Selection for height of nectar in the corolla tube of English singlecut Red Clover

1971 ◽  
Vol 77 (3) ◽  
pp. 347-350 ◽  
Author(s):  
R. P. Hawkins
Keyword(s):  
Honey Bees ◽  
Red Clover ◽  
Corolla Tube ◽  
Bumble Bees ◽  
Selection For ◽  
Selection Of

SUMMARYPollination of red clover by honey bees would be expected to increase if varieties could be produced in which the nectar is within 7 mm of the mouth of the corolla tube and so within the bee's reach.Pollination by honey bees in a small glasshouse increased the height of nectar in the resulting stock of red clover but when this was again pollinated by honey bees there was no further increase.Selection of plants with above average nectar height ultimately produced a stock in which the nectar height was 0·76 mm higher than in the original; a difference which was significant. There was also a considerable and significant increase in the proportion of florets with nectar within 7 mm of the mouth of the corolla tube.It was concluded that the height of nectar can be increased by selection; this would be of particular value for the pollination of red clover varieties with long corolla tubes grown for seed where there are insufficient numbers of bumble bees.

Corolla Tube Length and Nectar Height of Fl Red Clover Plants (Trifolium pratense) and Their Seed Yield Following Honey-Bee Pollination

1968 ◽  
Vol 70 (1) ◽  
pp. 5-10 ◽  
Author(s):  
D. A. Bond ◽  
J. L. Fyfe
Keyword(s):  
Genetic Variation ◽  
Seed Yield ◽  
Honey Bees ◽  
Trifolium Pratense ◽  
Red Clover ◽  
Corolla Tube ◽  
Inbred Lines ◽  
Tube Length ◽  
Bee Pollination ◽  
Continental Origin

SummaryCrosses between nine inbred lines of diploid doublecut red clover were measured for corolla tube length and nectar height, caged with honey-bees, and observations made on the number of bee visits and seed yield. There was evidence of additive genetic variation in nectar height, corolla tube length, bee visits and seed yield. The possibilities for improvement in these characters by selection are discussed. Attention is drawn to a remarkable discriminating behaviour of honey-bees, in that they could apparently recognize plants which had only one parent in common. A cage with a strong colony of honey-bees produced more than twice as much seed as a cage with a weak colony, and plants near to hives gave significantly more seed than plants distant from hives. Plants of English origin tended to have higher and more accessible nectar, more bee visits and greater seed yield than plants of continental origin.

Variation between tetraploid red clover plants in corolla tube length and height of nectar

1968 ◽  
Vol 71 (1) ◽  
pp. 113-116 ◽  
Author(s):  
D. A. Bond
Keyword(s):  
Honey Bees ◽  
Red Clover ◽  
Corolla Tube ◽  
Tube Length ◽  
Residual Variance

SummaryCrosses between eelworm-resistant tetraploid red clover plants varied significantly in corolla tube length and in the distance between the top of the nectar and mouth of the corolla tube. Variability between plants in height of nectar above the base of the corolla was positively correlated with corolla tube length but a significant residual variance in nectar height was independent of corolla tube length.Tetraploids had higher nectar but longer corolla tubes and greater distances for bees to reach than those in related diploids which were previously reported.The implications of the findings are discussed in relation to the improvement by breeding of the attractiveness of tetraploid red clover to honey-bees.

Further Studies on the Food-Gathering Behaviour of Bumble Bees (Hymenoptera: Apidae)

1962 ◽  
Vol 94 (5) ◽  
pp. 538-541 ◽  
Author(s):  
G. A. Hobbs
Keyword(s):  
Food Preferences ◽  
Red Clover ◽  
Corolla Tube ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Experimental Field ◽  
Foraging Experience ◽  
Innate Behaviour ◽  
The Individual

