INFLUENCE OF CYTOPLASM ON SEED SETTING IN ALFALFA

1978 ◽  
Vol 58 (2) ◽  
pp. 341-346 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE
Keyword(s):  
Seed Set ◽  
Pollen Grains ◽  
The Other ◽  
Seed Setting ◽  
Positive Effects ◽  
Male Function ◽  
Reciprocal Differences ◽  
Negative Effect ◽  
Medicago Sativa L ◽  
Partial Hybrid

Differences in cross-fertility were observed when four alfalfa (Medicago sativa L.) clones designated A, B, C, and D were used reciprocally as male or female. The clone C cytoplasm was determined to be the source of these reciprocal differences. Plants with clone C cytoplasm performed poorly as male parents, but normally as female parents. The mode of action of the clone C cytoplasm on the male function was not determined, but it appeared to be different from that which causes incomplete pollen development. Plants containing clone C cytoplasm produced an abundance of normal appearing pollen grains. In general, clone C cytoplasm had a negative effect on seed set, clone A and D cytoplasms had positive effects, and clone B cytoplasm had no effect relative to the other three. Selection among cytoplasms in alfalfa for improved seed set and for use in the production of partial-hybrid varieties was discussed.

scholarly journals Pollen adaptation to ant pollination: a case study from the Proteaceae

2020 ◽  
Vol 126 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Nicola Delnevo ◽  
Eddie J van Etten ◽  
Nicola Clemente ◽  
Luna Fogu ◽  
Evelina Pavarani ◽  
...  
Keyword(s):  
Seed Set ◽  
Germination Rate ◽  
Pollen Grains ◽  
Relative Effect ◽  
The Other ◽  
Pollen Load ◽  
Pollination Services ◽  
Ant Pollination ◽  
Negative Effect ◽  
Floral Visitors

Abstract Background and Aims Ant–plant associations are widely diverse and distributed throughout the world, leading to antagonistic and/or mutualistic interactions. Ant pollination is a rare mutualistic association and reports of ants as effective pollinators are limited to a few studies. Conospermum (Proteaceae) is an insect-pollinated genus well represented in the south-western Australia biodiversity hotspot, and here we aimed to evaluate the role of ants as pollinators of C. undulatum. Methods Pollen germination after contact with several species of ants and bees was tested for C. undulatum and five co-flowering species for comparison. We then sampled the pollen load of floral visitors of C. undulatum to assess whether ants carried a pollen load sufficient to enable pollination. Lastly, we performed exclusion treatments to assess the relative effect of flying- and non-flying-invertebrate floral visitors on the reproduction of C. undulatum. For this, we measured the seed set under different conditions: ants exclusion, flying-insects exclusion and control. Key Results Pollen of C. undulatum, along with the other Conospermum species, had a germination rate after contact with ants of ~80 % which did not differ from the effect of bees; in contrast, the other plant species tested showed a drop in the germination rate to ~10 % following ant treatments. Although ants were generalist visitors, they carried a pollen load with 68–86 % of suitable grains. Moreover, ants significantly contributed to the seed set of C. undulatum. Conclusions Our study highlights the complexity of ant–flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. Conospermum undulatum has evolved pollen with resistance to the negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species.

CYTOLOGY OF 2n POLLEN FORMATION IN DIPLOID ALFALFA, MEDICAGO SATIVA

1979 ◽  
Vol 21 (4) ◽  
pp. 525-530 ◽  
Author(s):  
Nicholi Vorsa ◽  
E. T. Bingham
Keyword(s):  
Medicago Sativa ◽  
Seed Set ◽  
Pollen Grains ◽  
Genetic Constitution ◽  
2N Pollen ◽  
Diploid Parent ◽  
2N Gamete ◽  
Medicago Sativa L ◽  
Pollen Formation ◽  
Mother Cells

Four diploid (2x) clones of alfalfa, Medicago sativa L., which produced good seed set when used as male parents in 4x-2x crosses were selected for study. The 2x clones descended from 2x haploids of cultivated 4x alfalfa. Fertility in the 4x-2x cross was due to the production of pollen with the unreduced chromosome number (2n pollen) from the 2x parent. The cytological mechanism of 2n pollen formation was found to be disorientation of spindles at metaphase II in up to 38% of the pollen mother cells. Thus, both n and 2n pollen were produced by all four diploids examined. Normal spindles at metaphase II were oriented such that they defined the poles of a tetrahedron and resulted in normal tetrads in a tetrahedral arrangement. Disoriented spindles were basically parallel to each other and resulted in formation of dyads and occasionally a triad. Dyads developed into two 2n pollen grains; triads developed into one 2n and two n pollen grains. Since both n and 2n pollen grains are produced by the diploids, they can be maintained as diploids or they can be used as male parents in crosses to tetraploids. The genetic constitution of 2n pollen resulting from parallel spindles is similar to that expected after first division restitution of meiosis and much of the heterozygosity of the diploid parent is conserved in the gametes. The 2n gamete mechanism has potential application in germplasm transfer and in maximizing heterozygosity in tetraploid hybrids.

