Variation in flowering time and in some growth characteristics of Townsville lucerne (Stylosanthes humilis)

1965 ◽  
Vol 5 (16) ◽  
pp. 49 ◽  
Author(s):  
DF Cameron
Keyword(s):  
Flowering Time ◽  
Significant Variation ◽  
Growth Habit ◽  
Northern Territory ◽  
Growth Characteristics ◽  
Diameter Growth ◽  
Stylosanthes Humilis ◽  
Stem Colour

Significant variation (P<0.001) in flowering time was found between collections of Townsville lucerne (Styloanthes humilisHBK.) from a number of localities in Queensland and the Northern Territory. Collections also varied in plant diameter, growth habit, stem colour, and degree of hard-seededness. Further avenues of study to elucidate the origin and significance of this variation are briefly discussed.

Flowering time and the natural distribution and dry matter production of Townsville lucerne (Stylosanthes humilis) populations

1967 ◽  
Vol 7 (29) ◽  
pp. 501 ◽  
Author(s):  
DF Cameron
Keyword(s):  
Flowering Time ◽  
Dry Matter ◽  
Growth Habit ◽  
Correlation Coefficients ◽  
Annual Rainfall ◽  
Late Flowering ◽  
Matter Production ◽  
Northern Areas ◽  
Stylosanthes Humilis ◽  
Significant Yield

The flowering times of 58 collections of Townsville lucerne from typical sites in northern Australia have been recorded in three spaced plant experiments near Townsville. Thirty-six collections were grown in 1963-64, 15 in 1964-65, and 17 in 1965-66. All the late flowering collections came from sites receiving at least 45 inches annual rainfall. The five collections from south of Rockhampton were all of the early or midseason type and all collections from the far northern areas were late flowering. Partial regression analysis was used to relate the flowering time of a collection to the rainfall (for the five months interval from January to May) and latitude of the collection site. In the first two experiments rainfall, latitude and (latitude)2 all contributed significantly to the regressions, but in the third experiment only rainfall was significant. Correlation coefficients for 1963-64, 1964-65, and 1965-66 were +0.83, +0.97, and +0.93 respectively. A selection was derived from a collection by bulking seed from single spaced plants selected for uniform flowering time and growth habit. The dry matter yields of some collections and selections were compared in two sward experiments near Townsville in 1964-65 and 1965-66. In 1964-65 there were significant yield differences between collections (experiment A, P<0.01) and between selections (experiment B, P<0.001). There were differences in the rates of vegetative growth and differences in the length of growing season, with late flowering types being able to make better growth late in the season when early types were flowering and seeding. Types with erect growth habit had the highest yields and seemed to compete better with sown grasses than the prostrate types. There were no significant yield differences in 1965-66, a very dry year, and the late flowering types failed to set seed.

Life history and allozyme variation in populations of the weed species Setaria faberi

1987 ◽  
Vol 65 (7) ◽  
pp. 1396-1402 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
Life History ◽  
Significant Variation ◽  
Allozyme Variation ◽  
Growth Characteristics ◽  
Population Variation ◽  
Weed Species ◽  
Setaria Faberi ◽  
Single Genotype ◽  
Variable Population ◽  
Low Levels

Life-history features and allozyme variation were examined among and within eight populations of Setaria faberi collected at the northern limits of its distribution range from 39 to 45° N latitude. Statistically significant variation among the eight populations was evident for all 16 characters relating to morphology, phenology, and growth characteristics of the plants. Very low levels of allozyme variation were detected in the eight populations, i.e., only 3 of the 22 loci surveyed were polymorphic. Nine multilocus genotypes were present. Six of the eight populations contained a single genotype, whereas the most variable population (A) contained eight genotypes. Estimates of within-population variation of nine life-history features indicated that population A was the most variable with 7 of 9 characters showing statistically significant among-family variation.

scholarly journals Effects of ambient temperature and photoperiod on flowering time in faba bean (Vicia faba L.)