Brian (1954) discussed the evidence in the literature concerning whether the correlation between the length of the proboscis of a bumble bee and the length of the corolla tube of the flower it visits for nectar results from learned or innate behaviour. She hesitated to accept the views of Kugler (1943), who supported the ‘learned’ hypothesis and considered that the individual bumble bee is instinctively attracted to a flower by its colour, scent, etc., but must learn which flowers are suited to its bodily build, because he had done no work on bees raised in isolation and therefore known to be without foraging experience. The work of Cumber (1949), which reported that there were differences in proboscis lengths between individuals of a species that visited different flowers and which therefore also supported the learned hypothesis, was suspect because he gave no data on corolla lengths. Hobbs et al. (1961), who recorded the food-preferences of certain of the workers, queens, and males of honey, bumble, and leaf-cutter bees on an isolated experimental field containing plots of alfalfa, red clover, alsike clover, and sweetclover, concluded that the preference exhibited by a bee was linked with the ease with which it could gather nectar from a flower. They found, as did Cumber, that differences in prolboscis-lengths between individuals of a species resulted in preferences for flowers of different corolla-tube lengths, e.g., the queens of Bombus hunti Greene (mean length of proboscis 8.7 mm.) greatly preferred red clover, whereas the workers (m.l.p. 6.3 mm.) preferred sweetclover.

scholarly journals Factors Underlying Seed Yield in Red Clover: Review of Current Knowledge and Perspectives

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 829
Author(s):  
Tim Vleugels ◽  
Helga Amdahl ◽  
Isabel Roldán-Ruiz ◽  
Gerda Cnops
Keyword(s):  
Seed Yield ◽  
Management Practices ◽  
Current Knowledge ◽  
Red Clover ◽  
Corolla Tube ◽  
Male Meiosis ◽  
Future Research ◽  
Ploidy Levels ◽  
Poor Seed ◽  
Selection For

Red clover is a valuable forage crop, but often copes with unsatisfactory seed yield. Management practices to increase seed yield include fertilization, adequate weed and pest control, the synchronization of flowering through pre-cutting in spring, and the application of plant growth regulators to prevent lodging. Seed yield problems may have variable underlying reasons, such as inadequate pollination, fertility or genetic problems, or a combination of such traits. In this review paper, we summarize the results of recent publications that shed new light on the traits explaining seed yield differences between red clover genotypes. The main seed yield components are the number of flower heads per plant and the seed yield per flower head. Seed yield differences between diploid and tetraploid red clover are largely explained by the lower seed number per head. Recent research showed that, although inadequate pollination can lead to poor seed yield in certain areas, pollination cannot explain differences in seed yield between genotypes, cultivars, or ploidy levels. Correspondingly, corolla tube dimensions are not associated with seed yield, in spite of what is often believed by seed producers. On the other hand, fertility problems such as aberrations during male meiosis tend to occur more frequently in tetraploid genotypes and/or genotypes with low seed yield. A recent genetic study revealed 34 candidate genes for seed development, which opens perspectives for marker-assisted breeding. A final and remarkable finding is the occurrence of self-fertility in tetraploid red clover and its association with high seed yield. Breeders should be aware that selection for seed yield in tetraploid red clover may lead to unintentional selection for self-fertility, with possible consequences for inbreeding. The implications of recent findings for seed yield breeding and for the creation of novel tetraploids are discussed. Future research opportunities are considered.

Length of tongue in a honey bee in relation to the pollination of red clover

1969 ◽  
Vol 73 (3) ◽  
pp. 489-493 ◽  
Author(s):  
R. P. Hawkins
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Red Clover ◽  
Corolla Tube ◽  
Original Data

SummaryRed clover florets are generally longer than a honey bee's tongue. Original data are submitted showing that honey bees can reach to a depth of 7 mm into the corolla tube of a red clover floret. The importance of this figure is discussed in relation to breeding bees with longer tongues and the breeding of red clover with shorter corolla tubes. Breeding a variety of red clover with more nectar so that honey bees can reach it is considered to be the best solution and would produce an increase in yield of both seed and honey.

scholarly journals The formononetin content in some Polish di- and tetraploid red clover cultivars

2013 ◽  
Vol 44 (1-2) ◽  
pp. 81-85 ◽  
Author(s):  
Stanisław Burda ◽  
Piotr M. Górski ◽  
Marian Jurzysta ◽  
Michał Płoszyński
Keyword(s):  
Red Clover ◽  
Biochanin A ◽  
Additional Test ◽  
Selection For ◽  
Selection Of

The concent of formononetin, the predominant estrogen, was analyzed in four cultivars of red clover. Its highest content was found in cv. Jubilatka (tetraploid) - 0,57 % DM, next, in cv. Hruszowska (diploid) - 0,44%, Radyka (tetraploid) - 0,39 % and Skrzeszowicka (diploid) - 0,3 %. High variation from plant to plant was found in all of the analysed cultivars, which makes it possible to select for a low forrmononetin clover population. The content of formononetin in individual plants in two consecutive years was positevely correlated. The content of biochemin A in two cultivars was also analysed employing a semi-quantitative TCL test. It was found that the concent of these two estrogens in individual plants was positively correlated. However, some individual plants containing high ammount of only one estrogen were also found. Because of that in the selection for low-estrogen red clover, after selection of low formononetin plants, an additional test for biochanin A is recomended.

