Procedure for standardization of in vitro pollen germination medium of Cajanus spp. The best medium which gave In order to improve germination, first boric acid concentration was altered keeping Ca NO 3 2 at ppm. Then, the concentration of calcium nitrate was modified keeping boric acid concentration at ppm to further improve the germination of C. At ppm Ca NO 3 2 , pollen of C. Increasing the Ca NO 3 2 concentration to ppm showed. The complete pollen germination medium for C.
In the medium D Set I only initiation of germination was observed whereas no germination was observed in media A, B and C. To control the bursting of pollen grains sucrose level was raised to In order to standardize optimal media for pollen germination different methods of pre-conditioning the pollen were attempted. Pre-hydration for 30 min in Petri dish lined with moist filter paper also did not improve germination.
The stamen of pigeonpea is diadelphous five short and five long stamens. Thus, germination percentage did not vary between different anthers. Out of six combinations of media tried, the PGM with ppm boric acid and ppm calcium nitrate showed maximum normal pollen tubes. Another pre-treatment of pollen was tried by incubating young buds 12 h or 36 h before anthesis at Then upon anther dehiscence, pollen was collected and germination was tested on six different media.
The pollen from treatments a , b and c showed good germination on medium G 5 but burst soon after. For treatments d and e media G 1 —G 6 were used both for pre-treatments and germination tests. The pollen from the treatment d showed much variation for germination and bursting. Pollen extracted from the treatment e showed improved germination for C. Pusa 33 and IMS Thus, the complete media for both Pusa and IMS-1 should have the following composition:.
The results of studies on in vitro pollen germination of Cajanus cajan and its wild species are summarized in Table 1. Results of in vitro pollen germination of C.
Based on the initial tests on C. It was noticed that there are genotypic differences for pollen germination. Similar response was seen with wheat pollen germination. This is adjudged as the best medium since it did not require supplementing either EACA or peptone.
These varieties responded poorly when peptone water was increased beyond mg which reduced the pollen tube length Table 2. Among the varieties tested, two of them viz. Similar kind of genotypic differences for pollen germination requirement have also been reported [ 1 ]. A simple or a complex medium may be developed to suit the germination requirement of pollen binucleate or trinucleate pollen.
The protocol suggested would give a better guidance in development of PGM. The author has developed pollen germination medium PGM for many crops viz. These media were supplemented with polyethylene glycol, e-amino caproic acid, peptone etc. Grasses pollen so far considered as recalcitrant can also be germinated in the artificial medium e. This trait makes it unsuitable for in vitro germination.
The grasses pollen was so far classified as recalcitrant [ 31 ]. It is observed that monocots require low salt content than the dicots in the pollen germination medium.
Also wild species require minimal medium than the domesticate ones. Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3. Help us write another book on this subject and reach those readers.
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Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. Downloaded: Abstract Pollen germination in vitro is a reliable method to test the pollen viability. Keywords in vitro pollen germination grasses PGM pollen germination method.
Introduction Pollen germination in the stigmatic tissue of Portulaca was first observed as early as by Amici and later he observed the germinating pollen tube entering ovule. Pollen germination methods Pollen is collected from freshly opened flowers and enough pollen is dusted over medium and culture by any one of the following methods: Cavity slide technique Rangaswamy and Shivanna [ 12 , 13 ] : It is used for liquid pollen germination medium PGM.
Standardization of in vitro pollen germination medium for C. Standardization of in vitro pollen germination media for C. Pretreatments In order to standardize optimal media for pollen germination different methods of pre-conditioning the pollen were attempted.
Agarified medium containing Thus, the complete media for both Pusa and IMS-1 should have the following composition: Sucrose Optimal media composition C. Table 1. Varietal response to PGMs It was noticed that there are genotypic differences for pollen germination. Table 2. Response of wheat genotypes in pollen germination medium. More Print chapter. How to cite and reference Link to this chapter Copy to clipboard.
Cite this chapter Copy to clipboard Jayaprakash P June 6th Available from:. For each step, the pollen was inoculated on the surface of a Petri plate containing 20 mL of culture medium with the aid of a brush to obtain a uniform distribution over the surface of the medium. Subsequently, the Petri dishes were capped and kept in the absence of light for 72 h. The numbers of germinated and non-germinated pollen grains were counted with the aid of a microscope with a 10x objective lens.
Grains were considered germinated if the size of the pollen tube was greater than twice the diameter of the grain Chagas et al. Experiments were conducted in a completely randomised design with four replications, where each replication corresponded to one Petri dish and consisted of five fields of view. The experimental design was completely randomised with four replications, where each replication corresponded to one Petri dish and consisted of five fields of view.
