TRISOMIC TRANSMISSION IN LOTUS PEDUNCULATUS

1968 ◽  
Vol 10 (3) ◽  
pp. 648-654 ◽  
Author(s):  
Chi-Chang Chen ◽  
W. F. Grant

Transmission of the extra chromosome was studied for four primary trisomic types of Lotus pedunculatus Cav., named Broad, Pointed, Narrow, and Small (trisomic for chromosomes 3, 4, 5 and 6, respectively). Despite the low frequency of transmission (average 9.2%), parental trisomics were recovered in all of the four trisomic types. No significant difference was found between pollen and ovule transmission. It was suggested that either there is no difference in germination and tube growth between the n and n + 1 pollen grains, or selection against the n + 1 male gametes in pollen germination and tube growth is balanced by the mechanism (s) selecting against the n + 1 female gametes. Although there were variations in transmission rate within the same trisomic types, the shorter extra chromosomes tended to be transmitted more frequently than the longer ones. This was interpreted as reflecting the degree of genic unbalance created by the extra chromosome in gametes and zygotes. The longer the extra chromosome, the greater would be the unbalance, and hence the less chance there would be for the n + 1 gametes and 2n + 1 zygotes to be viable. The trisomic types Small and Narrow produced a few unrelated trisomics in their progenies. It was considered that meiotic irregularities in these trisomic types could account for the production of such unrelated trisomics.

2021 ◽  
Vol 74 ◽  
Author(s):  
Thomas Sawidis ◽  
Gülriz Baycu ◽  
Elżbieta Weryszko-Chmielewska ◽  
Aneta Sulborska

Abstract In vitro culture of Lilium longiflorum pollen grains was carried out to determine the role of manganese in pollen germination and pollen tube growth. Pollen germination was adversely affected by the presence of manganese (>10 −8 M), whereas low concentrations (10 −12 –10 −10 M) stimulated the process. Manganese caused morphological anomalies during tube growth, characterized by irregular pollen tube thickening and swollen tips. The main effect was the anomalous cell wall formation at the tip, in which the presence of several organelles reduced the number of secretory vesicles. A loose network of fibrillar material and spherical aggregates, mostly in the tip region, was detected, and this material was progressively loosened into the surrounding medium. As a response to potential toxicity, the excess manganese was isolated in vacuoles, which formed an internal barrier against penetration of manganese to the tip area. Elevated manganese concentrations might affect plant reproduction, resulting in anomalies in gamete development. Consequently, the loss in genetic diversity and decreased fruit set ultimately lower yield.


2008 ◽  
Vol 35 (2) ◽  
pp. 152 ◽  
Author(s):  
Kanjana Luangsuwalai ◽  
Saichol Ketsa ◽  
Apinya Wisutiamonkul ◽  
Wouter G. van Doorn

Dendrobium flowers, pollinated with pollinia from individuals of the same cultivar or other cultivars, usually show rapid post-pollination effects such as floral epinasty, a change in flower colour and early perianth senescence. However, pollination with the pollinia of cv. Karen or cv. Kenny flowers did not produce these effects. We compared these two cultivars with cvv. Pompadour, Willie and Sakura, and tested the hypotheses that the differences were related to levels of 1-aminocyclopropane-1-carboxylic acid (ACC) in the pollinia, ethylene production by the pollinated flower, pollen germination, or pollen tube growth. The pollinia of cvv. Karen and Kenny contained as much ACC as the pollinia of cv. Pompadour, but less than the pollinia of cvv. Willie and Sakura. Ethylene production after pollination with cvv. Karen and Kenny pollinia was much lower than after pollination with pollinia from the other cultivars tested. The pollen grains showed normal germination, but cvv. Karen and Kenny pollen grains exhibited much less tube growth than those of the other cultivars. Pollen tube growth in cv. Pompadour was positively affected by ethylene. Ethylene was required and sufficient for the induction of epinasty, rapid perianth colour changes and early perianth senescence, very similar to the changes after pollination. The absence of these effects after pollination with cvv. Kenny and Karen seems to be due to the low ethylene production induced by the pollinia of these cultivars. This low ethylene production could not be accounted for by the ACC content in the pollinia of cvv. Kenny and Karen.


HortScience ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 440-442 ◽  
Author(s):  
Nina Devrnja ◽  
Jelena Milojević ◽  
Ljiljana Tubić ◽  
Snežana Zdravković-Korać ◽  
Aleksandar Cingel ◽  
...  

