Responses to selection for seed weight and seedling vigour in Phalaris

1974 ◽  
Vol 25 (1) ◽  
pp. 33 ◽  
Author(s):  
RJ Clements ◽  
BDH Latter
Keyword(s):  
Seed Weight ◽  
Leaf Size ◽  
High Rate ◽  
Hybrid Population ◽  
Direct Selection ◽  
Seedling Vigour ◽  
Developing Seed ◽  
Selection For ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Significant responses were obtained to three cycles of directional selection for seed weight, seedling weight, leaf size, and rate of leaf appearance in a broadly based P. tuberosa population. The responses were linear in both the high and low directions, and the realized heritabilities of the characters were 0.35, 0.12, 0.61, and 0.38 respectively. Leaf size was positively correlated with seedling weight and negatively correlated with rate of leaf appearance. Selection for high seed weight resulted in marked correlated increases in seedling weight and leaf size, but selection for heavy seedlings or large leaves did not significantly increase seed weight. Selection for light seedling or small leaves, on the other hand, led to a correlated decrease in seed weight. A hybrid population obtained by crossing the parents of the high leaf size line with those of the high rate of leaf appearance line had seedlings nearly as heavy as those of the high seedling weight line and significantly heavier than the mean of the two parent lines. This effect, together with other evidence of the effect of inbreeding on all characters, indicated some degree of directional dominance, particularly for leaf size. Plants in the high seed weight line matured earlier and had fewer heads. However, because they had heavier seeds and more seeds per head, there was no apparent decrease in seed yield per plant in this line, compared with the control population. Areas of the spikelets and leaf sheaths were greater in the high seed weight line, but areas of the flag and penultimate leaves were unchanged, and there was no evidence that increases in seed weight were accompanied by increases in the amount of photosynthetic area available to each developing seed. It was concluded that selection for large leaves is a relatively efficient means of increasing seedling weight, but results in a reduced rate of leaf appearance and possibly a slower rate of tillering. Selection for seed weight, though inefficient, exploits a source of variation largely untapped by direct selection for seedling weight.

scholarly journals Developmental genetics of leaf formation in Lolium: 1. Basic Patterns of Leaf Development in L. Multiflorum and L. Perenne

1967 ◽  
Vol 9 (2) ◽  
pp. 233-245 ◽  
Author(s):  
K. J. R. Edwards
Keyword(s):  
Lolium Multiflorum ◽  
Leaf Size ◽  
Repeated Measurements ◽  
Developmental Genetics ◽  
Initial Growth ◽  
Leaf Elongation ◽  
Leaf Formation ◽  
Selection For ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

1. Repeated measurements on the growth of individual leaves in seedlings and young plants of ryegrass combined with dissections of the apex of the shoot and of very young leaves have shown that the basic pattern of leaf formation is very similar in Lolium multiflorum and L. perenne.2. The initial growth rate of a leaf primordium is low but increases suddenly at a point when the primordium is somewhat longer than the apex and about 1 mm. in length. After this transition, which I have called the unfolding of the leaf, the rate of elongation is faster and more or less linear until the leaf is nearly mature.3. The time of unfolding of a leaf is very closely associated with the time of maturity of the next older leaf on the same side of the apex. Thus a leaf ceases growth when the next younger leaf immediately above it starts elongating rapidly, though which is cause and which is effect is it not possible to say.4. This close relationship between duration of leaf elongation and rate of unfolding of successive leaves holds for both species in two seasons. It leads one to predict that selection for increased leaf size, in so far as it is a result of greater duration of leaf elongation, is likely to be accompanied by a slower rate of leaf appearance, and conversely that selection for rate of leaf appearance is likely to result in smaller leaves.

scholarly journals Developmental genetics of leaf formation in Lolium: 2. Analysis Of Selection Lines