SELECTION FOR SEED SET IN NONINBRED AND PARTLY INBRED POPULATIONS OF ALFALFA

1977 ◽  
Vol 57 (3) ◽  
pp. 873-881 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE
Keyword(s):  
Medicago Sativa ◽  
Seed Set ◽  
Exponential Model ◽  
Seed Setting ◽  
Medicago Sativa L ◽  
Selection For ◽  
Inbred Populations ◽  
The Relationship ◽  
Advanced Generation ◽  
Coefficient Of Inbreeding

Alfalfa (Medicago sativa L.) is a highly heterozygous cross-pollinating species, and most breeding efforts have been conducted on noninbred populations. The purpose of this study was to determine whether greater breeding progress could be made by selecting within partly inbred populations rather than within noninbred ones. One hundred and twenty F1 (noninbred) and 120 S1 (partly inbred) plants that were issued from crossing and selfing four alfalfa clones were evaluated for self-fertility. The most self-fertile 10% of the plants from each family were selected in each population. The selected plants within each level of inbreeding were intercrossed to produce an advanced generation in which the effectiveness of the selection was evaluated. Selection increased both self- and cross-fertility in the advanced generation. Selection was more effective at the F1 level than at the S1 level. Fertility was reduced drastically by inbreeding. The average self-fertility of the S1’s was only about 7% of the cross-fertility of their parental clones. An exponential model was proposed to describe the relationship between seed setting and the coefficient of inbreeding in the developing zygote. This model explained 95% of the variation among 11 unselected populations having differing levels of inbreeding.

scholarly journals Pollination and Seed Production in Viola

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 633-639
Author(s):  
Daiichiro Miyajima
Keyword(s):  
Seed Set ◽  
Pollen Grains ◽  
Germination Percentage ◽  
Fertilization Success ◽  
The Other ◽  
Flowering Period ◽  
Flower Longevity ◽  
Ovule Number ◽  
Germination Of Pollen ◽  
Mature Seeds

The seed producing system in viola (Viola ×cornuta) was investigated to improve seed yield and to save labor. In a flower five anthers sequentially dehisced; pollen grains were continuously supplied to the anterior petal, which played a significant role in pollination, throughout the flowering period. Evidence from pollen and ovule number suggests that the species is facultative autogamy. Each flower opened more than 10 days was independent of the success in fertilization and kept seed producing ability during the flower longevity period. Pollen grains also maintained viability during the flower longevity period. Pollinators were indispensable for pollination of viola, but pollination in viola was done by a different mechanism from the typical insect-mediated pollination that sticky pollen grains adhere to the exposed stigmas. Pollen grains, accumulated around the entrance of the stigmatic cavity, entered into the cavity by the movement of pollinators. Although the visitation of pollinators was occasional, solitary bees primarily contributed to the pollination of viola. On the other hand, germination of pollen grains on the stigmatic surface was under 50%. Seed set was much lower than the germination percentage of pollen grains. A viola flower had the ability for additional pollinations and fertilization for some days after the fertilization success in some ovules in the flower. This characteristic suggested that repeated pollination is effective to increase the number of mature seeds in a capsule.