The pollen morphology of aromatic Tanacetum vulgare L. (Asteraceae), which has wide horticultural and medicinal uses, was examined using light microscopy and scanning electron microscopy. The investigation revealed that pollen grains are radially symmetrical, isopolar, spheroidal, tricolporate, and echinate–perforate. Average pollen length was 21.32 ± 1.12 μm, whereas average pollen width was 20.04 ± 0.98 μm (length:width ratio 0.94). Spine length was 2.72 ± 0.29 μm. Average distance from the spines was 7.15 ± 0.31 μm. Pollen exine consisted of 1–3 pores. Pori are elongated and also with a distinct margin. The porus latitude is smaller than the colpus latitude. One to three perforations were noticed on 1 μm2 of exine. Fluorescein diacetate was used to assess the viability of T. vulgare pollen. The effect of sucrose (1%, 5%, 10%, 20%, and 30%, w/v) on pollen germination and tube growth was evaluated. Overall, the inclusion of sucrose in the medium improved both pollen germination and tube growth. Also, pollen nucleus status was determined. Binucleate and trinucleate mature pollens were observed. Overall, the palynological features of this species may be helpful for further taxonomical and pharmaceutical investigations.


Silva Fennica ◽  
2019 ◽  
Vol 53 (2) ◽  
Author(s):  
Yan Liu ◽  
Yuan Zhang ◽  
Qing Zhou ◽  
Jian Wu ◽  
Pingdong Zhang

Colchicine is widely used as a mutagen to induce production of diploid gametes in plants. However, whether colchicine affects induced pollen viability remains unclear. To clarify whether colchicine affected the viability of induced pollen, we induced production of diploid pollen by colchicine, followed by pollen germination and crossing induced pollen with normal gametes to produce triploid in Carrière. The results showed that the predominant meiotic stages and the number of colchicine injections had significant effects on the occurrence rates of induced 2n pollen. When the colchicine injection was given at diakinesis, a significant decrease in the pollen production per bud was observed ( < 0.001). The morphology of the colchicine-induced 2n pollen was similar to that of the natural 2n pollen in its ectexine structure. The pollen germination experiments revealed that there was also no significant difference in germination rates between the induced diploid pollen and natural 2n pollen grains, and 68 triploids were created by crossing colchicine-induced pollen. Our findings revealed that colchicine injection could induce to produce 2n pollen and will not lead to dysfunction of induced diploid pollen.in vitroPopulus tomentosapP. tomentosa


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3162 ◽  
Author(s):  
Seif Aldin Dawina Abdallah Fragallah ◽  
Pei Wang ◽  
Nuo Li ◽  
Yu Chen ◽  
Sizu Lin

Pollen grains produce certain metabolites, which can improve or inhibit germination and tube growth. Metabolomic analysis of germinating and growing Chinese fir pollen has not been reported. Therefore, this study aimed to analyse metabolites changes, content and expression in the germinating pollen of Chinese fir. To understand the metabolic differences, two clones from Chinese fir were selected. Metabolomics analyses were performed on three stages (1-, 24- and 48-h) during in vitro pollen germination. The metabolites profiles at different time points were analyzed by using liquid chromatography-mass spectrometry. The results showed that 171 peaks were screened; the corresponding differential metabolites of 121 peaks were classified into nine types of substances. The expression of metabolites showed significant differences across and between clones, and the variation was evident at all germination stages. The expression was obvious at the early stage of germination, which differed clearly from that of the late stage after pollen tube growth. Moreover, the metabolites were mainly enriched in 14 metabolic pathways. Pollen germination and tube growth and metabolites expressions changed per incubation time. Since this work is preliminary, we suggest further investigations to understand the relationship between the differential metabolites and pollen development, and factors affecting pollen germination process.


HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Sandra M. Reed

Little information is available on the reproductive behavior of Hydrangea macrophylla (Thunb. Ex J.A. Murr.) Ser. The objectives of this study were to investigate time of stigma receptivity, viability of pollen from sterile flowers, and self-incompatibility in this popular ornamental shrub. Pollen germination and pollen tube growth in styles were examined using fluorescence microscopy. Stigma receptivity was examined in cross-pollinations made from 1 day before anthesis to 8 days after anthesis. Maximum stigma receptivity for the two cultivars examined occurred from anthesis to 4 days after anthesis. Viability of pollen from sterile flowers was evaluated through pollen staining and observations of pollen tube growth. No significant difference in percent stainable pollen between fertile and sterile flowers was observed in any of the six taxa examined. Pollen germination and pollen tube growth were studied in cross-pollinations made using pollen from fertile and sterile flowers of two cultivars. For both cultivars, pollen tubes from fertile and sterile flowers grew to the same length and had entered ovules by 72 hours after pollination. Self-incompatibility was evaluated by comparing pollen germination and pollen tube growth in cross- and self-pollinations. In the five taxa examined, self pollen tubes were significantly shorter than cross pollen tubes in flowers that were examined 72 hours after pollination. This finding indicates the presence of a gametophytic self-incompatibility system in H. macrophylla.


Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 353-356 ◽  
Author(s):  
J. Janse

Male transmission of the translocated extra chromosome 5R3R was studied in a tertiary trisomic of rye (Secale cereale L.) using two pollination densities. With abundant pollen, male transmission reached 4%. When a mean of four pollen grains were brought on every stigma (restricted pollination), a transmission rate of 20% was obtained. Seed set, mean seed weight, germination percentage, and the percentage of plants finally surviving were lower in the case of restricted pollination. It was concluded that certation between euploid and aneuploid pollen grains plays a decisive role in male transmission of the translocated chromosome. Although it was previously shown that aneuploid microspores have a delayed development, a large proportion must have reached maturity before anthesis. Therefore, genetic factors determining male transmission rate will primarily be expressed during pollen germination and tube growth rather than before anthesis. Key words: rye, tertiary trisomic, euploid pollen grains, aneuploid pollen grains, certation.


2020 ◽  
Vol 193 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Bo Song ◽  
Yongqian Gao ◽  
Jürg Stöcklin ◽  
Minshu Song ◽  
Lu Sun ◽  
...  

Abstract Specialized bracts of Himalayan ‘glasshouse’ plants are well known for adapting to diverse stresses in alpine environments, thus ensuring normal sexual reproduction. However, little information is available on how such specialized plants cope with the elevational increase in stress. In this study, we determine the elevational pattern of ultraviolet (UV) protection provided by the translucent bracts of Rheum nobile, a giant ‘glasshouse’ plant species, endemic to the high Himalayas, and examine its effect on pollen germination and pollen tube growth. Both UV-A and UV-B radiation in the open air increased with elevation, but their intensity beneath bracts remained constant with elevation, suggesting that the bracts of R. nobile growing at higher elevations have an increased ability to screen UV radiation. Enhanced UV-B radiation, equivalent to that experienced at higher elevations (4800 m a.s.l.) compared to that at lower elevations (4200 m a.s.l.), significantly reduced pollen germination and pollen tube growth. Pollen grains from plants at higher elevations were not more tolerant to UV-B radiation. UV absorbance and the content of flavonoids in bracts increased with elevation, but a similar trend was not found in either UV reflectance or adaxial trichome density, suggesting that bract UV absorbance may play a more active role than bract UV reflectance in helping plants cope with the increasing UV radiation. Our results indicate that the bracts of R. nobile have the ability to cope with enhanced UV radiation with increasing elevation through increased UV absorbance, thus protecting pollen grains from injury caused by higher levels of UV radiation, and consequently ensuring normal sexual reproduction in stressful high-alpine conditions.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 762A-762
Author(s):  
Wol-Soo Kim* ◽  
Sang-Hyun Lee

In order to investigate the cause of differences of mature pollen in Asian pear (Pyrus phyfolia) that are collected from various sources for the artificial pollination, various factors were measured as below: the composition of nonstructural carbohydrate in bud at 30 days after full bloom, the contents of crude protein in skin, cytosol and membrane, and the affinity for lectin (CON-A: Concanavalin, type III A) of glycoprotein in cytosol of pollen were measured. Contents of sucrose and glucose in buds influenced pollen germination rate and pollen tube growth, respectively. Therefore, soluble types of carbohydrates stored in bud were regarded as influencing on pollen germination rate and pollen tube growth. Pollen, which showed low activity, had low affinity on CON-A, lectin of glycoprotein, because it had fragile membrane, proteins in cells were denatured to pollen surface and certain enzymes concerned in pollen germination lost stability and activity. Pollens that showed high activity contained 92 kDa protein while others not. This was assumed as influencing on control of pollen viability.


1934 ◽  
Vol 10 (2) ◽  
pp. 190-198 ◽  
Author(s):  
W. P. Thompson

There are several possible causes of the absence or low frequency of many chromosomal and genetic types in crosses between 42- and 28-chromosome species of wheat. The actual effects of these possible causes are:1. Pre-gametic causes — effect small. Among pollen grains which develop normally all chromosomal types are found but not quite in theoretical proportions; those with chromosome numbers intermediate between the 14 and 21 of the parents are somewhat deficient. Intermediate numbers are more abundant among retarded grains.2. Gametic(a) Male(1) Outright abortion of pollen grains — 5 to 10%.(2) Retardation of development — 25 to 30%.(3) Failure of pollen germination — the above 25 or 35%, plus probably as much more.(4) Competition and selective fertilization — impossible to determine accurately but probably some effect.(b) Female — very little. Apparently nearly all female gametes are capable of functioning but 50% usually remain unfertilized.3. Endospermic — abortion and abnormal development cause important effects particularly in relation to female gametes but they cannot be separated completely from possible direct embryonic effects.4. Embryonic — about half the embryos abort before the seed is ripe and at least half the F2 seeds usually fail to germinate. These are in part and may be wholly endospermic effects.The gametic and endospermic influences are such as to reduce the proportion of plants with chromosome combinations intermediate between those of the parents.


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