1967 ◽  
Vol 9 (2) ◽  
pp. 247-257 ◽  
Author(s):  
K. J. R. Edwards
Keyword(s):  
Leaf Growth ◽  
Selection Criterion ◽  
Leaf Size ◽  
Italian Ryegrass ◽  
Correlated Response ◽  
Response To Selection ◽  
Leaf Formation ◽  
Selection For ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Detailed measurements of leaf growth and leaf dimensions in the seedling stage were made on lines which had been selected either for large or small leaf size or for fast or slow rates of leaf appearance within one population of Lolium multiflorum (Italian ryegrass) and two populations of L. perenne (Irish perennial and Hunsballe perennial ryegrass).Selection for either character had no effect on the rate of initiation of primordia at the apex, but did change the rate at which successive primordia became leaves. This rate of unfolding was very highly correlated with the rate of visible appearance of leaves and in all cases showed a parallel response to selection for the latter, as did also the rate of maturation of leaves. All three rates showed a negative correlated response to selection for leaf size.Selection for increased leaf size in all cases led to a longer duration of the elongation of an individual leaf, but selection for faster rate of leaf appearance always reduced this duration. The rate of elongation of individual leaves increased under selection for larger leaf size but showed irregular changes under selection for faster leaf appearance, going down in Irish but up in Hunsballe.Data for dimensions of cells from the lower epidermis showed that changes in leaf length under selection were sometimes associated with changes in cell length, some-times in cell number and sometimes with both.Selection had in no case disrupted the close association between the maturation and cessation of growth of a leaf on the one hand, and, on the other, the unfolding from the apex and onset of rapid growth of the next younger leaf on the same side of the apex. Thus in all lines only two leaves (one on each side of the apex) were elongating rapidly at any one time, and an increase in the rate of unfolding was associated with a decrease in the duration of elongation and vice versa.This association was the basis of the observed negative correlated responses between leaf size and rate of leaf appearance. But the fact that the rate of elongation could change independently of the duration opened up the possibility of setting up a selection criterion which would increase the total rate of leaf area formation.The value of this kind of analysis of a character complex in a plant-breeding programme is suggested to lie in discovering physiologically or developmentally limiting processes rather than merely identifying morphological components.

SELECTION FOR DRY MATTER YIELD IN LOLIUM PERENNE L. II. CORRELATED RESPONSES UNDER TWO CUTTING REGIMES

1980 ◽  
Vol 60 (2) ◽  
pp. 501-508 ◽  
Author(s):  
S. CECCARELLI ◽  
M. FALCINELLI ◽  
F. DAMIANI
Keyword(s):  
Lolium Perenne ◽  
Dry Matter ◽  
Leaf Size ◽  
Dry Matter Yield ◽  
Correlated Responses ◽  
Lolium Perenne L ◽  
Selection For ◽  
Cutting Regimes ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The correlated responses to divergent selection for dry matter yield within an ecotype of Lolium perenne L. were evaluated in two experiments under different cutting regimes. Both experiments showed that selection for dry matter yield did not affect leaf size and caused asymmetrical correlated responses on the rate of tiller production and the rate of leaf appearance. Selection for high dry matter yield resulted in an increased rate of tiller production without change in the rate of leaf appearance. Selection for low dry matter yield did reduce both the rate of leaf appearance and the rate of tiller production.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 3. Appearance and expansion growth of leaves of spinach

1995 ◽  
Vol 43 (2) ◽  
pp. 247-260
Author(s):  
H. Biemond
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Field Trials ◽  
Leaf Expansion ◽  
Mature Leaf ◽  
Leaf Emergence ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Main Factor

In a series of greenhouse and field trials, spinach cv. Trias plants were supplied with different amounts of N fertilizer in various split applications. Rates of leaf emergence and expansion were recorded, as well as final leaf size. The rate of leaf appearance varied between 0.16 and 0.57/day across experiments, but was hardly affected by N treatment. The rate of leaf expansion and mature leaf area increased with leaf number, reaching maximum values at leaf pair 3+4 or 5+6 and decreasing subsequently. Both characteristics were positively correlated with N supply. The duration of expansion was not influenced by N treatments and varied between 15 and 30 days in most experiments. The rate of leaf expansion was the main factor determining mature leaf size. Specific leaf area over all green leaves slowly decreased with time in most experiments and was around 300 cmsuperscript 2/g. As the differences in the number of leaves were small, the differences in total green leaf area per plant resulted from differences in the areas of individual mature leaves.

scholarly journals Variability of the «mass of seeds from a plant» sign in the soybeans hybrids of the different groups of ripeness

2019 ◽  
Vol 24 ◽  
pp. 53-58
Author(s):  
R. A. Vozgegova ◽  
Y. O. Lavrynenko ◽  
V. V. Bazaliy ◽  
T. Y. Marchenko ◽  
V. O. Borovik ◽  
...  
Keyword(s):  
Seed Yield ◽  
Seed Weight ◽  
Seed Mass ◽  
Comparative Methods ◽  
Hybrid Population ◽  
Genotypic Variability ◽  
Effective Selection ◽  
Selection For ◽  
Efficiency Of Selection ◽  
Population Yield