2017 ◽  
Vol 68 (11) ◽  
pp. 893 ◽  
Author(s):  
Samuel C. Catt ◽  
Jeffrey G. Paull
Keyword(s):  
Ambient Temperature ◽  
Flowering Time ◽  
Vicia Faba ◽  
Faba Bean ◽  
Significant Variation ◽  
Controlled Environment ◽  
Significant Determinant ◽  
Genotype By Environment ◽  
Vicia Faba L ◽  
Main Factor

Flowering time is a vulnerable stage of plant development and is therefore a significant determinant of adaptation and grain yield in faba bean (Vicia faba L.). It is largely controlled by genotype, environmental factors of temperature and photoperiod, and genotype-by-environment interactions. The aim of this study was to evaluate variation in flowering time and the responses of flowering time to ambient temperature and photoperiod in Australian faba bean. Time of sowing experiments were carried out to assess variation among lines for flowering time (measured in days to flowering, thermal time to flowering and node of first flower) and to determine plant sensitivities to ambient temperature and photoperiod by regression analysis in the field, while four controlled environment experiments of differing temperature and photoperiod were undertaken to further analyse the variation in responses. Results showed significant variation in responses to both ambient temperature and photoperiod. Photoperiod was the main factor influencing variation in flowering time, with lines grouped as sensitive, intermediate or insensitive. The responses to ambient temperature were more complex. Most lines fit the traditional linear model, but with possible variation in optimal temperature and/or vernalisation response, while some lines showed temperature insensitivity.

The inheritance of flowering time in Townsville stylo (Stylosanthes humilis)

1976 ◽  
Vol 27 (6) ◽  
pp. 825 ◽  
Author(s):  
DF Cameron
Keyword(s):  
Flowering Time ◽  
Dominant Gene ◽  
Diallel Cross ◽  
Early Flowering ◽  
Multiple Alleles ◽  
Locus Model ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Maturity Groups ◽  
Early Flowering Phenotype

The inheritance of flowering time was studied in F1, F2 and F3 populations derived from a diallel cross among nine naturalized Australian lines of Townsville stylo (Stylosnnthes humilis) and in F1 and F2 populations from a small number of crosses between naturalized Australian lines and introductions from Mexico and Brazil. Strong dominance for lateness of flowering was observed in both the (Australian x Australian) and the (Australian x Mexican/Brazilian introductions) crosses, and some F2 and F3 progenies included small numbers of extremely early plants, flowering up to 55 days earlier than the earliest parent. The flowering time distributions of the (Australian x Australian) crosses could be explained by a three-locus model with multiple alleles at two loci. Proposed genotypes for the four maturity groups are as follows: late, LLM2M2EE; late-midseason, LLmmEE; mid-season, l2l2M2M2EE; early, l1l1M1M1EE; very early, LLM2M2ee. Only one major dominant gene for lateness of flowering could be detected from the distribution of the two (Australian x introduced line) F2 populations, but the segregation of extremely early types and the low recovery of the early-flowering phenotype suggested that other gene loci were segregating.

Herbicides for weed control in grain sorghum crops in the Northern Territory

1970 ◽  
Vol 10 (46) ◽  
pp. 588
Author(s):  
IMW Wood
Keyword(s):  
Good Control ◽  
Dry Weight ◽  
Grain Sorghum ◽  
Northern Territory ◽  
Research Station ◽  
Wet Season ◽  
Grain Yields ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Grass Weed

In experiments conducted in the 1968-69 wet season at the Katherine Research Station, Northern Territory, a number of herbicides gave good control of the grass weed Pennisetum polystachyon in grain sorghum crops. Linuron at 3 lb a.i. an acre and PCP at 20 lb a.i. an acre as pre-emergence applications effectively controlled grasses with no apparent adverse affects on the crop. With both there were significantly higher grain yields than on unweeded control plots containing an average of 1378 lb dry weight of P. polystachyon an acre. Fluometuron at 3 lb a.i. an acre late pre-emergence and early post-emergence and chlorthal at 7 lb a.i. an acre pre-emergence controlled grasses but did not increase grain yields. Further investigations are warranted with these herbicides, as banded applications to the interrow may overcome the apparent problem of crop phytotoxicity. Chlorthal at rates that gave good grass control had no adverse effect on Townsville stylo (Stylosanthes humilis). This could be an important advantage when sorghum is sown in rotation with Townsville stylo pasture or where the crop is undersown with Townsville stylo.

