoot mass per plant, with no difference in root mass compared with non-waterlogged seedlings. Waterlogging at the 3-leaf stage was deleterious to only a few cultivars. On average, larger seed resulted in greater plant growth for most of the cultivars, and seed mass was positively related to the plant biomass and adventitious nodal root mass under waterlogged conditions. A decreasing oxygen concentration with increasing duration of waterlogging and soil depth did not affect the plant growth and visual stress symptoms, chlorosis, until the oxygen concentration decreased to less than 10% in the bottom depths. The highest yielding triticale cultivar, Muir, and wheat cultivars Brookton and Frame had the greatest seed mass, plant biomass, and relative growth rates under waterlogged conditions, compared with the lowest yielding wheat cultivars, Amery, Silverstar, and More. However, the degree of 'waterlogging tolerance', expressed as the percent ratio of plant biomass or growth rates under waterlogged conditions relative to the non-waterlogged control conditions, appeared to be greatest for the low-yielding cultivars, indicating a 'cautious approach' when screening tolerant cultivars.

Seed mass and nutrient content in nutrient-starved tropical rainforest in Venezuela

1997 ◽  
Vol 7 (3) ◽  
pp. 269-280 ◽  
Author(s):  
Peter J. Grubb ◽  
David A. Coomes
Keyword(s):  
Seed Size ◽  
Tropical Rainforest ◽  
Forest Type ◽  
Seed Mass ◽  
Nutrient Content ◽  
Dry Mass ◽  
Seed Number ◽  
The Mean ◽  
Trees And Shrubs ◽  
Poor Soil

AbstractMean seed dry mass values were determined for 27 species of trees and shrubs in Amazonian caatinga (a forest-type especially short of nitrogen) and for 11 species in adjacent much taller forest on less poor soil. The tall trees (> 15 m) of caatinga have smaller seeds than the tall trees in adjacent forest on less infertile soil (both overall and in six taxonomically controlled comparisons), and than the tall trees in lowland rainforests elsewhere. The smaller seed size is interpreted in terms of a major advantage of keeping up seed number outweighing the marginal advantages of larger seed size. For trees of caatinga and adjacent forest considered together, there is a significantly greater concentration of P and Mg, and almost significantly greater concentration of N, in the embryo-cum-endosperm fraction of smaller-seeded species, but the content per seed of N, P and Mg is smaller in smaller seeds. The mean contribution of the seed coat (including endocarp for pyrenes) was 17% for dry mass, 3% for content of P, 10% for N and Mg, 15% for K, and 30% for Ca.

YIELD OF PURE AND MIXED STANDS OF TWO SPRING WHEAT CULTIVARS SOWN AT FIVE RATES OF SEEDING

1977 ◽  
Vol 57 (3) ◽  
pp. 1005-1007 ◽  
Author(s):  
R. J. BAKER
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Yield Components ◽  
Triticum Aestivum L ◽  
Pure Stand ◽  
Wheat Cultivars ◽  
Seeding Rate ◽  
Mixed Stands ◽  
Yield And Yield Components

Yield and yield components were measured on two spring wheat (Triticum aestivum L. em Thell) cultivars, Neepawa and Pitic 62, and a 1:1 mixture of the two sown at five rates of seeding in each of 2 yr. Lack of agreement between performance in pure and mixed stands was observed when, at the highest seeding rate, the mixture yielded higher in 1974 and lower in 1976 than either of the component cultivars grown in pure stand.

SURVIVAL OF COMMON SPRING WHEAT CULTIVARS GROWN IN MIXTURES IN THREE ENVIRONMENTS

1980 ◽  
Vol 60 (4) ◽  
pp. 1309-1313 ◽  
Author(s):  
HUGH McKENZIE ◽  
M. N. GRANT
Keyword(s):  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Kernel Weight ◽  
Pure Stand ◽  
Wheat Cultivars ◽  
Average Yield ◽  
Wheat Stem Sawfly ◽  
Percent Survival ◽  
Southern Alberta ◽  
Site Ranking

Population shifts occurred in mixtures of six cultivars of common spring wheat (Triticum aestivum L.) grown for 6 or 7 yr in three different environments, nonirrigated, irrigated, and infested with the wheat stem sawfly (Cephus cinctus Nort.). On the nonirrigated site, ranking of cultivars was the same for percent survival in the mixture as for yield in pure stand. Rankings, with one exception, for average number of kernels per spike were similar to those for average yield and survival on the nonirrigated site. On the irrigated site, rankings for percent survival in the mixture and for yield in pure stand were similar except that one cultivar was at a disadvantage due to shorter height. Rankings for average kernel weight, again with one exception, were similar to rankings for survival on the irrigated site. On the sawfly-infested site, rankings for survival in the mixture were similar to those for yield in pure stand. On all three sites, the data support the contention that natural selection will increase the frequency of high-yielding plants in mixed population of spring wheat in southern Alberta.