Humor usage by sellers and sales performance: The roles of the exploration relationship phase and types of humor

2018 ◽  
Vol 33 (2) ◽  
pp. 5-23 ◽  
Author(s):  
Renaud Lunardo ◽  
Laurent Bompar ◽  
Camille Saintives
Keyword(s):  
Sales Performance ◽  
Mediating Effect ◽  
The Other ◽  
Subsequent Performance ◽  
Positive Effects ◽  
Negative Effect ◽  
The Relationship ◽  
Exploration Phase

For sellers, the efficacy of humor to create trusty relationships and achieve performance with buyers remains unknown. Specifically, the question of if – and when – sellers should use humor still deserves examination. To answer this question, this research builds on the four phases that characterize long-term relationships (exploration, buildup, maturity, and decline) to argue that humor might be inefficient when used in the exploration phase. Two studies conducted among buyers ( n = 322) then reveal that although constructive humor has overall positive effects on the performance of the sellers through a mediating effect of trust, this effect is not observed during the exploration phase. The other type of humor – offensive humor – has a negative effect regardless of the phase in which it is used. Taken together, these results first indicate that sellers may gain from using humor only if the relationship with their buyers is not at the exploration phase since this particular phase is the only one when a negative effect of humor on trust and subsequent performance is observed. Furthermore, these results indicate that offensive should be avoided in all the relationship phases.

scholarly journals Effect of Fresh or Cryopreserved Pollen on Seed Setting of Intervarietal and Interspecific Crosses of Gladiolus

2013 ◽  
Vol 14 (1) ◽  
pp. 31-34
Author(s):  
Tul Bahadur Poon ◽  
TM Rao ◽  
PE Rajshekharan ◽  
C Aswath ◽  
DP Kumar
Keyword(s):  
Interaction Effect ◽  
Seed Set ◽  
Science And Technology ◽  
Indian Institute ◽  
The Other ◽  
Interspecific Crosses ◽  
Seed Setting ◽  
Fresh Pollen

An experiment was conducted in the field of Indian Institute of Hortricultural Research, Hessaraghatta, Bangalore during August 2006 to June 2008. The experiment consisting of eight treatment combinations were laid out in ‘2x4’ factorial RCBD with 5 replications to assess seed set per capsule. The results revealed that highly significant differences were observed for number of well-developed seeds and underdeveloped seeds. Among four cross combinations ‘H.S. 88-10-22 x Shobha’ (27.63 well-developed seeds per capsule) and ‘H.S. 84-7-11 x Shobha’ (27.01 well-developed seeds per capsule) were significantly higher than those of other two cross combinations. The interaction effect of fresh pollen- cum- ‘H.S.88-10-22 x Shobha’ produced significantly higher number of welldeveloped seeds (41.02 per capsule) than those of the other treatment combinations. In contrast, treatment combinations viz., cryopreserved pollen- cum- ‘H.S. 88-10-22 x Shobha’ produced the lowest number of welldeveloped seeds (10.85 per capsule).Inclusion of fresh pollen to genotype ‘Shobha’ and cryopreserved pollen of H.S. 88-10-22' revealed better performances for maximum seed set per capsule. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 31-34 DOI: http://dx.doi.org/10.3126/njst.v14i1.8874

scholarly journals Avaliação de diferentes doses de inseticida e fungicida no tratamento de sementes de trigo sob a influência no desenvolvimento da cultura nas fases iniciais

2021 ◽  
Vol 4 (2) ◽  
pp. 13-20
Author(s):  
Tatiane Solarski ◽  
◽  
James Matheus Ossacz Laconski ◽  
Paulo Henrique da Silva Nogueira ◽  
Lucas Belcamino Vila Real ◽  
...  
Keyword(s):  
The Other ◽  
Initial Development ◽  
Positive Effects ◽  
Negative Effect ◽  
Methyl Thiophanate ◽  
Wheat Seeds

The objective of the work was to evaluate the effect of insecticide and fungicide in the treatment of wheat seeds. The treatments were, T1: control, T2: thiamethoxam (1.5 ml / kg of seed), T3: thiamethoxam (3 ml / kg of seed), T4: pyraclostrobin + methyl thiophanate + fipronil (PTF) (2.0 ml / kg of seed) and T5: PTF (4.0 ml / kg of seed). The treatment with TPF in the dose of 4.0 ml / kg of seed stood out over the other treatments, providing positive effects on the development of the culture, since thiametoxam in the dose of 3.5 ml / kg of seed, showing no difference between treatments, and provided a negative effect on the initial development of the plants.

scholarly journals Some Unresolved Issues of Measuring the Efficiency of Pollinators: Experimentally Testing and Assessing the Predictive Power of Different Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Ram Chander Sihag
Keyword(s):  
Foraging Behavior ◽  
Seed Set ◽  
Reproductive Potential ◽  
Pollen Grains ◽  
The Other ◽  
Transfer Efficiency ◽  
Optimum Number ◽  
Pollen Transfer ◽  
Pollen Transfer Efficiency ◽  
Northwest India