Five flower buds of each cultivar stage 65 - BBCH Scale were randomly collected to count the number of pollen grains per flower. The experimental design used in this study was completely randomised with 28 treatments cultivars , where each treatment included 12 replicates and each plot consisted of average four Neubauer chamber readings. This value was then multiplied by two the number of anthers that exist in each olive flower.
The results obtained were subjected to an analysis of variance; a regression analysis was used for quantitative data, and Scott and Knott was used for qualitative data. According to the analysis of variance, there was a significant interaction between the factors agar and boric acid. However, boric acid plays a more specific role in the formation and development of the pollen tube and may show different responses depending on the species.
As boron plays a role in pollen grain germination and pollen tube growth, both processes are compromised when boron levels are absent or insufficient. In addition, the absence of boron results in a low sucrose absorption efficiency and a decrease in the growth rate of the pollen tube Lewis Lewis, D.
Are there any inter-relations between the metabolic role of boron, synthesis of phenolic phytoalexins and the germination of pollen? New Phytologist, 84, This was most likely related to a gradual increase in the solute concentration of the medium that disrupted the integrity of the pollen grain cell structure Dantas et al. Revista Brasileira de Fruticultura, 27, The application of boric acid in the field raised the pollen grain germination of loquat Nogueira et al.
There was a significant interaction between sucrose and pH. The addition of sucrose as a carbohydrate source is used to meet the metabolic demands involved in growth.
It can act both as a source of energy generation and as a source of carbon skeletons for biosynthetic cell, differentiation processes Chagas et al. Thus, the high percentage of germination under increased sucrose concentrations may be explained by the increased energy supplied in the form of carbohydrates, favouring the growth of the pollen tube. A study of pollen germination of blackberry and loquat concluded that the highest germination rates were achieved at the highest concentrations of sucrose added to the medium Figueiredo et al.
Bragantia, 74, The higher pH levels caused an increase in the pollen grain germination percentage. However, the germination rate decreased with a pH of 5. An optimal pH for the physiological processes involving pollen grains is associated with higher pollen germination capacity, thus ensuring greater chances of fertilisation, larger and better fruit sets, and a better production rate in the field Salles et al.
In the experiment with varied levels of calcium nitrate and magnesium sulfate, a significant interaction was found among these factors. However, the highest rate of pollen grain germination was obtained in the absence of both components Similar results were observed when using calcium nitrate in the in vitro germination of pollen grains of peach and pear trees Chagas et al.
Similarly, according to Nogueira et al. Among the evaluated temperatures, it was observed that the highest rate of pollen grain germination occurred at The temperature to which the pollen is exposed during the germination phase is directly related to the development of the pollen tube. Very low temperatures lead to decreased metabolic activity, thereby preventing germination, whereas very high temperatures cause the degradation of proteins and enzymes fundamental to the development of the pollen tube Wahid et al.
Heat tolerance in plants: an overview. Environnmental Experimental Botany, 61, Under field conditions, the correct environmental temperature is fundamental for the favourable germination of pollen grains as well as pollen tube development and flower and fruit set. A comparison of two temperatures Studies on self- and cross-pollination of olives. California Agriculture, 15, The present study found that a pollen tube emission time of 72 h resulted in a germination rate of Regarding pollen grain germination, a large variability in the germination capacity was observed for the different olive cultivars examined in this study Table 1.
The best result was obtained with the cultivar Manzanilla These results agree with Giordani et al. There was also a large variation in the number of pollen grains per flower of each cultivar Table 1. Certain olive cultivars are self-incompatible and produce little or no fruit in mono-varietal orchards. In this case, cross-pollination favours larger and more regular yields.
Although self-incompatibility is an important feature to the production of olives, the mode of inheritance of this self-incompatibility remains unknown for this species. New hypothesis elucidates self-incompatibility in the olive tree regarding S-alleles dominance relationships as in the sporophytic model. Comptes Rendus Biologies, , The pH should be adjusted to 5. Cultivar Manzanilla showed the highest germination rate Abrir menu Brasil.
Abrir menu. Key words: Olea europaea L. Figure 1 Percentage of in vitro germination of pollen grains of Arbequina olive tree under different concentrations of agar and boric acid. Figure 2 Percentage of in vitro germination of Arbequina olive tree pollen grains under diff erent pH levels and sucrose concentrations.
Figure 3 Percentage of in vitro germination of pollen grains of Arbequina olive tree under diff erent concentrations of calcium nitrate and magnesium sulfate. Figure 4 Percentage of in vitro germination of pollen grains of Arbequina olive tree in diff erent temperatures. Figure 5 Percentage of in vitro germination of pollen grains of Arbequina olive tree under diff erent incubation times. Table 1 Average germination and number of pollen grains per flower of different olive tree cultivars.
Bradley, M. Breton, C. Chagas, E. Cuevas, J. Dantas, A. Fabbri, A. Ferreira, D. Figueiredo, M. Giordani, E.
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