YIELD PERFORMANCE OF EIGHT WHEAT CULTIVARS IN TWO- AND THREE-ROW PLOTS

1975 ◽  
Vol 55 (1) ◽  
pp. 37-39 ◽  
Author(s):  
R. M. De PAUW
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Row Spacing ◽  
Wheat Cultivars ◽  
Early Generation ◽  
Yield Performance ◽  
Generation Progeny ◽  
The Mean ◽  
The Relationship ◽  
Range Test

Yield performance of eight wheat cultivars (Triticum aestivum L.) was compared in two-row plots with 38 cm between rows and in three-row plots with 19 cm between rows. The cultivar × row spacing interaction was nonsignificant in each of four tests. The range of cultivar yield from two-row plots as a percentage of the mean was similar to that for cultivar yield from three-row plots. Duncan’s multiple range test was applied to yield of cultivars grown in two-row and three-row plots. The grouping of cultivar yield from two-row plots was very similar to the grouping of cultivar yield from three-row plots. The standard error of a mean and coefficient of variation were consistently lower for three-row plots than for two-row plots. The relationship between yield performance of a line in two-row plots and three-row plots was positive, such that two-row plots would be suitable for early generation progeny yield tests with final evaluation in multiple-row plots.

scholarly journals Seed size and dormancy in Rumex obtusifolius

1999 ◽  
Vol 35 (No. 3) ◽  
pp. 103-107 ◽  
Author(s):  
A. Martínková ◽  
A. Honěk ◽  
F. Pudil
Keyword(s):  
Seed Size ◽  
Seed Dormancy ◽  
Seed Mass ◽  
Size Variation ◽  
Germination Percentage ◽  
Plant Materials ◽  
Rumex Obtusifolius ◽  
Ex Post ◽  
Germinating Seeds ◽  
Range Of Variation

We tested the hypothesis, suggested by literature data, that in Rumex obtusifolius L. the germination of matured seeds harvested from dry standing shoots and achene morphology are correlated. In these seed materials the level of germination is determined by the incidence of primary seed dormancy. The regression of the percentage of germinating seeds on achene, perianth and seed size and mass were calculated for seed materials of 30 plants. The materials in which achene morphology was investigated were selected ex post from a set of seed materials of 241 plants to cover the range of variation of germinability of individual plants which was between 0-66%. There was no relationship between any characteristic of achene quality and germination except for a positive correlation between germination percentage and achene mass calculated only for seed materials of plants which pro­ duced germinable seeds (i.e. when plants with 0% germination were excluded from the analysis). The second part of the study investigated the effects of size variation on germinability among seeds harvested from one plant and after removal from the perianth. This variation was tested using sets of 20 size-assorted groups of 50 seeds, each originating from a particular plant; materials from six plants were tested. There were significant differences in the average germination between plants. However, in the material from the same plant there was no consistent relationship between seed mass and percentage of germination. We conclude that there exists no direct relationship between achene, perianth or seed size or mass and incidence of primary seed dormancy.

scholarly journals Is There More to Within-plant Variation in Seed Size than Developmental Noise?

2021 ◽  
Author(s):  
Christophe Pélabon ◽  
Francesca De Giorgi ◽  
Øystein H. Opedal ◽  
Geir H. Bolstad ◽  
Astrid Raunsgard ◽  
...  
Keyword(s):  
Seed Size ◽  
Size Variation ◽  
Developmental Instability ◽  
Source Population ◽  
Short Term ◽  
Plant Variation ◽  
Environmental Predictability ◽  
Environmental Unpredictability ◽  
The Mean ◽  
Developmental Noise

AbstractWithin-plant variation in seed size may merely reflect developmental instability, or it may be adaptive in facilitating diversifying bet-hedging, that is, production of phenotypically diverse offspring when future environments are unpredictable. To test the latter hypothesis, we analyzed patterns of variation in seed size in 11 populations of the perennial vine Dalechampia scandens grown in a common greenhouse environment. We tested whether population differences in the mean and variation of seed size covaried with environmental predictability at two different timescales. We also tested whether within-plant variation in seed size was correlated with independent measures of floral developmental instability and increased under stressful conditions. Populations differed genetically in the amount of seed-size variation occurring among plants, among infructescences within plants, and among seeds within infructescences. Within-individual variation was not detectably correlated with measures of developmental instability and did not increase under stress, but it increased weakly with short-term environmental unpredictability of precipitation at the source-population site. These results support the hypothesis that greater variation in seed size is adaptive when environmental predictability is low.