Knowledge of efficiency of pollinators is valuable in the derivation of (i) the degree of mutualism specialization of a flower visitor in the natural plant communities, (ii) the optimum number of pollinators needed for the maximum pollination in a plant population, and (iii) the pollinator risk assessment in the sustainable agriculture. Earlier researchers used many direct and indirect methods for measuring the pollination efficiency (PE) of flower visitors. However, a great ambiguity exists in the usage of this terminology that necessitated its fresh scrutiny. I tested the available three standard methods afresh to find the efficiency of pollinators. These included comparing the (i) number of pollen grains removed and deposited by the visitors; (ii) seed set resulting from a single and the multiple visits of the visitors; and (iii) “pollen transfer efficiency (PTE)” derived from the foraging behavior and abundances of the visitors. Observations were recorded on the visitors of four plant species in an agroecosystem of Northwest India. These plants represented a wide variety of the floral types across the angiosperms. The first two methods, namely, the “number of pollen grains removed and deposited” and the “seed set resulting from a single and the multiple visits,” were appropriate in finding differences between the efficiency ranks of the pollinators of those flowers where the number of deposited pollen grains was less than the number of ovules in the ovary. However, these two methods completely failed in situations where exactly reverse condition of pollen grains and ovules existed. Thus, these two methods of measuring the PE of visitors had limited approach and lacked a universal application over the entire angiosperm taxa. On the other hand, use of “pollen transfer efficiency”, derived from the foraging behavior and abundance of the visitors, seemed to have an edge over the other two methods as this was helpful in finding differences between the efficiency ranks of the pollinators of plants in all the three situations tested in this study. However, validation of all the three methods through the plant reproductive potential seemed to be an integral confirmatory step for drawing inferences about the efficiency of pollinators.

Pengaruh Luka Iris Pada Tikus Dengan Paparan Hidrogen Peroxida 3% terhadap Epitelisasi dan Pembentukan Eksudat pada Permukaan Epitel Kulit.

2020 ◽  
Vol 17 (2) ◽  
pp. 172
Author(s):  
HARMAN AGUSAPUTRA ◽  
MARIA SUGENG ◽  
AYLY SOEKAMTO ◽  
ATIK WULANDARI
Keyword(s):  
Hydrogen Peroxide ◽  
Wound Healing ◽  
The Other ◽  
Delayed Wound Healing ◽  
Peroxide Group ◽  
Hemostatic Effect ◽  
Significant Difference ◽  
Negative Effect ◽  
Wound Healing Effect ◽  
Epithelial Growth

<p><strong>Abstract</strong></p><p><strong>Background:</strong> Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) as antiseptic has been used frequently to clean woundsin in hospitals and clinics. Hydrogen peroxide has the effectof strong oxidative that can kill pathogens. It can clean up debris and necrotic tissuesin wounds. Hydrogen peroxidealso has hemostatic effect that can help to stop bleeding. Besides antiseptic effects, hydrogen peroxide i s suspected of having negative effect in wound healing. Hydrogen peroxide presumably could cause delayed wound healing by exudate formation and delayed epithelial growth.</p><p><strong>Method</strong>: This study was conducted in the laboratory using 48 white mice that were divided into 2 groups. All the mice were purposely wounded. Afterwards in one group the wounds were clean up using hydrogen peroxide, while in the other group without hydrogen peroxide as control. The wounds of both groups were observed on day 1, day 3 and day 7. On day 1 and day 3, both groups did not show significant difference.</p><p><strong>R</strong><strong>esult</strong> : on day 7 showed that the wound healing in hydrogen peroxide group were delayed. Fifty percent of them had the formation of exudate and 62.5% of them showed delayed epithelial growth.</p><p><strong>Conclusion </strong>: This study could show hydrogen peroxide as wound antiseptic has delayed wound healing effect.</p><p><strong>Keyword</strong>: hydrogen peroxide, wound healing</p>

Study on floral traits and seed setting in parental lines of hybrid rice during early ahu and kharif seasons

2018 ◽  
Vol 78 (3) ◽  
Author(s):  
Aradhana Phukan ◽  
P. K. Barua ◽  
D. Sarma ◽  
S. D. Deka
Keyword(s):  
Seed Set ◽  
Flag Leaf ◽  
Pollen Dispersal ◽  
Pollen Sterility ◽  
Leaf Length ◽  
Floral Traits ◽  
Opening Angle ◽  
Leaf Angle ◽  
Seed Setting ◽  
Parental Lines

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.

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