Aim. The purpose of the research is to determine the manifestation of the feature “seed weight from a plant” (the, parental forms) and hybrids, to establish the level of variability behind the soybean varieties in the F2–F5 hybrid combinations, to determine the effectiveness of selections for productivity in terms of the “seed weight from a plant” indicator from the hybrid populations of the F2–F5. Methods. The field, selection and genetic, calculation and comparative methods of the research were used. The varieties that are different in terms of fecundity and origin, also hybrids F1 and hybrid populations F2–F5 were studied. Selections on the basis of the “seed weight from a plant” were carried out in the F2–F5 populations. Results. It has been established that in soy characteristic “seed mass from a plant” has significant genotypic variability and has significant differences in varieties of different groups of ripeness, which may be a prerequisite for predicting the effective selection for this factorial trait. A high correlation of this trait with seed yield was also established. The proportion of the families from the selections, that were carried out in the F3 populations, exceeded the seed yield standard and was in the range of 28.0–37.5%. In the second generation of hybrids the efficiency of selection was 1.5–2 times lower. Conclusions. The highest yield of high-yielding genotypes, reached by the “seed mass from a plant” indicator was obtained from the F3 populations. To create the new high-yielding soybean varieties with a 3.5–5.5 t/ha yield under irrigation conditions, it is promising to use in the crossings the variety samples which are contrastive by groups of ripeness and genetic pedigree. Keywords: variety, soybean, hybrid, population, yield, irrigation.

scholarly journals Heritability and Correlations Among Popping Characteristics and Seed Weight in a Broad-based Temperate-adapted Nuña Bean (Phaseolus vulgaris L.) Population

HortScience ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 214-216 ◽  
Author(s):  
Jesse Vorwald ◽  
James Nienhuis
Keyword(s):  
Phaseolus Vulgaris ◽  
South America ◽  
Seed Weight ◽  
Genetic Parameters ◽  
Unique Property ◽  
Direct Selection ◽  
Phaseolus Vulgaris L ◽  
Selection For ◽  
Photoperiod Sensitive ◽  
Seed Characteristics

Nuña beans are a type of common bean (Phaseolus vulgaris L.) from the Andean region of South America that possess the unique property of popping. To develop temperate-adapted nuña bean cultivars, knowledge is needed regarding the inheritance and relationships among popping characteristics and seed weight. Nuña bean landraces are often photoperiod-sensitive; thus, to obtain estimates of the genetic parameters associated with seed characteristics, populations adapted to the long days of northern temperate climates were developed. Four sets of 10 families, sampled from a temperate-adapted population, were crossed in a Design II mating design. The heritabilities of seed weight, popping percentage, and the coefficient of expansion were relatively high, 0.77 ± 0.04, 0.87 ± 0.07, and 0.74 ± 0.09, respectively. Large positive phenotypic (0.773) and additive genetic (0.539) correlations were observed between popping percentage and the coefficient of expansion. Correlations with seed weight were not significant. The results indicate that direct selection for either increased popping percentage or coefficient of expansion will simultaneously improve both traits with little or no change in seed weight.

Temperature and day length response of some cocksfoot populations

1967 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
P BrouT ◽  
CN Williams ◽  
CA Neal-Smith ◽  
L Albrecht
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Leaf Size ◽  
Day Length ◽  
Relative Growth ◽  
Dactylis Glomerata L ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Short Days

Seedling plants of seven cocksfoot (Dactylis glomerata L.) populations were exposed to day/night temperatures of 20/15, 15/10, 12/7, and 9/4°C at day lengths of either 8 or 16 hr. Leaf size, rate of leaf appearance, and relative growth rate decreased as temperature decreased. At higher temperatures, relative growth rate was greater in long than in short days, but at 9/4° it was greater in short days. Long days increased leaf size but slightly reduced the rate of leaf appearance at higher temperatures; the increased leaf size, however, more than compensated for the slightly lower rate of leaf appearance, so that relative growth rate was greater in long than in short days. At 9/4°, however, greater leaf size did not compensate for the much slower rate of leaf appearance in long days. Growth rates were consequently lower in long than in short days at 9/4°. The populations showed a general similarity in response, although significant differences between populations were recorded for particular treatments. There was no apparent relationship between seedling growth rates at low temperatures in this experiment and winter growth of these populations under field conditions.

Selection for crude protein content in Phalaris tuberosa L. III. Physiological relationships between crude protein content and seedling vigour.