scholarly journals A novel approach for nitrogen diagnosis of wheat canopies digital images by mobile phones based on histogram

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Qi ◽  
Yanan Zhao ◽  
Yufang Huang ◽  
Yang Wang ◽  
Wei Qin ◽  
...  
Keyword(s):  
Neural Network ◽  
Mobile Phones ◽  
Mean Value ◽  
Wheat Cultivars ◽  
N Content ◽  
Color Parameters ◽  
The Neural Network ◽  
The Mean ◽  
Leaf N Content ◽  
Leaf N

AbstractThe accurate and nondestructive assessment of leaf nitrogen (N) is very important for N management in winter wheat fields. Mobile phones are now being used as an additional N diagnostic tool. To overcome the drawbacks of traditional digital camera diagnostic methods, a histogram-based method was proposed and compared with the traditional methods. Here, the field N level of six different wheat cultivars was assessed to obtain canopy images, leaf N content, and yield. The stability and accuracy of the index histogram and index mean value of the canopy images in different wheat cultivars were compared based on their correlation with leaf N and yield, following which the best diagnosis and prediction model was selected using the neural network model. The results showed that N application significantly affected the leaf N content and yield of wheat, as well as the hue of the canopy images and plant coverage. Compared with the mean value of the canopy image color parameters, the histogram could reflect both the crop coverage and the overall color information. The histogram thus had a high linear correlation with leaf N content and yield and a relatively stable correlation across different growth stages. Peak b of the histogram changed with the increase in leaf N content during the reviving stage of wheat. The histogram of the canopy image color parameters had a good correlation with leaf N content and yield. Through the neural network training and estimation model, the root mean square error (RMSE) and the mean absolute percentage error (MAPE) of the estimated and measured values of leaf N content and yield were smaller for the index histogram (0.465, 9.65%, and 465.12, 5.5% respectively) than the index mean value of the canopy images (0.526, 12.53% and 593.52, 7.83% respectively), suggesting a good fit for the index histogram image color and robustness in estimating N content and yield. Hence, the use of the histogram model with a smartphone has great potential application in N diagnosis and prediction for wheat and other cereal crops.

scholarly journals Growth and population biology of the sand-bubbler crab Scopimera crabricauda Alcock 1900 (Brachyura: Dotillidae) from the Persian Gulf, Iran

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Sana Sharifian ◽  
Vahid Malekzadeh ◽  
Ehsan Kamrani ◽  
Mohsen Safaie
Keyword(s):  
Persian Gulf ◽  
Population Biology ◽  
Slow Growth ◽  
Carapace Width ◽  
Population Data ◽  
Natural Mortality ◽  
Frequency Distributions ◽  
Iranian Coast ◽  
The Mean ◽  
The Persian Gulf

Abstract Background Dotillid crabs are introduced as one common dwellers of sandy shores. We studied the ecology and growth of the sand bubbler crab Scopimera crabricauda Alcock, 1900, in the Persian Gulf, Iran. Crabs were sampled monthly by excavating nine quadrats at three intertidal levels during spring low tides from January 2016 to January 2017. Results Population data show unimodal size-frequency distributions in both sexes. The Von Bertalanffy function was calculated at CWt = 8.76 [1 − exp (− 0.56 (t + 0.39))], CWt = 7.90 [1 − exp (− 0.59 (t + 0.40))] and CWt = 9.35 [1 − exp (− 0.57 (t + 0.41))] for males, females, and both sexes, respectively. The life span appeared to be 5.35, 5.07, and 5.26 years for males, females, and both sexes, respectively. The cohorts were identified as two age continuous groups, with the mean model carapace width 5.39 and 7.11 mm for both sexes. The natural mortality (M) coefficients stood at 1.72 for males, 1.83 for females, and 1.76 years−1 for both sexes, respectively. The overall sex ratio (1:0.4) was significantly different from the expected 1:1 proportion with male-biased. Recruitment occurred with the highest number of annual pulse once a year during the summer. Conclusions The results, which show slow growth, emphasize the necessity of proper management for the survival of the stock of S. crabricauda on the Iranian coast of the Persian Gulf.

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