The effect of daylength and temperature on the growth and reproduction of six strains of Townsville lucerne (Stylosanthes humilis)

1967 ◽  
Vol 7 (27) ◽  
pp. 351 ◽  
Author(s):  
RW Downes ◽  
IB Staples ◽  
PA Colman ◽  
L Pedley
Keyword(s):  
Seed Yield ◽  
Plant Morphology ◽  
Temperature Treatment ◽  
Growth Characteristics ◽  
Relative Response ◽  
Stylosanthes Humilis ◽  
Stems And Leaves ◽  
Lower Temperature ◽  
Short Days ◽  
Growth And Reproduction

Growth studies of Townsville lucerne were conducted in the phytotron at Canberra to gain an understanding of the relative response of six strains to daylength and temperature. Vegetative growth was promoted by long days in all strains. Some strains flowered under these conditions but other strains appeared to require short days before they were induced to flower. The effect of daylength was reflected in seed yield and in the relative effort that plants devoted to reproduction. In these characters, various strains showed differential responses. For most other characters, a response to daylength was detected, but all strains reacted in a common manner. Weights of roots, stems, and leaves were significantly higher under the lower temperature treatment. A tendency in this direction was also detected in several other characters. Variation among strains in plant morphology and response to photoperiod were pronounced. This suggests a relation between growth characteristics and the ecological background of these strains of Townsville lucerne.

scholarly journals Development of pre-breeding diploid potato germplasm displaying wide phenotypic variations as induced by ethyl methane sulfonate mutagenesis

2019 ◽  
Vol 99 (2) ◽  
pp. 138-151 ◽  
Author(s):  
Ashok Somalraju ◽  
Kaushik Ghose ◽  
David Main ◽  
Benoit Bizimungu ◽  
Bourlaye Fofana
Keyword(s):  
Potato Breeding ◽  
Growth Habit ◽  
Functional Characterization ◽  
Yield Potential ◽  
Phenotypic Characterization ◽  
Diploid Potato ◽  
Ethyl Methane Sulfonate ◽  
Methane Sulfonate ◽  
Ethyl Methane ◽  
Stem Colour

Mutations are the key drivers for evolution and diversification in plants. In varietal selection, sources for variation are always sought as starting breeding materials. Thus, in the absence of desired natural variations in breeding populations, targeted or random mutagenesis is applied to induce variations. Cultivated potato (Solanum tuberosum L.) is autotetraploid crop species with a narrow and highly heterozygous genetic base, and the complexity of its genome makes its genetic studies more difficult. In the current study, induced mutagenesis was performed in diploid potato using ethyl methane sulfonate (EMS) to enlarge the genetic variability for its use as pre-breeding materials in both polyploid and diploid potato breeding. As starting materials, true potato seeds were treated with 1.2% EMS for 4–6 h along with untreated seeds as controls. A large variation in terms of germination rate, plant, flower, and tuber phenotype was observed in EMS-treated plants compared with their untreated counterparts. In particular, abnormal phenotypes including twisted stem, partial and (or) completely chlorotic leaves and stems, variations in stem colour and weak-stemmed plants with lateral growth habit as well as plants with determinate growth habit were observed along with normal plant characteristics. Moreover, variations in flower colour and tuber colour, shape, and size, as well as yield potential, were observed in EMS-treated lines. The reported phenotypic characterization of EMS mutagenized diploid potato collection is to our knowledge the first in its kind and represents a premium genetic resource for potato breeding programs and plant biologists for genes functional characterization in potato.