Identifying Measurement Invariant Item Sets in Cross-Cultural Settings Using an Automated Item Selection Procedure

Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid
Keyword(s):  
Measurement Invariance ◽  
Optimal Solution ◽  
Selection Procedure ◽  
Cross Cultural ◽  
Item Selection ◽  
Ant System ◽  
Item Quality ◽  
Ant System Algorithm ◽  
Selection For ◽  
Selection Of

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.

ESTIMASI NILAI HERITABILITAS BOBOT IKAN MAS VARIETAS PUNTEN DALAM PROGRAM SELEKSI INDIVIDU

2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Base Population ◽  
Breeding Programs ◽  
Male And Female ◽  
Body Weight Trait ◽  
Population Selection ◽  
Selection For ◽  
Weight Trait ◽  
Selection Of

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).

Evaluation of Large-Sunflower Lines of Sunflower on Quantitative Morphological Traits

2020 ◽  
pp. 46-55
Keyword(s):  
Fertility Restoration ◽  
Morphological Characters ◽  
Direct Selection ◽  
Oilseed Crops ◽  
Turkish Origin ◽  
Self Pollination ◽  
Special Area ◽  
Pericarp Color ◽  
Selection For ◽  
Selection Of

Confectionery sunflower - a special area of use of sunflower, which requires the creation of marketable seeds quality features. One of the possible ways to create large-fruited sunflower is to create production hybrids and lines. Objective: to evaluate the created new large-fruited sunflower lines by a complex of morphological characters and determine the best lines for use as large-seeds hybrids as parent components or source material. In 2016-2019 years on the basis of the Institute of Oilseed Crops NAAS a study was conducted to assess the economic characteristics of large-fruited sunflower lines. We studied a collection of 27 lines of large-seeds sources. The lines were created by direct selection or crossing and sampling: Reyny of Argentinean origin, Zaporizhzhya confectionery variety, confectionery hybrid with striped pericarp color of Israeli origin, white seed of Turkish origin, synthetic population - donor of complex resistance. To study from the collection, lines were drawn that went through at least 7 generations with selection for seed size. Experience has shown that the shortest growing season for lines 174d and KP11 was 99 days, and the longest for lines I2K670 was 109 days. In the studied collection, the greatest mass of 1000 seeds has the KP11-146.47g line, which is the mother component and does not have branching. The second by weight of 1000 seeds (109 g) stood out line 168v, which also had branches and pollen fertility restoration genes and will be used as the paternal form. The third largest is also one basket line ZKN51-100. The collection included lines originating from the same combination, but with a different morphotype for the presence and absence of branching. So, based on the combination of KP11 x Zaporizhzhya Confectionery, three lines were obtained. A mass of 1000 seeds was observed in 98-86 g, with the branching line having the largest mass of 1000 seeds. The lines created with one combination VK678 x ZKN32: with a branch 168a had a mass of 1000 seeds 95g, and a line 168b - without a branch 109 g. Of the two lines obtained from the descendants of the combination KP11 x the striped hybrid both had branches, but the seeds were much smaller (weight of 1000 seeds 59 and 79 g). The collection also studied samples created on the basis of varieties and populations 160c, 174, 175b, the mass of 1000 seeds of which turned out to be more acceptable for large-fruited use from 83 to 99 g. Summing up the results of studying the collection of newly created lines, we can highlight the lines 162d, 168v, 175b, KP11 that are potentially promising for use in hybrids. The selections showed that large-fruited lines can be obtained from large-fruited varieties, self-pollination of large-fruited hybrids and crossing lines with hybrids and varieties. Self-pollination and selection of large-fruited lines in several generations does not provide the necessary variability for positive changes in selections. The result of the selection by weight of 1000 seeds in the offspring from crosses and from populations creates opportunities for new large-seeds sunflower.

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