1973 ◽  
Vol 24 (1) ◽  
pp. 47 ◽  
Author(s):  
RJ Clements
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Seed Weight ◽  
Crude Protein ◽  
Flag Leaf ◽  
Leaf Node ◽  
Crude Protein Content ◽  
Seedling Vigour ◽  
Relative Growth Rates ◽  
Selection For

Seedling growth of half-sib families from two lines of P. tuberosa previously selected for high and low herbage nitrogen contents respectively was examined in a glasshouse during the autumn and winter. Seedlings from the high nitrogen line were smaller than those of the low nitrogen line but had similar whole-plant relative growth rates. Differences in the rate of nitrogen absorption by the roots (h), and in the rate of seedling weight increase per unit of absorbed nitrogen (EN), accounted for most of the variation in herbage nitrogen content between families. The heights of seedlings were closely correlated with the weights of seeds from which they originated and with EN, and when these two characters were held constant the partial correlation between nitrogen content and seedling weight was negligible (r = -0.05). Among 10 clones differing markedly in herbage nitrogen content in the field, seed weight was closely correlated with the photosynthetic area above the flag leaf node available to each seed, particularly that contributed by the spikelet (r = 0.82***). Two alternative interpretations of this result are discussed. Relationships between nitrogen content, spikelet number, and the areas of photosynthesizing organs above the flag leaf node suggest that seed weight could be maintained during selection for increased nitrogen content by concurrently selecting either for large seeds, or for large flag leaves and a reduced number of spikelets per head. Even so, some loss of actual or potentially attainable seedling vigour seems almost inevitable because of the dependence of nitrogen content on IN and EN and because EN is an important determinant of vigour.

scholarly journals Developmental genetics of leaf formation in Lolium 3. Inheritance of a developmental complex

1970 ◽  
Vol 16 (1) ◽  
pp. 17-28 ◽  
Author(s):  
K. J. R. Edwards
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Leaf Length ◽  
Developmental Genetics ◽  
Time Interval ◽  
Total Leaf Area ◽  
Total Leaf ◽  
Leaf Formation ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

SUMMARYUsing four lines derived from a single base population of Lolium perenne by selection for large leaf size (LL), small leaf size (SL), fast rate of leaf appearance (FR), and slow rate of leaf appearance (SR), the inheritance of a number of related characters specifying various aspects of leaf development was studied. F1 and F2 generations were produced for all possible crosses between these four lines.The genetic differences between the selection lines were largely additive for all characters studied and entirely so for rate of leaf appearance, duration of elongation of a single leaf and for the time interval between the maturation of leaf 3 and the unfolding of the next youngest leaf on the same side of the apex, leaf 5. The non-additive variances noted in rate of total leaf area formation, individual leaf size and its components length and width, and in the rate of leaf elongation, were associated with a tendency towards heterosis in these characters. This was quite marked in some crosses and tended to be larger for the more complex characters, rate of total leaf area formation and leaf size, suggesting that the heterosis was, to a considerable extent, due to interactions between genes controlling component characters.The data confirmed the earlier finding that the negative correlated selection response between leaf size and rate of leaf appearance was due to a basic association between the maturation of a leaf and the unfolding (onset of rapid elongation) of the next youngest leaf on the same side of the apex. Thus an increase in rate of leaf appearance reduces the duration of elongation of a leaf and this in turn will reduce leaf length. However, the basic association, which seems to be controlled by vascular development of the young leaf, is not entirely invariate.

Inheritance of Cowpea Yields under Different Soil Conditions in Papua New Guinea

1978 ◽  
Vol 14 (1) ◽  
pp. 23-28 ◽  
Author(s):  
W. Erskine ◽  
T. N. Khan
Keyword(s):  
Soil Fertility ◽  
Grain Yield ◽  
Papua New Guinea ◽  
Seed Weight ◽  
New Guinea ◽  
Indirect Selection ◽  
Direct Selection ◽  
Soil Conditions ◽  
Selection For ◽  
Broadsense Heritability

SUMMARYBroadsense heritability, and correlations of grain yield and related characters, were estimated in three crosses under two levels of soil fertility, which profoundly affected heritability of height and seed weight. Grain yield exhibited heritability of 51–81%, and in one cross significant heterosis in F2. Amongst yield-related characters only pods/plant and seeds/pod were both correlated to yield, and also lacked negative genotypic correlations with other economic characters. However, direct selection for grain yield was considered more efficient than indirect selection using yield-related characters.

Sign in / Sign up

Export Citation Format

Share Document