Post-Zygotic Seed Abortion in Sexual Diploid × Apomictic Tetraploid Intraspecific Paspalum Crosses

1994 ◽  
Vol 42 (4) ◽  
pp. 449 ◽  
Author(s):  
GA Norrmann ◽  
OA Bovo ◽  
CL Quarin
Keyword(s):  
Pollen Tube ◽  
Success Rate ◽  
Pollen Tube Growth ◽  
Endosperm Development ◽  
Tube Growth ◽  
Seed Abortion ◽  
Self Incompatibility ◽  
Incompatible Pollen ◽  
Incompatibility System

In many species of Paspalum, diploid (2x) cytotypes are usually outbreeders due to a self incompatibility system, while tetraploid (4x) conspecific counterparts are pseudogamous self-fertile apomicts. Intraspecific crossability between 2x female and 4x male cytotypes was investigated using classical methods of crossing in P. almum, P. brunneum, P. rufum, P. intermedium and P. quadrifarium. Expected triploid BII hybrids were obtained in P. intermedium (crossability: 0.004%) and in P. brunneum (crossability: 0.015%). In P. rufum, only tetraploid BIII hybrids were achieved with a crossability of 0.025% Looking for a better performance, in vitro ovary rescue was attempted 5 days after pollination in intraspecific 2x × 4x crosses of P. almum, P. quadrifarium, P. intermedium and P. rufum. The method was useful to recover some triploid BII hybrids in P. almum (success rate: 0.49%) and in P. rufum (0.59%), but failed in P. intermedium and P. quadrifarium. Pollen tube growth was usually inhibited at the stigma or style levels after self-pollination in 2x plants, confirming that diploids are self-incompatible. Pollen of 4x cytotypes germinated and penetrated the pistils of diploid conspecific cytotypes. This indicated that no incompatibility system exists in these species to keep the 2x cytotypes from hybridising with 4x conspecific cytotypes as pollen donors. However, after pollination of 2x cytotypes with pollen of 4x counterparts, most ovules showed embryo and endosperm development, but a few days later, endosperms collapsed and embryos stopped their development. As a result of these processes, sexual self-incompatible 2x cytotypes of Paspalum species produced very few triploid hybrids when pollinated with pollen of their apomictic 4x counterparts. Thus, the low diploid-tetraploid crossability was due to the existence of a post-zygotic abortive system and not caused by pre-fertilisation barriers.

Review Lecture Self-incompatibility: phenomenology and physiology

1983 ◽  
Vol 218 (1213) ◽  
pp. 371-395 ◽  
Keyword(s):  
Pollen Tube ◽  
Plant Breeding ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Cellular Interaction ◽  
Self Incompatibility ◽  
Intrinsic Interest ◽  
Incompatible Pollen ◽  
Inhibition Reaction ◽  
Made In

Angiosperm self-incompatibility systems have been attracting increasing attention in recent years, both because of their importance in practical plant breeding and in acknowledgement of their considerable intrinsic interest as examples of cellular interaction and recognition. Progress has been made in analysing the genetics of complex multi-locus systems in certain primitive families, and the inhibition reaction itself has been more fully characterized in certain species. The review deals mainly with homomorphic, gametophytic self-incompatibility systems, concentrating on aspects of pollen-tube growth and pistil function that appear to play key roles in the discrimination between compatible and incompatible pollen. Various implications of a recently proposed hypothesis concerning the operation of gametophytic systems are also discussed.

scholarly journals A new case of late-acting self-incompatibility in Capparis L. (Brassicaceae): C. jacobinae Moric. ex Eichler, an endemic andromonoecious species of the Caatinga, Pernambuco State, Brazil

2009 ◽  
Vol 23 (3) ◽  
pp. 764-768 ◽  
Author(s):  
Luis Miguel Primo ◽  
Isabel Cristina Machado
Keyword(s):  
Pollen Tube ◽  
Reproductive System ◽  
Pollen Tube Growth ◽  
The Other ◽  
Tube Growth ◽  
Self Incompatibility ◽  
The Third ◽  
Hand Pollination ◽  
Incompatibility System ◽  
Made In

We studied the reproductive system of Capparis jacobinae Moric ex Eichler (Brassicaceae), based on controlled hand-pollination and observation of pollen tube growth made in a fluorescence microscope. Of 105 self-pollinated flowers only one produced fruits (success = 0.95%), all the other flowers abscised at the same time, between the eighth and tenth day after anthesis. Nevertheless, self- and cross-pollinated pollen tubes reached the micropyle. The rate of penetrated ovules in self-pollinated flowers was lower during the first 24 h after pollination; thereafter this rate was similar between self- and cross-pollinated flowers for treatments of 48 h, 72 h and 96 h after pollination. In addition, we carried out two indirect estimates of the reproductive system, based on pollen/ovule and seed/ovule ratios, which resulted in typical features of xenogamous species. We concluded that C. jacobinae has a late-acting self-incompatibility system. This is the third record of this mechanism for the genus and the first for a species of Capparis endemic to the Caatinga. We suggest that this self-incompatibility system may occur in other species of the same genus and family.

scholarly journals Hyperoside promotes pollen tube growth by regulating the depolymerization effect of actin-depolymerizing factor 1 on microfilaments in okra

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Biying Dong ◽  
Qing Yang ◽  
Zhihua Song ◽  
Lili Niu ◽  
Hongyan Cao ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Actin Depolymerizing Factor ◽  
Specific Mechanism ◽  
Promoting Effect ◽  
New Research