The use of fire to establish Townsville lucerne in the Northern Territory

1966 ◽  
Vol 6 (22) ◽  
pp. 277 ◽  
Author(s):  
GC Stocker ◽  
JD Sturtz
Keyword(s):  
Northern Territory ◽  
Wet Season ◽  
Seeding Rate ◽  
Stylosanthes Humilis ◽  
Grass Growth ◽  
Rainfall Region

During the wet season of 1964-65 two trials were established near Darwin to determine if Townsville lucerne (Stylosanthes humilis H.B.K.) could be established in undisturbed annual sorghum (Sorghum intrans F. Muell. ex Benth.) pastures after wet season burning had controlled grass growth. In the first trial, plots were burnt at intervals throughout the wet season. Townsville lucerne pods were broadcast immediately after burning. Grass control and Townsville lucerne establishment were satisfactory in plots burnt after December 6. The second trial examined the effect on Townsville lucerne establishment and S. intrans control of burning, seeding rate, superphosphate, and weedicide treatments. Burning had the most important effect ; seeding rate had little significant effect and superphosphate none. The weedicide treatment was ineffective. The trials indicate that provided wet season burning is used to control S. intrans, Townsville lucerne can be established cheaply over wide areas of the higher rainfall region of the Northern Territory.

Fire and survival of Stylosanthes spp. in the dry savanna woodlands of the Northern Territory

1982 ◽  
Vol 33 (2) ◽  
pp. 203 ◽  
Author(s):  
JJ Mott
Keyword(s):  
Dry Matter ◽  
Northern Territory ◽  
The Other ◽  
Dry Matter Yield ◽  
Stocking Rate ◽  
Wet Season ◽  
Native Grass ◽  
Hard Seed ◽  
Stylosanthes Humilis ◽  
Good Germination

A series of burns was carried out during the early and late, dry season and early wet season, in mixed native grass-legume plots containing Stylosanthes humilis, S. hamata, S, scabra and S. viscosa as the legume component. The least mortality was shown by S. scabra, but its survival was poor in any sward more than 3 years old. After burning the other species relied solely on seedling regeneration for subsequent season's growth. Fire killed a considerable quantity of seed, but its heat softened hard seed in the soil and good germination occurred with summer rains. However, the presence of a large proportion of soft seed through the winter months could lead to out-of-season germination and subsequent death of seedlings after unseasonal winter rains. Although the total dry matter yield of swards was reduced by all fires, burning could play an important part in increasing yields of S. hamata in swards overgrown by dense native grass, since it increases the amount of soft seed in the soil. If burning causes a high mortality of mature plants of the perennials S. scabra and S. viscosa, a reduction in stocking rate may be needed to ensure regeneration of a productive sward, as these species have slow seedling growth rates.

Germination in Stylosanthes humilis Populations in the Presence of NaCl

1994 ◽  
Vol 42 (6) ◽  
pp. 717 ◽  
Author(s):  
MB Lovato ◽  
PS Martins ◽  
Filho JPD Lemos
Keyword(s):  
Salt Tolerance ◽  
Significant Variation ◽  
Germination Rate ◽  
Natural Populations ◽  
Germination Percentage ◽  
Percentage Germination ◽  
North East ◽  
Germination Response ◽  
Stylosanthes Humilis

The germination response to NaCl treatments (0, 67, 134, 201 and 268 mol m-3) was investigated in 6 natural populations of Stylosanthes humilis from 3 ecogeographic regions of Pernambuco State, north-east Brazil. In general, salt tolerance was high, with percentage germination unaltered up to 67 mol m-3 NaCl in 2 populations and unaltered up to 134 mol m-3 NaCl in the remaining 4. The estimated concentration which reduced percentage germination to 50% varied between populations from 200 to 295 mol m-3 NaCl. Salt affected germination rate even more than it did the germination percentage, being altered at 67 mol m-3 NaCl in all populations. The germination rate was reduced to 50% in the range of 131-176 mol m-3 NaCl. There was a significant variation in salt tolerance between these natural populations, and no relation was found between salt tolerance of the populations and the aridity of their provenance.

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