AbstractMature pollen germinates rapidly on the stigma, extending its pollen tube to deliver sperm cells to the ovule for fertilization. The success of this process is an important factor that limits output. The flavonoid content increased significantly during pollen germination and pollen tube growth, which suggests it may play an important role in these processes. However, the specific mechanism of this involvement has been little researched. Our previous research found that hyperoside can prolong the flowering period of Abelmoschus esculentus (okra), but its specific mechanism is still unclear. Therefore, in this study, we focused on the effect of hyperoside in regulating the actin-depolymerizing factor (ADF), which further affects the germination and growth of pollen. We found that hyperoside can prolong the effective pollination period of okra by 2–3-fold and promote the growth of pollen tubes in the style. Then, we used Nicotiana benthamiana cells as a research system and found that hyperoside accelerates the depolymerization of intercellular microfilaments. Hyperoside can promote pollen germination and pollen tube elongation in vitro. Moreover, AeADF1 was identified out of all AeADF genes as being highly expressed in pollen tubes in response to hyperoside. In addition, hyperoside promoted AeADF1-mediated microfilament dissipation according to microfilament severing experiments in vitro. In the pollen tube, the gene expression of AeADF1 was reduced to 1/5 by oligonucleotide transfection. The decrease in the expression level of AeADF1 partially reduced the promoting effect of hyperoside on pollen germination and pollen tube growth. This research provides new research directions for flavonoids in reproductive development.

scholarly journals Testing of self-(in)compatibility in apricot cultivars from European breeding programmes

2013 ◽  
Vol 40 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
D. Milatović ◽  
D. Nikolić ◽  
B. Krška
Keyword(s):  
Fluorescence Microscopy ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Reliable Method ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Breeding Programmes

Self-(in)compatibility was tested in 40 new apricot cultivars from European breeding programmes. Pollen-tube growth in pistils from laboratory pollinations was analysed using the fluorescence microscopy. Cultivars were considered self-compatible if at least one pollen tube reached the ovary in the majority of pistils. Cultivars were considered self- incompatible if the growth of pollen tubes in the style stopped along with formation of characteristic swellings. Of the examined cultivars, 18 were self-compatible and 22 were self-incompatible. Fluorescence microscopy provides a relatively rapid and reliable method to determine self-incompatibility in apricot cultivars.      

In Vitro Germination of Eucalyptus Pollen: Response to Variation in Boric Acid and Sucrose

1989 ◽  
Vol 37 (5) ◽  
pp. 429 ◽  
Author(s):  
BM Potts ◽  
JB Marsden-Smedley
Keyword(s):  
Pollen Tube ◽  
Boric Acid ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Sucrose Concentration ◽  
Response Surfaces ◽  
Tube Growth ◽  
Pollen Competition

The effect of boric acid (0-450 ppm) and sucrose (0-40%) on pollen germination and pollen tube growth in Eucalyptus globulus, E. morrisbyi, E. ovata and E. tirnigera was examined in vitro. Over the con- centrations tested, sucrose had by far the largest effect upon both pollen germination and tube lengths. The optimum sucrose concentration for pollen germination (30%) and pollen tube growth (20%) differed markedly with very little (<lo%) germination occurring in the absence of sucrose. The interaction of sucrose and boric acid was significant. However, in general both pollen germination and pollen tube growth were increased by the addition of up to 100 ppm boric acid, but above this level the response plateauxed. The four species differed significantly in their pattern of response to both boric acid and sucrose and the predicted optima derived from analysis of response surfaces differed between species. The predicted sucrose concentration for optimal germination and growth of E. urnigera pollen was consistently less than the other species and in terms of the optimal level of boric acid for pollen tube growth species can be ranked in the order E. globulus > E. ovata > E. morrisbyi = E. urnigera. Pollen germination and tube growth of all four species on a medium comprising 20% sucrose and 200 ppm boric acid would not differ significantly from the observed maximum response of each species and this could suffice as a generalised medium. However, if only percentage germination is to be assessed 30% sucrose would be preferable. It is argued that subtle interspecific differences in optimal in vitro con- ditions for pollen germination and pollen tube growth are likely to reflect differences in pollen physiology which in vivo may have important implications for the success of hybridisation where pollen competition occurs.

scholarly journals Transcriptome and translatome changes in germinated pollen under heat stress uncover roles of transporter genes involved in pollen tube growth

2020 ◽  
Author(s):  
Laetitia Poidevin ◽  
Javier Forment ◽  
Dilek Unal ◽  
Alejandro Ferrando
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
High Temperature ◽  
Heat Shock ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Heat Shock Genes ◽  
Germinated Pollen

ABSTRACTPlant reproduction is one key biological process very sensitive to heat stress and, as a consequence, enhanced global warming poses serious threats to food security worldwide. In this work we have used a high-resolution ribosome profiling technology to study how heat affects both the transcriptome and the translatome of Arabidopsis thaliana pollen germinated in vitro. Overall, a high correlation between transcriptional and translational responses to high temperature was found, but specific regulations at the translational level were also present. We show that bona fide heat shock genes are induced by high temperature indicating that in vitro germinated pollen is a suitable system to understand the molecular basis of heat responses. Concurrently heat induced significant down-regulation of key membrane transporters required for pollen tube growth, thus uncovering heat-sensitive targets. We also found that a large subset of the heat-repressed transporters is specifically up-regulated, in a coordinated manner, with canonical heat-shock genes in pollen tubes grown in vitro and semi in vivo, based on published transcriptomes from Arabidopsis thaliana. Ribosome footprints were also detected in gene sequences annotated as non-coding, highlighting the potential for novel translatable genes and translational dynamics.

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